Shortened 7 x 57 ?

[wmitty]

Purchased an Adams and Bennett short chambered barrel from Midway in 7 x 57 and rather than reaming to full depth to set headspace for the round could I not grind the bottom off of the sizing die and produce a wildcat with a somewhat longer neck which would chamber in the barrel as is? It is to be fitted to a M 93 action and strictly used for shooting cast ( grease groove and paper patched) boolits. I'm not concerned about the slight loss in case capacity or the fact that factory rounds won't chamber. Is there a hidden problem with this idea I don't see?

[HARRYMPOPE]

"short chambered"neck will be cut to the same length.I have done this with 30-06 riles before and it worked fine.It wasn't a disadvantage over the standard cartridge and gave slightly tighter chamber dimensions.

[uscra112]

"Short chambered" commercial barrels AFAIK are reamed only with a roughing reamer, which usually does not cut any throat at all, and may well have a small neck diameter as well, so you'd still have to run a finish reamer in to do that chore. That said, you could finish the chamber with a "neck and throat' reamer to get a longer necked 7x57, then cut off your sizer. Matching the sizer to the chamber will be tricky if you are using a rimless case. You run a serious risk of having a die that pushes the shoulder too far back, creating excess headspace. (Why I love rimmed cartridges!)

[mikeym1a]

"Short chambered" commercial barrels AFAIK are reamed only with a roughing reamer, which usually does not cut any throat at all, and may well have a small neck diameter as well, so you'd still have to run a finish reamer in to do that chore. That said, you could finish the chamber with a "neck and throat' reamer to get a longer necked 7x57, then cut off your sizer. Matching the sizer to the chamber will be tricky if you are using a rimless case. You run a serious risk of having a die that pushes the shoulder too far back, creating excess headspace. (Why I love rimmed cartridges!)
Curious. Would not that apply to only the first round? As long as the initial cartridge was loaded long enough to for the boolit to engage the rifling, would not the cartridge blow out to fit the chamber, and allow the loading die to be set to the proper length for this new chamber? I did something like this by re-purposing some POF blanks, and it worked for me. Interesting process, as I have considered buying a barrel or two like that, and wondered what to do about the 'short chambering'. Of course, I am in no way a gunsmith. Cheers!

[wmitty]

uscra112

Thanks for the heads up on the roughing reamer - I'll make a pound cast of the neck/ throat to see what I've got.

[RustyReel]

wmitty,

I'm very interested in hearing your results as I have been thinking about a project like that as well. I seem to remember reading somewhere, maybe on this forum, were someone had done just what you are talking about. Please keep us updated on your project...thanks!

[uscra112]

I've actually done it quite recently. There was an old and now very obscure wildcat in the 1890s called the Harwood Hornet, made from .25-20 Stevens (Single Shot) brass. As it happens, mid-March I acquired an 1894 Stevens rifle that had been chambered for it, until some bozo bushed the chamber and tried to make it a modern Hornet. Long story short, I recreated the Harwood Hornet chamber by using 2R Lovell reamers, held .230" short, then followed up with ordinary chucking reamers to clean up the neck. (The original throat is still there.) Made a sizing die the same way. Results are not all good - the badly done bushing job left a ring at the neck that precludes using anything but the lightest loads, but the old girl can speak in her mother tongue again.

It's a pure boolit rifle - predates even gas checks by a dozen years. Modern Hornet on the left, Harwood Hornet on the right.

103329

[wmitty]

I went ahead and made a pound cast of the neck/throat/ leade and it looked to me as if a finisher reamer has been used to short chamber the barrel. Looked like the throat tapered from the o.d. of the neck to the land diameter, which I'm not too happy about but we'll see if it will shoot boolits. Anyway, ground the bottom off of my Hornady sizer die enough to allow chambering the brass with the barrel shoulder snug against the receiver ring. I went by Oreilly's and got some lapping compound to allow lapping the bolt lugs to full contact (roughly 50-60% now) so maybe I'll gain a couple thousandths headspace. The shortened case does not look all that different from what those fired in the military barrel looked like except for the neck diameter; the fired cases from the original barrel were so oversize in the neck that a .30 cal boolit could nearly be seated.

4/28/14 - loaded up a couple of rounds with 3 gr of 700X and the 168 gr RCBS and fired them into the stack of books I use to catch boolits; looks like this is gonna work. I'm tightening the barrel on the action tomorrow and lapping the lugs to correct headspace. Trying to order a stock from Boyd's and will be looking for a receiver site to mount on it next.

[Larry Gibson]

The several S&B barrels I've fitted to actions all were finished reamed just about .010 short. Thus shortening the FL die should work just fine. When you trim the case necks trim to .003 under the chamber neck length not what length a 7x57 case neck is supposed to be. That's another side benefit (case necks that perfectly fit the chamber neck) to doing what you contemplate.

Larry Gibson

[wmitty]

Larry; I noticed that I am able to leave the necks much longer than I anticipated. I am having to seat the 168 RCBS to where the boolit's base is about even with the body/ shoulder junction of the case, in order to accommodate the throat. I was able to seat a Rem 175 gr pointed SPCL well out past the canelure (sp.?). I'm interested in getting it back together and some sights mounted on it to see how well it'll group.