.308 Win and .30-06 case lengths...Caution!

[TooTaxed]

Just decided to load a few hundred rounds of .308 Win and .30-06 once-fired cases...and discovered ALL of them, both commercial and military, need trimming to bring them to the max case lengths! Measured with a Lyman case length gauge, verified with a carefully calibrated dial caliper.

Over-length cases can lead to elevated pressures and chambering difficulties...be sure to check your case lengths!

 

[Smokey Joe]

Trimming cases

Tootaxed--Gooood point! And one that gets neglected often.

How do you trim yr cases? IMX, a Lee Zip Trim and the Lee Universal Collet, used with the Lee case trimmer mandrels and cutter, work great. You only get one length with the Lee set-up, but it's near the TTL, and you want all the cases the same length anyhow.

Be sure to chamfer inside and out after trimming. Inside, so the bullet passes easily into the case neck. Outside, so there's no square edge to catch on something when chambering the round.

 

[TooTaxed]

Right on, Smokey!

I'm using an ancient Forster hand trimmer...have done about 400 of these rifle cases and am developing the right arm of a gorilla! Will have to modernize one of these days... Also am using an RCBS double-ended hand reamer to remove the case neck burrs.

 

[Lennyjoe]

I trim rifle cartridges before every reload.

 

[milanuk]

Lennyjoe,

Just a wee bit of over kill, eh? Guess it depends on time available and volume loaded, but I think they make the trim-to length 10 thou less than the max case length for a reason... so you don't need to trim them all the bloody time. Still, if it tightens some nut inside your head (we all got 'em), knock yourself out.

Tootaxed,

Lot of options for powered case prep out there... most basic would be your existing prep tools and a 3/8 or 1/2" drill and a proper mount and some chuck adapters to hold the chamfer/deburring tools and a Possum Hollow Kwik-Trim, or a $50 benchtop drill press works pretty slick too. I've done both of those, used a Gracey for a while, and now have a Giraud (as close to heaven as case trimming is ever going to come).

YMMV,

Monte

 

[444]

I shoot a lot of the Korean KA-Headstamped .30-06 which is boxer primed, so I save the cases. I have thousands of them. After the inital firing, you trim what seems like 1/8" to bring them into spec. They are so long that you sometimes have to clear the trimmmer of the shavings in the middle of trimming a case. I have no idea what specs there were using when they loaded this stuff at the factory.
That being said, it seems to shoot pretty good.
But, I ain't throwing them away.
I have coffee cans of them that are trimmed, primer pockets uniformed, primer pocket crimp removed, and flash hole deburred.
Who knows if I will ever use them ?

 

[dakotasin]

i trim every load... if you wanna see real case growth, start loading for the 7 rem mag or 25-06 or 7 rum or 300 win mag, etc etc, and watch the cases grow before your very eyes! trimming is just part of the reloading process...

 

[milanuk]

Like I said, I trim down to the recommended trim-to length and leave it. If you have enough case length growth that you are seeing a need (actual need, not just a mental OCD thing ) to trim again after *one* firing (keep in mind for most cartridges the max length is 10 thou longer than the trim-to length)... I'd be watching for a case head separation! That 'growth' has to come from somewhere... That said, I normally don't full-length size per the directions that come w/ the dies; I usually only bump the shoulder a few thousandths, not the 10-12 that the factory directions seem to favor, so I probably don't see as much actual case length growth as some people might. I figure it's odd if I need to trim as often as every third firing... fifth is more like it. Trimming every firing isn't necessarily 'bad'; please don't think I'm saying that. I know some folks that I shoot with that have a dedicated tool head set up on their Dillons to trim cases every time for consistency, other people that have Gracey or Giraud trimmers like mine and trim every time... and neither shoots materially any better or reliably than mine which gets trimmed as a batch, as needed. More than one way to skin ye ole cat, I guess.

YMMV,

Monte

 

[Dave R]

Yup. Much of the factory ammo that I shot, and the kept the brass for reloading, was over-length.

Like milanuk, I just trim to .010 under the max length and check every few shootings. Depending on the cartridge, I generally get 4-5 loadings before I have to trim again. Then I trim the whole batch to keep all case lengths equal.

 

[The Bushmaster]

Hey Milanuk...I sure could use a box of fresh picked Delicious Apples. You know. The ones picked this year...

I use a RCBS Case Trimmer II and like Lennyjoe I trim (or check) each and every case before it is loaded again.

God I miss a real "fresh" apple from the Wenatchee Valley!!! With the juice runnin' down your chin...These one to two year old apples you get in the store just don't get it...

 

[Rockstar]

I use the Lee trim system, but with the shell holder chucked in a variable-speed drill motor. Can't imagine that the Lee Zip Trim could be as quick.

 

[milanuk]

Bushmaster... give me a holler off-forum @ [email protected]... I'll see if I can get ya something from that place down on the ave across from the convention center... Pak-It-Rite or next to it. Nice gift packs and whatnot of fresh stuff from the local area. I'm a recent import myself, from Nebraska.

Monte

 

[HankB]

I shoot a lot of the Korean KA-Headstamped .30-06 which is boxer primed, so I save the cases . . . Who knows if I will ever use them ?

You might want to think about this some more. The KA-stuff from Korea has corrosive primers.

Lots of guys with M1s use this with good results, and just clean their rifles thoroughly with water-based cleaner.

But I wouldn't be too keen on reloading brass cases that have been fired with corrosive priming compound unless I knew they'd been cleaned thoroughly shortly after firing. (And that means cleaned with water after depriming, not just run through a case tumbler.)

After the inital firing, you trim what seems like 1/8" to bring them into spec.

This seems VERY excessive. I'd be worried about where all that extra metal is coming from. Have you tried sectioning a case to see if there's any thinning just above the extractor groove which might lead to a future head separation if reloaded?

I know we reloaders are frugal, but IMHO it's false economy to take chances with questionable brass.

 

[Smokey Joe]

Zip Trim vs drill

Rock Star--Before I got the Zip Trim I too used a drill with the rest of the Lee equipment. That worked. Never timed either method, so can't give you a comparison. Can tell you that the ZT is very handy and I prefer it. It's probably about the same, time-wise.

 

[Big_R]

Checking case length is part of reloading 101, although a reminder never hurts. I too, trim my cases after each firing. Most of the time, very little if any is removed, but it keeps things consistent. This is especially important in cases that will be bullet-crimped. Consistent crimp = consistent accuracy.

Ryan

P.S. The most over-length cases I've ever seen were S&B 7.62 X 54R.