So ... ya want to make airguns .... do ya? haha.

Listen to this story.

Yesterday, while testing the Delta 32, I was placing shots with silly accuracy. Well, right at the end of my session, I thought I'd take another shot at a target. Actually, it was that Beaver target. And, I hit it ... but about an inch away from the first shot. Horrors! I said to myself ... WHAT???!!! But then, reality took over, and I reminded myself that I'd made the entire rifle and slugs from raw materials in my garage. Ok ......

But ... I thought I'd shoot another group. And, the group was good ... but it was low left. The group had moved. But ... I'd been shooting ... I was tired ... my hip hurt ... etc. I still wasn't convinced. You know I don't like that Leupold scope. I wondered if it was drifting on that friction tower I hate. Since the next gun to test wanted that Simmons 4X shotgun scope ... I thought I'd quickly mount it on the Delta. Of course ... I'd left the Simmons on the bench back in the shop. Nutz.

Ah, I realized ... it's 2:30. Kelly COULD possibly have time to bring it over. It would take forever to pack up and go get it. I couldn't leave the trailer/gun stuff unattended. I called, she could. I said I'd walk out the dirt road to the main road, so she wouldn't have to "bog" thru the mud puddles in her van. We timed the drop. It worked. I walked back and put the Simmons on the Delta. Pc. of cake! haha. Couple of shots and I was on. It worked ... but I couldn't tell if it was placing better than the other scope, cause I'd just mounted it, it was 4X for 50 yard groups, and the sun was now becoming an issue. Hummm. I figured I was being stupid anyway. Hey, I'd missed one shot by an inch at 50 yards. Don't be ridiculous.

Still .. that last group was a bit low left ....

Well, it also bugged me that all the gauges on my two tanks and regulator indicate a different psi. Different styles, ages ... unacceptable. Great if they are accurate - they are not. I wanted to tell the customer the exact fill pressure ... and "somewhere between 2 and 5 thousand psi wasn't tight enough. hahah

This morning, I drove in to a welding shop that fabricates truck bodies, mounts snow plows, etc. I'd bought nice guages there before. I asked for a 0-5K glycerin filled guage with tight markings. And ... they had one ... but only one. So, I bought it and ordered two more. Mounted it on one of my carbon fiber tanks. I wanted to do an accurate psi/velocity curve chart for the gun. I filled to 3K to start low. And the gun shot ... Pffft. Sounded weak. Something about 700 fps. What? I shot again. Faster than the last ... where it should be falling. What???? All wrong. I went to 3,100 on the gauge. Couple of fps LESS, where it should have been faster. What???? Again to 3,200 ... less velocity. The gun is under psi. clearly, but the numbers are all wring. I went to 3,500 psi ... and it was clearly air locked (but should not have been). Fine ... where's the camera? This is stupid.

I figure the guage is bad ... or clogged. I take it back off the tank assembly again (which means two joints because of the angle mount). I clean and examine and blow it out. Put it back. Test again. Same story. Nutz. So, I think ... ahhhh ... the other tank. That will show the guage is bad. I go to 3,500 psi and hear the "click" of the valve opening. Great ... it's not the guage ... it's in the gun.

I start examining. Of course, I suspect the firing valve. I'd had an issue with a spring riding up on a valve head recently ... it was a stainless steel spring. Every once in awhile, I get a rash of input from folks talking about stainless and stainless components. Of course, it sticks in my mind. And, although I've always wrapped my own valve springs, I sourced and bought a bag of expensive stainless steel springs of the correct size to use in a certain valve design. The one that failed had ridden up over the back of the small valve head. But! The valve head and spring body were close to the same O.D., and I thought maybe I'd not provided an adequate seat for the spring. With this issue though, I suspected a bound up valve again. However; in order to check, I had to take the whole gun down to pull the valve. Lovely. So, I tore the gun down. And ....



The ONLY part of the gun that I didn't make! A stupid commercial stainless steel spring. Right ... it looks as if it had been "coil bound" and then compressed farther yet. BUT ... not so. The spring never reaches a coil bound state in the gun, AND ... it has at least one and a half times it's coil bound length, to compress. No jamming posssible. But, the wire is too soft ... and it spread under load. Once it kinked, it started dragging on the annulus tunnel of the valve. Slowing the valve's responce. Causing the gun to shoot differently.

At first, it was just kinked and dragged rather consistently ... still allowing a good group ... but in a slightly different location. But then, for whatever reason, it jammed up even more ... and the valve began producing significant drag.

Quite a chase. Quite a waste as I won't get a dime for the time. I will renew the valve with MY OWN carbon steel spring. And, move on. Yet ... there's yet another day in the shredder. And, my stupid hip was killing me as I tore the gun down. Now, while I've been sitting here ... a pill has been at work ... and it's starting to help. Also ... just a demonstration here. If you could read and follow this ... then evidently the pain pills aren't making me goofy. haha.

And ... THAT's what making custom airguns is all about. Trusting your instinct, and following it thru to the end ... no matter where it leads.

Sure ... I'll have to take it back to the range after the rebuild and reassembly, in order to chart it for the customer. I'm glad the problem surfaced before shipping. It would not have been dangerous in any way ... just inconvenient. Glad I caught it.

Gary



Edited 1 time(s). Last edit at 02/25/2009 09:31PM by barnespneumatic.

You told me you never got a "big buck"...

Hey ... I did see two dead deer on the road on the way to get the gauge though!

Gary

Gary,

I always wondered if you made your own springs. I guess that just leaves the o-rings or do you make those too.

I know you have checked out some of your guns that had thousands of rounds shot through them. How did your springs hold up? Dory



Edited 1 time(s). Last edit at 02/25/2009 11:17PM by Dory.

Very well. Thanks.

Gary

Gary I hate it when time and effort gets wasted thru no fault of my own. I know that's the frustration you're writing of. I would be almost tolerable if it resulted in some new knowledge gained in the episode, but all you learn is you again can't seem to trust the work of others.

I'm glad you saw the bright side of finding the problem before it shipped.

I hope you also noticed a new record number of guests (53) yesterday. Way to go

Hope you feel better soon,
Kent



Edited 1 time(s). Last edit at 02/26/2009 01:55AM by Cajun Justice.

Hi Kent,

Thanks for your comments.

Doin' pretty good. Thanks.

Hey - the other good thing is I get to go back out and shoot it again. haha.

Gary

That... sounded frustrating.

----------------------------------------------------

Nah ... I just chewed a mouthful of ball bearings, and moved on ...

Gary