Small Base Dies or the "usual"

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K

*Kemosabe*

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When I knew very little about rifle reloading, a friend recommended that I use small base dies for ammo to be used in my AR-15. I’ve been using them for many years apparently without a problem.

I am going to buy another set of .223 dies to be used at another location and I was wondering:

Is there any advantage or disadvantage to using either the small base dies or the non-small base .223 dies?
 
If you load for multiple AR's or other AL rifles, and have one that needs that little extra sizing down toward the case head, then using SB would probably be the easiest solution to getting the same loads to fit all those actions, thus eliminating the need to load for individual rifles. So yes, you can use them as a standard approach to loading for any AR.

GS
 
Supposedly small base dies work the brass more and wear the brass out quicker. It's typically recommended to only use them if a set of regular dies won't size the brass enough to function in your rifle, this unfortunately means you normally find out the hard way after using regular dies. I've been there done that. I find so much good range pickup brass that wearing it out isn't an issue for me so I size all of my .223 with a small base die.
 
They just size the lower portion of the case a little more than a regular die. I doubt there's ever been a case that died from that little bit of extra squeezing. Split necks, loose primer pockets or (near) head separation kills brass and in the case of an AR grass and leaves eat more of my brass than anything else.
 
gamestalker, KansasSasquatch & MtnCreek all seem to be on the same wave length so that answers one question... thanks!

Because the small base dies can make the case less "snug" in the chamber and possibly lessen the concentricity of the long axis of the bore with the long axis of the cartridge, will the cartridges sized using the small base dies be less accurate than the "regular" dies?
 
IMHO, there will be no difference noticeable between a standard full length and small base die. Die selection and sizing technique will have an impact on the accuracy of your ammo, but I just don't see small base vs standard being a factor.

Are you going to shoot the same brass through multiple rifles?
Are you going to purchase once fired brass or new brass?
 
I have used standard RCBS dies since 1970 for use with AR-15's, Mini-14's, and CZ bolt action rifles.
Using almost 100% military brass.

Never a need for Small base dies so far in 44 years.

However, if I were buying new dies today?
I'd buy the RCBS AR series dies and Fobadaboutit.

The taper crimp die should be an improvement over my old seating die if you plan to crimp.

http://ads.midwayusa.com/product/62...aper-crimp-223-remington?cm_vc=ProductFinding

rc
 
I use a standard set of Redding dies to load .223 cases I've picked up off the ground at the range. Several different brands and no problems with feeding in My S&W M&P 15.
 
@ MtnCreek - I have at least 12,000 pieces of brass that are mostly military and about half are once fired. I have no plans on buying any new brass. I am currently shooting my reloaded rounds through Colt & Bushmaster AR-15s, 2 Mini 14s and a Daewoo without incident.

@ rcmodel - Since I’ve only used small base dies, I’ve never felt that I “needed” them. So if it ain’t broke, I’m not going to fix it. Like you said, I’m a gonna git it & fergit it. (I think you said that. ;))

@ Curt Blunt - Neither you or anyone else has ever told me that they actually needed a small base die set. But since I’ve been doing it my way for so long and it hasn’t caused me any problems, I’ll probably stick with what I know.
 
I have seen no difference in brass wear between the std and sb. The sb is just that, 0.001" smaller at the base. So nominal difference unless you have a really loose chamber. If I it was me I would buy the SB or AR series dies and not look back.

The only guns that I have owned that has required the SB have been Brownings. All other have gotten buy with the std dies.

Like they said buy std and try.
 
Dillon "only" makes small-based bottleneck dies........but they don't trumpet it. Wonder what they know that others don't? :)

I'd guess that they don't like call backs, or the "handload" reputation of rounds that don't chamber fully into battery in every gun.

Like RC, I've loaded for many, many years without a S.B. die set. But after a single experience with a new R25, I converted.

You just plain have more adjustment in a S.B. By the time you reduce the shoulder bumping in regular dies to work the shoulders the least you can, your bases are sometimes left wide enough to resist closing the bolt. You sure don't want that in a gas gun!
 
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rcmodel said:
However, if I were buying new dies today?
I'd buy the RCBS AR series dies and Fobadaboutit.
Click to expand...

I agree.

I recommend that if you do not have dies for your AR, get the small base sizer.

If you already have dies, I would not buy small base dies unless you want to be on the safe side.

I do have a combination of two AR-15 rifles and one standard 223 Remington sizer die that I will have chambering problems in one rifle using cases fired in the other rifle. It is a result of an accumulation of tolerances. A thousandths here and a thousandths there and eventually you got some real dimensional differences.

So that I do not have to segregate cases by rifle, I just small base size all of them and not worry about it.

Finally, my cases fail for other reasons before they fail for working the brass with the small base sizer die.

Or, I lose them.
 
Used brass = Small Base dies. I have used an old set of RCBS standard 223 dies for many different firearms. Note that the old and new sets are different, as i have one of each in standard.
 
Though they come in several different calibers, i've read that they're recommended for 5.56 brass fired from SAWs or 7.62 brass fired from various machine guns. I have a set for 300 Blackout simply because the Lee set I was using had an oversized expander ball. I used them on 250 cases so far and they work fine. I don't think they're necessary in my case though.
 
Small base dies are for one if two situations

The first is for "military" cases fired in who knows what.

The second is for folks who refuse to set a standard FL die up properly. IE a quarter turn into the shellholder after contact at TDC

With a standard die adjusted properly I've not met a piece of used brass yet that I can't make fall into a SAAMI case gauge. You are using a case gauge right?
 
R.W.Dale said:
a quarter turn into the shellholder after contact at TDC
Click to expand...
is not always the "proper" way unless you don't mind bumping the shoulders up to .006" more than it needs to be, and thus working that critical area of the brass that much more. But granted, for a regular die to size the base small enough, often over bumping the shoulder is necessary. Thus the die maker's "cam-over" instruction to make the base small enough to chamber.

The difference in my .308 Wilson case gage between rim-flush-high and flush low is about .006". That's a lot of shoulder bump if you size flush low, but yet still supposedly within the SAAMI spec. Safe to fire to be sure....but such works the brass a hell of a lot more than the measly .001" or .002" that a small base die squeezes below the bottom 1/2" of the case.

I'm only saying ..... that just making a case fall into a gage is not the holy grail of loading for your gas gun. IMO bumping the shoulders .002" is a better idea than "camming-over" and bumping .006" or .007", IF.... your case's base is sized small enough to chamber. That's why I prefer a small base die for my gas guns.

Using a S.B. die, "camming over" isn't always necessary because you can bump less and the base is still smaller than a similarly adjusted regular die cammed in and bumped to the max.
 
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I have a used set of lee .223 dies I paid $5.00 for. Several thousand loads of range trash brass on them and they have feed several different rifles. Small base are not needed.
 
R.W.Dale - “You are using a case gauge right?”
Click to expand...

Absolutely. I'm looking at my “DILLON” PREC. GAGE that's on my desk as I respond. Remember though, I have always used the small base dies and I’ve never had a case that didn’t pass muster.

@ GW Staar - Can you tell me the distance between the top flush level and the low level on a case gage? I have calipers, but I don't think that they would be precise enough.
 
I'm hoping this is somewhat on topic-Mods may disagree-

What's the deal with machine gun chambers? Do they bulge brass or what?

And:

That's a lot of shoulder bump if you size flush low, but yet still supposedly within the SAAMI spec.
Click to expand...


I'm sizing with a gauge, and I know how to get it to pass, and my ammo is firing fine but Im still a little bit bumfuzzled by the whole gauge and shoulder thing-

Do you want to be flush-high in the gauge, since that works the brass less? Im loading 223 for an AR15. (Or if their is a goal here, which is it? Low, middle, or high? Or is this an "it depends")?


Very, very, interesting thread for me, at my stage of this hobby, thanks for starting it Kemo, and others for contributing.
 
I have just fine luck with the Lee full length sizing dies. I understand from others that some brass can be problematic and require a small base die. I have one, a Redding just in case....that single die cost more than the entire Lee set! Use a case gauge to determine if all is well with your resized brass. I use the L.E. Wilson case gauge.

Russellc
 
I didn't read all the posts so this may have been asked. Is the 5.56 chamber "larger" width wise than a SAMMI 223 chamber. If so would that negate the need for a small base die in a 5.56 chamber?
 
The only rifles that I found that the Small Base Die worked better than the Standard dies in RCBS , were for my HK91 and an old Remington 742 in .308 with any brass.
The HK has a Fluted Chamber, and the Remington I had, had a Polished Chamber, that I think the previous owner " Bubba " over did it.
But I saw no advantage in other semi autos or lever actions in feeding or ejection.
But they are harder on the cases.
But with my Hk, I loose them before I wear them out, even with the ejector port buffer/ deflector.
 
GW Staar said:
is not always the "proper" way unless you don't mind bumping the shoulders up to .006" more than it needs to be, and thus working that critical area of the brass that much more. But granted, for a regular die to size the base small enough, often over bumping the shoulder is necessary. Thus the die maker's "cam-over" instruction to make the base small enough to chamber.

The difference in my .308 Wilson case gage between rim-flush-high and flush low is about .01". That's a lot of shoulder bump if you size flush low, but yet still supposedly within the SAAMI spec. Safe to fire to be sure....but such works the brass a hell of a lot more than the measly .001" or .002" that a small base die squeezes below the bottom 1/2" of the case.

I'm only saying ..... that just making a case fall into a gage is not the holy grail of loading for your gas gun. IMO bumping the shoulders .002" is a better idea than "camming-over" and bumping .006" or .007", IF.... your case's base is sized small enough to chamber. That's why I prefer a small base die for my gas guns.

Using a S.B. die, "camming over" isn't always necessary because you can bump less and the base is still smaller than a similarly adjusted regular die cammed in and bumped to the max.
Click to expand...


"Cam over" is not used to cram the case into the die than it's supposed to. It's done to accommodate the frame flex that's present in ALL reloading presses. You will get more accurate results camming over than you will chasing a shoulder bump with the shellholder off the die base which in turn allows the final headspace to vary according to variances in sizing difficulty and resultant press frame flex. Then if you want to push the shoulder back less you use a competition shellholder or shims on the face of the shellholder but you still cam over at the top of the stroke.
 
What's the deal with machine gun chambers? Do they bulge brass or what?
Click to expand...
Not so much bulged but MG brass is usually way oversized in body width particularly at the base, and length. MG chambers are generous to say the least. This is to be able to chamber and function without issues in the harsh conditions, dirt, dust, etc...
Small base dies do help with brass that is overspec to begin with.
 
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