IMR 4759 in...

[MontanaS]

...8mm. I have always wanted to do some cast shooting in one of my Kar 98's. I just received some 4759 that I'll be trying in my 40-65 rolling block. Does anyone know how this powder will work with a 150 grain 8mm bullet? What would the starting and maximum grains be?

[NuJudge]

Most of us here still call it SR 4759. It's from the line of Service Rifle (SR) powders that preceded Dupont's Improved Military (IMR) Powders. Looking on the IMR website, they list it in with their pistol powders, and I don't find anything for it in their on-line data, but they have a basic manual on-line that lists it with 150 gr bullets in Winchester brass:

http://www.imrpowder.com/PDF/Hodgdon%20Basic%20Manual.pdf

They say work up to the load listed.

Be careful you do not mix it up with SR 4756.

CDD

[jonk]

Well for the SR 4759, I do quite well with a 185 gr lead bullet and 18 gr. Something like 30 would probably be max for a 150, but like everyone, they low ball the published data for the 8mm fearing someone will shoot a .323 down a J bore rifle. So I'd start at 16 or so and work up.

[Shiloh]

It's what I will use when I start casting for an M-48.

Shiloh

[TCLouis]

I use Milsurp 4759 and the 170 some odd grain cast gas check GB boolit.
No chronoraph data but 18.5 - 22.5 grains was interesting and I could have likely gone higher.

18.5 21.5 grains of 4759 improved with every increase in powder (did it in 1 grain increments), but 22.5 shot a pattern . . . a very wide and high pattern.
Try it, YMMV.

[jonk]

TC Louis, that was a very similar experience to mine. Happiness was found for me in the gun I was testing (yugo M48) at 18 grains. 16 and 17 did fine too. At 19 things started to open up but were still fine until 21 and then it all went to heck.

[BerdanIII]

My experience with SR4759 in the 8mm Mauser is probably more enlightening for what I did wrong rather than what I did right. I used commercially cast Lyman 323470's (160-gr.) sized 0.323" (boo-boo) in reformed .30-'06 cases of "various makes" ('nother boo-boo). A COL of 2.816" and 18.0 grs. of SR4759 gave 5-shot groups of 2" and 1.5" at 50 yards, while 20.5 grs. gave a 2.5" group. A COL of 2.565" and 18.0 grs. gave a pair of 3" groups at 50 yards. Early Lyman manuals suggested 18.0 grs. of SR4759 for this bullet, while the third edition of the Cast Bullet Handbook gives a starting load of 20.5 grains and a COL of 2.370". I seated my bullets to a longer COL to keep the base of the bullet in the case neck. Lyman's "potentially most accurate load" is 27.0 grs. of IMR4198. This powder charge and COL's of 2.816 and 2.565 gave me groups averaging 3" at 50 yards. The universal load of 16.0 grs. of 2400 in Defence Industries (Dominion) "7.92mm 44" brass gave groups of 2", 2.25", and 3.25". I'm sure a 0.325" or larger bullet and cases from one maker would have given better accuracy.

[jonk]

Interesting; I've found that with plinker loads (Red dot, 4759, etc) that using 1 brand of brass isn't as important as with jacketed loads and powders that more or less fill the case.