advice for aluminum breech



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Offline anti-squirrel

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advice for aluminum breech
« on: January 03, 2019, 10:53:57 AM »
Looking for some input - got the aluminum breech- very nicely machined and anodized, comes with a steel bolt/handle too.  Excellent deal for the money.  However, I found the new breech won't let the bolt handle slide down into the groove.  This is using a stock 1377 barrel.

I have a couple options, neither of which is a problem with my "poor man's lathe" AKA drillpress.
1: turn down the bolt handle about 1 mm total
2: cut the force cone a hair deeper

I'm not averse to either, just looking for some input.  As this breech will be dedicated to my 1377, it's not a problem if I have to do one-off stuff since I have other Lego to play with: a 1740, 2400KT, and by mid-Friday, a Maximus.

film at 11 the lime-green arrow indicates the binding point.
Richmond VA

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Offline Sfttailrdr46

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Re: advice for aluminum breech
« Reply #1 on: January 03, 2019, 11:10:06 AM »
I would make the slot in the breech block slightly wider since it appears not to be a stress point in the breech block. Turning down the bolt handle will make it less robust. My vote is wider slot in breech
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Offline Gipper

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Re: advice for aluminum breech
« Reply #2 on: January 03, 2019, 12:00:34 PM »
Are you using a stock bolt?  Maybe you can just reprofile the tip of the bolt a bit? 
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Offline anti-squirrel

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Re: advice for aluminum breech
« Reply #3 on: January 03, 2019, 12:12:24 PM »
Thanks for the thoughts.   I'm averse to doing any reshaping on the breech itself- if I had a Versamill or even a basic Bridgeport that would be a different story, but I'm trying to avoid removing aluminum.  I have several extra bolt handles including a stainless one but after some rummaging I found some basic HSS capscrews with the right thread, so the problem may have self-rectified. 

I may consider re-working the force cone and leade down the road, but the barrel can wait for now.

EDIT: the force cones are off by twenty thousandths on two of my Crosman .177 barrels.  On a third barrel it's right on the money, but that barrel's too short for my project.   ::)

« Last Edit: January 03, 2019, 12:58:33 PM by anti-squirrel »
Richmond VA

SPA and Crosman stuff
Turkish & Czech springer

and some slingshots for when the pellets get low

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