Peterson Brass 6.5 Creedmoore

Snipe · July 4, 2021, 09:56 AM

Will it be safe to reload and shoot brass that measures 1.900 after resizing? This was new brass that was trimmed to 1.905 fired five times and resized, now they measure 1.900.

Thanks,
Snipe

**Unclenick** · July 4, 2021, 10:50 AM

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.

Snipe · July 4, 2021, 11:32 AM

Sorry I wasn't clear. I fl resized the new brass, then I trimmed all of them to 1.905 because that was the average size in the lot. Shot the round then fl resized them each time but I haven't trimmed again. Now they are measuring 1.900.

mikejonestkd · July 4, 2021, 01:04 PM

No worries, you are still at recommended min length.

RC20 · July 5, 2021, 08:06 PM

A bit odd to shrink but I over trim mine so I don't have to trim so often.

Snipe · July 6, 2021, 04:19 AM

Thank guys I thought it was strange also, Ill run with it.

603Country · July 6, 2021, 07:55 PM

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 · July 7, 2021, 09:53 PM

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

hooligan1 · July 10, 2021, 05:53 PM

I use Starline lp brass in my rifle, its consitent and has performed nicely with several powder/ bullet combos.
Also my rifle tends to like annealed brass, who knows why, I dont care.

July 4, 2021, 09:56 AM	#1
Snipe Member Join Date: March 30, 2017 Posts: 55	Peterson Brass 6.5 Creedmoore Will it be safe to reload and shoot brass that measures 1.900 after resizing? This was new brass that was trimmed to 1.905 fired five times and resized, now they measure 1.900. Thanks, Snipe

July 4, 2021, 10:50 AM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,057	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. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

July 4, 2021, 01:04 PM	#4
mikejonestkd Senior Member Join Date: January 3, 2006 Location: Brockport, NY Posts: 3,716	No worries, you are still at recommended min length. __________________ You are the bows from which your children as living arrows are sent forth.

July 5, 2021, 08:06 PM	#5
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	A bit odd to shrink but I over trim mine so I don't have to trim so often. __________________ Science and Facts are True whether you believe it or not

July 7, 2021, 09:53 PM	#8
kilotanker22 Senior Member Join Date: October 14, 2012 Location: North Central, PA Posts: 2,117	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 __________________ “We do not seek peace in order to be at war, but we go to war that we may have peace. Be peaceful, therefore, in warring, so that you may vanquish those whom you war against, and bring them to the prosperity of peace. – St. Augustine

July 4, 2021, 11:32 AM	#3
Snipe Member Join Date: March 30, 2017 Posts: 55	Sorry I wasn't clear. I fl resized the new brass, then I trimmed all of them to 1.905 because that was the average size in the lot. Shot the round then fl resized them each time but I haven't trimmed again. Now they are measuring 1.900.

July 6, 2021, 04:19 AM	#6
Snipe Member Join Date: March 30, 2017 Posts: 55	Thank guys I thought it was strange also, Ill run with it.

July 6, 2021, 07:55 PM	#7
603Country Senior Member Join Date: January 6, 2011 Location: Thornton, Texas Posts: 3,996	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.

July 10, 2021, 05:53 PM	#9
hooligan1 Senior Member Join Date: July 18, 2010 Location: Independence Missouri Posts: 4,585	I use Starline lp brass in my rifle, its consitent and has performed nicely with several powder/ bullet combos. Also my rifle tends to like annealed brass, who knows why, I dont care. __________________ Keep your Axe sharp and your powder dry.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search