[flipajig]

I have read and talked to other reloaders about useing a under sized sizeing die for reliable feeding. The brass that I'm intending on useing is range pickup and it's mixed headstamp.
Thank you

[cfullgraf]

In my opinion, if the brass was not fired in your AR, you should resize it with a small base resizing die.

If it was fired only in your rifle, a standard resizer would work fine.

[flipajig]

I should have also stated that I intend to full leanth size them And who knows who shot them most of them that I have looked at appear to be once fired.

[cfullgraf]

For an AR, full length sizing is the only option. It can be a standard or small base resizing die.

Neck sizing is not appropriate for a semi-auto rifle.

[45lcshooter]

Everything that isn't shot from my guns gets full legenth sized. Depending on condition of stuff that is shot from my guns, its just neck sized.

Its a good pratice because you never know the history of range brass.

[helotaxi]

Unless there is regularly someone with an M249 at the range where you're picking up brass, the small base die probably won't be required. A standard die, correctly set up and used with good lube will be sufficient, at least IME, 100% of the time which covers thousands of pieces of range pick-up .223/5.56 brass loaded for use in 6 different AR's.

[KansasPaul]

I would agree that a standard FL sizing die should be sufficient for sizing .223/5.56 for use in an AR. I did run into an issue with some brass earlier this year where even after FL sizing it didn't chamber in either of my AR rifles. In this case the brass that I used may have been old and had hardened - I do not know the history of it and I ended up pitching it because after attempting sizing multiple times I still had the same problem. Since that experience I have purchased a set of RCBS small base dies to size all unknown origin brass for my first loading. My thought process is that the initial investment in an extra set of dies is better than having issues with a locked up bolt when I go out to shoot my rifle.

[918v]

A small base die sizes the base .001" more than a standard die. This additional .001" is an insurance policy against NATO chamber fired brass that has expanded so much it can't be correctly resized with a standard die. Such brass springs back more, and when sized by a small base die it ends up the same size as a standard chamber fired brass sized by a standard die.

I would get the small base die. .001" is nothing in the greater scheme of things, but the pain in the arsch of a stuck case is a big, big deal.

[WVRJ]

I use range pickups in my AR and full length resize with a standard die with no problems at all.

[918v]

That's just you. Others stuck cases in their rifles. That's why small base dies exist.

[Hondo 60]

I have a set of Lee dies - full length resizer & seater.

I've never had any issue with ammo chambering in my AR.
(new & range pick-up)

[helotaxi]

That's just you. Others stuck cases in their rifles. That's why small base dies exist.
And others have no business at a reloading bench (don't read anything into that). Used properly on brass that hasn't gone through a machine gun (unless there's simply a ton of it an you have no other sources, that stuff might not be worth the hassle even with a small base die) a regular die will get the bras back into spec. If it doesn't the only two possibilites are an out of spec die (unlikely but "possible") or user error.

[cfullgraf]

With all the different AR 223 Remington chambers out there and the tolerance variables, cases fired in one rifle and resized in a standard resize die may not chamber in another AR.

I have two ARs that fit the above situation. No machine gun involved. No Range pick up brass involved.

It is difficult to believe until one experiences it first hand because the combinations of what works and what does not work is not cut and dried.

I have 4 223 Remington ARs and to avoid chambering issues and segrating ammunition for each rifle, I small base size all my 223 Remington cases.

[918v]

And others have no business at a reloading bench (don't read anything into that). Used properly on brass that hasn't gone through a machine gun (unless there's simply a ton of it an you have no other sources, that stuff might not be worth the hassle even with a small base die) a regular die will get the bras back into spec. If it doesn't the only two possibilites are an out of spec die (unlikely but "possible") or user error.

When you're buying brass on the Internet, you get all kinds of cases. Why are you making such a big deal over such a small amount of additional sizing. Why do you hate on the SB die.

You're a basist!

[W.E.G.]

Don't even worry about that "small base" thing.
I challenge you to find anywhere on the internet that a credible statement is made where use of a "small base" die made any difference.

What case gage are you using to make sure you set the case shoulder to the correct dimension?

http://www.youtube.com/watch?v=H_T7gteAlkc&feature=share&list=UUWeRA6uCWj8l_rk2cAgI0qw

http://i227.photobucket.com/albums/dd7/rkba2da/ammunition/precisionmic.jpg

[918v]

What are you saying? That .001" of additional base sizing won't make a difference between a stuck case and another that chambers OK?

[W.E.G.]

What are you saying? That .001" of additional base sizing won't make a difference between a stuck case and another that chambers OK?

Prove it.

[Kyle M.]

When you think about just how incredibly tiny .001" is it's hard to believe it makes any difference. I work in a machine shop where I have to hold tolerances of +/- .0005" on bronze bushings anywhere from 3" to 15" diameter on a daily basis, thats a half a thousandth and this is being done on machinery from the mid 50's. If a half thousandth tolerance is important in the equipment these bushings go in I can imagine .001" could make a difference in whether the round will chamber or not. Will it make a difference? I guess that all depends on the brass and you rifle, if the FL sizer doesn't work you can always add the SB die. IMO the guy who invented the small base die most likely knew what he was doing and had a need for it, I find it incredibly hard to believe that SB dies are just some worthless tool that manufacturers want you to buy simply to line there pockets.

[cfullgraf]

Don't even worry about that "small base" thing.
I challenge you to find anywhere on the internet that a credible statement is made where use of a "small base" die made any difference.

What case gage are you using to make sure you set the case shoulder to the correct dimension?



It is not the length of the case, it is the diameter of the body. Commercial case gauges do not measure the diameter of the body, they cut generously in that area. They only measure the shoulder position and overall case length.

As I already said, I have a combination of two ARs and a full length sizing die. Cases fired in one rifle and resized will not chamber in the other rifle. If I use a small base die, no issues.

If the cases sized in the standard full length sizer die are inserted in the rifle it was fired in, no issues.

Remember, ARs do not have the chambering forces available that bolt rifles have.

[rcmodel]

I have been loading GI M-16 brass for numerous AR's and Mini-14',s and even a few bolt-actions since 1970 something.

I use a standard RCBS die set.

IMO: A small base die is not necessary unless you have a match chambered .223 Rem. (not 5.56 NATO) rifle & GI MG brass.

My theory is, why work the brass any more then necessary, if it's not necessary?

rc

[W.E.G.]

I have a combination of two ARs and a full length sizing die. Cases fired in one rifle and resized will not chamber in the other rifle.

What case gage are you using to measure the distance from the base of the cartridge to the shoulder?

[cfullgraf]

Dillon 223 Remington case gauge and a Sinclair bump gauge.

[GLOOB]

As I already said, I have a combination of two ARs and a full length sizing die. Cases fired in one rifle and resized will not chamber in the other rifle. If I use a small base die, no issues.
Your chambers are cut differently, is all. If one of your rifles will regularly not chamber FLR pickups, it is likely a tight chamber. If your range pickups generally fit both rifles until after fired in the other rifle, then that rifle likely has a large chamber. People that own certain 1911 barrels might go through the same issues. But you wouldn't recommend people use an undersize die if they shoot any 1911. Only if they use that tight match barrel.

So the question is... what's so special about an AR? If they have typically have bigger chambers at the base to ease feeding.... then they'll still chamber that same round after it's fired and expanded.

It seems like you'd want a small base die if you loaded for a 223 boltie. To fix all the AR brass you find. Not necessarily the other way around. Basically what RC said:
IMO: A small base die is not necessary unless you have a match chambered .223 Rem. (not 5.56 NATO) rifle & GI MG brass.

Also, WEG brings up a good point. Headspace should always be carefully ruled out. A small variation in shoulder length is more likely to cause a consistent issue than a small variation in base size.

[helotaxi]

And one of my rifles is a very tight chambered .223 chamber. Still never had a round fail to chamber.

[Otto]

Don't even worry about that "small base" thing.
I challenge you to find anywhere on the internet that a credible statement is made where use of a "small base" die made any difference.
From the RCBS website: http://www.rcbs.com/guide/#faq

Q. I see a Small Base Die Set listed for my caliber. Do I need these or should I buy a Full Length Die Set or Neck Die Set? How does each set differ?

A. The Small Base Die set is intended for use for ammunition to be used in auto, semi-auto, and lever action rifles so that the loaded round chambers and extracts easily. The Small Base Sizer Die sizes the case from the shoulder to the head of the case a couple of thousandths smaller than a Full Length Sizer Die. In certain calibers it also sets the shoulder of the case back a thousandth or two more than the Full Length Sizer Die. The Full Length Die Set or Neck Die Set is not normally recommended for ammo to be used in auto, semi-auto, or lever action rifles.

[medalguy]

I've also been loading 5.56 since the late 70's and all I have ever used is a standard FL die. Never had a chambering/extraction problem in any of the probably 15 rifles I've owned in that time.

Now this is not to say you don;t have a tight chamber and may need a SB die. Remember there's a tolerance in everything-- chamber dimensions, die dimensions, and so forth. If you happen to have a chamber on the minimum side of the tolerance, and you have a die that's on the maximum side of the tolerance, you might experience a problem.

I'd recommend using a standard die and load a few hundred rounds and see if they function OK. If so, great, stay with the standard die and don't overwork your brass. However, if you have chambering or extaction problems, try a SB die and see if that fixes the problem. Just be aware you may see a shorter case life if that's what you end up with.

[helotaxi]

From the RCBS website: http://www.rcbs.com/guide/#faq

Q. I see a Small Base Die Set listed for my caliber. Do I need these or should I buy a Full Length Die Set or Neck Die Set? How does each set differ?

A. The Small Base Die set is intended for use for ammunition to be used in auto, semi-auto, and lever action rifles so that the loaded round chambers and extracts easily. The Small Base Sizer Die sizes the case from the shoulder to the head of the case a couple of thousandths smaller than a Full Length Sizer Die. In certain calibers it also sets the shoulder of the case back a thousandth or two more than the Full Length Sizer Die. The Full Length Die Set or Neck Die Set is not normally recommended for ammo to be used in auto, semi-auto, or lever action rifles.
Why would they say otherwise? They're trying to sell dies. How better to sell someone another of something that essentially lasts forever than tell they need the one they have doesn't work?

No one but RCBS makes any mention of small base dies for autos or leverguns. If they were that essential, everyone would make them and recommend them. Tells me one of two things, either they aren't essential, or the standard RCBS dies are out of spec. Redding makes small base dies but only recommend them for custom chambers that are tighter than SAAMI spec.

[cfullgraf]

One of the issues is the number of 223 Remington/5.56 NATO chambers out there. The attached link shows dimensions for eight different chamber reamers.

http://ar15barrels.com/data/223-556.pdf

223 Remington, Wylde, Compass Lake, 223 Remington Match, and 5.56 NATO. I am sure thee are other variations out there.

With variations in reamer dimensions and machining tolerances of the dies and cutting chambers the possibility of a mis-match is a real possibility, a low possibility, but still a possibility.

As far as case life with small base resize dies, I see no difference in case life from before when I was using standard resize dies versus now when I am using small base dies.

If standard resize dies are working with your AR, there is no need to change, but I recommend to someone getting started with AR reloading to avoid the potential chambering problems in the first place and start with a small base resizing die.

[918v]

Exactly.

[303 hunter]

I use Lake City brass exclusively in my 5.56 AR's. Always use standard dies,no problems. My 6.8 is more picky. I have to watch my shoulder setback carefully,or they get sticky. I've thought about small base dies for 6.8.