6.5 Japanese bullet accuracy issues.....anybody out there load for them?

[Muskyhunter1]

I hate to go down the "J" projectile road here - sorry. I have an Arisaka Type 38 Carbine in 6.5 with iron sights. I have been shooting 140 grain Lyman GC sized to .266 dia with decent results. I even tried those "J" things and it shot great till yesterday.................

A couple of weeks ago I loaded up a bunch of rounds that were 140 grain Hornady SST boat-tail spitzers with 30.0 grains of IMR 3031. I fired an awesome 10 shot group that pretty much took out the orange bullseye at 50 yards. I was a happy boy and was ready to take the old gal hunting.

Yesterday, I tried 120 grain Sierra hollow point boat-tail with 31.5 grain of IMR 3031. I got a group of about 8 inches at 50 yards. I was not impressed:(. To make myself feel better I pulled the last 6 rounds from my ammo box that were still loaded with the 140 grain Hornady SST spitzers and fired them at the same target at 50 yards. I got a 2 1/2 inch group but to my horror 2 (maybe 3rd started) of the bullets key-holed now. That load and bullet shot really well a couple of weeks ago what has changed? Even with the bullets turning sideways it is a decent group for my old eyes with iron sights on a milsurp at 50 yards.

96197

I did some research and it appears some of the 6.5 Arisaka rifles were made with metford rifling (click link below to see metford rifling) and as such apparently don't like boat-tail bullets????? I believe mine is metford rifling. One fellow even claimed he got much better groups with heavier 180 grain Sierra Pro Hunters?????.

http://photos.imageevent.com/badgerdog/generalstorage/piclinks/Enfield%20Rifling%20_Medium_.JPG

Does anyone have any experience with the 6.5 Jap as far as flat base and boat-tail and heavy bullets go. It seems 139/140 grain was pretty much the milsurp weights during WW II. As I said I have been shooting a Lyman 140 grain cast GC sized to .266 with adequate accuracy but they don't key hole. I also tried cast 170 grain cruise missiles GC also sized to .266 dia and their accuracy was not that great. I think the 1:9 twist is maybe (????) not quite fast enough for those long cast boolites. I can see the rifle wants to shoot I just need to find the right combination. The bore looks decent.

Today I found a box of 120 grain Sierra flat base bullets in the l;oading bench. I loaded it with a slower powder 38.0 grains IMR 4350 (light load). I am out the door in the next few minutes to the range to see how she will do. I will post my results when I get back.

Any solid advise will be greatly appreciate. If you have a pet "J" bullet powder combo for the Type 38 I would really appreciate to hear it.

Thanks.

[Larry Gibson]

If you slug the bore of your 6.5 you'll probably find it closer to .268 than .264. Long heavy FB'd jacketed bullets generally will shoot ok because they have more bearing surface to grip what rifling they can. Some, because of the mass, even obturate to fill the bore better. My 6.5 Arisaka (.268 groove) shoots the 129, 140 and the old 160 gr Hornady's quite well. It also shoots the 266455 very well if I just crimp the GC on in a .266 H&I die but do not size the bullet. I then TL them in LLA and at .267+ the shoot well. I've a 268469 to try in it one of these days and expect them, at .268+ to do quite well.

Hornady makes/made some 160 gr RNs for the 6.5 Carcano that are .268 diameter and they shoot extremely well in my 6.5 Arisaka because the fit. I've tried a couple jacketed BTs also with very poor accuracy also. Probably too much gas blow by in the .264 bullets in the .268 bore.

Larry Gibson

[Shooter6br]

Mine is "a minute of deer" at 50 yrds

[Muskyhunter1]

Wow Larry you shoot .268 Hornady's out of yours. I will have to slug my bore for sure - thanks bud.

I just got back from the range. As mentioned I loaded up some rounds with Sierra 140 grain flat base. It was really busy at the range and there were a bunch of fellows with AR platform rifles and semi 22 LR's. Anyway, I set my target up at 50 yards and shot 10 of my 15 rounds. I checked my target and apparently some idiot decided he would shoot at my target so it was peppered it with holes (no keyholes either his or mine - good thing). Anyway I set up a fresh target and fired the remaining 5 rounds I had. It appears the flat base don't key hole as easy and my target was not too bad (always room for improvement).

Shooter6br. What is a "minute of deer" by PA standards - lol? I am trying to be nice now - but that should be a pretty small group - right :kidding:

Thanks Lads.

[bruce drake]

I ran into the same problem with boattail J-words in both of my 6.5mm T38 Arisakas with the Metford Rifling. I did the same as Larry as my Flatbase bullets seems to obdurate a bit better for accuracy past 50 yards.

Bruce

[ukrifleman]

I have some pulled Jap bullets which are flat based and measure an average .261 diameter.
They shoot better than FMJBT in my T38.
I also use 140gn RCBS silhouette bullets, gas checked to .265 which work well.
ukrifleman.

[CENTEX BILL]

Do these constraints apply to the Type 99 7.7mm rifle? I have one which appears to chrome plated and have rounded edges. It slugs at 0.314. If it does have metford rifleing then can I expect the boattail 174 bullets to shoot worst than the flat base bullets. By this criteria, then I may be better using the .312 Hornady SST flat base or the 150 gr spire point 312.

I would appreciate your thoughts on this.

Thanks.
Centex Bill

[HamGunner]

I have a T-38 6.5mm Arisaka carbine that was rechambered to .257 Roberts (6.5mmx257 Rob). Like Larry, mine slugged at .268 and I use that Hornady 160gr. Carcano (268) round nose when needing a jacketed load. It has done well on Missouri deer and is very accurate, although I throated my chamber so that I can seat it out long. A bit of $ laid out for a throater/reamer, but was certainly worth it in my case. I can easily get 2,450 fps out of the 19" barrel with that big long 160gr. flat base bullet, but then it is no longer a 6.5mm Jap chamber either. I am sure that the lesser powder capacity of that smaller Jap cartridge would slow things down a bunch.

I have done well enough with the 266469 149gr. cast also, but I size and lube that bullet at closer to .270 in my now modified sizing die and that cast bullet also works out much better in that throated chamber. The gas check does not seat deeper than the bottom of the neck.

I suspect that if you are using slightly small for groove bullets, that the flat based will do you better. I bought this little carbine from a guy that was attempting to shoot .257 Roberts factory shells through it. He gave up after half a box; he could not keep it on a paper plate at 50 yards. Proper sized bullets are a must. I suggest that you slug your bore so that you will know what you need in order to make it shoot. They will shoot and the Arisaka is a very strong action.

[Muskyhunter1]

Well I am going to have to slug it tonight. My other project is a 6.5 Carcano so I am set up with oversized 6.5 bullets. It was kind of nice thinking I had one milsurp that shoots standard 6.5 bullets - oh well that is what makes them projects.

The Arisaka certainly has a good strong action. I always feel better pulling the trigger with that gun than the type 38 TS Carcano. Of course that is my personal opinion.

Centx Bill - I would have not doubt you have metford rifling too. Sorry bud you will have to do some research to confirm that.

Thanks Guys.

[WRideout]

I acquired a Type 38 a few years back in an impulse buy. When it was new (to me), I shot handloads of 140 gr Rem 6.5mm sp over IMR 3031; it worked well for most purposes. The rifle was a safe queen for quite a while, but I decided to try it out with cast recently. I bought a Lee Cruise Missile from Midsouth, and cast up a few. Used as cast, with gc pushed on by hand, thinned LLA for lube.

I tried some loads from advice I got on this forum, but found that light charges of anything just would not work. I got keyhole hits at twenty-five yards. Finally found a load for 170 gr jacketed in an OLD Lyman manual, and used that. I ended up with 26 gr of IMR 4198, CM boolit as cast with gc, LLA lube, Fed primer, Norma brass. OAL 2.95 ". This particular rifle/ctg combination seems to like velocity. BTW: the 4198 was from my stepfather, and is probably pushing fifty years old.

If you look down the barrel of a Japanese rifle, and it appears to have no rifling at all, you probably have Metford. I believe only the Type 38 had that.
Wayne

[bruce drake]

slightly off-topic but it answers a question posed above. Type 99's had standard rifling but the barrels had chrome-coated bores. Nice thing about that is that the corrosive primers of the cartridges of the time didn't affect the bores of these rifles. Most WWII rifles look a lot worse for wear due to those primers. Size your bullets to .314 and you should have an accurate 7.7mm cartridge barring crown or bedding issues.

Bruce

[EDG]

I have one of the school rifles with the stacked cannon balls stamped into the MUM.

It shoots keyholes with Sierra 140 grn BT. It shot fine with Hornady 140 grn flat based spitzers.

The chamber if the Type 38 has no throat in the sense that you would expect.

The chamber has no step at the case mouth. The chamber just tapers into the rifling. The entire lenght of the taper is about .470.

[frkelly74]

I ended up boring out and polishing a .243 Lee push through sizer die to get a die that would only just crimp the gas check on a 266469 boolit. It ended up at about .268 and as others have stated, that is what it took to get good accuracy from the Jap. Mine also liked the 140gr Remington Corelokt but not the 120 gr so much. I now have a custom 6.5 mold that casts a nice fat boolit of about 140 gr that I am going to try this summer. Fun, fun fun!!