7.7 Arisaka Load With Unique? Think My Load Is Ok?

[emrah]

I have a 7.7 Arisaka I'm trying to develop a good CB load for. Nothing barn-burning, but a good plinker/100 yard deer load type of thing. I have gas checked boolits I sized down from .321 to .3155. Can't remember the mold off the top of my head. GC'd, and LLA lubed it checks in at 182 grains average.

I'd like to use 14.0 grains of Unique. I used 12 grains with a 165 gr. non-GC boolit before and it wasn't the greatest. The Metford rifling doesn't help, so I'm hoping the GC will do better. Anyway, I can't find 7.7 cast bullet info. Think my load is ok? I decided on it by comparing .303 British and .30-06 data. I figure it should be close.

Any comments?

Emrah

[Eddie2002]

I've just started reloading light weight cast bullets as plinkers for my 7.7 Arisaka. Right now I'm trying a .311 100 grain cast bullet over 5.5 grains of Bullseye. I'm hitting paper at 50 yds but there is a lot lacking in accuracy. Think I need to go up to a .312 or largerr bullet but can't find any moulds that will drop a light one that size. From what I've seen with reloading data for the 7.7 your load should be in the ball park with GC bullets. The British 303 is a lot closer to a 7.7 jap while a 30-06 is slightly smaller in the bore and doesn't have Metford rifling so pick a .303 load instead of a 30-06.
I tried my 100 grain cast bullet with no GC over 5.5 grains of Bullseye in a 30-06 at 50 yds and it was super accurate, it is surprising what a couple thousands in bullet diameter can do.

[Janoosh]

Eddie2002. Try Lyman 313359 as a plinking boolit. Also do a search for Larry Gibson 32 cal pistol boolits in 30ish rifles, these are loads of fun and easy on the shoulder for kids.

[Gibbs44]

From the Lyman Cast Bullet Handbook, 3rd edition. It is recommended that you slug the bore due to the range in diameters from .310 to .317. For Unique they have a max load of 14.0 grains listed for a their #311299 at 200 grains #2 alloy. They have a max of 15.0 grains for their #311466 at 151 grains #2 alloy.

That's all I got. I've been wanting to try some cast in Dad's beautiful Arisaka, but that is a project for a later time.

[emrah]

My bore is .313-ish. My boolits sized to .3155 get slight engraving as the bolt is being closed the last 1/4 inch. This happens with my .30-30 with .311 boolits too, so I think it's ok. I've seen some stuff about 10-12 gr. of Unique, but also up to 15 grains. I figured 14.0 would be ok. I'm shooting pure stick-on wheel weights.

Emrah

[Maven]

emrah, I use Unique in various .30cal. cartridges (including metric ones) with 175gr. - 195gr. gas checked CB's and find that 12.5 - 13.0grs. works extremely well. You may want to drop your charge by 1.5grs. and work up if necessary.

[curator]

14 grains of Unique might be a bit much for the 7.7 Jap. I have never gotten good accuracy with "hot" loads with the Jap unless it contained some kind of filler. !0 grains of Unique with a 180 grain gas-checked boolit (Lyman #314299 sized to .315") was my best load in 4 different Type 99s. Either Cream of Wheat or Plastic shot buffer will allow you to push the velocity up a notch and will help with accuracy. The Metford rifling is only part of the problem. Large-long throats exacerbate the issue. War issue Jap barrels have serious quality control issues with tight and loose spots along their length.

[Eddie2002]

Janoosh, I'm using the Lee .311 100 mould made for .32 pistols right now. I'll check into the Lyman 313359 mould, my Arisaka bore runs .312 which is why my plinker load is all over the place. I'm having a ball with the 30-06 plinker load, it costs less to shoot than a .22 right now and is accurate as all heck. Good motivation to work up the same for my Arisakas. Wonder if there is a way to "bump" up the diameter of the bullet to fit the 7.7?
I've one 7.7 which has a good bit of throat wear, when I slugged it from the barrel end the slug dropped through after about 8 inches. Ended up slugging from the breach for about a foot then pushed it back down. It starts at .313 at the breach and is .312 at the end of the barrel. From the looks of the rifle it might of seen action.
I'm using resized 30-06 brass which I've sized 20 thousands longer to help compensate for the short bullet I'm loading, it helps get the bullet closer to the lands. don't know if it helps but it seemed like a good idea to try.

[RoyEllis]

My bore is .313-ish. My boolits sized to .3155 get slight engraving as the bolt is being closed the last 1/4 inch. This happens with my .30-30 with .311 boolits too, so I think it's ok. I've seen some stuff about 10-12 gr. of Unique, but also up to 15 grains. I figured 14.0 would be ok. I'm shooting pure stick-on wheel weights.

Emrah
Harden up that alloy some, you're shooting loads very similar to some of my .308 loads. I use 50/50 ww & soft lead with some tin and if I push them any harder than these loads I heat treat them in the oven to harden further.

[emrah]

They're water dropped. Not sure of BHN but I'm guessing 12-15 ish.

Emrah

[Janoosh]

Eddie2002, try Lyman 311291. One of my Arisaka's (old number seven, because of the serial number) luvs this boolit. I use this boolit beagled at times for some of my more worn Arisakas.

[Eddie2002]

I think trying to beagle the mould will be next, only need a few thousands to get a better fit for the Arisakas. I have a die set with a .312 neck resizer along with the RCBS .311 resizer for the 7.7 so I can go a little larger with the bullet. The local range has shut down for renovations, looks like it is time to work up some loads and equipment in the shop.
I used to shoot a 180 grain .312 jacketed bullet and had a lot better accuracy than any .311 bullet I've been shooting now either cast or jacketed. Guess it is a hint on which way to go with bullet size. Still want to keep the weight on the light side till I find out if increasing the diameter works.

[RoyEllis]

If you are using plain stick on WW, they should be 99.5% pure lead, approx BHN 6. Clip on WW will go BHN 11 or 12 air cooled & heat treat to around 18 to 20. No matter what heat treatment you do, pure lead won't get any harder.

[emrah]

I tried to take down on of the rounds today and just buggered up the boolit and got the gas check stuck in the neck. I was going to back down to 12 or 13gr. They're next to impossible with a kinetic puller and the collet type works but the gas check stays behind and I can't get it out.

So... is there anything inherently dangerous in the 14.0 gr. I have? I don't think I'm over max or anything. I'd just like to shoot these if possible.

Emrah

[emrah]

Ok, I pulled them down...

I popped the boolits out with the kinetic puller. Tapped the gas check back into the case, dumped the powder out, then got the gas check out with really, really, really skinny needle nose pliers.

I reloaded them with 12.0gr. this time. New boolits. Just didn't want to risk it.

Thanks for the advice anyway.

Emrah

[swheeler]

185 gr lee GC , 17 bhn, cci 200 pr, 12.0 unique 1410 fps, 13.0-1458 fps- 14.0-1502fps, 2.980 oal, type 99 11-29-2011

[Newtire]

I get good accuracy in that size with 11 grains Unique.
I've used more with "j-word" m-1 carbine bullets in 06 but with cast, much more than 11 grains and my groups start going south.

[RoyEllis]

Emrah, PM me your email addy & I'll send you a scan of the 7.7 jap load page from my older Lyman Cast Manual. Shows several powders for 3 different boolits....14gr Unique shows as max load so that may also be part of the difficulty for you. At least you'll have a page of published cast loads to reference.

[swheeler]

3rd edition lyman shows 200 gr bullet and 14.0 unique at 1449fps, your 182 gr should be fine with this data although would guess velocity will be closer to 1500 fps- see post #16