.303 British

[artkat2]

Here's one for you re-loaders, actually two questions;
  First, 300 yards, 11"x17" paper, actual target approximately 11"x11", target backer around 3'x3'. 60 rounds, first 20, IMR3031, PPU brass, WLR primer, sierra 174gr HPBT, 3MOA group about 4-5 MOA low (6 o'clock).
  Second 20, Reloader 15, primer, brass and bullet same as above 3 MOA group about 3-4 MOA right (3 o'clock).
  Third 20, Privi Partisan 174 gr FMJ HPBT, 3 MOA group dead center.
All fired through a Savage made Enfield #4 mk1*, 5 rds slow prone, 5 rds rapid etc...with each 20 rd box.
disclaimer..(the majority of rounds 17/20 were in the groups listed above, not all. I'm not that good ...Yet!)
  I understand the low group, and the dead center group (spent some time with JB at Piru 11-09! collecting data on that rifle and Privi ammo), question is why right?
  I'm inclined to beleive "operator error" is there any reason a hand load would impact right, or is it me?

Next question, how to store spent brass? I've got a little over 200 emptys left from Piru 11-09! Should I de-cap and clean it before storage, or just box it up as is 'till I'm ready to work it?
  Thanks
Andy

[Son of Martha]

Most likely shooter error, but if it is duplicatable then consider this:

The barrel vibrates as the projo is moving, the muzzle describes a more-or less circular path, and the bullet exits at some point in the arc of the circle(ish) pattern.  Barrel vibrations are affected by EVERYTHING, bedding, temp, wear, load, projectile, sling tension, steadiness of the position, phase of the moon...

Most of the time the significant factors TEND to lead to vertical dispersion being the dominant artifact.  You have found a load were that is not the case.  This is one of the reasons that you can't change to a different load in the same bullet weight/type and assume that the POI will be the same as before.  Sounds like you have in the second lad a rather consistent barrel time (time of bullet in barrel) and vibration, and the bullets are exiting at around 3 O'clock in the oscillation.  (Just a guess.  I am ready to be corrected by someone who knows better.)

I had a rather extreme example with an M1.  With Lake City milsurp, my 200 yard zero was + 8, like the book says.  Switching to Greek HXP in the same rifle put the 200 yard zero at + 23 (!).  Since the trajectory of the loads was the same, the comeups didn't change, just the zero.

http://www.rifle-accuracy.com/harmonics.htm

SoM

[hawkeye]

I store my brass in a large zip lock bag ,100 rounds per bag. I like to have the brass cleaned and primed so it's ready to load, but you can store it with out cleaning no problems as long as it's not corrosive primed. I have .22 hornet brass that I've been saving for about 35 years and still looks good.

[artkat2]

SoM,
  Thanks for that link, very interesting. I love technical articles like that, makes me feel smart when I can understand the point they are trying to make.
  Although I believe I am a careful re-loader, I have a hard time believing that I can produce a load that exits the muzzle at the same precise point in the arc 80 percent of the time.

  Just for fun, I think I will mix up another batch and see what happens, maybe run 5 home made, 5 factory for a couple of magazines, see what happens!
  Thanks again for the reply.

hawkeye,
  I've been wondering about storing primed brass for a while, thanks I think I'll just clean, size and prime it all and store it in zippers. Ready to go right DwayneH?

Thanks guys!
  Andy






 

[jacques]

Hey Arkat. I store my brass in ziplock bags also. Put them in card board boxes in the garage. I haven't had any problems. I don't prime until I load.

Got my Enfield out and all cleaned up finally.