Home Forums Hunting & Shooting Combination Guns and Drillings Re-bore/Re-chamber ?'s

I have noticed, perusing gun sale sites, that there are ALOT of combo and drilling guns out there with either 2-1/2" or 2-9/16" 16g chambers or the old .318 8x57mm (J) chamber or both. It is driving me UP THE WALL trying to find one in 2.75" 16g and 8x57 JRS.

How feasible is it to re-chamber and/or rebore one of these older guns to meet the specs I am looking for? Possible? Hideously expensive?

Lenthening the chamber on a shotgun barrel is very easy and inexpensive, and there's usually enough barrel thickness to do so. But numerous tests have proven there isn't any significant rise in pressure when shooting 2-3/4" ammo in 2-1/2" chambers. partly this ie because a lot of supposedly 2-1/2" or 2-9/16" chambers are actually a little longer than that, but it's also because the old stories about pressure rises just aren't true.

Reboring a drilling's rifle barrel is more difficult and expensive, but not impossible.

It's also possible to get a die to size down .323" 8mm bullets to .318". A good friend of mine does this regularly with 180-grain Nosler Ballistic Tips, one of the "heavy jacket" BT's, and has shot a bunch of African plains game with them, no problem, including blue wildebeest and kudu.

The 16 ga 2 1/2" shotgun ammo I have says RST Ltd. Box 127 Center Conway, NH 03813.

The .318" X57 JR mm ammo was/is made by Norma and may still be made by others.

I made a die to size bullets to .318".

It's easy to do the 32 Special ones.

Just buy the gun as it is and shoot it with the ammo made for it.

I bet if you slugged the bores of 10 8X57JR drillings you would have about 6 that were .320-.321, about 3 that were .319 or .319+, and MAYBE one that was .318.

For years we used 32 Special .321 bullets in our "J" bore guns with never a problem. The 170 round nose Core-Lokt bullets worked great...very accurate. I still have two boxes stashed.

Woodleigh and Hawk supply .318s if you need some. With S&B factory ammo at $19.00-$20.00/box I do little loading for my drillings in 8X57JR. The S&B ammo regulates well in my guns.

MD - I didn't know if that was the case with the shotgun ammo and I didn't have any strictly 2-3/4 chambered guns to check it out. I am sincerely hoping to stay away from the whole bullet swaging thing... I don't know enough to do a decent job of it. I also hate having to "Bubba Fix" things. It should work properly from the start as designed or changed to do so... anything else is eventually asking for trouble imo. Thanks for the info.

S99 - Thanks for the info. I was looking for component ammunition for reloading and really don't want to mess around with resizing (swaging) bullets. While I can appreciate the attributes and craftsmanship of a vintage firearm I have no inclination (nor derive enjoyment from) trying to reload for them and cobble together ammunition not designed for said rifle.

L2S - I had run across the Woodleigh and Hawk bullets in my research but they didn't really push my buttons. Bullet availability and variety is one of the big reasons I never pulled the trigger on a 94 or 336 in 32 WS. Speer and Hornady are pretty much the only game in town for component bullets and the Hornady bullets were reputed to have size issues (underbore) affecting stability. Buying a gun and being boxed in to a single ammunition type will pretty much kill the deal before it gets off the ground.

I don't konw that I would call reforming brass to the proper chamber dimensions so it can be used in vintage firearms or swaging bullets to fit the bore "cobbling" or a "Bubba Fix". Especially since by your own admission you don't know enough to do it right. Pray tell, what is the difference between reforming a parent case and bullet to fit a firearm or modifying the firearm to fit an ammunition? I would do the former much before the latter.

Reforming brass was never part of the original question. We were speaking of bullets.

Swaging from what I can tell involves squeezing a bullet to a slightly smaller non-design spec diameter by running it through a single or series of dies. While this squeezing of the bullet may be akin some of the processes used to make the bullet originally it is not a process that someone sitting on a bench in a garage somewhere can reasonably expect to have any meaningful control over from a quality control standpoint. Yes, you can make it fit. Is it the same internally as you pulled it out of the box? No. Are you going to waste otherwise useable bullets from your tinkering? Most likely.

If you are comfortable doing this sort of tinkering go for it. I am not. Things that go boom are designed to specific tolerances for a reason.

The aim of my original question was to determine the feasibility of altering a firearm purchased at a reasonable price to fire current standard munitions. I have no interest in messing around with obsolete cartridges or paying out the nose for antique cartridges from some boutique manufacturer. If that is your interest... more power to you.

As for repeating all of this "Bubba Fixing" every time a bullet or a case is prepared... every step you add to production introduces a chance of failure, a chance to introduce uncertainty to the end product. I like my hands, arms and face in their current configuration. Loading a bullet that could cause a catastrophic over-pressure event is something I would rather avoid.

A lot of bandwidth to just say - I don't wanna.

Ha! If I didn't put the rest in the inevitable "Why not?" was the next thing that was going to rear its ugly little head. Less hassle to just get it out there.

The Norma .318" bullets I have as components shoot better in my 8X57JR than the 170 gr .321" Hornady's I swaged down to .318".

No, why not was never going to be a part of it. It matters not to me what you want to do or how much you want to spend to make an inexpensive drilling shoot, your words, not mine. Spend a little more in the first place and you won't have to do anything but buy the ammo or reload it. It was the rather insulting implication that spurred my original response. You are right, however, you do not know enough to be doing any of it.

I'm finished with the thread now.

Changing bore size from .318 to .321 would require drilling the barrel out and sleeving it. It would be a whole lot cheaper to buy a few boxes of ammo from Norma, or to buy some .318 bullets from Huntington's. Ross Seyfried used to paper patch .308 bullets up to .318 before .318 bullets were generally available in the USA, but swaging .321 bullets would be easier.

Just use the .321 bullets as is. It works fine. Anyone ever read Ackley's experiments in this regard?

S99 - Thank you. Very sharp looking drilling there. Norma makes a quality product and I am not surprised they would shoot better than a resized Hornady.

Or " I can't "

One thing that enjoying combo/drilling type arms require for max enjoyment, is a go with the flow type attitude/personality. They are far more fun to shoot and hunt with, if you simply use them as they are, and not try to make them into something they are not. Your sanity, and your wallet, will thank you later! You simply must be flexible, or really wealthy!

Jeff

Or...resigned to remain gun-poor.

I get some pretty good deals on oddball ammo in small gun shops and gun shows. The dealers buy estate and garage sale lots, and I may be the only guy in there that summer who wants 7x57R or .32-20. That won't work for the truly obsolete cartridges, but it will for "semi-wildcats".

I suspect that you've had some pretty fantastic combo gun experience over the years, Bruce. Really appreciate the advice you've passed on to us, both in private, and here on the 'fire.

Jeff

I agree! Half the fun to me was figuring out what the rifle was chambered for and then trying to find out how to make the cases. I did it all in the late 70's which was well before Al Gore invented the internet.

The other half of the fun is carrying a gun that looks like the one below. This isn't a high cost drilling that shoots a rifle cartridge that you can buy at WalMart, but it is an effective firearm that has had a new lease on life because I could make the obsolete cases from cases that were readily available. Now almost 40 years later I can buy ready made cases for it! It is a 16X16X8x57R360.

Classic combo guns pretty much box you in, simply from their nature. They, like double rifles, have been regulated for a single load; you pretty much have to stick with what shoots well in your gun. It's a price we pay. Still, you can experiment a bit within the pressure limits and find other recipes.

Crafted by a master.

I'm a drilling buff used my first one in the 1960s to d0 control work for the state of WI, still don't own one but shoot a couple of combo guns for coyote hunting. Personally I feel that most of the drillings availible are in calibers that have ammo that can be purchased over the counter although can be expensive.

If you can afford a drilling you can afford the ammo. I'll have one by the end of the summer.