DIfference between small base, etc die sets?

[Caimlas]

I'm looking into what kind of equipment I'm going to get to start reloading, and I've stumbled upon a question I'm having a difficult time finding the answer for: What is the advantage of a small base die set for .223? The word I've gotten so far is that it's preferrable for semi-auto, but I'm not clear on why. I believe the alternative is 'full length', but I'm not sure on that.

My understanding is that the 'small base' just resizes the head, whereas 'full length' resizes the whole cartridge. Correct? Which is preferable?

 

[cracked butt]

Small base dies size all the way down to the case head.

If you are reloading brass that was fired in another rifle you'd want to use a small base die to bring the brass back into spec in case the rifle had a looser chamber than your own. I don't think a small base die is really necessary for anything else. I don't reload for my AR yet, but I use a standard FL die for my M1, and never had a problem- though I've always started with virgin brass.

FWIW, when I first started reloading, not knowing any better, I bought a set of Mall base dies for my .308 bolt action. Resizing was a lot harder than it needed to be, and I was only getting 5 reloadings out of my brass. I've since bought a regular Full length die and a Lee collet die, and life has been much easier.

 

[LHB1]

Sizing dies can be Neck Sizer, Full Lengh Sizer, or Small Base Sizer. Small base sizer IS a full length sizer but sizes the lower portion of case (near head) to a smaller diameter than standard full length sizer. Some rifles (semi-autos, lever actions, pumps, and some single shots) have less camming action than bolt actions when seating a new cartridge into the chamber. By using a small base sizer, the brass case is reduced to a slightly smaller diameter and thus should seat into the chamber easier. Using a small base sizer die does work the brass more in the lower area and theoretically the brass will not last as long as brass sized in a normal full length die.

Good shooting and be safe.
LB

 

[Walkalong]

My understanding is the small base dies size to minimum sammi spec. at the base. Most often used for autoloaders because of the brass expanding more and for reliablity in functioning. (feeding)

 

[fog]

which type of firearm are you reloading for?
bolt pump semi auto?
in my 25 + years of reloading experiences i have found out or learned the following:
if for a bolt and you want to strive for the most accurate start with new unfired brass and get a set of neck dies. use this brass only in this weapon!

if for a pump use full length dies watch overall length

if in a semi auto such as a mini 14 use small base die and any kind of brass you want

i have found in a ar type like a bushmaster the full length dies can work
hope this helps and remember my 2 cents worth

 

[Caimlas]

fog,

The reloading will be for an AR15 with a 5.56NATO. I'm guessing that I'll want the small base resizer, as I seem to recall hearing that the AR15 chamber is tighter than most. But... I don't want to reduce the life of my brass too much, either.

 

[Chawbaccer]

Try the regular die first, if it works you dont have to bother with the sb die.