220 gr. 7.7 Jap data

[sukivel]

Can't find any data for a 220 grain cast load for my 7.7 Jap. I usually have H4895, H4198, H335, Imr4350, Unique, 700x...

Any help? Thanks!

[Ben]

The suggested starting load for the 30-40 Krag with the 311284 would be a good , safe place to start with your 7.7 Jap.

[curator]

You can also use .303 british load data for the 7.7X58 Jap. They are essentially the same cartridge, one rimmed and the other rim-less. I have an older Ideal mould for 311284 which drops ACWW alloy boolits right at .303/314. This design does not shoot accurately in either of my M99s but Lyman #311467 (also .314") shoots great. I suspect the medford-type rifling does not support long bore-ride boolit designs well. Of your powder choices, I have the best success with IMR4198

[Eddie2002]

I would think the H4895 would be a good powder since it is designed for reduced loads. The IMR 4350 is a slower burning powder and some say that it can give you some problems. Are you gas checking the boolit or just using it as dropped?

[bruce drake]

Curator beat me to the answer. 303 Brit case volume is nearly identical to 7.7 Arisaka. I also have to agree with him on bore-riding designs. I have a 160gr Louverin mold that casts out at .314 and I get so-so results at 100 yards but when I switched over to a 8mm Spitzer mold from Herters (323170) and sized it down to .314, my groups shrank in half with the same amount of powder (H4895). That Louverin in my 2 Enfield No4s is my preferred boolit but for my T99, I stick with my Spitzer mold.

Bruce

[sukivel]

Yes i am checking them. Great i will look at .303 & .30-40 data.

Yeah i got this mould a while back and have yet to try it. It drops a .311 220 gr bullet and a .266 117 gr bullet. Got it for my 6.5 Jap. Kinda cool...

[bruce drake]

Who made that mold? You are set for both types of Arisakas.

[sukivel]

I have been trying to find out who made this mold myself, but I almost think is was made for the Arisakas.

[runfiverun]

if the handles are roll pinned to the mold similar to a LEE I would guess it is a Rapine.
they are out of business.
I only have one of their molds [2 cav.] and it will crank out a pile of boolits in a hurry.
no tapping, no problem, open pour, open pour.

[sukivel]

They are not pinned. I use a pair of Lee handles on them.

[sukivel]

Alright I am having problems with this mold filling out. I cast a few when I first got it some time ago, and they looked okay, but now I can't hardly get the 220 gr to fill out right at all. If I only fill the 6.5 I can get pretty good looking boolits. I tried hotter melt, and even leaving the mold in the Lee pot for longer to try and heat it up. It almost appears to me that maybe the hole in the sprue plate is too small for the 220 cavity. Any thoughts?? I almost am to the point of trading it off for some other 6.5 boolits or a mold.

[3006guns]

Are all the vent lines clear?

Have you tried adding some tin to your alloy? It causes the mix to be more "fluid". Some 50/50 solder should work and it will normally cure "fill out" problems with long boolits.

[sukivel]

Yeah I have added quite a bit of 50/50. Vent lines look ok, but will double check.

[leadman]

From the look of the 220gr cavity the vent lines might need some work and also a piece of lead stuck by the nose?? Are you using a candle or wood match to smoke your mold? The candle can leave an oily deposit that can cause fill out issues.
Could try loosening the sprue plate pivot bolt a little to see if this helps.
That is a very good looking and practical mold to feed those old rifles with.

[sukivel]

What could i do to the vent lines? Clean them out better? I only smoked it the day I got it. Yeah I hope i can get it running right!