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All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Topic started by: JonnyReb on July 15, 2011, 09:51:20 AM
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Just curious if some of you folks are quite happy with your aluminum breeches that you've modded onto your various crosmans, i've tried 2 and thought they were both very rough feeling in comparison to my factory steel breech. Do some of you have aluminum recievers with steel bolts that are smooth cocking and work perfectly? What kind are they? Thanks, J
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Jeff,
I haven't had any experience with aluminum breeches, but here are a couple of things to check. Check both parts for burrs and smoothness. Use jeweler's files on the slots in the breech block and or some 400 grit paper to smooth any roughness. Check the operation with the hammer spring removed to make sure it moves freely. Most important, I would lightly coat the aluminum surfaces with anti-seize compound. In fact, I always use anti-seize on aluminum sliding or threaded parts to prevent galling.
Maybe that will help some.
Lloyd
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I have one breech that has a steel bolt and like Lloyd said it is all about making sure the parts are smooth plus I camfered the rear of the bolt that when cocking would tilt from the pressure applied and possibly risk gouging the inside of the breech. With the minor use it has seen it is fine so far. Anodizing would help also.
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I have had experience with aluminum breech's. Also wondered about how they would wear compared to steel breech's. So far so good.
As Lloyd said anti seize is a good idea. I smear a very thin film of white litheum grease on my bolt shaft. Also make sure the steel bolt has not burrs around the threaded hole where lever screws in. Outside of that everything works great...:)
I have bought a couple different aftermarket extended type bolts and both need to be deburr where lever screws into hole.
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Thanks Lloyd, R35 and Gene,. Yup galling would be a good word for it. The CB barn breeches that gave me trouble probably needed a bit more finish work to smooth out. I've been looking at genes disco with its required high breech and thinking how much i want one but didn't want to trade out my slick steel breech for a more troublesome one, Sounds like anodizing might be a good idea. J
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You would be surprised how far some polishing and anti-seize would go toward smoothing up an aluminum breech. Proper fit between the bolt and breech is key too. If the bolt is too loose it can cock in the bore which will allow it to dig into the aluminum.