M71 browning gunsmith CHAMBER CAST

Thanks John....That's about what mine are too. But I'll bet you can push a bullet back into a fired case....I can't. So I still think this thing has a tight neck and is not releasing the bullet gently enough when it's fired....
 
The only differnce I've heard of with regards to chambers is that the Browning 71's have short throats. I use same loads in my Brownings and Winchester 71's no problems. Only hitch is that my 250gr cast bullets are too long to use crimp groove and work in my Browning carbines but fit just fine in my Winchesters. After 5 resizings I shift brass to cast bullet loads (lower velocity and pressure loads) and neck size only, segregating this brass for mu cast bullet dedicated 71 , my oldest , most finish worn 71. Yeah, I have several 71's, more than I care to admit :redface: But I regularly shoot a Browning 71 carbine and my cast bullet 71 and a bolt peep 71. I don't shoot my 2 Deluxe 71's ( I did put a few rounds through both of them when I got them), I just had to, I am sure you understand. I'd love a Winchester 71 or at least a lever rifle section for us lever loonies.

Oh yeah, I sent you a pm about your problem;)

big bear, dumb old guy:cheers:
 
thepitchedlink said:
Thanks John....That's about what mine are too. But I'll bet you can push a bullet back into a fired case....I can't. So I still think this thing has a tight neck and is not releasing the bullet gently enough when it's fired....
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Yes, no problem and with about the same degree of fit and effort as with other calibres I have
 
big bear said:
The only differnce I've heard of with regards to chambers is that the Browning 71's have short throats. I use same loads in my Brownings and Winchester 71's no problems. Only hitch is that my 250gr cast bullets are too long to use crimp groove and work in my Browning carbines but fit just fine in my Winchesters. After 5 resizings I shift brass to cast bullet loads (lower velocity and pressure loads) and neck size only, segregating this brass for mu cast bullet dedicated 71 , my oldest , most finish worn 71. Yeah, I have several 71's, more than I care to admit :redface: But I regularly shoot a Browning 71 carbine and my cast bullet 71 and a bolt peep 71. I don't shoot my 2 Deluxe 71's ( I did put a few rounds through both of them when I got them), I just had to, I am sure you understand. I'd love a Winchester 71 or at least a lever rifle section for us lever loonies.

Oh yeah, I sent you a pm about your problem;)

big bear, dumb old guy:cheers:
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Thanks Bear....where do you find cast 348's??? Cast yourself?
 
So more tinkering here. Got a piece of Cerro safe on the way, so that should be interesting. I tried measuring headspace. I measured the rim of a new piece of brass, .059" Then seated a fired primer, lightly, then chambered the round and let the bolt face seat the primer, then measured the protrusion...= .0085 So total is .0675 according to the SAMMI spec sheet, min is .070", max is .077" not an exact science, but seems to show that the chamber might be shorter as opposed to longer....dunno if that tells me something or not....the cast wil l tell all I hope....
 
So did my first chamber cast tonight....not that hard to do by the way...anyway, my neck measurements are .375-376" So this is telling me that the neck is tight and not able to release the bullet properly....giving me the pressure signs....Anybody else go any ideas?
 
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I am perplexed by the rifle being out of spec. How could this happen? I have owned and shot 4 Browning 71's and they all were fine with the loads I continue to use. I now still shoot two Browning 71s regularly without a hitch . The Browning replica levers all have reputation for quality of manufacture. Any ideas how this situation could have occurred?

Oh yeah, I bought a bunch of cast 250 gr bullets and am starting to cast my own.
 
big bear said:
I am perplexed by the rifle being out of spec. How could this happen? I have owned and shot 4 Browning 71's and they all were fine with the loads I continue to use. I now still shoot two Browning 71s regularly without a hitch . The Browning replica levers all have reputation for quality of manufacture. Any ideas how this situation could have occurred?

Oh yeah, I bought a bunch of cast 250 gr bullets and am starting to cast my own.
Click to expand...

Mine had a completely messed up chamber from the factory.
 
guntech said:
So you have actually chronographed some loads? ? ?

I know this was asked but it was never answered...
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with 200gr Hornadys...
50 IMR 4895 = 2351. Super flat primer. you can see pics in my other thread " m71 Primer Strikes". I don't know how to link
60 H4831 = 2038, up to 65 = 2322
57 H414 2340, 58 = 2381 Gives good group at 50 and 100 yards
55 RL17 = 2204 , 56=2230,57=2281,58=2318,59=2386 Best groups so far, but all had primers with flow back, but not as sharp edges as some of the others

now I tried some lower charges to see if I could get the primer to stop flowing back....
55 H4350 = 2249, but blew a primer
42 IMR3031 =2312, ridge on primer but not too sharp
54 RL19 = 2176, same primer as above
50 IMR 4064 = 2415, primer quite flat with sharp flowback
50 Varget = 2224, 51 = 2270, flat primers

I've not tried factory loads as I've never seen a box of factory 348 in a store

none of these loads are ever hard to extract, but all show this "ridge" on the primer. Even those low charges of RL19 and 3031. I'm trying to stick to the K.I.S.S. principal here and not over complicate things...but if I can't place a bullet back into a fired case, then somethings not right. I guess I will try turning some neck brass, but I can't find a shop that has neck turning gear instock
 
here are some pics



in the second pic, that's H414 on the right, then 3031, RL19,H4350 (blown primer), H4381

thanks for all the replys ( the missing primer in the right, H414, is removed by me)
 
Seems to have a problem somewhere, My two new production Winchester 71 shoot at their best with 60.5gr of Imr4350 (Horn. 200gr) with no sign of pressure and case that can be load forever...
Ghislain
 
Here's my cast....not the best I know....but help me read this thing.....to me it shows no throat at all really. The rifling starts right at the end of the neck, and the neck is .003" under sized....shouldn't there be a small amount of area with no rifling? Isn't that the throat?

 
I have a forster O/S neck turner that you can have if that's the route you want to go but you need the forster case trimmer.
But to me it looks like you should have someone enlarge the neck area and throat the rifle.
Neil
 
I did an impact sizing for my 348, and the leade is very short, and abrupt when it turns to rifling.

I did it a few years ago and sent it away to LBT in the states for a "custom" mold. He returned it when he sent me the mold. It's around here somewhere...

My mold drops air cooled wheelweights around the 210 grain area.

My cases look exactly like yours, and only run my loads around the 2000fps mark chronographed. I figured this was normal, but my TrailBoss loads don't beat up the primers.
 
My cases look exactly like yours, and only run my loads around the 2000fps mark chronographed. I figured this was normal, but my TrailBoss loads don't beat up the primers.[/QUOTE]

Hi Lionel. So your primers look like mine eh....do you think that it's developing high pressure every time? Or is that just the way the gun is?
Mine appears rough when the rifling starts as well...doesn't appear to be much leade in mine at all. I'm going to try neck turning some brass and see how that goes...but I might end up buying a neck/throat reamer and recutting this chamber to be more like an original Winchester M71. I have no need to "hotrod " this gun, but I want to be able to get close to full potential out of the 348 case
 
Sorry for the late reply. Truck driver.

I use CCI 200's for my primers. Mostly because that's what I have. I don't know if they're harder or softer than what you're using. But looking at a box of fired brass, I can say I'm not getting the deep marks on my primers like you are. And my load data says 50 gr of IMR 4895. I can't find my chronograph data for that load, but the photocopy page I have in my notebook says somewhere in the 2200 fps ish range.

I found the impact casting I made, and the chamber is about .045" longer than the case and then abruptly changes to rifling, identical to your picture.

Maybe this weekend if I can find the time I might drag out the chronograph and check some loads.
 
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