Another attempt at .270 cast, with stipulations.....

[j20owner]

Ok, I've searched and searched and read and read threads about shooting cast in .270Win rifles. I've decided that gents like ktw, BCB, Gabby, and Calamity Jake have all had some success with it.

One thing that seems to be the common thread with them is a 'stuck-breech' rifle, as in a bolt-action or single shot. The stipulation I'm facing in a Remington 742 semi-auto.

Am I asking for trouble trying to get cast loads that's shoot and work the action without incredible amounts of leading?

FWIW, it will be attempted with RCBS mold 270-150-SP, sized and checked to .278 with Lars BAC(hey, it's what's on hand). I'm not wanting jacketed velocity, just a shootable load that's easy on the gun and the barrel.

Powders in inventory are:
Unique(probably not 'action-working'able)
2400
Ramshot TAC
Ramshot Hunter
IMR4895
Varget
IMR4350
IMR4831

Also, I DO have load manuals, but I DO NOT have any access to Lyman Cast Bullet manuals.

So, am I a lost cause? [smilie=l:

And, for fun, a pic of the boolit in question.
Boolit (http://xaclan.com/Heinrich/heinrich/Casting/0823092247-00.jpg)

Well, didn't realize the pic was so big, so I just linked it.

[GabbyM]

4895 would be the best powder choice. Slower stick powder they say gives inconsistent ignition at reduced pressure and the ball powders won't reach the required load density in that big case.

Now just find a load to give you around 1,900 fps. About the accuracy limit with a 1-10” twist barrel. Just a guess but you may try 25 grains of 4895 to start. You may end up around 30 gr to get your gas gun to work but I really have no idea other than a guess. I'd think your 742 will work fine at 1,900 fps with 4895.

The ballistic coefficient of the RCBS-270-150-SP is B.C. .327

The old Lyman book doesn't show powders slower than IMR 3031 and their new book doesn't list cast bullet loads for 270 Win. Which is odd since just last year they were still selling moulds for 270.

For 3031 with a 136 gr bullet they list 29.2gr start at 2104 fps, 21,500 C.U.P.
49.0gr for 2808 and 44,700 C.U.P.

Those are some optimistic velocities if you ask me. You may reach 2,200 fps but I've never tried it with mine. IMO you push the edge and you'll get a load that will shoot in this 90 degree temp. Then in winter it will fail due to cold air density. That's just one of my ideas based on common wisdom. At any rate I'd want a load in 270 backed off a full grain from where the accuracy went bad.

[j20owner]

Alright, sounds like somewhere to start. Thanks for the response.

[Rico1950]

J20owner,
This may help.
RCBS Cast Bullet Manual #1 (and only)
.270 Winchester
Rem. 700
22" barrel
W-W cases
CCI 200-CCI 250
270-150-SP
IMR 3031 32.0 1888
IMR 3031 34.0 2009
W748 CCI 250 28.0 1825
W748 CCI 250 30.0 1937
Re7 26.0 1898
Re7 28.0 2037
IMR 4198 25.0 1896
IMR 4198 27.0 2039
SR4759 22.0 1914
SR4759 24.0 2042