HELP... I have a problm !!!

[scamp62]

If I load my reloads one at a time I get 2” groups at 100 yards ! and I’m pretty happy with this. I In fact I’m very happy with it considering it is a very non-molested 1943 M1, with original barrel , But if I load it with an En-Bloc (8 rounds) the shots all go up, and spared out like a shotgun pattern (9.5” inch) I did let the barrel cool between groups, and this is repeatable ??? can the feeding processes beat the piss out of a round so bad that it makes such a drastic change in accuracy ? or am missing something ??

[ko4nrbs]

If I load my reloads one at a time I get 2” groups at 100 yards

Check the OAL of your reloads.
Bill

[RDS]

Check your rounds in the middle of the string. Shoot 4 rounds, clear the loaded round from the chamber and eject the partially loaded clip. Examine the 4 loaded rounds. Measure the OAL and make sure its the same length as loaded to.

[jak]

What is the time between shots when you load one at a time vs shooting 8 from an enbloc ?

[Phil McGrath]

What's your load data?

[TJT]

My guess is that when using a full clip you're losing your "cheek weld" and you're having to muscle the rifle back into position each time, or, the rifle is slipping on your shoulder, hence the sight picture is moving and not consistent shot to shot.
Jon

[RAMMONT]

Along the lines of TJT's thinking, I'd say that you're firing position is changing due to the rate of fire and recoil. It's common for a person who shoots rapid fire to try to fire a round and then simply pull the rifle on to the target and squeeze their muscles as tight as possible to try to overcome the effects of rapid recoil cycles, that usually results in a climbing impact. In the military we were always taught that any rapid fire process will make your rounds climb high and left for a right hand shooter and high and right for a left hand shooter. If this is what's happening in your case then you need to pay special attention to where and how you are placing your weak hand on the fore end and avoid manhandling the rifle on to the target (as opposed to using a natural point of aim). If you've never heard of a natural point of aim then I'll define it simply; a natural point of aim is simply where the rifle points to when you relax in your firing position. When you fire rapidly you tend to loose that natural point of aim and most shooters will simply attempt to muscle the rifle back on target, that will cause the vertical stringing that you usually see when rapid firing.

I also agree with the posts that recommend checking your cartridge overall length, check your rounds for bullet movement. If the recoil is pushing the bullets deeper in to the case then the pressures and velocities will rise and the bullet impacts will rise.

[lapriester]

Yes, the loading system can "beat the piss out of a round" if your neck tension isn't high enough and the bullet (OAL) shifting longer. As others have said shoot half an enbloc, extract a loaded, unfired round and check OAL. Do it several times with different rounds. Second round on one, fourth on another and so on. If the OAL changes consider that your sizing die or the expander button are defective. You could also try lightly crimping and see if it improves your groups though it generally won't.