Made an aluminum breech
My breech O-rings were worn so instead of just replacing them I decided to make a new breech lol. I machined this one out of 6061 instead of the factory delrin and made the tolerances tighter so it doesn’t flop around. I also grooved it for 3/32″ o-rings instead of the original 1/16″. I cut the grooves to the tolerances listed in the machinery’s handbook but I think I need to go back and loosen them up a bit as the cocking effort is a little bit too high right now but it won’t be a problem to fix. Looks cooler and no more wasted air out the breech.
I had a member ask me if I could make him a breech out of bronze, has anyone tried that? I’m thinking the breech will be so heavy it will absorb a lot of the hammers impact rather than transfer it to the t-hat. This aluminum one “feels” about the same as the delrin but I don’t have a gram scale.
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The frame and breech are both aluminum, but the breech O.D. is cut to where it doesn’t make contact with the frame I.D. The breech rides on the steel barrel when cocking and sits on the o-rings when everything is snapped in place.
When the gun is cocked the breech will move back and forth under the drag of the o-ring without much force. However when cocking forward once the rearmost o-ring starts to ride over the barrel the force required to get the sear to latch goes up siginificantly. I’m fairly confident once I get the o-ring groove sizing correct I’ll be okay, I just haven’t had a chance to mess with it since I made it on Fri.
Exactly the problem I had (Oh yeah, sweet looking breech by the way!)
I think theres enough give between oring and barrel to allow the breech to bind on the frame or the ali’ contacts the steel barrel and binds.
Skimming the OD of the breech may help some.
Thanks for the kind words fellas.
The frame and breech are both aluminum, but the breech O.D. is cut to where it doesn’t make contact with the frame I.D. The breech rides on the steel barrel when cocking and sits on the o-rings when everything is snapped in place.
When the gun is cocked the breech will move back and forth under the drag of the o-ring without much force. However when cocking forward once the rearmost o-ring starts to ride over the barrel the force required to get the sear to latch goes up siginificantly. I’m fairly confident once I get the o-ring groove sizing correct I’ll be okay, I just haven’t had a chance to mess with it since I made it on Fri.
Let us know how it goes with the ali’ breech. I spent months trying to get an ali’ breech to cock smoothly without success… Tried smaller OD, bigger ID, bigger oring seats, repositioning of the cocking knob etc. Finally came to the conclusion that an ali’ breech binds on just about anything it touches..
LET ME KNOW IF YOU GET IT WORKING NICE!!!!! 😀 😀
That is a sweet looking breach!!!
If the frame is aluminum you can’t use aluminum to slide against it, it will gall… Has to be a harder or softer material…
I tried to use some aluminum rod sliding inside a hole in aluminum channel and it would bind like a bastard (to the point of scoring the rod as deep as 1/16″ and locking tight), a steel rod had no problems even after a few years of use… (Not a breach..).
Looks Great there M/H! 😀
Mike
That could be I know when I bought my gun it came with the Leapers scope Accushot 8-32 x56 30MM so far no complaints for the price they seem to be a nice scope, seemed like a big scope for an Air Rifle but after using it I can see why they want the magnification and I really like the side wheel paralex adj never had a scope that had that makes it nice for target shooting.
Eddie, you’re right. The recess is so the sear can pop up and hold the hammer.
I may have jumped to conclusions on the scope. I was having focus problems but after looking at the gun closer this weekend I noticed the tri-rail is jacked. I think it may have been putting enough torque on the scope body to cause the problems I was having.
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Dude, I tried everything 👿
I just got through tearing mine down “first time” they aren’t really bad to take down I did it just to get familiar with the parts, I never thought about the fit on the OD of the breach you are right really doesn’t have to be tight because of it sliding over the barrel onto the o ring. I do have a question I really didn’t think about looking at it really well when I tore mine down because I was checking everything out to make sure it all went back together right, but there is a small cut out on the breach bolt what is that for? I went back and looked at a print and I am going to assume that is clearance so the hammer can cock? like I said I seen it but thought about it after it was back together just curious. What you made looks great I always did like the flutes on the outside. Oh yea what happened to your Leapers scope I have one on mine just wondered what went wrong with it?
Will do Pablo. I polished the breech slide area of the barrel and lightly lubed with silicone, did you try that?
I’m hopeful as it’s not too bad the way it is, I just think the O-ring grooves are not deep enough making it a bit too tight when the rear O-ring slides over the barrel as the breech is cocked forward. Right now I’m using the 3/32″ O-rings and if I can’t straighten those out I’ll try stepping back down to the 1/16″.
Metal’
Let us know how it goes with the ali’ breech. I spent months trying to get an ali’ breech to cock smoothly without success… Tried smaller OD, bigger ID, bigger oring seats, repositioning of the cocking knob etc. Finally came to the conclusion that an ali’ breech binds on just about anything it touches..
LET ME KNOW IF YOU GET IT WORKING NICE!!!!! 😀 😀
Thanks Eddie. I had the whole gun torn down earlier this week for cleaning and the scope is going back to leapers for warranty.
I measured the I.D. of my frame for making the barrel bushings & shroud, but the breech rides on the barrel so it doesn’t need to fit snug on the O.D. In fact when I pull it out next time I will machine a little more off the O.D. as it’s going to rub a little paint off when the breech is pulled back how it is now.
The I.D. of the breech I made is reamed to .3125″ and the barrel O.D. is .310″ so there is .0025″ clearance. The muzzle side of the stock breech was oval shaped from how it rides off the end of the barrel and it had a greater clearance to begin with which is why the stock pieces are sloppy feeling.
Nice peep sights Metal should be good out past 100 yards don’t you think LOL! I just had to post that. your work looks great did you measure the inside of the frame to get a tighter fit or just trial and error until if fit good just curious as I usaully am thanks Eddie
Thanks!
It’s just blasted, primed, and painted with some ceramic header paint for now. If it doesn’t hold up it’s easy enough for me to blast it off and try something else.
good looking breech! Did you anodize, powdercoat ,or paint?
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You could give it a spray moly coating available for firearms from Brownells. It will make it as slick as Trons box of dicks.
http://www.brownells.com/.aspx/pid=1145/Product/TEFLON_MOLY_OVEN_CURE__GUN_FINISH