MEASURE TWICE, CUT ONCE!

[mgatc]

Resized, cleaned and primed Tuesday night. Read some more and decided to charge and load tonight. I used the instruction pamphlet that came with the RCBS .308 dies to set the bullet seater starting height.

First cartridge came out at 2.750. At this point I am incorrectly working under the premise that the OAL is a minimum of 2.80. So I backed the die out a half turn and the next one is 2.758. Continued backing out the die until the last cartridge of 6 came out at 2.797. Perfect! or so I thought until I re-read the Lee manual which shows the 2.8 as the MINIMUM overall length.

The Speer manual is a bit more ambiguous stating that the shells they tested were 2.8 COAL but "this is a guideline and not gospel". This manual gave much more detailed instructions on setting the die height and had I followed it instead, I would not have make such a rookie mistake(even though I am a rookie!)

So the question is are these shells safe to use or do I need to pull them and start over?

Thanks,
m

[312shooter]

Yes the minimum can also be thought of as "no shorter than" and you have exceeded that minimum very slightly. Its best to keep safe as you start reloading and keep the manuals information as a strict guidline. BTW what bullet weight are you loading, what powder charge?

Just my personal experience but I have found some data in the Speer manual is a bit on the higher pressure side, make sure you cross reference your charge weights with 2 or 3 manuals before you load. I have knocked out primers with some of the Speer 308 loads!

[mtnboomer]

I'm not sure what you're asking here, m.

All my manuals shows an industry-standard overall cartridge length of 2.810". That length can change if your gun has a short or long chamber. But the 2.810" length is what is accepted as universal cartridge length for the .308 Winchester round.

Are you asking what the minimum COAL is, or for the maximum COAL?

[Lee C.]

If 2.810 is your minimum cartridge lenght, thats your starting point. Take a measurement of your chamber to the lands and thats what you have to play with that lenght in between. Where you seat the bullet will make your load more accurate in the end.

[steve4102]

OAL is not manual specific, it is rifle specific. The Max OAL listed in manuals and cartridge drawings is for Ammo manufactures. This is to insure that their factory ammo will fit into every rifle chambered in that cartridge. The SAAMI max OAL should be use and a guideline only.

From the reloading Accurate Powder reloading manual.

SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must
be seen as a guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of
the barrel, 3) ogive or profile of the projectile and 4) position of cannelure or crimp groove.

From the Hornady Manual.



Barnes recommends that you seat their bullets .050 off the lands for best accuracy. Can't get that from a book as the book doesn't know your exact chamber dimensions.

Nosler doesn't even list an OAL in their manual, no point, it's up to the handloader to find the best, most accurate OAL specific to his or her rifle.

Like the manuals say, the individual handloader if free to adjust OAL to fit their rifle/bullet combination. The SAAMI max is for ammo manufactures and is only a guideline, not written in stone as far as the handloader is concerned.

[mgatc]

I am below the minimum OAL indicated in both the Lee and Speer manuals. Just trying to find out if these shells are safe to shoot since they are slightly shorter than the minimums.

Guess I will pull them and start over.

I used the starting charge. 42gn of Varget with Hornady Match 168gn BTHP and a Winchester Long Rifle primer.

m

[mgatc]

All good info and I appreciate it
.
The nagging question for me however is it safe to shoot these rounds? Does a bullet seating below the Saami standard increase pressure to an unsafe level?

What is a simple method for determining the distance to the start of the lands? I shoot a Rem 700 Tactical.

[The_Vigilante]

You never indicated which powder you are using and how much. We would need this info to be able to recommend whether you should tear them down or shoot them.

[mgatc]

Its in post # 6

Starting Charge: Varget 42gn
Hornady Match: 168 gn BTHP
Winchester Long Rifle Primers
Remington cases

[mikld]

.003" under minimum with a starting load isn't a dangerous load, IMO. One reason for not going under minimum is the bullet intrudes on the case capacity, making a smaller combustion chamber, causing higher pressure. I think your loads are safe to shoot.

[steve4102]

Originally Posted by mikld

.003" under minimum with a starting load isn't a dangerous load, IMO. One reason for not going under minimum is the bullet intrudes on the case capacity, making a smaller combustion chamber, causing higher pressure. I think your loads are safe to shoot.

In a straight walled pistol round Yes, not so in a bottle necked rifle rounds. Scroll down to "From the Lab". You will see that shorter OAL actually had less pressure in most cartridges tested.
http://www.barnesbullets.com/resourc...rnes-bullet-n/

Here is another chart that shows reduced OAL produces Less pressure.

[steve4102]

What does it all mean. It means you set your OAL to whatever you wish. The criteria for this is, 1) fits the mag and cycles, 2) has at least one diameter of bullet inserted into the case, 3) bullet is not pig jammed into the lands, unless you are using this technique intentionally. And finally "Start Low and Work Up.

[JLA]

Steve offers spot on advice. Furthermore, dont waste your time completely disassembling all your ammo, simply put it in a kinetic hammer and whack it one good time on whatever you use to whack it on, this will move the bullet out far enough you can reseat them to your desired OAL without redoing the entire load.

[mgatc]

thanks to everyone! Great advice. Lessons have been learned and corrections have been made.
sincerely appreciate the feedback.
m