I have a barrel that started life as a 32-40 Remington, .308” groove. Some genius re chambered it in 30-40 Krag. Other than limiting it to very light bullets for a very large cartridge, the chamber seems to line up with the bore,

The question is to those that have had barrels re bored, how well does it work out if the new bore size does not eliminate the chamber?

I’ve thought about going to possibly 35 Krag, that would seem to make alignment critical. 

40-50 straight seems like a better option and of course is an original chambering. But the new chamber would not completely replace the old.

Just wondering what kind of success others have had?

gnoahhh wrote on Aug 6^th, 2026 at 11:24am:


Rifle is a Hepburn. 
Purpose is entertainment, needs to be fun to shoot. So recoil might be a factor. I doubt there would be a much difference between the two. Reasonable accuracy and easy to load for.

Resale is always a factor.

I’m considering JES. I’m sure once some one gets the barrel, it can be checked and it becomes clear if it can work or not, which has a better chance of success.

Really just looking for feedback on success or failure and why.

I believe that the Hepburn was chambered in 30/40 originally if there is nothing wrong with the barrel, I would leave it that way. Your never going to make it original again and the 30/40 can be very accurate and with much less recoil than a 35 or 40 cal.

In my first year (1985) of collecting and match shooting, a HW in 30/40 was one of my first 4 rifles. It was and still is very accurate. 

I almost, only shot it BSed with just a straight, push seater and RL 187 gr tapered bullet but, did shoot some full power jacket fixed ammo too.

I mostly shot cast with a reduced capacity, machined case, with just a 5/16 hole, back to the primer pocket, with that, it shot as well as any 32/40 on the line. I also shot with factory cases and using 14.0 gr 4227 and 17.0 gr 4759 fixed (lower right in last target), it also shot very well.

With match jacket bullets (168 & 190) it shot as well as any match 308 in the '90's.

Here are some targets that I shot. First target is 200 yds, the rest are 100.

The original 32-40 Remington twist is 1/16, bore is marginal. So as is it’s a 30-40 Krag limited to about 165 grain bullets. Might have been able to go longer with a better bore.

Boring it out to 35 Krag would replace the shoulder and neck with a new reamer. 

The  40-50 the chamber would be cut off just in front of the neck body junction with slightly less taper. The chamber might actual clean up in a perfect world.

In theory, I could also go to a 32 caliber. Certainly wouldn’t be the strangest cartridge is shoot.

frnkeore wrote on Aug 6^th, 2026 at 1:17pm:


Yes, they offer 330/338. Not sure of the twist. 

That’s a little more interesting.

Dellet wrote on Aug 6^th, 2026 at 10:59am:


A good gunsmith can bore the chamber out and line it; then bore the whole barrel out and install whatever liner you like and rechamber it.

One of my favorite rifles for 200 meter cowboy silhouette is a one piece stocked HiWall in 30-40 with a sporter weight  barrel. The barrel is probably a cut down military, so a 10 twist which likes a heavy cast bullet (311284 - 214 grain) which Lyman said was for the 30-40 and I guess they were correct. Load is 19.8 grains of 4198. I don't see why a 30-40 case and a lighter bullet in a slower twist barrel would be a problem to work up a good load for.

Looking at stability calculators online (I am not a great ballistician by any means) it looks like a .310 caliber cast bullet 0f 175 grains 1" long is stable at 1700 fps.  Accurate Molds 31-175 G looks like a good bore riding design.  You could have them shorten the bore riding section 0.050 t0 0.100 to be sure of low velocity stability.  You can customize any dimension to your liking.  It is a shorter version of the 31-200L bullet that I shoot in my 1:10 twist 30/40 rifles.  The cost of a mold is way cheaper than a rebore and you might have a tack driver already.  Tom