small base dies

[lppd4]

I want to load for my AR-15 should I use Full length resizing or small base dies? Whats the difference?

[RePete]

Go SB.

They tend to go down a little further on the brass and also squeezes the brass down to factory dimensions.

[goat68]

+1 in SB dies and make sure the sizing die is set so that you get the last couple thou out of the die or you will have rounds stuck in your chamber.

[Boxerglocker]

If your running Dillon rifle dies in any caliber, they are already SB. FYI

[Clay1]

I know that I am a little late to the party but don't you think you need more info to answer that question correctly?

First thing that I would ask is, how is your AR chambered? Is it 5.56 or 223 or a 223 match chamber. 223 match chamber, target gun = small base dies sure. A 556 chambered AR, full length is better in that the brass will last longer since it won't be work hardened as much. Just one guys thoughts.

[Smokecloud]

I run SB dies to make the brass just a wee bit smaller for reliability in my AR's. When the gun gets dirty and hot, think 100+ rds on a stage, it adds a little margin for reliability when the chamber starts heating up. On tight chambered guns, at around 120 rds, I have had the guns start choking with standard size brass, less so with SB sized brass. I really dont care about work hardening the brass, I try to load my once fired brass with nice stuff the first time around, match prepping the case, then after I fire it again, it gets loaded with FMJ for grunt work at matches. Most large matches, you dont get to pick up your brass anyhow, so it becomes someone elses problem after that.

[bigedp51]

The AR15 5.56 chamber is .002 larger in diameter than a .223 chamber and should not need a small base die, a standard .223 full length resizing die is smaller than the AR chamber.

If you have a tighter match grade chamber then a small base die "might" be needed, it will not hurt to have both type dies in case you buy once fired Lake City cases that were fired in a M240 machine gun with an even larger chamber and need to size them down to the proper size.

NOTE: In 26 years of reloading I have never needed a small base die for any rifle.

[CocoBolo]

After two sets of regular dies I went to the small base dies, with the taper crimp. The regular die worked in a single stage press but didn't get the job done in the LNL AP. Drop checking seemed normal however when cycleing the gun or shooting them they got stuck in the chamber. The small base die took care of that problem. In the LE Wilson drop check, if I see any brass edge sticking up, it goes in the practice pile.

I think the key in loading for the AR is to get the lube right, so that sizing doesn't deform the cases. I alwasy drop check after deprime and size and toss off the ones that stick up in the case guage.

[tohm]

Here is the answer I got when I asked Redding about the difference. I am sure others are the same. The difference between the Body die and Full Length is the Body die does not size the neck inside or out and not de-cap.

"I am sorry but Redding does not give out die dimensions, they are considered proprietary. Redding standard body die will reduce all dimensions below SAAMI Min Chamber, and our small base dies will reduce the base of the case an additional .003-.005" depending on the cartridge."

The chambers on the AR rifles vary so it depends on which AR my Rock River will eat anything I can throw in a magazine and my Stag is finicky still working out exactly what it likes.

[Lebayer]

The habit of drop checking brass after sizing is a good one and saves lots of headaches, not to mention lost components - or bullet pulling. I do the same with 9mm Major now and have no issues with the loaded rounds. All my problem children are caught up front. As an aside, for you 9mm Major shooters, when I resize/decap, I actually hold the die in place because it is lower than the threads on the Lee U die will go. It gets the die down .002-003" more and reduces the amount of brass lost to bottom swell.

[9milli]

I've used a small base die for over 30 years with no chambering probs. I polish the expander ball down a half thou or so for a good neck fit on the bullet.

Grab a Wilson headspace gage for correct shoulder setback to set your resize die with. A lee factory crimp die if you want more crimp or depending on bullet.

My .02 cents