How many folks use small base sizer dies rather than standard sizer dies to reload for their AR15s?

I do, I like to go with reliablilty,

This, no issues, thousands of rounds, several rifles.

I have both SB and regular and no one in our group has an AR that requires the SB. SB overworks the brass with nothing gained.  I recommend regular Redding and also buy the carbide sizing button to go with the die so that no inside the neck lube is required. Regards

Standard RCBS dies turn out a case that is good for bolt actions but marginal for reliability with autoloaders.  SB RCBS dies reduce the body diameter of the case another .001 to .002 on the diameter compared to the RCBS standard sizing dies.  

The AR (.223) RCBS die set contains a taper crimper and a SB FL die.  The taper crimp allows one to crimp the neck to the bullet, even with smooth bullets and no cannelure or crimp groove.  This is the set I would recommend for reloading .223 for autoloaders like the AR series for reliability.  

If you are trying to get 15X reloads out of your AR brass, then the standard FL might be a better choice, with some added risk of FTF.  

Check the brass body diameter of your favorite factory ammunition and get an idea of the brass body diameter used for maximum feed reliability.

Some sizer dies from other vendors are already set at SB dimensions but are not advertised as such.

37 years of pulling handle, never used a small base die.

I picked up a Redding 223 Rem small base body die a couple of years back for really cheap.  I figured what could it hurt?  Well, it didn't hurt anything, but the very first fired case I picked up after using it, I could see soot all over the case body...same with the rest of the 50ct box. Way past the necks, way past the shoulders, a good third to a half down the body.

That's just pressure that's not forcing the bullet down the bore.

They work, or this one does at least, I'll grant them that.  At Christmas, I bought their standard 223 Rem body die, so if anybody needs a nice...

Chris

I've used RCBS standard size dies (.223 Rem and .308 Win)  since the mid '70s and never had a problem. All shooting was in AR15, M1A, or .308 M1 Rifles. This was enough shooting to wear out a couple of dozen barrels.

I do because my wife bought me the dies as a gift and just told the guy .223 for his AR and that's what he handed her. I haven't gone through my brass enough to know how long or short it lasts, seems I always get new once fired coming through from somebody.

+1

I use a standard FL die.  I am curious about those who use the small base dies for added reliability, have you ever had a rifle  that would function better with small base dies vs. full length?

Thanks for all the responses.  I have always used SB dies in my M1A in matches, and my FAL with no problems what so ever.

I see them as a "use if needed" item. For those who use them for "reliability" I can understand that especially if you have a few AR's and don't have "pet" loads for each. My only experience actually using a SB dia was in .308 Win. This was actually by accident. My friend ordered a full length die set and it came with a SB die in it instead of the regular full length die. The only reason we found out was he started to get case head separations as early as on the 3rd or forth reloading. This is less than half the life as usual.
Every time you push a case up into a full length die you roll a wave of brass towards the base. When this wave rolls over the transition from case body to web (where the head starts) it thins that area. this is why brass grows in length. A small base die makes this (the base) even smaller thus accelerating the thinning above the web.
Also a possible decrease in accuracy may accompany the looser fit of SB sized ammo.

Humbarger

Measure the base diameter of military and commercial cartridge cases you plan to reload. The majority of American made cartridge cases run to the small side of minimum base diameter manufacturing tolerances. Meaning in 45 years of reloading I have never had to use any small base dies for any reason and a small base die when used can shorten case life greatly if you have a normal size chamber.

At Accurateshooter.com a poster was asking why his fired and resized Winchester cases looked different than his Lapua cases. SAAMI manufacturing tolerances for base diameter for his .308 Winchester are .4703 maximum to .4623 minimum and the reference base diameter of the chamber opening is .4738.

The base diameter of his Winchester cases were .463 and new Lapua brass measures .469.

WHY would you need small base dies when the Winchester cartridge case is already .010 smaller than the chamber opening?

Someone told my uncle he needed small base dies for his Remington 760 Game Master pump, and he kept complaining to me about case head separations with his reloaded ammunition. I told my uncle to get rid of his small base dies and get a standard set of reloading dies and "STOP" over resizing his brass.

If a cartridge case will chamber reliably after resizing with standard resizing dies you "DO NOT" need small base dies. Variables do exist between chambers, the base diameter of the cartridge case and your resizing dies, BUT very few people actually do need a small base resizing die. A standard full length resizing die is designed to return your fired cartridge cases to "minimum" case dimensions.


And military chambers run on the large side in diameter and length (headspace) and using a small base die would be like parking a VW Beetle in a blimp hangar.

I use Dillon 223 die, but I hear they are small base.  I don't know for sure.

This is a touchy subject for sure, I personally use RCBS Small base dies, but before the forum goes nuts I would like to agree with any number of the posts above that if you do not need them don't use them. I disagree with some that say that Small base dies over work the brass. I have .223 cases with 4 firings on them and I trust them to be reloaded again and again. Now, in my above disclaimer I said if you don't need them dont use them, so then why do I use them? In my situation as I have said in another post it simply boiled down to me picking up a lot of range brass that a normal full length sizer die could not get to the base on. What rifle these people were firing it in I don't know but, I tried a friends normal set of RCBS dies and I also bought a Lee full length set. Keep in mind that I have been loading for well over 20 years and I never ever in all of my thousands of rounds loaded, never needed a Small base set. I know how to adjust a die too, If you are going to be buying your own new ammo and reloading the very brass that was fired in YOUR OWN CHAMBER then there is absolutely no need for a Small base set. As for range brass fired in Bubbas worn out chamber well, that's up to you.

Shannon

+1

I can't and won't argue with your reasoning but I currently have about 40 pounds of .223 & 5.56 brass that I either picked up at the range or had given to me by somebody and all of it has been "processed" by me using a standard Lee full length die. So far I have had ZERO failures due to case sizing. I don't think that is just good luck.
BTW: 4 cycles is not much but don't be surprised if by the 5th or 6th sizing you start to see the line of death. How often do you have to trim your brass? Every time you trim remember where that length came from.

Don't disagree with you and won't argue either, I do notice that it is mostly foreign headstamps that cause my issues, mostly will almost always be military something or other. It's no secret I think that my Smiths chamber may be a little tighter. And so using that situation I use Small base dies for this gun only. As for trimming I do it every time though with my load I don't think I'm killing the brass either. Never needed small base in my life, for my gun though I do use them.

Shannon

Shannon,
This trimming you mention "every time" is not normal unless you only trim to max. If you are trimming to "trim length" (I think most publications has it at 1.750") and after sizing it is beyond the 1.760" max (I hope I'm remembering this correctly) then you are on the fast road to case failure. I can get 2 to 3 re-sizing's before needing to trim again. The brass you are trimming off of the length is coming from the case body just above the web. This is why most here are not recommending the small base die when it's not needed. As you say, if you have a rifle with a tight chamber then you really are not working the brass much more than normal but the need to trim is an indicator. You just can't keep trimming away brass. Every time you trim the case body is getting thinner.

Motor1, I trim because I want consistent case length for bullet seating and for a consistent crimp. It matters not if I trim the hell out of a case and always go to max trim length. The fact is this: the web of the case thins every time we fire and size, regardless of what I trim away at the neck. True, I could leave it there, but the case still gets longer and thinner no matter if the neck is trimmed or not.
I should note that I am sizing and trimming to max length only.
Shannon

Ps you are correct @ 1.760 max case length.

I've used standard RCBS FL dies in .223 and .308 to load for numerous semi-autos since the late 70s.  In .223 guns were various manufacture AR-15s and several Ruger Mini-14s.  .308 guns were M1A, HK91 and AR10s.  Never had a problem.  YMMV.

I guess I should have made it more clear. It's the amount of growth, in case length, per sizing that I was referring to. If your case length goes from 1.750" to 1.760" or more in one use than that is more than normal and you will see a shorter case life accordingly. 2 to 3 sizings between trimming would be about .003" to .005" for me. My Lee trimmer cuts mine to 1.745" and I don't crimp.

Gotcha mate and will throw in a good ole fashion agree with you clause I've found that proper lubing of the case and inside of the neck help a hell of a lot when it comes to Small base. My growth is really no more than .006 with these dies and in most higher quality casings runs at the realm you describe. As I recall it worked the brass just a bit more without lubing the inside of the neck though. Obviously hotter loads play there part too. Question: what Lee trimmer are you using?

Shannon

Shannon,
I use the Lee cutter with length rod and their shell holder/stop or what ever they call it. There was another thread in the past week that discussed trimmers and several guys that use the Lee posted their results and they did vary a lot. It seems that with repeated use or maybe switching from rod to rod that the cutter can dig into the rod some and thus will trim shorter. That shortcoming aside (pun intended) it has to be the most accurate as in repeatable results trimming system dollar for dollar that there is.

Thanks Motor1 I'll try it out, had wondered if they were good.
Shannon

Standard Fl dies size the case diameter and set the shoulder back .002-3" below min chamber dimension and SB FL dies size the case diameter and set the shoulder back .004-5" below min chamber dimension.

It's best to know your chamber diameter and your brass diameter and from that determine if the SB dies are needed, those using them just cause they think they are getting more reliable ammo without knowing anything about the clearance they actually have are probably not gaining anything, and more than likely doing more harm than good.

I have SB dies but don't need them for any of my rifles but I do process allot of brass and some people want their brass processed with SB dies so I use them when needed, everyone else I process brass for gets standard FL dies and I haven't had a complaint yet of brass not fitting a rifle and I've processed brass for a BUNCH of them.

if you have your fl die set up right you will never need sb dies.

On my dies and press,  I control the amount of shoulder set back or "case headspace" of the bottleneck cases by adjusting the vertical position of the die body in the press frame.  But, maybe I am doing it wrong.

Is this a question? If so I would say no. You are just taking it a step farther. It's like adjusting you bullet seat depth to shorten bullet jump. It's an option. Personally, I set my FL die(s) to full depth according to instruction which is a light cam over for standard steel dies and what ever the stand-off is per instruction for carbide. The only time I back off my FL die is when I am using it to "short size" or neck only size with the FL die. You can't really call it neck only sizing though because often the case body does come into contact with the die although it's usually very little.

If you have gages and want to adjust your FL die to a specific headspace dimension. Go for it.

One of my AR's with a DPMS barrel would not feed reliably unless the cases were sized using a SB die. FL sized cases (trimmed) dropped right into the case gage. Shoulder was right, but would not chamber without slight pressure for the last 1/8". I borrowed a friend's SB die and everything worked out fine. So I got my own die.

Well I am the "family" reloader  [sons,daughters n grandkids]...I have loaded for near on to half a century ...starting with a lyman "Ideal" hand loader and then added "lee" hand loaders ....now use Dillon 550B in about 15 calibers ....in 223 and 308 alone I load for 15-16 different rifles ...running from AR15's to AR10's to FAL's M1As etc ....with shooter ages from 16 to 65 ....all shooters I have trained to safety proceedures in firearms handling and maintainence ....USING THE 223 IN MY EXPLAINATION BUT APPLY IT TO ALL OF THE HIGH PRESSURE BOTTLENECK CTGS I LOAD to be used in AUTOLOADERS]

every brass before re-loading is inspected  INSIDE and out for damage and stress...[an ice pick with the tips turned 90 degrees will feel a case seperation
                                                                                                                                          often before it is visable on the outside]

every brass is brought to case shortest case OAL of 1.750 [this puts the crimp EXACTLY in the cannalure EVERYTIME][you better be crimping on an autoloader]
                                                                                  [it also eliminates the round from possibly sitting high in the chamber which could addt o a slamfire situation]
                                                                                  [it also insures magazine clearances from brand to brand...metal to plastic]

every brass is sized through a small base sizing die [not only insures fitment in all rifles but again keeps a high round from contibuting to a slamfire]

every primer pocket is cleaned EVERYTIME [a high primer is a bomb waiting to happen in most of the autoloaders we are speaking of loading for ....most
                    have floating firing pins so the firing pin hits the primer when the bolt slams home ..YOU CANNOT RISK A HIGH PRIMER DUE TO A DIRTY POCKET]

every round that is subject to an autoloader use is loaded with a "miitary" like property primer READ=> [  http://www.sksboards.com/smf/index.php?topic=56422.0 ]

Additionally I pick the load with the most RPM and the LOWEST operating pressure so I am not subjecting the brass to the limits of it' endurance

Pards slamfires are a real danger  ....every time you properly slam the bolt home the inertia will cause the firing pin to hit the primer [most miitary actions DO NOT HAVE a retention spring on the firing pin]....yes ...you always point the rifle "down range" ...but that is the small end of this discussion ....some of the weapons we load for WILL FIRE out of battery ...NOT LOCKED UP!!!! ...when that happens guns are bombs ...bombs maime and injure

So for me no short cuts,keep the brass short and use a small base sizing die ....for all this added safety I give up a loading or two on the brass and a bit of accuracy ............sometimes.

Bear

And finally, as food for thought, look at these measurements on standard die formed .308; SB die formed .308; and FGMM right out of the factory box and as-fired in my SAI SOCOM 16.
http://www.ar15.com/forums/t_6_42/373980_Something_to_be_said_for__308_factory_vs__std__FL_vs__SB_FL_cases___.html&light=FGMM
FGMM out of the box has smaller base (body diameter) than any of the RCBS FL sized brass, standard or small base.

I am a little like Bear, in that I am loading for four .308's. (or 7.62 x51), two for me and two for a friend.  SB keeps them all running with the same prep on the case.

I've been in defense of short base for awhile now. I get my ass kicked regular for it. It's a terrible argument every time. Those like bear and CCW which can see a benefit and those that have been using full length forever. I once was a full length only type of guy, but my situation changed that. Use what works, enjoy your reloading.

Shannon

I set my full length sizer to headspace in my case gage.  It's typically much less sizing than what the die's instructions call for.

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This has become a "to each his own" conclusion. Just thinking of my own statements here it occurred to me (I'm one of the only do it if you need to crowd) that I kind of do the same thing with my bolt action hunting rifles. I have and use neck only size dies for most of them but the ammo that I load for big game hunting is always full length sized. Why? To ensure a quick smooth fallow up shot if needed. Same reasoning just different hardware.
I guess that is why I never had an interest is case gages. It was always neck only or full length. Now with the AR it's full length and that works just fine. I see no reason to back off or go small base.