Under pressure

  • (Mm ba ba de. Um bum ba de. Um bu bu bum da de)

    I actually made it to the range today! I had an chance to break in my .308 some more and finally shoot a pressure test to start load development.

    But I learned something today:
    The hardness on them varies wildly. Clearly not ideal for our purposes. Reminded me of .mil stuff.

    I shot 12 rounds for the test. Three gave me light strikes and had to be hit twice in order to fire.

    Before anyone asks, this is all virgin Peterson brass. Full length sized, neck skimmed, uniformed pockets, primer seated against the bottom of the pocket with the bullet seated ~15 thou off the lands.
    The rifle is a TS custom surgeon actioned .308. It has 101 rounds down it before this test.

    I've got pictures and I'm going to post them, but I basically consider this test invalid.

    I'll reload and try it next time with cci 200's or something. Major downer.

    I'm around 5000 feet, there's snow on the ground and according to apple weather it was 39 degrees when I fired this test. Testing the pressure on 175 SMKs and Varget with WLR primers. I shot 39.5-45 grains in half grain increments. The photos are from 41.5-45 grains. If I were to pick I'd go around 43 grains and hope I pick up some velocity as the barrel breaks in and the temperature comes up some.

    Oh yeah. Happy new year everyone.

  • I have had problems also with some of the Winchester LRP lots.
    I am slowly, but surely, replacing brass and primers to all small primers in my .308.

  • ragnarnar

    Did you measure runout on the Peterson brass (case necks or bullets). Mine was wildly inconsistent across multiple dies abs setups. Tried to contact the company but got no replies to multiple emails.

  • @a_marks

    No sir I did not, it was just a pressure test so I didn't worry about it too much.

    Were you experiencing this problem off virgin brass or was it fired?

    However I neck turned the brass as part of my prep and I was experiencing an uneven cut down the shoulder. After speaking with the guy who made my turning tool, we concluded it was because the runout on the brass.

    I think I have some pictures.

    Never mind. I found the thread and you've already seen it

  • @ragnarnar

    Yes, I have been following on here every time it comes up. I'm interested to hear what your findings are.

    100 rounds have 4 firings and 100 have 2 firings. I've consistently struggled with runout. I annealed and neck turned one lot after 3x firings. Runout improved but still not as consistent as my un-neck turned Norma brass.

  • @a_marks

    Well that's disappointing.

    I'll try again with my pressure test and see if I can get you some runout numbers.