Reloading for 308 win SA

[Kawasaki]

For context, I have no experience reloading. I'll be hunting an AR-style semi-auto platform next year, reloading for 308 win.

Do I need a small-base sizing die? Based on what I'm seeing I have two options: size the brass to saami spec or bump the shoulder back and reduce neck size by 3-4 thou. I can accomplish either of those w a standard FL die though, right?

I know I'll need a seater die that taper crimps and the $ difference for the SB set vs a seater die is minimal. Just want to make sure what I think I know is actually correct.

 

[BHPSteel]

If you small-base size your brass, you can be more confident that rounds made from recycled brass will chamber more reliably in a semi-auto, because the case diameter will be sized a bit smaller than SAAMI. The alternative is the full-length sizing die, which returns the brass to SAAMI specs.

Both types of sizing die can be set to give you your shoulder bump and resize the neck to the right dimensions. That neck size will be one or two thou less than the diameter of the bullet, so when you seat the bullet, the tension will hold the bullet in place - although some reloaders put a crimp on their bullets (whether the bullets have cannelures or not). There are arguments for- and against- doing so, but some reloaders who have dies that can seat and crimp back the crimping feature off of the brass.

From personal experience, resizing 308 brass with a small-base die can be hard work. I actually went out and bought a really chunky single-stage press because I was concerned I'd damage my Hornady progressive press. Oh, and don't forget lube on those cases when you're resizing.

 

[Jackie Graham]

Make sure you have a decent case gauge. Lyman makes a decent one and they are pretty inexpensive. You can't just assume that the brass is back to specs just by running it through the sizing dies. This goes for any manufacturer of the die.

 

[CTS Tactical]

I personally use full length sizing dies and adjust them to just bump the should back a few thousandths. I have never owned a set of small base dies. If you set your dies up using brass fired in your rifle then you should be fine even when sizing range brass or what ever. I have also never owned a case gauge. A case guage is only good for full length sizing back to factory specs which does you no good if you are bumping the shoulder. I use a Hornady Head space comparator to determine shoulder bump and it has worked fine for me.

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I also do not use the crimp feature on the seating die. I use Lee Factory Crimp dies. It is an added step but in my opinion it works much better than the seating die crimp.

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This is my method. Not saying it is better than others but has always worked well for me and I get good accurate loads that cycle just fine in my rifles.

 

[greg vess]

I am getting ready to start my 308 reloading and I read where a guy did quite a bit of load development and was able to replicate the Federal Gold Medal Match, Sierra OTM ammo. Now all barrels are different but his load was 42.3 gr. of RE-15 under a 168 gr. OTM projectile. I am going to start there and work from that. Federal GMM is the most accurate shelf ammo I have ever used. Expensive but accurate!

 

[BHPSteel]

OP, one of the things you'll find is that there are many, many ways to skin a cat when it comes to reloading. Like CTS Tactical above, I use the Lee Factory crimp (although I'm still evaluating whether it really gives me any benefits). My original thought was that I'd have more consistent neck tension and more 'robust' ammunition if I was moving them around.

Now I'm starting to think that maybe, I'll be better off actually mic-ing the neck size for consistency. It may not be clear to you, but these kinds of ideas can really drive you down a rabbit-hole when it comes to experimentation (for a not very extreme example, differences in brass thickness in different brands of case, means that the dimensions of the outside of the case neck don't necessarily tell you very much about the inside diameter of the neck, and vice versa)

I think the thing is - you will try things and get equipment that after a while, you realize you won't use. It's just one of the characteristics of the hobby.

 

[Kawasaki]

Much appreciated, gents - thank you.

 

[Torn]

If you buy unfired brass it will most likely be SAAMI spec and you will not need a small base die or shoulder bumping. However bulk fired brass (especially military such as LC) may have been run through a machine gun that have looser chamber tolerances and allows more case expansion. I have an FN/FAL that was a full auto and it allows the brass to expand more than my AR-10 and I keep this brass separate.

I use a small base die for resizing because I have a lot of various headstand brass but you can avoid this is you buy unfired brass to start off with. As folks said above, there are different ways to achieve the same goal it depends on how much effort you want to put into it. Good luck and enjoy.

 

[BHPSteel]

One last thing - if you want to go the extreme accuracy route (I kind of suspect you don't, since you're talking about firing a semi-auto) then a small base die is unlikely to give you the precision you could expect from brass sized with a full length die.

 

[SOLGardener]

I have used standard full length dies for years. No need for small.base in Saami chamber.
I use a Lee factory crimp die as a separate action. I don't like seating and crimping in the same stroke.

Also, I shot semi.a loooong time without crimping. If your dies resize the neck right you should have enough tension to avoid setback. I did same in a hk91 that is pretty violent action.