Another update on my T38 Arisaka.
I had some time to work up loads. 100 gr BTs shot pretty good, but I couldn't get anything heavier to group to my expectations - 1.5-2.0". Plus I had a lot of flyiers. I wanted this for a shooter and hunting and didn't want to put a hole lot of money into it. So I re-barreled this T 38 with a Midway Adams & Bennett .264, chrommoly barrel. Had my gunsmith thread and chamber the barrel again to 6.5 X 57mm Mauser, cut and crown to 22". I cold blued the barrel temporaily.
I purchased an older Hornady reloading book with 6.5 x 57mm load data at a gun show. So I went back to 120 gr, A-Max bullets. The Hornady data for their 120 gr started at 43 grains of IMR 4350 and maxed out at 47.5 grains for a velocity of 2,900 fps. I used Nosler 7 x 57mm brass to form the 6.5 X 57mm case. I loaded in half grain increments from 44 to 47.5 grain. The Adams & Bennett barrel fowled easily and was cleaned after each 5 to 10 shot firing. But the barrel shot better as more rounds were fired. Break was done with previously loaded ammo. Group size reduced as the load charge increased. Best load was 47.5 grains, but bolt was hard to open and velocity was 3,040 fps. According to the Hornady book the 47.5 charge should have had a MV of 2,900 fps. Other than the bolt being hard to open the cases showed no signs of high pressurer. I assume the Nosler 7 X 57mm brass was a little thicker brass. In the end I went back to 44.0 of IMR 4350. this last week, I fired eight shots into a .8" group, MV 2,744 fps. I will used this load for this coming deer season.
