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Peterson Brass 6.5 Creedmoore
- Thread starter Snipe
- Start date
You are fine. The SAAMI spec calls for 1.900" to 1.920" case length, so you aren't even outside the commercial ammo limits. The standard trim-to length is in the middle of that range at 1.910".
When you say you fired five times and then resized, I assume you were neck sizing for the five reloads. If the trim was done to the new, unfired brass, expansion to fill your chamber could well pull the neck in. Growth in resized cases happens because of pressure ring stretching, but with neck sizing, you won't have that after the first firing. So I don't think this is particularly strange. If you go through the same cycle again, I would expect a little growth after the next resizing.
Note that the SAAMI minimum case length isn't magic. It's just part of ammunition standardization which generally assumes the use of bullets with cannelures that will be crimped. The neck length range needs to be controlled for crimping so the alignment of the cannelure doesn't require you to seat the bullet too deeply and give up powder space or raise pressure. For handloads that you load singly, you can put the bullet and neck anywhere that works safely. Letting the neck get too long and jam into the throat is a bad idea because of its potential to affect the pressure. But if your neck were below 1.900", you would mainly be sacrificing the amount of hold on your bullet, but not doing damage.
When you say you fired five times and then resized, I assume you were neck sizing for the five reloads. If the trim was done to the new, unfired brass, expansion to fill your chamber could well pull the neck in. Growth in resized cases happens because of pressure ring stretching, but with neck sizing, you won't have that after the first firing. So I don't think this is particularly strange. If you go through the same cycle again, I would expect a little growth after the next resizing.
Note that the SAAMI minimum case length isn't magic. It's just part of ammunition standardization which generally assumes the use of bullets with cannelures that will be crimped. The neck length range needs to be controlled for crimping so the alignment of the cannelure doesn't require you to seat the bullet too deeply and give up powder space or raise pressure. For handloads that you load singly, you can put the bullet and neck anywhere that works safely. Letting the neck get too long and jam into the throat is a bad idea because of its potential to affect the pressure. But if your neck were below 1.900", you would mainly be sacrificing the amount of hold on your bullet, but not doing damage.
mikejonestkd
New member
No worries, you are still at recommended min length.
603Country
New member
It really is no big deal, the brass being a bit short. Once upon a Super Bowl I was trimming 220 Swift cases and not paying attention to what I was doing. I trimmed em way too short. But, being the only 220 brass I had, I loaded them up and used them time and again. No degradation in accuracy either.
kilotanker22
New member
I ran Peterson brass in my 6.5 Creedmoor, before I switched over to Lapua. I remember some of mine shrinking after firing. I also recall that the Peterson brass did not seem to grow much at all.
I screwed up and even trimmed some much shorter than they should be by accident. I did not have any real issues, except for a loss in velocity and opening up my extreme spread. I presume this was due to the decreased grip on the bullet by the neck. All else was equal
I screwed up and even trimmed some much shorter than they should be by accident. I did not have any real issues, except for a loss in velocity and opening up my extreme spread. I presume this was due to the decreased grip on the bullet by the neck. All else was equal