Case Length

[LR-Shooter]

I reload .30-06 cartridges and the manuals all say the case trimmed length should be 2.484". I started with virgin brass and have fire formed the cases 3x. I have found a few cases that are SHORTER than the minimum length; one of them measures 2.470"! What gives? Do I destroy the extra short ones and cut my losses or do I continue using them? I don't know if it's safe to use them. I need some guidance here.

 

[J E Custom]

I reload .30-06 cartridges and the manuals all say the case trimmed length should be 2.484". I started with virgin brass and have fire formed the cases 3x. I have found a few cases that are SHORTER than the minimum length; one of them measures 2.470"! What gives? Do I destroy the extra short ones and cut my losses or do I continue using them? I don't know if it's safe to use them. I need some guidance here.

They are supposed to be shorter than the SAMMI spec. in order to fit all chambers without
hitting the end of the neck chamber(A common cause of excessive pressure)

The trim length is the absolute Max length and most people trim around .020 thousandths
shorter.

So I would measure the shortest piece of brass and trim all the rest to that length unless it
is .050 or .060thousandths short.

Your brass is fine.

J E CUSTOM

 

[Edd]

Saami shows case length of 2.474" - 2.494".

 

[LR-Shooter]

J E Custom:
As mine are at least .014" shorter than book minimum does that mean my brass is still ok to use?

 

[LR-Shooter]

Edd:
You said SAMMI specs call for case length to be---2.474" to 2.494". My shortest case is still shorter than specs (2.470"). I wonder if the brass will stretch with more firings???

 

[sp6x6]

It most likely will, and in my OP you dont have anything to worry about.

 

[LR-Shooter]

J E Custom, Edd, sp6x6, and the rest of the folks here at LRH have been very helpful. Thanks to all.

 

[J E Custom]

Edd:
You said SAMMI specs call for case length to be---2.474" to 2.494". My shortest case is still shorter than specs (2.470"). I wonder if the brass will stretch with more firings???

. 020 to .030 is an ideal trim length on most cases but shorter does not meen it is bad.

The 30/06 has a neck length that is longer than one caliber(.308) by .077 thousandths.

Most shooters prefer at least one caliber of neck length .308 for a 30 caliber, But there are
lots of cartriges that have less and perform very well(300 rum is .300 for a 308dia.) the
300 Win Mag is only .264 .044 thousandths shorter than the dia (.308) and it a has a
reputation for being very accurate.

The only downside to shorter necks is the buildup of carbon at the end of the neck chamber
and a good cleaning regiment can solve this.

Trim them all the same length and have fun.

J E CUSTOM

 

[LR-Shooter]

Thanks J E Custom, that sets my mind at ease. I'll trim all my cases to equal the shortest one and go from there.

 

[LR-Shooter]

Another ?.

Why do some of my cases get soot at the back ie. where the ejector grabs the case. There is also some soot on the last 1/4 of the case. This only happens for the first 5 to 7 shots! After that, no soot.

 

[LR-Shooter]

Still another ?.

How does one clean the fouling from the bolt lug area and the surrounding area without damaging the throat, rifling, chamber, etc. etc. etc. and without getting any cleaning solution in the trigger?

 

[rscott5028]

It sounds like your chamber may be slick from cleaning and the brass isn't sealing it off good until 5-7 shots are fired.

Be sure to get your chamber clean and dried out. Not slippery with lube. And, wipe the lube off of your brass after seating the bullet.

-- richard

 

[rscott5028]

Still another ?.

How does one clean the fouling from the bolt lug area and the surrounding area without damaging the throat, rifling, chamber, etc. etc. etc. and without getting any cleaning solution in the trigger?

When the brass seals the chamber properly, you shouldn't get fouling in the lug area.

All it should take to clean that area is perhaps a cotton shotgun swab of the appropriate size to blot out any excess solvents that might've leaked past your bore guide. Just don't scratch your chamber and/or throat with the twisted steel wire center.

-- richard

 

[LR-Shooter]

It sounds like your chamber may be slick from cleaning and the brass isn't sealing it off good until 5-7 shots are fired.

Be sure to get your chamber clean and dried out. Not slippery with lube. And, wipe the lube off of your brass after seating the bullet.

-- richard

Richard, I use Imperial Sizing Die Wax and I always clean the cases after resizing. I also use a bore guide, so if that's the culprit, than I may have to buy a bore guide that seals the chamber better.

Manny