Small Base Dies Needed?

[alamogunr]

I've just finished my first .223/5.56 AR build. It is very basic but I don't have a die set yet. Is a small base set needed(desired)? I don't anticipate anything other than AR's in this cartridge.

Is one brand preferred over others? I'm going to buy new so the options are wide open.

[Artful]

Small Base Die I have only had one gun that required 'em
- And that was for initial sizing of once fired military cases before use in it.
Most AR's have enough chamber that you don't need 'em - Most any brand will work for ya.
One of my buddies bought RCBS X-die's and says he won't buy anything else now.
http://www.midwayusa.com/product/519159/rcbs-x-die-full-length-sizer-die-223-remington

Product Information
The X-Sizer Die features a specially designed mandrel that eliminates the need for repeated trimming after an initial trim of .020" off the maximum case length. The mandrel contacts the case mouth during sizing and reduces the growth rate. Because of an extremely close tolerance between the mandrel and die neck wall, the neck wall of the case does not thicken as the case length is pushed back. Cases repeatedly sized in the X-Die will initially grow a few thousandths of an inch, then stabilize below the maximum case length with no discernable loss of accuracy or case life. Shellholder sold separately.

http://www.rcbs.com/downloads/instructions/XDieProductInstructions.pdf

I've sort of been kicking around the idea of getting a sizer myself.

[Scharfschuetze]

It's probably going to depend on your chamber dimensions, particularly in diameter of the chamber. My suggestions won't hold water against what your rifle tells you so start out with your normal sizing die and if it works, you're good to go. I have a small base sizing die on the shelf that I bought cheap at a gun show some 30 years ago, but it remains unused to this day.

In my experience of shooting ARs I've never needed a small base loading die for them, not even for my match chambered custom "space gun" AR-15 or my son's match chambered service rifle class AR-15 for National Match competition. Rack grade AR-15s, as noted above, have pretty generous chambers.

As a lot of surplus 5.56 brass from the military is fired through the M-249 SAW and a SB die may be of some value to sort that stuff out. Perhaps that was why Artful needed the SB die for his surplus GI brass.

[bob208]

I have one small base die for .308. because my m1 was set up with a min. or match chamber. and I had a lot of .308 brass that was fired in a machinegun.

[GabbyM]

Have an AR with a 223 SAMI chamber. Don't even use a small base die for that. Basically a 223 die is small base for a NATO chamber. For one thing the headspace on a NATO chamber is .004" long. Shoulder is something like .001" wider. I just bump that shoulder a little. If you try to run a fired NATO case all the way up in a 223 die you'll generally have to trim them very time. That of course depends upon just how big your chamber actually is.

I actually have an old worn out 223 FL die here I use for my 5.56mm. it's worn out enough it won't size down a mil surplus fired piece of brass to chamber in a 223 SAMI rifle. For my 5.56mm NATO rifle I don't even run it all the way to the shell holder. That's target shooting and sporting ammo. For dusty condition battle pack stuff I'd use a new condition 223 die or maybe even a small base. But my battle packing days are getting thin.

Bought myself a new 22 CF bolt gun last week. Got it in 222 Rem for two reasons. One was to get a 14 twist barrel for cast boolits. Other was ease of separating ammo and brass. Three 223/5.56mm rifles. None of which use the same ammo. Is enough complication.

[zuke]

I reloaded about 3-4000 once fired 556 and used the LEE die. Followed the instruction's and screwed it down and made sure it full length sized every case.
I've used that ammo in an AR,Galil and now a BRNO bolt action. Never had a problem with chambering .

[Larry Gibson]

If your chamber is standard spec you will not need SB dies or even the RCBS "AR" dies (that is a sales gimmick). I suggest the RCBS standard .223 X-die. With it you will get a much greater number of firings per case and will not have to trim. I've been using them for my own ARs for some years and other X-dies in numerous other cartridges with complete success.

Larry Gibson

[alamogunr]

Per the above recommendation, I bought the RCBS .223 X dies. Just so happened that they were on sale at Midway. While I was at it, I got a set of check weights. Both my balance scales weigh the same but I've had one for about 20 years and the other was won on Ebay so I don't know how old it is. Better safe than sorry. Someday I intend to get a digital scale and the check weights will be absolutely necessary in my opinion.

[kostner]

Was having a problem with cases getting stuck in the chamber and read that a small base die would correct this. Tried to order one from Midway and it was on backorder. Keep surfing the AR sites and found that by "over caming" the full length sizing die would eliminate this problem. It has worked very well and found that a case gage is a valuable tool to have when reloading 223/5.56 Good luck.

[Scharfschuetze]

+1 on the case gauge Kostner.

[Jal5]

Case gauge eliminated all the probs I was having reloading form my AR.

[alamogunr]

I'll order a case gage. I'm still having trouble with dummy cartridges sticking in the chamber. My dummies were made up just like a regular reload except no powder or primer.

My RCBS Rockchucker doesn't "cam over". I've got the die just kissing the shell holder. One thing I haven't tried is coating the brass with magic marker and chambering it to see where the interference is located. Will this tell me anything?

[GabbyM]

For setting a FL size die. For maximum sizing. Set your die to touch shell holder. Then turn 1/8th turn down. Insert a lubed case and run it in. Stop the ram in full up position. Duck over and view any gap between shell holder and die that may have been created from flex in the press. You may be surprised.
Most instructions will tell to give the die an extra 1/4 turn from just touching. Depends upon how much your press flexes. You can spring a press from setting dies to tight.

More often than not. Chambering issues after FL sizing are caused by the neck expander plug being pulled up through an un-lubed case neck which is also being grossly undersized by poorly dimensioned dies. This force pulls the shoulder up in a bulge shape. If you have much force on the up stoke during neck expanding we need to use lube. Like graphite applied with a brush. Most dies need the neck portion honed out some.