Home Forums Hunting & Shooting Mausers and Military Rifles Ethics of chamber reaming unmolested milsurp?

So I recently acquired a Type 38 Arisaka carbine in a trade, and I’m a bit hesitant to either buy or load some 6.5 Arisaka for it as it has a smoked bore and sloppy chamber. Brass is a bit more than I want to spend for that being the case, but from looking around it seems like .260 Remington is barely larger than the 6.5 Arisaka but based on a cheaper case to find. While this rifle has an unmolested stock and bluing, it does have the mum ground off, a bent sight ear up front, and the bore isn’t great, so it’s not necessarily a big bucks collector piece. Would it be wrong to ream the chamber out since it’s unmolested, but unlikely to be a tack driver or to get more than probably a half dozen uses out of 6.5 Arisaka brass?

If the bore is smoked, why bother? Leave it as-is or sell it and buy something worth shooting.

If you fireform the brass to fit the chamber, and then only neck size it, the case life may surprise you. What may help with getting the cases fireformed so that they expand concentrically (rather than bulging on one side), is putting a small o-ring around each case the first time you fire it, immediately in front of the extractor groove. Alternatively you could cut a narrow strip (about 1/10" wide) of masking tape and wrap it (a couple of thicknesses) around the case immediately in front of the extractor groove.

The idea is to hold the case concentric with the bore axis, so that it expands evenly. If you neck size, and avoid FL sizing, you save the overworking which tends to be the early death of brass in oversized chambers.

I do this in Lee Enfields I have with generous chambers, where the o-ring (I used to use tape) on the first firing also has the benefit of holding the case hard against the boltface, so that it expands forward to fill the chamber rather than stretching. The same effect should be achievable in an Arisaka if you make the o-ring or tape big enough, or alternatively you could expand the necks and then partially neck size back down to make a sort of false shoulder as far forward as is necessary to hold the case back against the boltface. You only have to do it on the first firing.

I may have to try that if I end up rolling some loads for it, as I may end up getting rid of it if I catch flack for my latest acquisition

I've looked into this myself, I have a really nice/well done Type 38 with Lyman rear peep. It used to be quite common to run a .257 Roberts reamer through the chamber, and 6.5-.257 dies are still available. I ended up doing a chamber casting of mine to make sure, its still a standard ("sloppy") 6.5x50 Japanese.

I never could figure out if a .260 reamer would adequately clean up the chamber, but I also thought about maybe even a 6.5x57. Unless you simply have extra .260 brass laying around, or want to go through the trouble of forming your own, 6.5x50 brass really isn't any more expensive right now than .260 (I just ordered a couple bags from Grafs). Bore issues would be a concern more than the chamber, though. I actually have another .260 rifle, and have a decent amount of .260 brass...otherwise, its easier to just by the correct brass and be easy with the resizing die.

I would be very interested in your stock, if you decided to get rid of anything on the rifle. I have a few Type 38's, one with a cut down/sporterized stock (everything else is mostly original, with mum intact). I'd love to be able to put it back into an original stock! As far as one with a ground mum, I wouldn't hesitate unless it was some rare model/type/arsenal.

This is one of the nicer sporterized ones I've seen...

Honestly, it would stay unmolested outside of the chamber reaming if I did that, everything I’ve seen suggests it should clean it up a little but not much.

I have one that has been reamed to 6.5 Roberts. With 120gr bullets it shoots 3.5" patterns. But, with 140gr hunting bullets it goes .6" with 4064 powder. If your bore is good, ream it and go shooting. If the bore is bad, you can get a factory contour barrel or a sporter contour barrel in any cal that will fit. If you are concerned about Ethics and you have a bad bore, part out the stock and then the metal to somebody who wants it as a project.

Nice looking 38, Jason!!

Ended up deciding to leave it in 6.5 Arisaka for now, but the stock set got swapped for a rifle I swapped for an 1891 Argentine. Got a set of dies for $30 elsewhere so went ahead and bought a bag of PPU brass when I placed an order for more stuff for my Vetterli.

Thought I may disagree with milsurp Bubba of pristine specimen... Otherwise, your rifle. Do as you please. My only ever requet. "Leave appropriate tracks!" Consider a 'next owner'!
Best!
John

It’s value is not worth worrying about considering the bore and ground mum. They aren’t rare so if it were my rifle I would do whatever I wanted to it including selling it or getting it rebored and rechambered by JES.

Good luck with your project whatever you decide.

I've got a sporterized type 38 with a really nasty chamber bulge, and a good supply of new 7X57 brass. I'm probably going to get Dave Manson to grind a 6.5 X 57 reamer and stretch the chamber out a little. I've got a set of 6.5 Rem Mag dies that will work to neck size the brass down to .264. It's way down on the project list, and the only reason I'm even considering putting it back in service is its history. My father's late business partner owned it since the early 1950's and gifted it to me when I started gunsmithing in the mid-1980's.

Smoked bore? Figure out a good choice and have it re-bored to something useful to you. There’s a gazillion old relics out there, why fuss about one more (or in this case, less). What’s to be learned from one more?