308 brass trimming

[S-Hurt]

I was told the best overall length for 308 brass is between 2.005 - 2.010 I recently aquired some 308 win brass (free) which measures 2.000 or 2.001 oal. Is this brass alright to use for loading in a DSA 308 semi auto rifle? I also purchased some Lake City brass which was 2.020 oal and I cut them down between 2.005 and 2.010. But, what if a piece of brass sneaks in at 2.015? Yes, I'm new to loading 308 and would like to know how picky I should be for these overall length tolerances when cutting the brass?

[Chris]

Did you size them first then measure? The length will change after you size them and the neck will require trimming to length.

Make sure they drop into a HEADSPACE gauge (not case gauge) and are within the tolerances. Rifles headspace from the shoulder and not the rim like a pistol, so the shoulder needs to be at the correct dimensions.

You can use a Wilson or a Dillon headspace guage to check the brass and adjust your dies with.

[S-Hurt]

I deprimed the brass with a Dillon sizing die and then took it to a guy who commercially processes the primer pockets for military brass although the winchester brass did not need this process. I then put the brass through the Dillon trimmer which also sized them I guess a second time. I purchased a Dillon headspace guage and they all appear to be fine.

I wondering how exact these overall length tolerances should be? Are the casings that are 2.000 oal all right to use or are they too short? If I have a casing that is 2.015 oal is that a big deal?

[BillL223]

Per my Hodgdon manual, maximum case length is 2.015" so you should be O.K. They recommend 2.005 as a trim to length dimension. I wouldn't worry about your 2.000" being .005" short.

[S-Hurt]

Thanks for the info ...... I've tried to educate myself through this website and other Internet articles. I'm finding reloading rifle brass is a different animal than pistol and I'm asking a ton of questions. I've ordered two semi auto 308 rifles and the first one will be here on the 13th so I'm excited to start reloading the brass I have processed.

[Banker Bob]

Thanks for the info ...... I've tried to educate myself through this website and other Internet articles. I'm finding reloading rifle brass is a different animal than pistol and I'm asking a ton of questions. I've ordered two semi auto 308 rifles and the first one will be here on the 13th so I'm excited to start reloading the brass I have processed.

In case you get back to this--you may find 308--particularly the gas guns, are hard on brass --watch for stretch ring ahead of the case head.--the Lake City is a little heavier so will last longer(don't use max win loads in the LC brass without dropping back--) ----the case length final test is to try to slide a new bullet in the fired case--if there is resistence at the neck tip , such as a crimp would feel, the neck may be contacting the front of the chamber and creating a " crimp" when fired. You then know that the case needs trimmed! (If you are shooting mil brass that was crimped --trim much of that crimp off that off --easier to get consistency than to straighten out the mil crimp)-- I found that my M1a springfield SM required its brass to be trimmed every firing--whereas the bolt gun brass would go 4-or 5 before trimming--so I just adopted a practice of trimming every firing--that was a pain so got a Gracey to make the effort easy !

I have known HP gas gun shooters (High Masters-not beginners) that just rimmed to 1.9--knowing that the case was due to separate well before it reached a problem length. Short is much better than too long!

BB

[Rufftytuffty]

I trim to 1.950 as i'm using the x-die.

The x-die then resizes the case every loading and i never need to trim again.

As an FYI...i have just retired my first batch of 10 x fired brass (WIN headstamp) out of with i had about 3-4 primers fall out and 6-7 neck splits.

Not bad for 1,500 rounds through a DPMS (AR-10).

~Mike

[barney88pdc]

Ok I have been reading and trying to decide on what trimmer to get. Everyone recommends a Giraud. Correct me if I am wrong but...the Giraud indexes off of the shoulder so it is going to trim from the shoulder to the neck a given amount each time. So distance form the neck to the shoulder would be consistant correct? But the distance from the case head to the neck could vary? Meaning the neck to shoulder distance would be constant but the OAL would vary? Am I correct on this? So in simple terms if the case head is point A, the case neck is B, and the case mouth is C. Then distance B to C would be constant but OAL A to C could vary because we have not accounted for variance in A to B length?

Now if I got say the Redding 2400 I would get consistan OAL because the distance from the collet to the trimmer would be constant. So OAL (A to C) would be constant but distance from the case neck to the case mouth (B to C) would vary? And also A to B?

Now I know that bottle neck rifle cases index off of the neck so I guess having the same amount of brass in the neck area (B to C) would mean equal neck tension for each round. But I am thinking that if the case body length differs (A to B ), due to the fact that the trimmer indexes off of the shoulder, then the distance that the bullet is seated into the neck would differ due to a possible difference in OAL (A to C) of the CASE (Again due to the fact that the length from A to B is not being standardized. Or am I looking way too far into this and the A to B is standardized in the resizing die). Meaning I know every round "in theory" would be say 2.800" OAL because in the seating station the distance from the seating die to the sell plate is constant. BUT if the case of one cartrage is a little longer than another then the bullet would be seated deeper into that case if the case was cut by being indexed off of the shoulder. Therefore the bullet would have more brass "to pass" before exiting the case. Now I guess for say a semi auto rifle who cares this small varation probably would have a consideraly less effect on accuracy than other variables. But what about in a good bolt gun?

Next topic dies.......LOL.

Edited August 5, 2009 by barney88pdc

[uscbigdawg]

I recommend the Lee Zip Trim (seriously).

Rich

[Chills1994]

@ Banker Bob and S-Hurt...

see my posts in this thread here:

http://www.brianenos.com/forums/index.php?...p;#entry1030161

[Ray_Z]

Scott

If I read your post correctly, you resized the brass, have the pockets done, then put the brass through a Dillon electric trimmer. I just got finished loading 2000 308's for my son. I trimmed the brass first, then did the pockets, then resized and decapped. It seemed to me that to resize then trim would make the neck tension different on the bullets.

Also, I use the Dillon primer pocket swaging tool. The people that I've talked to that do this for a living cut the brass away that was swaged over the primer. The Dillon tool just puts it back where it started out being. It only takes a couple of seconds to do this and with the money you would be paying someone else to do this you would pay for the tool.

Just my 2 cents worth

[Chills1994]

^^^ I'm thinking it all depends on which resizing/decapping die you have.

I am of the mindset that as you push back up on the press's handle and the ram goes down, the case mouth/neck gets pulled back over the expander ball on the decapping rod. Again, I am of the mindset that this pulling causes the case neck to stretch, which then later has to be trimmed. There are just neck or mouth sizers out there where I think you have to buy correctly dimensioned bushings. And there are universal decapping dies that don't size at all. Maybe, just maybe you could get by reloading your .223 brass that has been fired though your AR by using just a mouth/neck sizer and a universal decapping die...but...BUTTT... I would think after time the shoulder dimensions would get out of spec and your AR's bolt wouldn't have enough ummph to get completely shut on those rounds. I think.

FWIW.... I don't know if any manufacturer like RCBS or Hornady or Redding is making an all in one neck sizing/decapping die.

Anything that would eliminate or reduce trimming or what causes the case to grow, so that bottlenecked rifle cases could be treated like straight walled semi-auto pistol brass when it came time to progressively reload would be sweet.

So far, I think the closest thing I have found is the RCBS X-sizer die.

[charliez]

This looks like SAAMI specs: http://www.saami.org/Publications/206.pdf

Reading that, 308 Win case length is 2.015 to 2.020 inches (if I read it right, YMMV, )

Edited August 6, 2009 by charliez

[Jack Suber]

^^^ I'm thinking it all depends on which resizing/decapping die you have.

I am of the mindset that as you push back up on the press's handle and the ram goes down, the case mouth/neck gets pulled back over the expander ball on the decapping rod. Again, I am of the mindset that this pulling causes the case neck to stretch, which then later has to be trimmed. There are just neck or mouth sizers out there where I think you have to buy correctly dimensioned bushings. And there are universal decapping dies that don't size at all. Maybe, just maybe you could get by reloading your .223 brass that has been fired though your AR by using just a mouth/neck sizer and a universal decapping die...but...BUTTT... I would think after time the shoulder dimensions would get out of spec and your AR's bolt wouldn't have enough ummph to get completely shut on those rounds. I think.

FWIW.... I don't know if any manufacturer like RCBS or Hornady or Redding is making an all in one neck sizing/decapping die.

Anything that would eliminate or reduce trimming or what causes the case to grow, so that bottlenecked rifle cases could be treated like straight walled semi-auto pistol brass when it came time to progressively reload would be sweet.

So far, I think the closest thing I have found is the RCBS X-sizer die.

You don't want to neck size a semi-auto case. Neck-sizing is better suited for Bolt rifles.

FWI - Ken Waters Pet Loads and Lyman list trim to length for 308 Win at 2.005". My Sierra manual lists 2.015. I am trimming my rounds to 2.005" for my M1A and they are working fine.

I have noticed that since I have started using a "small-base" resizing die, the cases are not requiring as much trimming.

[uscbigdawg]

Redding has a Neck Sizing and Decapping die.

I full length resize my bolt rifle ammo...long explanation, but I'm still sub-MOA at 1k in a factory Remington 700 SPS Varmint.

Rich

Edited August 13, 2009 by uscbigdawg

[Franksremote]

So does RCBS, with either you can remove the decapping stem if you're using a universal decapping die, same for the FL (stem can be removed).

+1 of the Giraud or Gracey I got the latter with the Giraud upgrade and it makes trimming stupid simple (like sharpening a pencil in an electric sharpener). You have to FL resize first (I decap as well) as the neck is stretched by the FL sizing, not to mention it uniforms the shoulder on all the cases. You can have them make collets for NK sizing only.

ChrisS turned me onto the Lee Trimmer w/ a drill (and I've got 'em as a backup) but it's just easier and FASTER (8-12 cases a minute) to use the Gracey, err.. it's kinda fun too