Brass dimples around neck ??

[BackWoods Billy]

Attachment 57027That is NOT a dent... that is case collapse. It is a phenomenon caused by a low pressure load that does not seal the neck and thus gas escapes around to the case and the pressure is trapped between the case and the chamber. Notice the soot on the neck/shoulder area, that is a sign of either not enough powder, or too slow of powder. It's a situation that has more to do with the pressure curve. The peak pressure is occurring too late for the neck to seal. There are several factors that contribute to the pressure curve, ignition from the primer, burn rate of the powder, and the length of the barrel.


The above is what I found.

Thank you so much for taking the time to show me this..All of you guys have been very helpful.I'm always learning something about this stuff on here.That's half the fun of this hobby-sport.

Thanks.
Bill

[JIMinPHX]

I'm on board with the guys saying that may be caused by your pressure being too low. Another possibility is that your chamber neck is too big in diameter.

If you can, I'd check the chamber neck diameter with a ball gauge or a pin.

[Mike H]

Your load is too light,work up half a grain at a time until it stops the dents.

[JonB_in_Glencoe]

Attachment 57027That is NOT a dent... that is case collapse. It is a phenomenon caused by a low pressure load that does not seal the neck and thus gas escapes around to the case and the pressure is trapped between the case and the chamber. Notice the soot on the neck/shoulder area, that is a sign of either not enough powder, or too slow of powder. It's a situation that has more to do with the pressure curve. The peak pressure is occurring too late for the neck to seal. There are several factors that contribute to the pressure curve, ignition from the primer, burn rate of the powder, and the length of the barrel.

The above is what I found.

Thanks tomme boy,
I've never heard of this.
I learn something everyday
Jon

[tomme boy]

I have had it happen on several Mosin Nagants. Russian and Finns. It seemed to always be with RL15 powder for some reason. And it was with some fairly heavey loads. I ended up having to deep seat the bullet and use a mag primer to stop it. I just ended up switching powders as I felt something was just not right. I have told others about this powder as well as they had the same problems.

[uscra112]

Agree 100% with Tommee Boy.

There's no data because that powder is way too slow for that application, even if it were with heavier j-warts. Quickload says that load is only 19K psi. At that low a pressure it may not even be lighting up well, so some shots may have been way below that. I don't know the O.P.'s seating depth, so I can't be very precise, but even a caseful of 4895 calculates to a low pressure for that powder. I'd for sure be looking at faster powders for that case and that bullet. 4227 was a much better one. Lil'Gun, 4198, RL-7, 5744 all might work. Save the 4895 for another job.

[longbow]

You might get some useful reloading info from this article:

http://castboolits.gunloads.com/show...Rifles-Article

Longbow

[o6Patient]

Is the bullet your using a little too small in diameter for the bore? would give same signs of low pressure.
(I would not use a magnum primer to ignite that small amount of 4895)
Some communist guns(if memory is serving me correct) are a couple of thou more than our .308 and could
be exasperated by an eroded throat. (thinking out load...could be nuts)

[BackWoods Billy]

Is the bullet your using a little too small in diameter for the bore? would give same signs of low pressure.
(I would not use a magnum primer to ignite that small amount of 4895)
Some communist guns(if memory is serving me correct) are a couple of thou more than our .308 and could
be exasperated by an eroded throat. (thinking out load...could be nuts)

My bore slugged out to .3135 and at this time I'm using a .313 boolit.