I am shooting a 300 blk. Brass is ejecting fine. But the bolt is not picking up the next round at all. I am getting 1042 fps with 9.2 of H110 and 200 accubonds. I am thinking a lighter buffer... What else could be going on?

I would check to see if the magazine is fitting far enough in the mag well sound like the bolt is riding over the ammunition who made the lower, to check take the upper off of a 223 and check the correct height and then do the same with the 330 RNB

It's short stroking. The bolt isn't coming back far enough to let the next cartridge pop up so the bolt can pick it up going back into battery. If you're going to shoot light loads like that a lighter buffer may help you, but remember to take it back out when shooting hotter ammo.

When I pull back on the charging handle, it picks up the next round just fine.

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It's short stroking. The bolt isn't coming back far enough to let the next cartridge pop up so the bolt can pick it up going back into battery. If you're going to shoot light loads like that a lighter buffer may help you, but remember to take it back out when shooting hotter ammo

+1
When you manually pull it back you make sure it is coming back all the way.

Well you performed the test p dog suggested and it was okay that way. Let me ask you this, if you just put one cartridge in the magazine, chamber and fire it, does the bolt lock back? If it doesn't you're short stroking. If it does then you may have a magazine related problem.

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Originally posted by SmokinJ:
Well you performed the test p dog suggested and it was okay that way. Let me ask you this, if you just put one cartridge in the magazine, chamber and fire it, does the bolt lock back? If it doesn't you're short stroking. If it does then you may have a magazine related problem.

No, it never locked open on the final round.

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Originally posted by Rine Everett:

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Originally posted by SmokinJ:
Well you performed the test p dog suggested and it was okay that way. Let me ask you this, if you just put one cartridge in the magazine, chamber and fire it, does the bolt lock back? If it doesn't you're short stroking. If it does then you may have a magazine related problem.

No, it never locked open on the final round.

I would have to 100% say it's short stroking, probably do to the cartridge you have loaded not having enough energy to work the action fully. Now if the rifle is brand new it still may be stiff, but I doubt that. Do you require to be at the velocity you posted? If not up the charge and if you have to switch to a different powder. You might also try another powder that will give you around the same velocity, but requires more grains of powder to do so. This may produce more gas volume or spread the push out over a longer period of time.

Rine,

SmokinJ has suggested the appropriate test (and correct diagnosis). It is referred to as the "one round" test. It is as he describes above. If the action does not stay back (assumes undamaged mag and release) on the empty mag the rifle/ammo combination is most likely undergassed. You may need to run several "one rounds" through to diagnose a borderline undergassed condition.

Upping the pressure level, or the dwell (time under pressure) with a slower burn rate, may resolve the issue.

That your action spring has enough power to strip and chamber new rounds is certainly good, but not relevant in this case.

Sam