Small base dies

[jaysouth]

I am going to start loading rifle calibers on dillon 550s. I have been reloading a variety of cartridges on a Rockchucker for decades.

Including .223 that I shoot through ARs. Dillon thinks I need a small base resizing die for reloading AR .223 ammo.

Why can't I stick my RCBS full length regular base die in the appropriate station and run with it?

 

[Walkalong]

No reason at all. Most folks don't use small base dies for ammo used in ARs. If you have a problem, maybe then.

 

[RussellC]

When I first started to reload .223/5.56 I bought a small base full length die from Redding, but the Lee full length die has always done perfectly...I'm sure yours will to. Like you, I was told it would be a good idea to have around "just in case", (BTW it works fine too), but I understand it works the brass a little harder?

Russellc

 

[GRIZ22]

I've been reloading 223 for a variety of sa rifles, ARs, Mini 14s, HK, etc. for 40 years. Never needed a sb die for any of them.

 

[MEHavey]

If you're going to reload "salvage" brass that may have been shot in a military automatic weapon like a M249/SAW,
I recommend an SB die for initial sizing. Sized once, then shot in your weapon, regular dies suffice thereafter.

 

[ArchAngelCD]

I have been only loading .223 ammo for an AR style rifle about 2 years. I have never needed a small base die but that doesn't mean some time in the future I won't get a rifle with a very tight chamber and might need one. For now, like you, I will be using my time proven RCBS full length sizing die. Like said above, use your current die and don't worry unless you have a problem.

 

[ants]

Personal choice, most experienced handloaders with most guns don't need it.

Try your existing die. Here's a trick with some dies like Lee in a Dillon:
If you have to screw the die so deep into the tool head that you can't get
the lock ring on top, just move the lock ring underneath the tool head.
Lock it down from below. That's what I did on both XL650 and RL550B.

 

[Barrelgal]

I've never found the need for a SB die, and that includes minimum SAAMI spec barrels. So IMO it just depends on the chamber, but I've yet to come across one that needed one.

BG

 

[dh1633pm]

As MEHavey noted above. Most of the time a small base is only needed during initial sizing of surplus brass that has been shot in a machine gun with a generous chamber. It sizes farther down the brass where previous expansion might be too big to allow it to chamber in your rifle. I had the problem with some LC brass and a Rifle with a tight chamber. Fixed the problem pretty fast. In most instances you might never need one, I thought so, but learned from the experience.

In my instance the brass would chamber with a hard bolt closure, but extraction was a problem. A case gauge finally showed me the problem. It was a matter of thousands, I just needed the base to be a hair smaller. Hence the small base.

 

[carbine85]

Not all small base dies are created equal. I used the RCBS small base with no problems at all for 30 years. I have also used the Lee Die for about 5 years with no problems.
I have a AR15 target rifle with a Wilson Wylde chamber and it requires the small base die to ensure proper feeding. The chamber on this rifle is tighter then you typical AR barrel.

 

[MtnCreek]

I load 223 for AR's using a SB die, but I've also used standard FL without issues. You might consider Dillon only sells a 223 sizing die that is SB.

 

[shooter1]

My ARs are my primary social weapons. One will not reliably chamber ammo loaded with standard sizing dies. As my ARs absolutely must function with any ammo I might feed them, I use a Redding small base resizing die in station one. Brass life is not a major concern as I am not likely to pick up my own brass from all the brass left on the ground at a carbine match, or for that matter, from the rifle range in general. I have on several occasions, seen ARs have chambering problems with reloads. I don't see a downside to using the SBD for ammo to be used in an auto loader. If the standard sizing die works for you in your chamber, and you are not concerned about the possibility of your ammo not working in another rifle, then you're good to go.
str1

 

[Blue68f100]

Try what you have before purchasing a SB die. I have a min spec 223 that I can use std sizing die on with no problem. I purchased 2500 once fired brass which came off a military range. None required a SB die to size. Now some took a little more force but all worked just fine. I have several 223R die sets, Hornady ND, and Redding, and Type S sizier all work fine. My Wylde chamber AR has a lot more room than the min spec. My Wylde spec barrel does not like light bullets but that's another story. I should note that I use an annealing machine during my brass prep. This keeps the brass neck and shoulder soft so sizing is a lot easier.

 

[Laphroaig]

I made the switch from Rockchucker to 550 last year, including .223. I just put my RCBS dies on a toolhead, and started loading without any issues.

The Dillon dies are small base and include a dedicated crimp die, neither of which I feel is necessary. To me, not worth the investment when what you already have works.

Laphroaig

 

[cfullgraf]

Try what you have before purchasing a SB die.

I agree.

As others have said, if the case was fired in your rifle and full length sized, it most probably will chamber in your rifle.

If chambering problems happen due to lack of base sizing, it most probably happened when swapping cases between rifles.

Once fired SMG cases are a constant problem and range pick up cases can be a source of chambering problems after sizing. But it can happen between two AR-15s as well.

I have a pair of AR-15s where cases fired in one rifle and standard full length sized will not chamber in the other rifle. I could segregate cases by rifle by I'm lazy and just small base size all my 223 Remington cases.

 

[maxxhavoc]

My advice on small base dies is that if you already have a die, use it unless you get a rifle that doesn't reliably chamber rounds made with those dies. Fire off at least a few mags before you go town and reload all of your brass with it. A dirty chamber can make your rifle more picky. If you do not have ANY dies and plan on loading for a AR, might as well get the SB sizer.

My RCBS sizes brass to a size larger than new factory ammo, smaller than a Lee FL resizing die.

I have 6 .223's, 1 of them doesn't like ammo made with my Lee standard FL resizer. The rest are fine. SB sized ammo runs more reliably in a dirty chamber than FL sized on a couple of mine.

Some rifles NEED SB dies, most do not. I have not noticed any decrease in brass life with SB sized brass.

 

[W.E.G.]

If you don't use a small-base die for loading for the AR15, one day you will have an incomplete battery incident, and you will wonder.

For building ammo for an autoloader, it won't HURT anything to use a small base die.