Small Base Dies for AR-15?
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DickM
Member
I asked the same question when I got my first AR, and was told (correctly) that it wasn't necessary.
R.W.Dale
Member
A properly adjusted FL die will do all the resizing you'll ever need.
IMO small base dies are reserved exclusively for folks who don't adjust thier dies properly
IMO small base dies are reserved exclusively for folks who don't adjust thier dies properly
mongoose33
Member
I use SB, and since I may reload for any number of rifles I want to ensure I'll have no feed problems.
rcmodel
Member in memoriam
Not needed unless you have a tight match chambered ar-15.
And even then, probably not.
Standard RCBS dies for me for the last 40 years with nary a problem with many semi-auto .223 rifles of different makes & models..
rc
And even then, probably not.
Standard RCBS dies for me for the last 40 years with nary a problem with many semi-auto .223 rifles of different makes & models..
rc
I started using them because I load for six .223s (four ARs, one Galil and A FAL) and was having to adjust the dies for the FAL and Galil because they have .223 chambers. Since I started using small base dies the problems went away. The other ARs (two Bushmasters, a Colt, and a unknown surplus upper on a Mega lower) feed anything that you can put in a magazine.
RustyFN
Member
I never needed one. I use a standard Lee FL sizing die.
I have used one in the past, but no longer. I bought a bunch of machine gun fired Lake City brass. After full length sizing about 2-3 pieces out of 100 would not pass into a case gage.
I bought a small base die hoping I could salvage this brass, but even with the small base die, most of it still would not pass into a case gage.
I bought a small base die hoping I could salvage this brass, but even with the small base die, most of it still would not pass into a case gage.
I use one but it was the first 223 die set that I bought and haven't needed to change it. I load for several 223s and never had a chambering problem. I get 10-15 sizings out of good brass so the 'un-necessary sizing leads to premature brass failure' argument doesn't hold water around here.
Pumpkinheaver
Member
I just shot my first AR reloads through my first AR. I sized them with regualar FL dies because I already had them. They fed great!
I don't recommend SB dies unless you really need them for a particular rifle because in my opinion the over work the brass. I have a good friend that has built numerous AR's and has never ran in to a chamber that his reloads with standard resizing hasn't fed. I believe what some of the others have already said that if the resizing die is properly set up it should work for all rifles that have their chamber within spec.
LeverGunJunkie
Member
Not sure why all the high horse responses on the SB dies. I use them almost exclusively after a bad FL resizing experience on a couple lever guns. According to some, that makes me less of a reloader? Wow. All I know is, I haven't one failure to feed since I went to SB dies. Maybe when I get some spare time I'll head out to Arkansas to attend the krochus school of reloading. Then I can learn how to adjust dies. Those RCBS guys are marketing masters...taking advantage of us ignorant reloaders and making a whole line of dies no one needs.
snuffy
Member
Yup, and you bought it hook-line-and-sinker! Congratulations on being gullible.
A properly adjusted FL die will size enough for MOST rifles. So your above statement has some truth, the part that says "no one needs". SOME rifles may need them, but only for the first sizing. Use of a SB die EVERY time you load, will over-work the brass and be hard on the press, and your arms!R.W.Dale
Member
My statement comes from the direct observation 100% of the time on any reloading forum when a person is inquiring about the need for SB dies because their loads will not chamber that the issue in question miraculously disappears once we finally convince them to properly set up their FL die. With lots of "I don't want to break my press" complaints along the way.
IF you're just running the die in against the fully raised shellholder and locking it down YOU ARE NOT! full length resizing. Now there's not to say there are a few rifles out there that are out of spec in the small side that a SB die might let you squeak by with. But that's a RIFLE problem not a reloading problem and to date they've not popped up in any threads I've taken part in.
Save your $$$ on SB dies and buy a case gauge instead, you be much better served in the long run
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I am always surprised by the out right hostility towards small base dies. I consider them mandatory for M1a’s and Garands to reduce the risk of an out of battery slamfire. Thank goodness I have never heard of an out of battery AR15 slamfire. I have experienced and seen in battery slamfires with AR15’s, so they do happen.
Since I have a number of mouse guns to feed, small base sizing just increases the interchangeablity of my ammo between rifles.
And I have been on the firing line where folks had problems with their reloads in AR's. If the case is too tight for the chamber they often get stuck cases.
I called RCBS and a small base die sizes the head of the case .002” more than their standard die. My Lyman SB die size a trifle more than the RCBS. Which is all to the good.
The myths that SB dies will overwork brass are because the people that happened to did not use cartridge headspace case gages to set up their sizing dies. With the older SB dies, if you simply “sized to the shell holder plus a quarter”, then you would have set the shoulder way too far back with a SB die. Die manufacturer’s must be tired of hearing that refrain because my new RCBS Small Base X-Die won’t bump the shoulder below minimum.
There is another limitation in using small base dies, you have to use a decent sizing lubricant. Spray on lubes won’t work, at least for 308/30-06 sized cases. It is just about impossible to small base a case with those spray on lube, they are just not slippery enough. Now Imperial Sizing wax and RCBS water soluble are great lubes and that is what I use with small base dies.
With RCBS water soluble lube, the difference in sizing resistance between a standard sizing die and a SB is barely noticeable. There is a significant difference in resistance in sizing 308/30-06 cases, but it is not objectionable for me. I am currently using a Redding T-7, and I have sized a gazillion cases with a Lyman T-Mag press.
Regards of what die you use, you should always set up your rifle dies with a cartridge headspace gage. Period.
Slamfire1
Maybe it would be helpful if you could explain how to use a case gage to set up your sixing die.
I have never used a SB die but I only have one AR to load for. I am interested in the X die because I hear it cuts down on the need to trim.
Thanks
Maybe it would be helpful if you could explain how to use a case gage to set up your sixing die.
I have never used a SB die but I only have one AR to load for. I am interested in the X die because I hear it cuts down on the need to trim.
Thanks
I have a bunch of Wilson cartridge headspace gages. They cost $15.00 or so. There are two ledges on the back. Each ledge corresponds exactly with “GO” and “No Go” chamber headspace gages. The deeper ledge is the “Go”, the upper ledge is the “No Go”.
Depending on the resolution of your screen, these ledges might be hard to see in the attached picture. The difference between "Go" and "No go" is only around .006".
You set up your sizing die by simply sizing a case then dropping it in the gage. If the shoulder to base length of the case is above the “No go”, you turn the die in a little more to size the case a little more. If the case base is below the “Go”, you are oversizing your case and need to back the die out a bit.
I recommend to size to gage minimum for gas guns. Bolt guns are less fussy with ammo so you can play around with shoulder depth to extend case life.
There are more sophisticated gages on the market and many bolt gun users set the case shoulder back an exact amount, like .003” or so.
Wilson gages are cut with a special reamer: the distance from shoulder to base is correct but the gage is cut big between the shoulder and the base. You can drop a fired case into one of these gages and determine from the expanded case if you have a headspace issue with your rifle chamber. Plus or minus a little error.
There have been a few times when I found I could not size a case below the "No Go" of the gage no matter how much I turned the sizing die down. That is when I figured out that the die was too long and I had to grind material from the bottom of the die to get the sized cases to the proper length.
You will occasionally read threads where this happens to other folks. They completely full length size a case and can't figure out why they are having stiff bolt closure. Without gages they did not know they had a sizing die problem.
You will also read threads where reloaders claim that small base dies "over work" the brass. Mostly likely they are oversizing their cases in the small base dies and don't know what they are doing because they don't have a gage.
The bottom line is having a way to measure how much you are sizing your rifle cases is a great thing. It will solve problems and keep you from having problems.
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Good explanation. I too use Wilson gages to check sized brass. I just set the die up per manufacturer instructions and they have always measured properly in the gage...so I guess I haven't had to set the die up using the gage yet.
Dillon also makes the same type gage, but I haven't tried one.
Dillon also makes the same type gage, but I haven't tried one.
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