Overtrimmed .308 brass. Can it be saved?

AL45 · June 30, 2017, 10:34 PM

I've been reloading .308 for about 6 years with no problems. Today I was trimming some brass and got carried away and trimmed it to 1.95 when it should be about 2.0015. I didn't realized what I had done until I had seated 32 bullets. The overall length is 2.75 which is what is called for. Is there enough neck to hold the bullet? Are there any other problems that could occur. These are 150 grain BTSP bullets with 43.5 grains of IMR 4064 and CCI Large Rifle Primers.

F. Guffey · June 30, 2017, 11:24 PM

Quote:

Today I was trimming some brass and got carried away and trimmed it to 1.95 when it should be about 2.0015.

If you purchased a RCBS X die set you would start by trimming all of the cases .020". To reloaders it was not very clear, they thought the X die stopped case growth. It would have been more clear if some one had said by the time the case requires trimming again it is time to start on another set of cases.

And then there are wildcats, I form wildcat cases that shorten .045" from the time I form the cases to firing. That does not seem to be a problem to most but I have one wildcat that has a neck length of .217". On that one I use 280 Remington cases.

F. Guffey

James K · June 30, 2017, 11:50 PM

Assuming everything else is OK, you should be able to fire those few rounds without any problems, but then discard the cases so there are no more mistakes. There should be plenty of neck to hold the bullet (unless you are firing it from an M60 MG). There should be no detectable erosion of the neck area of the chamber from a few short rounds

Jim

308Loader · July 1, 2017, 09:11 AM

Quote:

trimmed it to 1.95 when it should be about 2.0015

max 2.015, trim 2.005, SAAMI min 1.995

Don Fischer · July 1, 2017, 09:31 AM

I'd use them. Two or three time's through the FL die and they will be normal again. The expander really does pull on the neck pretty hard.

**Unclenick** · July 1, 2017, 10:14 AM

Intentionally shortening cases was common when the M14 was still the primary service rifle for match shooting. The hard extraction with a full power load caused everyone to favor military brass for its greater head and rim toughness, but it was common for that brass to have detectable internal pressure ring thinning after about the fourth reloading (fifth firing, counting the original factory load, if there was one), so it had to be tossed. Since it could grow as much as about 0.010" per load cycle, a lot of fellows started trimming 0.020" to 040" below minimum spec when they first got the brass, just so they'd never have to trim it again before they retired it. I've never heard of this causing and issue. Their bullets would mostly have been the 168 grain Sierra MatchKings, so they had a little more bearing surface than a 150 grain BT has to hang onto. They shot fine.

Consider that most chambers have throats about 0.005" to 0.020" longer than a maximum length case to begin with, and you can see that extra room, by itself, is not an issue. What will be a potential issue is the shorter necks may simply not hold onto the bullet well enough to get best start pressure. You would learn about that with a chronograph by looking for increased velocity standard deviation. Otherwise, though, if the bullets don't fall out, you are probably good to go ahead and use them until they grow back.

ShootistPRS · July 1, 2017, 11:45 AM

Go ahead and use them. As long as the bullet doesn't fall out the brass will likely grow back. It might be different if you had a gun that required crimping the bullets but a bolt action 308 should be fine.

T. O'Heir · July 1, 2017, 01:20 PM

"...SAAMI min 1.995..." Um, no. SAAMI minimum is 2.490". Max case length is 2.810". 2.015" is the trim-to. 2.0015" has an extra '0'.
I'd be inclined to shoot 'em then pitch 'em too.

**Unclenick** · July 1, 2017, 01:46 PM

No, he is talking about cases. 2.490" and 2.810" are minimum and maximum COL's for magazine fit and feed function, and are with bullet protrusion included.

The case spec is 2.015" maximum, with a tolerance of -0.020", so he is correct that the minimum case length to be within SAAMI standards is 1.995". The trim-to normally given is between those two numbers at 2.005" for this cartridge.

AL45 · July 2, 2017, 12:32 AM

As an update, I fired 9 of the rounds through a Ruger Scout bolt action and they fired fine. I was shooting standing from 25 yards away through iron sights and the third 3 shot group was about an inch. I have not inspected the brass yet to see if there was anything unsual about it. Thanks for your earlier replies.

RC20 · July 4, 2017, 05:23 PM

You are worrying too much!

You affect the neck hold a minuscule amount.

F. Guffey · July 5, 2017, 09:55 AM

If the OP did nothing to the necks the neck would be .305" long as in from the end of the neck to the neck/shoulder juncture. If he followed the X die instructions he would have a neck that was .285"" long.

What does that mean? The 30 Gibbs has a neck length of .217"; why isn't the neck of the 30 Gibbs too short? Too short? The 300 Win Mag neck is 'about' .275" long, if the 300 Win Mag is not too short what is the problem with trimming the 308W case .020" ? Again, RCBS X die instructions suggest trimming .020" before starting

F. Guffey

Stats Shooter · July 5, 2017, 10:09 AM

Quote:

If the OP did nothing to the necks the neck would be .305" long as in from the end of the neck to the neck/shoulder juncture. If he followed the X die instructions he would have a neck that was .285"" long.

What does that mean? The 30 Gibbs has a neck length of .217"; why isn't the neck of the 30 Gibbs too short? Too short? The 300 Win Mag neck is 'about' .275" long, if the 300 Win Mag is not too short what is the problem with trimming the 308W case .020" ? Again, RCBS X die instructions suggest trimming .020" before starting

I shoot a lot of .300 win mag, it has a short neck...I trim it below minmum by about 0.005"...why? Because sometimes the brass i buy new is just below or above minimum, and some of it is even a few thousandths below minimum. Despite the short necks, and my trimming a few thousandths below minimum, I get outstanding results.

The .30-06 has a much longer neck, and could probably be trimmed to half its length (I am not recommending this, just an example) and still perform well.

I would not hesitate to load and shoot them, but I would separate them out from my other cases unless you wanted to trim them all that short.

June 30, 2017, 10:34 PM	#1
AL45 Senior Member Join Date: December 12, 2012 Posts: 754	Overtrimmed .308 brass. Can it be saved? I've been reloading .308 for about 6 years with no problems. Today I was trimming some brass and got carried away and trimmed it to 1.95 when it should be about 2.0015. I didn't realized what I had done until I had seated 32 bullets. The overall length is 2.75 which is what is called for. Is there enough neck to hold the bullet? Are there any other problems that could occur. These are 150 grain BTSP bullets with 43.5 grains of IMR 4064 and CCI Large Rifle Primers.

July 1, 2017, 10:14 AM	#6
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	Intentionally shortening cases was common when the M14 was still the primary service rifle for match shooting. The hard extraction with a full power load caused everyone to favor military brass for its greater head and rim toughness, but it was common for that brass to have detectable internal pressure ring thinning after about the fourth reloading (fifth firing, counting the original factory load, if there was one), so it had to be tossed. Since it could grow as much as about 0.010" per load cycle, a lot of fellows started trimming 0.020" to 040" below minimum spec when they first got the brass, just so they'd never have to trim it again before they retired it. I've never heard of this causing and issue. Their bullets would mostly have been the 168 grain Sierra MatchKings, so they had a little more bearing surface than a 150 grain BT has to hang onto. They shot fine. Consider that most chambers have throats about 0.005" to 0.020" longer than a maximum length case to begin with, and you can see that extra room, by itself, is not an issue. What will be a potential issue is the shorter necks may simply not hold onto the bullet well enough to get best start pressure. You would learn about that with a chronograph by looking for increased velocity standard deviation. Otherwise, though, if the bullets don't fall out, you are probably good to go ahead and use them until they grow back. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

July 1, 2017, 01:20 PM	#8
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...SAAMI min 1.995..." Um, no. SAAMI minimum is 2.490". Max case length is 2.810". 2.015" is the trim-to. 2.0015" has an extra '0'. I'd be inclined to shoot 'em then pitch 'em too. __________________ Spelling and grammar count!

July 1, 2017, 01:46 PM	#9
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	No, he is talking about cases. 2.490" and 2.810" are minimum and maximum COL's for magazine fit and feed function, and are with bullet protrusion included. The case spec is 2.015" maximum, with a tolerance of -0.020", so he is correct that the minimum case length to be within SAAMI standards is 1.995". The trim-to normally given is between those two numbers at 2.005" for this cartridge. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 30, 2017, 11:50 PM	#3
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Assuming everything else is OK, you should be able to fire those few rounds without any problems, but then discard the cases so there are no more mistakes. There should be plenty of neck to hold the bullet (unless you are firing it from an M60 MG). There should be no detectable erosion of the neck area of the chamber from a few short rounds Jim

July 1, 2017, 09:31 AM	#5
Don Fischer Senior Member Join Date: March 2, 2017 Posts: 1,868	I'd use them. Two or three time's through the FL die and they will be normal again. The expander really does pull on the neck pretty hard.

July 1, 2017, 11:45 AM	#7
ShootistPRS Senior Member Join Date: January 3, 2017 Posts: 1,583	Go ahead and use them. As long as the bullet doesn't fall out the brass will likely grow back. It might be different if you had a gun that required crimping the bullets but a bolt action 308 should be fine.

July 2, 2017, 12:32 AM	#10
AL45 Senior Member Join Date: December 12, 2012 Posts: 754	As an update, I fired 9 of the rounds through a Ruger Scout bolt action and they fired fine. I was shooting standing from 25 yards away through iron sights and the third 3 shot group was about an inch. I have not inspected the brass yet to see if there was anything unsual about it. Thanks for your earlier replies.

July 4, 2017, 05:23 PM	#11
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	You are worrying too much! You affect the neck hold a minuscule amount.

July 5, 2017, 09:55 AM	#12
F. Guffey Senior Member Join Date: July 18, 2008 Posts: 7,249	If the OP did nothing to the necks the neck would be .305" long as in from the end of the neck to the neck/shoulder juncture. If he followed the X die instructions he would have a neck that was .285"" long. What does that mean? The 30 Gibbs has a neck length of .217"; why isn't the neck of the 30 Gibbs too short? Too short? The 300 Win Mag neck is 'about' .275" long, if the 300 Win Mag is not too short what is the problem with trimming the 308W case .020" ? Again, RCBS X die instructions suggest trimming .020" before starting F. Guffey