Help With Cast .308 M1A!!

[captain-03]

Using RCBS 308-165 SIL -- once checked and lubed, it is weighing in about 173gr. Using heat treated WW that test at about 29BHN with Lee tester.

I have tried 3 loads using the loading data provided in the RCBS Cast Bullet Book. I used 3 different powders (H110 - Red Dot - 4756). I stated with the minimum charged and worked my way up to the maximum charge using all three powders. None the of the loads will function the action on my M1A. Even with the max charge, there seems to be no indication of excess pressure - all rounds extracted easily manually - no flattened primers.

Anyone got a load for this cast bullet (or another between 173 - 175gr) that will function the action on an M1A?

[Larry Gibson]

There is a "sticky" on loading for the M1A.

The reason the powders you used did not function the action is because they are too fast burning and did not have sufficient gas port pressure to function the M1A. A medium or slow burning powder is required.

I'll suggest you start at 28 gr of 4895 (any flavor) and work up in 1/2 gr incriments. Use a 1/2 gr dacron filler over the powder. Work up untill accuracy goes south (when is going to depend on whether your rifle has a 10, 11 or 12' twist barrel). I use this

Larry Gibson

[Mallard57]

Using RCBS 308-165 SIL -- once checked and lubed, it is weighing in about 173gr. Using heat treated WW that test at about 29BHN with Lee tester.

I have tried 3 loads using the loading data provided in the RCBS Cast Bullet Book. I used 3 different powders (H110 - Red Dot - 4756). I stated with the minimum charged and worked my way up to the maximum charge using all three powders. None the of the loads will function the action on my M1A. Even with the max charge, there seems to be no indication of excess pressure - all rounds extracted easily manually - no flattened primers.

Anyone got a load for this cast bullet (or another between 173 - 175gr) that will function the action on an M1A?

How accurate were loads with the faster powders?
Jeff

[captain-03]

Jeff -- only loaded three of each to test for function -- did not test for accuracy!