Man, that is excellent accuracy!! .5 in group at 100 yards is almost unbeleiveable for bigbore. Neil, do you know its averaged group? It should be close to that size, just curious. Good job!!by peter-n - Airgun Rendezvous Main Forum
Yes Gary, the rear bolt is smooth and has thread on the bottom one third to thread down into the bottom housing like you said.by peter-n - Airgun Rendezvous Main Forum
You have a very good eye Gary for observing things even through the pictures. You're right about everything you said regarding the bolt locking points and the strengh/weakness of the maching screw heads. That was why I took the closeup shot and knew that you would understand it right away, after all you're a Master airgun builder. His later design on the bolt/receiver lockup is better due to witby peter-n - Airgun Rendezvous Main Forum
This is the .50 Bontrager bigbore. It was the first 500 fpe bigbore I ever had, and I really love it, it is my BABY. It's accurate, powerful, and goodlooking. I know it's not a Barnes' he..he..but it's my most favorite airgun in my airgun arsenal. When I firsrt recieved this gun, I was in love with it, I couldn't take my eyes off it for a while due to its look and its immense power. It has plentby peter-n - Airgun Rendezvous Main Forum
Gary, The .50 gun was his earlier design, the bolt handle, bolt and the breech was built different than the 20 guage. The 20 guage has a 1/4 inch diameter screw screwed down from the top of the reciever to the tube at the rear in addition to the stem curved lever/bolt handle lock down. I had the bolt body blew back from me once and hit the rear retainer screw and bent it. I couldn't remberby peter-n - Airgun Rendezvous Main Forum
Thanks Kent and Lon for your inputs! This gun seems to be very stoutly built, it has three bolt safety catch built in in case of a bolt fly back, and the reciever and the bolt also look pretty thick. I looked over it throughtly and I'm sure it could handle a lot more breech pressure. I was afraid to take it apart before for fearing not be able to put it back, but after I did it, I'mby peter-n - Airgun Rendezvous Main Forum
I plan to get a more powerful spring for my custom gun. The spring is 6 in long, .6 diameter, 1/16 in thick wire diameter, I wonder If I should get a longer( how much longer to be ok?), or thicker wire diameter, or both? This gun is already powerful with 500 fpe using the 370gr bullet, and it has a lot of air, by swapping to the much more powerful spring and use a heavy 600 gr .50 slug; I believeby peter-n - Airgun Rendezvous Main Forum
Nice post Kent! Looks like you guys have a lot of fun. It's always nice to go out and shoot or hunt with airgun, all the stress from work and life is gone at that moment when you're having so much fun shooting.by peter-n - Airgun Rendezvous Main Forum
That is very interesting Gary! I've never had someone exlpained so clearly how the bullet react in the airgun's bore like that before. Good stuff for learning.by peter-n - Airgun Rendezvous Main Forum
That is a good classic mushrooming of the slug. Great expansion and still has a good bullet shank for deep penetration. Great work Gary!by peter-n - Airgun Rendezvous Main Forum
It's a gorgeous looking gun! I really like the look.by peter-n - Gary's Galleries
Yeah, I've never casted bullets before, that was why I looked at the wrong equipment like the $180 electronic casting furnace and the $180 RCBS sizing press. I like the idea of casting my own slugs, it's fun and it's the only way to get the slugs that I really wanted for my custom guns.by peter-n - Airgun Rendezvous Main Forum
Thanks Gary for the infos! I'll check into Lee's products. That sounds cheap compared to mine. I don't need the top of the line product, just the simple casting is fine for my use. That would save me a bunch. Oh, one more thing and this confused me a little, If I ordered a mold with exact size for my gun do I still need the sizing die? They say they always make the mold a few thousandths of anby peter-n - Airgun Rendezvous Main Forum
I've been thinking about casting my own slugs for my .50 and 20 guage bigbores. When I researched the equipments I would need and the total price, I was a little shock to find that it gets pricey. Let's see....a custom 20 guage mould $200, a .50 custom mold $100, 2 sizing dies $100, a resizing press $180, a casting furnace $180, a casting ladle $40, lead thermometer $40, casting glove $20, a hoseby peter-n - Airgun Rendezvous Main Forum
I answered a post on this question before on another forum. According to a neurolgist( I did a resarch on it) the animal wouldn't have enough time for its brain to register a sound with a projectile at 600 fps and above to react and move away at 100 yards and under( maybe the most at 1 or 2 inch) With bow and arrow and 300fps and less it is, it can "jump the string" But then again, that's accordby peter-n - Airgun Rendezvous Main Forum
Thanks guys for the infos! That is some good engineering of the valves. One question Gary, if the intake valve failed, what normally need to be replaced? The orings? I want to find out in case mine get failed in the future and be able to fix it myself.by peter-n - Airgun Rendezvous Main Forum
Good to see you feel better. I know a close person who has the same problem but from the neck injury, so I know how it feels.by peter-n - I'm just sayin'
My 20 guage works perfect with the Dangerous Game slug(it's a slug with a plastic sabot fit into the base of the slug to seal the gas/air and stablelize it during flight, supposedly), but with any other loose slug, it would not fit snugly. This gun was intended to use with the Dangerous Game slug by the builder, but the slug is so hard, it gets about 100 fpe less than the other slugs with the samby peter-n - Airgun Rendezvous Main Forum
I've always been curious about how many shots can a well designed bigbore valve take before it failed. With the powerful mainspring to smash the hammer into the valve stem, it takes a lot of abuse. A few thousands shots? Tens of thousands of shots? Have always been curious on this one.by peter-n - Airgun Rendezvous Main Forum
When I load my 20 guage smoothbore with the slug, sometimes carrying it barrel down it would slide down the bore due to no rifling to hold it in place, I wonder if I shoot it, it would act as a barrel obstruction and be dangerous? I know in firearm it is, but not sure about airgun. That's why I always hold the barrel up on this gun to prevent the sliding. Does your smoothbore has the same problemby peter-n - Airgun Rendezvous Main Forum
That's why I love this forum. It has a very knowledgeable Master airgun Builder to help me out with any airgun related questions and a great group of friendly and respectful guys on this forum. I'd learned a lot of valuable informations over the year on this forum and I appreciate that!!by peter-n - Airgun Rendezvous Main Forum
Yes my gun been shooting the 370 gr Maxiball. Where can I get a sizing die? Midwayusa? I want to try out a few different slug sizes, and will only keep the ones with good accuracy and good energy. The Maxiballs are fine, but some other bullets might even be better. Thanks for your help Gary!by peter-n - Airgun Rendezvous Main Forum
I've just ran across this site, and it has what I've been looking for a long time, the 600 to 700 gr hardcast bullets, and smoothwall soft lead for the .50 caliber. One question, my bore sized is .510, if I use the .510 diameter 700 gr hard cast, grooved bullet, I wonder if it would have too much back pressure? or do I need to go with the a couple thousandth of an inch smaller? They don't haveby peter-n - Airgun Rendezvous Main Forum
Nice work Gary. Excellent accuracy.by peter-n - Airgun Rendezvous Main Forum
That's pretty cool! 200 yards is really long range for airgun. Good job!by peter-n - Video Library
That sounds like a good idea. As for me, my favorite is the small metal cans. I save them sometimes for the range. They make a satisfying sound and rolling around when hit.by peter-n - Airgun Rendezvous Main Forum
Thanks Gary, that's a great advice!by peter-n - Airgun Rendezvous Main Forum
I have a Bontrager .50 custom bigbore, with the 370 grain bullet, it gets 3 full power shot at 530 fpe, 475, 460, and 2 weaker shots at 350 fpe at 3200 psi. So this gun has a lot of air and potential for modding for more power since it has great air capacity.. I wonder if just by swapping the more powerful mainspring it would increase another 50 to 100 fpe. The air transfer port is .5 inch in diby peter-n - Airgun Rendezvous Main Forum
Thanks Jim! That is very interesting read. So semiauto big bore is possible, but it won't give us the best accuracy, and big power. It still would be fun to own one he...he..by peter-n - Airgun Rendezvous Main Forum
No problem Tofaz. I've been reading from the forum for years, and still learn something new everytime. That's why the forum is such a good place to learn from one another. I learned how to mod the gun for more power from your post and you learned about the round ball ballistic, good trade huh? he..he..by peter-n - Airgun Rendezvous Main Forum