I recieved a 6000psi 524 CF of Helium today...Cost was $226.34 for fill and $18.00 per month tank rental...gonna have a little fun with this stuff...Allen.

Hello Allen,

Careful your guns don't float away.

What do you know about it. I only know what was talked about ten years ago. That it has a smaller molecule ... is a bit harder on seals IIRC. Supposed to move faster. I think I recall people were using it cause they could get the high pressure in tanks. What are your plans?

Thanks for posting.

Gary

I hope my voice doesn't sound like Mickey Mouse using this stuff...I always wanted to try it in air rifles, it can add approx 50% velocity over air or nitrogen...Allen.

Hi Allen Garry and all,I did a little experimenting with CO2 a while back. We are in for some law changes in NZ in regards to air rifles that will limit the ownership and use of higher powered pcp's(in exess of 36 jules/24 ft lb's) to persons who are vetted by the police to have a current NZ firearms licence.Up untill now anyone over 18 years could own and use any air rifle regardless of it's power output.The law change does not apply to springers or CO2 powered guns.Anyway I saw this as a challenge and reconfigured a couple of my guns to run CO2.The most I could get out of the .60 was 160 ft lb and the .30 was 47 ft lb.Now I made note of the preasure that the CO2 was running at and useing the same guage filled both guns with air to the same preasure.With air I got 17 percent more power for the same preasure but a lot less shots.I know I can get at least 20 percent more power from a perpose built CO2 gun which will give me close to if not in excess of 200 ft lb from a .60 which is enough to take deer out to 100 yards, and the amount of shots you can get off a fill is about ten times that of compressed air. Now CO2 is more dense than air which may be the reason it is a little sluggish. Helium is much less dense than air of course so may therefore be more responsive. There was a guy in Dunedin who ran a big bore smoothie on Helium to shoot possums, I never got to meet him but by all accounts he was getting some quite phenomenal power. Do keep us posted Allen, it will be interesting to follow.Danny.

I'll be standing by for some before and after results. I've heard the same regarding velocity but I've never seen it documented well.

Jerry Wrote:
-------------------------------------------------------
> I'll be standing by for some before and after
> results. I've heard the same regarding velocity
> but I've never seen it documented well.
Hello Jerry, good to hear from you...I still have some of your .25 slugs and will do a comparison with my Talon Tuned Condor...BTW do you have any .457 slugs of Garys, I picked up a .457 Quack....and would like to try them with helium. Thanks, Allen.

.457 is sort of an "in between size" for us. I think we have a mold that will cast at .457 or a split hair above but the slugs are best when sized down a touch. In any case, we won't be able to do those slugs untill after the 20th given current comittments.

I'll be amazed to see a 50% velocity rise. But ... there ya go Jerry ... run your Yukon on Helium. What was the velocity that gave it .... 735 foot pounds IIRC? If you raise the velocity by 50% with helium .... the energy should be well over the Maryland requirement of 1,200 foot pounds for airgun hunting of deer.

I'm in the house now. I forget the numbers. But ... let's see .... must have been about 765 fps .... 563 grains ... that's 731.8 foot pounds. Sounds right. Add 50% velocity with helium, or another 382.5 fps .... to a total of 1,147.5 fps .... 563 grains .... should give you 1,646.5 foot pounds. There ya go.

Not trying to be funny, but ... you read these claims year after year. Those are simply the numbers you should expect in the field. I'd eat my hat ... but I guess stranger things have been true. I just wonder why everybody hasn't been running their guns on helium for a decade now, since I've been hearing this claim about that long.

Hello Gary...I was hoping someone would pickup on the required velocity Maryland requires for air guns...Helium maybe the way to go to get by the law...here is a link from Tim at mac 1

[www.network54.com] .Allen.

another link...[www.network54.com]



Edited 2 time(s). Last edit at 10/02/2010 02:12PM by allen avram.

OK ... just to keep the terms straight .... he said 50% more POWER. That's the FPE. Not the velocity. That's a big difference, as power is a factor of "velocity squared".

So; I'd have to do my projection numbers again. That would give 1,102.5 foot pounds with the current set up. That would need about 940 fps ... I'm still a bit skeptical ... but ... who knows.

Gary

dont try and breath it , balloon gas has 4% o2 added to stop people dying when they try the funny voice thing , its also been outlawed to sell it as a legal high ,,, but ill be looking forwards to the results too.

I was interested power versus recoil. Yukon long eye relief for sure.db

Hi Don,

Power and recoil are going to go together. Can't have one without the other. Newton's law. Equal and opposite reaction....

I'm sure you've picked up that I'm very skeptical regarding the helium issue. I wouldn't get your hopes all up on anything being that simple. As I said ... ten years of talking about it .... I've not heard proof that that's the ticket to easy power. I'm sure I read the thread referred to above, many, many years ago too.

First thing you'd want to know is if it degrades the seals in the gun. I don't know myself ... but it sure seems it would have been easy to prove or disprove the power issue immediately.

Might also be a silly question, but I don't know this either ... can you carry it in regular carbon fiber tanks? They have an aluminum bladder inside. Seems the helium tanks are always steel. Probably because of the six thousand psi commercial fill. But, you'd have to transfer to the carbon fiber for range use. Are the valves and seals the same?

Gary

Just curious about the issue and it is obvious. I would take your word before any other.db

I'd love for it to be true. I just think it would be extremely easy to prove, instantly. So; I'll be glad to see the results.

The fact that I've been hearing of the possibilities for so many years, makes me wonder why it hasn't become standard practice, if it works so well. There must be a down side, of we'd all know about the results by now.

There was a fellow, at the 99 Michigan shoot, that had a 9mm single shot Korean gun running hot. The rumor was that it "wasn't running air". But, it was my understanding that it was just using the higher pressure from some gas. I forget the exact numbers, but it was around 300 foot pounds. I did beat it with my first 56 Expedition rifle. That was only running about 320 fpe or something like that, at the time. And my accuracy was better. I still have the target I shot here in the office.

Point was .... that was 1999. That's the closest thing to documentation I know of.

Best,
Gary

Here is some old data taken from another forum if the link works.

[www.network54.com]

Well, that verifies what I said ... "I don't know anything about it".

So; do you know if it's screws with the seals? That thread said something vague about it not "normally" hurting your gun.

Gary

I know that it is more prone to leak due to smaller molecules, not sure if it can be absorbed into the o-rings like CO2 does if the right seals are not used. I thought it gave a lower number of shots per fill as well but going by this post that is not the case.

Thanks Joe,

I'd sure want to know that before I'd ever try it. It would be a real bummer to have to totally disassemble a rifle to replace all the seals. By the nature of the seals, they are "inside". You can't make them easily accessible. It's a good bit of work to take a gun down and not scratch it up, etc.

Gary

Allen ...

We're dying for data here. How's it coming? Have you shot it yet?



Gary

Hello Gary...Sorry, I have been busy at my office (Avram Funeral Home) ...seems God's waiting room has been busy, he won't let me see his day book to be able to plan extra curricular activities...I will keep all of you posted with results...Allen.

Ah .... when I said we "were dying for data here" .... ahhhh .... I was just kidding Allen.

You go ahead and take care of the other people first .... ..... We'll wait.

Gary

Hey Allen,

If you ever get the chance to see his day book, please scan it and send a copy to us. He, he, he.

HEHEHE, we need a foot in the mouth smiley for that Gary.

Like this one Joe? haha. Ya don't know the riches ya have Son. hahah.

Gary

Hello Gentlemen...I had a chance to try Helium charge late this afternoon, it was to dark to chronograph today and will do this tomorrow. I have to say though that the gun felt like comparing co2 to a 3000 psi rifle...this stuff is awesome, I feel like a kid with a new toy. Respectfully submitted, Allen.

That's great Allen,

Be neat to see the numbers.

Thanks for posting.

Gary

Good morning gentlemen...here are some numbers with Helium
Gun used is what Brent and myself made....40 cal. shooting a 200 grain slug sized to .408, bullets were purchased from Hunters Supply...Lead does have brinell hardness, not dead soft...
Charged to 3500 psi
1st shot...1056 fps
2nd 1037 fps
3rd 978 fps
Charged to 4000 psi
1st shot 1050 fps
2nd 1020 fps
3rd 1050 fps
4th 890 fps

215 grain slug @ 4000 psi
1st shot 980 fps
2nd 982 fps
3rd 956 fps

Notes to ponder...Using nitrogen the gun can be charged to 2800 psi, any higher and valve lock occurs...using Helium and valve lock occurs at about 4600 psi...fps difference between nitrogen and helium is about 200 fps...bullet grouping did not change with increase speed...all clover leaf @ 50 yds...Chronograph was set at 30 ft from muzzle...I wanted to test more but Gods waiting room got busy (Wish I could see his daily planner)
After shooting with helium it will be hard to go back to anything else...more testing later...Respectfully submitted, Allen.

Hello Allen,

Interesting stuff there. The part I'm missing, didn't seem to be included though. I understand that you said valve lock occurs at a different psi ... that's interesting, and I can't imagine why. But ... what I'm missing is the "relative difference" between performance at the "same" psi between the two gases.

The other question was that of sealing. Let us know when you determine if the guns hold their charge, or if the seals degrade.

Interesting research. Thanks for posting. (Don't forget ... we like to look at the pictures ...

Gary



Edited 1 time(s). Last edit at 10/12/2010 01:45PM by barnespneumatic.

I glad you saw the difference in valve lock...remember that helium is less dense the nitrogen...you can use a lighter spring with helium compared to nitrogen...valving is alot more efficient with helium than nitrogen...good comparable is water flowing thru a valve vs molasses...we charged the gun to 4500 psi overnite with no leaks, we do not use O-rings in the charge tube, the ends are threaded...hope this helps, Allen.

Hello Allen,

Thanks for the comments. I'm very interested in your research.

I understand the difference in valve lock you are quoting. I still don't understand the logic though. 4,500 psi is 4,500 psi. That's pressure acting on the surface area of the valve head. That pressure, and the area (factor of diameter) of the valve head, is the determining factor of what's holding the valve closed. I don't understand the density of the material having effect upon it's back pressure. I'm not disagreeing with you .... just telling you this is news to me.

I'd still love to see what .... say ... 3,000 psi of air produced ... say ... 900 fps ... and 3,000 psi of helium produced ... ???? fps. That's the comparison I'm seeking.

Regarding sealing your reservoir ... no O rings. Interesting. I thread reservoirs too. Still, it's the O rings that do the sealing. Are you using a thread seal product or some such device? Obviously it works, and I'm not assigning value ... just asking.

Thanks again for posting.

Gary

barnespneumatic Wrote:
-------------------------------------------------------
> Hello Allen,
>
> Thanks for the comments. I'm very interested in
> your research.
>
> I understand the difference in valve lock you are
> quoting. I still don't understand the logic
> though. 4,500 psi is 4,500 psi. That's pressure
> acting on the surface area of the valve head.
> That pressure, and the area (factor of diameter)
> of the valve head, is the determining factor of
> what's holding the valve closed. I don't
> understand the density of the material having
> effect upon it's back pressure. I'm not
> disagreeing with you .... just telling you this is
> news to me.
>
> I'd still love to see what .... say ... 3,000 psi
> of air produced ... say ... 900 fps ... and 3,000
> psi of helium produced ... ???? fps. That's the
> comparison I'm seeking.
>
> Regarding sealing your reservoir ... no O rings.
> Interesting. I thread reservoirs too. Still,
> it's the O rings that do the sealing. Are you
> using a thread seal product or some such device?
> Obviously it works, and I'm not assigning value
> ... just asking.
>
> Thanks again for posting.
>
> Gary



Edited 1 time(s). Last edit at 06/23/2011 02:38PM by allen avram.

Good morning everyone...We did some more testing yesterday...3500 psi charge of nitrogen, .40 cal/230 gr. hollowpoint, two shots@880fps. 3500 psi charge with helium same bullet two shots 1080 fps...hope this helps, Allen.

Hello Allen,

Well, that's an amazing difference.

Thanks for sharing.

Gary

Hello Gary...sorry it took so long to reply...3000 psi charge with helium netted one shot at 1050 fps/ nitrogen 900 fps with one shot, 2nd shot bullet dribbled out of barrel...thread seal used on charge tubes...hope this helps, Allen.

Hi Allen,Garry and all.Thats real interesting data.Like Gary I'm very interested in the valve lock occuring at diffferent preasures with the different gas's.As Garry has quite rightly said, preasure is preasure,however it would seem that the difference in density ulters the flow characteristics which initself ulters the effect that the flowing gas's have on the valve. I'm also interested in the data you get with HPA.Regards Danny.

Here's a little bit of info. If you're like me it just brings more to mind. But here it is anyways. This seems to be a topic of interect everywhere at the moment.

[www.network54.com]...

Not trying to take the discussion from here. Maybe this will bring more info to light and kick start the chatting. In this thread, Carl Hall is the guy with the experience.

maybe because of the smaller size of helium molecules the stuff flows easier , so offers less resistance to movement in some way , accounting for lock up changes ,, just a thought.

Here is a picture of our test rifle...Just figured out how to downsize photo to fit...Hope you like...Allen.



Edited 1 time(s). Last edit at 10/20/2010 03:01PM by allen avram.

Hello Allen,

Your rifle looks nice. Sounds like it's working well.

Have you found any down side to your helium experiments yet? I've found it interesting. Still have not tried it as I have not had time to research if it might infiltrate O rings and destroy them. Bummer to have to tear down a gun to replace all the seals.

I know you've said you've sealed yours with thread locker. Does that mean you'd have to heat/warm your components to take things down then - should the need arise?

Interesting info. I'm sure it will suck me in sooner or later. haha.

Gary

Hello Gary...thread locker works good , the down side is you have to heat the charge tube to allow the locker to release...we are still testing other means to be able to seal as well...I haven't seen any down side in using helium, the guns respond very well, once you try this stuff it is hard to go back to compressed air...you have to make sure that the charge tube is able to handle higher psi, 4000lb+...thanks for the kind words about our rifle, over two years testing, hopefully will be complete very soon...Allen.

Allen,

Very nice info and a great read.

What is the difference in FPS/FPE with HPA (regular high pressure air) and HELIUM with any bullet you select. Can you please post those numbers. Thanx

Hi Cedric,

You probably missed this part of the thread - his last post from a few days ago (the bulk of the post it a year old).

copy:

allen avram [ PM ]
Re: Helium
June 23, 2011 09:39AM IP/Host: adsl-75-21-166-150.dsl.sgnwmi.sbcglobal.net
Registered: 2 years ago
Posts: 26

Good morning everyone...We did some more testing yesterday...3500 psi charge of nitrogen, .40 cal/230 gr. hollowpoint, two shots@880fps. 3500 psi charge with helium same bullet two shots 1080 fps...hope this helps, Allen.

End copy:

Heck of a difference, isn't it Cedric?

Gary

I'm thinking about building a fusion reactor. The reaction yeilds a helium atom and a neutron. Anyone have use for the netrons?

Just kidding...I have a neutron valve in work.

Seriously, the helium made a huge difference. What are the downsides? Cost, shot count?

Here is a formula for you....FPE = (fps)*(fps)*(wt)/450240
880x880x230gr./450240= 395.59 ft. lbs. energy -----Nitrogen
1080x1080x230gr./450240= 595.80 ft. lbs. energy ----Helium

shot count goes down with helium...you may have to test your own gun to see how many shots...We can get two good shots with helium compared to four good shots with nitrogen

see my post re: cost of helium, it isn't much more than shooting nitrogen...hope this helps, Allen.

Hello Allen,

Those are amazing results. Especially with a 230 grain slug. I don't think I'd want to be behind a 925 grain slug on Helium! Thanks for sharing. Good detail, I apprecitate it.

To the readers: I always feel some sort of obligation to caution you to not over-drive your PCP. Some guns have been designed and built for a particular power range. From Allen's results, it would seem that power could increase 50% or more, with Helium. Bolt action retaining systems must be built for the potential power, or you could end up with a bolt down your throat. Be cautious - stay safe.


Gary

Sounds like a MFG warning. So are my guns safe with Helium? I don't want to inviolate my warranty or take a bolt down my throat. I already had my tonsils out. Dory

Hello Dory,

I made your guns to have reduntant safety factors for the power level and fuel intended. You and yours can use them safely for the next hundred years, as built. I have "NOT" tested the guns on helium, or at any other power level than that for which they were designed. Therefore; I won't sign off on any experimenting or hot rodding of my guns.

I think Allen demonstrated a possible use for the Helium fuel - with a small to medium weight slug shot just under supersonic. Taking a gun like your Justice, already producing about 720 foot pounds, and running it on helium .. is in the realm of the unknown to me. I'd suspect it would break you in half.

I'd really like to see the guns used, far more, and reported on here ... within the bracket which I built them, and extensively tested them. I know that "Turn It UP!!!!! is the anthem of today, and I'm rather antediluvian; but it makes it nearly impossible for engineers to build in reduntant safely factors for the use of their products, if a user is hell bent upon rolling back those safely factors by pushing the envelope.

I really don't understand why we haven't seen a stamped to helium, given the results Allen has reported with no reported downside. Yes - bolts down the throat from lightly built guns would be a downside, but there's been no shortage of people taking simple guns and hot rodding them. I don't know the answer to that one.

Gary

When testing with helium our goal was to use a bullet that shot good groups with compressed air or nitrogen...We found that Mr. Hollow point (Bob Vogel) .230gr/.40 cal worked great. This bullet weight would be good for just about any game that you want to hunt, now if all you have to do is change gas to increase velocity by about 200fps and the gun shoots flatter with less holdover now you have a gun that can do more for you...keeping the bullet subsonic will allow you to still use dead soft lead with no smearing...now if you use round ball it will have to have some brinell hardness to work and they really scream out of the gun...I would like to try some of Gary's/Jerrys slugs for the .457 and see how they work, i'll bet the they will really sing when they fly...I want to say if any of you try helium is to work up to your max fill psi...example: If your guns max fill psi is 3000psi. then charge the gun to 2200psi. and go from there...be safe and have fun...Kind regards, Allen.

Thanks Allen,

I'd offer the following, as additional thought:

It's easy to think of PSI as PSI as PSI ...and what's the problem? The concern I'm discussing, is the resulting "ENERGY" which is produced from, perhaps, the same psi. It's the energy which is going to tax machinery. There are friends and readers here, who have gotten a mouth full of broken teeth and been knocked out by flying bolts. I'm glad to say, not from my guns. Now - it's entirely possible that user error was much of the equation. Perhaps the bolt wasn't closed correctly. Or perhaps the locking mechanism was designed in such a way that the shock of firing allowed the components to slip registry. Then, there are the examples where the energy upon firing either bent, snapped, or in some way broke components of the gun, and let the bolt escape. Often because the gun was being used in a manner that was not recommended by the builder. See my comments regarding redundant safety margins. The point is, it can happen. And it's not a good range day when it does.

I'm well aware that I come off, often; as sounding sort of Nanny like for a big bore builder. But people don't consider the basic laws of physics, when they're just out for an afternoon of sport, and the "one uppmanship" starts to brew. Just using the incorrect slug diameter and weight can cause the breech pressure to rise quite a bit. PSI is not just PSI. The pressure inside the gun's breech only rises to a point where the bullet starts to move down the barrel. Loosen the slug or lighten the slug, and it starts to move earlier with less psi behind it. Choke off the breech with a slug that's too heavy or too tight, and the pressure has to rise way up before it can "pop the cork" of the slug in the breech. Basic airgun mechanics that should be understood. It's why changing from a pellet design, or a round ball design (both with tiny contact surfaces between projectile and barrel) and moving to a full length solid bullet head projectile ... of the "same diameter" .... dramatically raises breech pressure. The new trial bullet head's long sides are totally in contact with the barrel walls ... might be ten or twenty times the engagement length, and no grooves or sections to break up the resulting drag. All things that a good maker takes into account, when designing the total system he sends out. The rub comes when the user decides he's bored with what the maker proofed, and needs to improve it all. It can result in some Dentist getting a new golf bag.

If you've read carefully, I have not come down on Allen for his research. It's very interesting. I'm sure, someday; I'll build something specifically for Helium and learn more about it. He's cautioned everyone to proceed carefully. But neither he nor I, know what gun you are thinking of trying on Helium. Nobody can project the results of using a machine other then as it was designed and tested. You're on your own there.

You'll note that I personally just can never get past the fact that there are dozens and dozens of guns out there, under beds and in closets ... that don't get shot at all. Nothing gets posted here. But ... one might be dragged out to test with some new miracle hot rod technique that could be risky. I make 400 fpe guns, and I make 800 fpe guns. But, I know, beyond a shadow of a doubt ... that most would think it would be far more fun to try to turn the 400 fpe gun, into an 800 fpe gun (on their own) ... than to shoot the 800 fpe gun that was tested and proofed. I guess it's just human nature, and won't ever change. It's different from my end of the cycle.

Well, what a buzz kill I am. I know.

Gary



Edited 1 time(s). Last edit at 06/28/2011 06:22PM by barnespneumatic.

Yukon on that sounds scary and would rip off my shoulder,db Hope you are feeling good Gary. Saotome and Messores are waiting for the arrival and want to try it out. If you want to know who they are look on the web.db

Gary,

Thanks for pointing out that you were fully aware that the helium pressure was the same as the nitrogen pressure for the test when you issued your warning. I was wondering if your concerns were related to just max possible pressure or if the total released energy number was the concern.

It's funny how interest migrates to the biggest and most powerfull but lots of times one can have a lot more fun with smaller and lighter. I don't think anyone would want to do the full Woods Walk with the Yukon! The Maverick sure got a lot of shots there though!

Sometimes I think there are a lot of folks taking a gun and hot rodding it to the point they can only use it half as much.

Allen,

I'm just musing here, I think the helium experiments are excellent and it looks like you are going to get to a gun that fits the intended purpose. It just occured to me that some folks hot rod themselves out of a fun gun...

Jerry,

You're seeing what I'm seeing. Now ... consider the catch 22 for a custom maker. The talk all centers around the biggest and baddest, and how to take the biggest/baddest and make it MORE big and bad. Then, ask folks what they shoot and what they enjoy shooting, and it's the exact opposite end of the scale.

We pretty much never get a thread on a small bore gun here. But that's what everyone shoots, if they shoot at all.

Just observations. I'm nobody's mother. Careful ... heheh.

Gary

Thanks for all the comments gentlemen...years ago when the only gas available was the CO2 cartridges for a power source and then came along the PCP's and that was a big step in the capabilities of air rifles. A few years ago I heard of a few fellows trying helium as an alternative but I never was able to get some hard numbers for comparables and this is why I thought well lets give it a try and see what the outcome is. I have let many people shoot our gun with both gasses and their response has it written all over their face with no words said except can I shoot it again? So my next test will be with a Talon Tuned Airforce .25 cal. rifle with Jerrys slugs and lets see what numbers it will produce...Kind regards, Allen.

One thing I don't get tired of when I shoot is the slow but powerful slug. In bright sunlight it's like shooting a tracer. When I don't blink. Sounds like a cannon. and hits a like a hammer. And I really don't think the recoil is that bad. Just don't do it often enough.

Allen suggested starting with lower pressure but that low, wouldn't mechanically work right I believe.

When switch to 400 lb gun like shooting a bb gun. It's all about perspective. Dory

Hello Dory,

Yes, part of the equation that I don't understand is the "Valve Lock" points Allen has mentioned. This is an old thread - there's a lot of info. in it. Some long time back, Allen mentioned a gun that valve locked at 2,800 psi with Nitrogen IIRC, but that would still open it's valve at 3,600 psi IIRC with Helium. I don't follow that. Psi acting upon the surface area of the valve head, determines the pressure holding the valve head into it's seat. If the PSI is the same and the surface area is the same, I just don't have the experience to tell you why it would be easier for the valve to open with Helium.

In addition, if it was then that much easier to open the valves, I'd be concerned that our powerful hammers would "overdrive" the valve mechanisms and pound them as if shooting on a nearly empty reservoir. Thus, potentially causing damage. If I am following, then a gun designed for Helium would require a different sort of hammer design. Just to be clear: if you have a hammer that provides enough umph to open a huge valve being held shut by 3,500 psi of breathable air, and you fired it on a charge of helium that will open as if it were a thousand psi lower or more ... then you could drive the valve into last Tuesday.

The last issue I've never had answered is that of O rings. Allen has said that he seals his reservoirs with a thread locker. I use O rings. Now ... somewhere in my ancient history, I seem to remember hearing that Helium required different O rings, or would degrade conventional rings, or that it was just harder to seal. I'd sure hate to ruin O rings in a gun, and need to tear down the gun to replace the O rings. Just questions that would need to be understood before I'd try it.

Gary

To answer some questions Gary...Valve lock last year with nitrogen as opposed to higher psi helium...good debate item over coffee, your guess is as good as mine....overdrive valve mechanism: We never had any issues with hammer/valve because when testing with a chromograph when velocity fell off alot we just stopped shooting and refilled with gas...I'am sure that common sense comes into play that you don't dryfire a big bore rifle...most air rifles the valve stem will only travel a pre-determined distance with the hammer bottoming out onto the valve base...Last year we used thread sealant and it worked great but it was to diffucult to reopen the charge tube for service so we now use O-ring sealing with no issues with leakage...If anyone is into scuba diving, this industry has been using helium for deep diving for years and all they use for sealing is O-rings with no issues...If you would like to call me and talk about this you are most welcome, cell phone 989-660-0279...Kind regards, Allen.



Edited 1 time(s). Last edit at 06/29/2011 02:58PM by allen avram.

Just had a whole post errased with one rouge series of key strokes. Boy that smokes me. I type fast. I have no idea what happens to highlight the whole darned screen and then the next stroke errases it all. Happens at the speed of light and it's gone!

Heck - I don't remember what I said.

I'm just asking the questions for my knowledge. Not down on the research.

The issue with valve lock is on initial firing ... not end of string firing. As Dory mentioned. You have a situation where it's known that the valves open much, much easier with Helium. Then, as suggested, you underfill to work up the power scale. Now, you have a fill psi of perhaps a thousand psi less than normal, and a valve that opens really easily. The first fire on that, with a powerful hammer, can really pound things. Yes - the hammer can bounce off the valve case, but I don't want it to do that.

There are all sorts of guns out there. Still a bunch of Farco shotguns from the Philipeans, no doubt. Brass tube reservoirs. I've seen one nut running his on HP air, where it was designed for 900 psi Co2 ... and maybe that wasn't a great idea. Then, there are the guns with the antique aircanes that were intended to run 500 psi (150 years ago) on a lapped and brazed iron tube reservoir ... and I've seen many run on Co2. So - folks will do questionable things. I figure a few typed words might make them think. I realize that they are not going to do or refrain from anything because I asked them to. But - I feel better having introduced the thread of caution - if it's used or not.

I forget the rest. maybe later. Interesting stuff. I'm sure I'll play with it at some time.

Gary

Hello Gary...I don't think the valve opens easier, you still have same psi. pressing on the valve head no matter if it is air, nitrogen, or helium it is the same, what is different is when the valve is open when fired more helium will get past the valve opening as compared to air or nitrogen because the helium gas is less dense...hope this helps, Allen.

Thanks Allen,

Well, that's interesting. Perhaps we just have a difference if definitions of terms. When I'd read "valve lock" ... I'd thought of a psi above which the gun would not fire. If it was to indicate something different, I don't want to put a fine point on it. Certainly not trying to trap you with your own posts. This has been one of my big question marks throughout this thread ... and it's probably all just a simple mistake. I've discussed it with Jerry, and we both wondered at the numbers that seemed to indicate the valve lock figure moving with the different gasses. Thanks for clearing that up.

Gary

Did a little more testing with helium with a 4000psi fill with 200gr solid hunters supply .408 sized bullet...we adjusted the valving to completely dump all gas from charge tube with one shot just to see what velocity would be. Here is the data...1380 feet/sec. with 845.7 ft./lbs energy...we placed a 1/4" plate steel target at 55 yds and put a hole completely thru it...Allen.

Thanks Allen,

What length barrel are you using Allen?

Oh ... BTW ... I did ask one of my welding gas suppliers about Helium. I said, what psi do you provide for your Helium tanks? Answered, "I don't know - you want to fill party baloons?" No. Are they the big chest high 6,000 psi tanks? "6,000 PSI!!! ... no ... might be 2,500 psi. What do you want to do with it?" Harry eye now. No ... just some shop use. Fill some pressure reservoirs. "YOU gonna FILL TANKS???" He sees me bypassing all the gubment rules and regs. I'm sorry I asked. But I don't feel like getting into an hour on big bore airguns. No - testing high pressure valve bodies ... nevermind. Just wondered. He probably called someone as I was leaving.

So; I'm sure I did it all wrong. But ... going in with a wide eyed ... "I'm gonna make a BB gun that will kill a buffalo" ... just never seemed my style. I never expected the fifth degree from a welding supply.



Gary

barnespneumatic Wrote:
-------------------------------------------------------
> Thanks Allen,
>
> What length barrel are you using Allen?
>
> Oh ... BTW ... I did ask one of my welding gas
> suppliers about Helium. I said, what psi do you
> provide for your Helium tanks? Answered, "I don't
> know - you want to fill party baloons?" No. Are
> they the big chest high 6,000 psi tanks? "6,000
> PSI!!! ... no ... might be 2,500 psi. What do you
> want to do with it?" Harry eye now. No
> ... just some shop use. Fill some pressure
> reservoirs. "YOU gonna FILL TANKS???" He sees me
> bypassing all the gubment rules and regs. I'm
> sorry I asked. But I don't feel like getting into
> an hour on big bore airguns. No - testing high
> pressure valve bodies ... nevermind. Just
> wondered. He probably called someone as I was
> leaving.
>
> So; I'm sure I did it all wrong. But ... going in
> with a wide eyed ... "I'm gonna make a BB gun that
> will kill a buffalo" ... just never seemed
> my style. I never expected the fifth degree from
> a welding supply.
>
>
>
> Gary
You should have been there when the undertaker went to the welding supply store and asked for a 6000psi tank of helium...he asked what the hell are you going to do with it and I just smiled and said you really don't want to know what I do with bad debts...he signed me up and no questions asked...almost forgot...26" barrel...Allen.



Edited 1 time(s). Last edit at 07/12/2011 11:23PM by allen avram.

Very good Allen!

Seems like nowadays, everyone feels free to ask about your business.