Small base dies in AR..... Necessary? Or a FL sufficient?

varminter .223

Active member
Ultimately my main concern is function for slinging lead at coyotes but as far as load data work would FL size better? Or am I splitting thin hairs? Will FL size dies invite chambering issues?
 
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I used a full length for years with no problems, was suggested a small base and all I did was get brass stuck in it. Went back to full length, no problems. That's my story.
 
Yeah, never needed them either. I was told a long time ago that if regular FL dies are not sizing them enough then try the SB dies. There is four in our little group that have AR-15's and we just use regular dies and never had a problem.
 
When its called for, SB die saves the day.
If factory ammo cycles good, then SB is not needed.
I have one AR10 chamber that doesn't like most factory ammo, so I use FL SB die for only that chamber.
One of my shoot'n buddies has a similar tight chamber and he was forced into a SB FL die.
 
There is a great article that talks about loading and how to do the small reasonable things to get the best accuracy from your rifle in the Fur Fish and Game mag. Feb 2017 version.

In it they talk about Bench rest techniques to get the same hole accuracy.

But in that article they talk about how the firing of a cartridge fits the case, and if you are using a bolt gun, short dies are fine, but if you are using the cases in autos or levers you are best advised to full length size, and trim in all cases regularly.

It was a good read.

I did disagree with a statement that a deviation of .1gr of powder wouldn't have much of an impact, after saying that weighing the cases for weight, using all the same brands, cleaning the primer hole, and primer picket, trimming, chamfering inside and outside the rim, playing with jump and a couple of other things to get the most consistent and accurate load to work with each rifle and it's whip/harmonics. If the stated goal was to get the most consistent seat, jump, and combustion, and then harmonics/barrel whip to get the best accuracy possible.

Then wouldn't it stand to reason that you also do the very best you can (within reasonable effort) to make sure that the load of powder going in is as close to the same weight as you can manage? shooting through a chrono tells a different story in my limited experience.
Especially if you get into looking at lots and batches for powder and primers?
 
I've had to go to small base dies on a couple of my ar's after some stuck case issue's with new barrels. As soon as I used a sb die the issue went away on both guns.
 
If you crimp your bullets then you need the small base die set for sure. The reason is the type of crimp each die makes. The regular set does a "roll" crimp, and the small base set does a "taper" crimp. The Tapered crimp is a lot better for feeding in a semi auto loading rifle.
 
Originally Posted By: MotoHunterIf you crimp your bullets then you need the small base die set for sure. The reason is the type of crimp each die makes. The regular set does a "roll" crimp, and the small base set does a "taper" crimp. The Tapered crimp is a lot better for feeding in a semi auto loading rifle.

Not really. Crimp and small based size dies are two different animals. Sizers and crimpers are totally different tools.

You can taper crimp standard sized cases as you are only dealing with necks. By and large the SB die SETS that have been out for years have all come with standard crimping dies. This whole TC thing is the new kid on the block. The DCM guns, AR or M14, have used SB dies off and on for years with the regular crimp if they crimp at all.

There TC has nothing to do with reliability or feeding.. There is no reason to crimp at all if the neck tension is set properly. SB sizers are needed on occasions but the crimp is not needed at in many applications. SB dies are also used in amy bolt gun applications when you get the custom chambers or the odd tight factory offering.

Greg
 
Originally Posted By: varminter .223Ultimately my main concern is function for slinging lead at coyotes but as far as load data work would FL size better? Or am I splitting thin hairs? Will FL size dies invite chambering issues?

Have you had any issues with any of your loads for the 22N or any others?

Thousands upon thousands loaded here, and the only instance I needed small base was to get once fired brass to chamber and extract smoothly in a BHW 20 practical barrel. They were known to have pretty small chambers.

It's not a bad idea to have a small base 223 die around for such instances but there's no need to use it unless it's found to be necessary IMO.

I've never shot a competition but that might change my opinion. Same for loading a bunch of SHTF ammo that might get used in a variety of guns.

Another thing I've read is about the differences in die makers. Supposedly some have different specs than others? In particular I think I read that Hdy dies are all basically small base dies, while RCBS has 2 different ones with small base being .002" smaller diameter? If that's the case then I guess I use a lot of small base dies after all. Can anyone confirm that?
 
Originally Posted By: 204 AROriginally Posted By: varminter .223Ultimately my main concern is function for slinging lead at coyotes but as far as load data work would FL size better? Or am I splitting thin hairs? Will FL size dies invite chambering issues?

Have you had any issues with any of your loads for the 22N or any others?

Thousands upon thousands loaded here, and the only instance I needed small base was to get once fired brass to chamber and extract smoothly in a BHW 20 practical barrel. They were known to have pretty small chambers.

It's not a bad idea to have a small base 223 die around for such instances but there's no need to use it unless it's found to be necessary IMO.

I've never shot a competition but that might change my opinion. Same for loading a bunch of SHTF ammo that might get used in a variety of guns.

Another thing I've read is about the differences in die makers. Supposedly some have different specs than others? In particular I think I read that Hdy dies are all basically small base dies, while RCBS has 2 different ones with small base being .002" smaller diameter? If that's the case then I guess I use a lot of small base dies after all. Can anyone confirm that?

I’ve never had any need in any of my personal rifles for SB dies. I suppose that encompasses somewhere north of 50 autoloaders. In the world of predator for money hunting I might opt for the SB but knowing my mind set if they run 100% on paper they will do it on fur. All I would change would be maybe an extra 0.002 shoulder pub as I do run mine pretty tight in most of my chamberings to decrease brass growth and work.

When I use a lot of once fired 223 brass I will occasionally run them through a Dillon sizer and trimmer if I want to make up some new 20 Prac, Tac or 17-223 and want a base case available in bulk. I am sure the Dillon is SB. I have also just used my regular standard dies for case forming and had no issues with them being reliable either.

I shoot various flavors of matches and they are loaded the same no matter what concerning sizing as all are FL. I FL size my bolt gun stuff in most situations except my 204 Rugers that are all neck sized. I run three and want them gun specific in that case. I do adjust the dies for each rifle as I want maximum for each and track lots of brass fired in each specific rifle.

I do have a few , cough, thousand SHTF cases laying around that are set up for SAAMI minimum that will run in ever y 55 I have. They are my plinkers generally of desert blasters. If I’m taking out family friends they are getting to shoot 55 FMJ’s not my 52 grain Bergers!!

Some die makers tend to the small. RCBS certainly has SB dies that are measurable from the Standards. My Hornady dies don’t seem overly small based on the ease of sizing after the cases are fired and looking at the sizing area. I’ve heard that the Reddings are smaller but once again I’m not seeing it. It may well be as mentioned every one we are loading with and are SB. Another dirty little secret? (I know that that’s not true BTW..LOL) I have had some Lymans over the years that were so small as to almost hour class the cases. I know I quit =using the 45 LC dies because of that.

At the end of the day I guess we just have to buy it to try it. Not all of the sets out there are identical even if the label is the same. Not every RCBS/Hornady/Redding turn out dimensionally the same case as the previous or future sets. Manufacturing tolerances raise heck on repeatability. I try to dedicate extra sets of dies for XXX rifle and that lets me feel like I know that when my 700 Remington 223 gets fed today it will have ammunition just like it did five years ago.

Greg
 
Since we are on the subject, I have a set of 300win X diesnthat I bought for use in a BAR. Would you use them in a bolt gun or buy a new set. I have been using them set to just bump the shoulder.
 
I did say "if" you crimp, and taper crimp is more preferred to roll crimp in auto loading rifles isn't it? That's all I was saying. I don't crimp either and have not found a need to as of yet. I have to use small base dies to load for my 7.62 x 51 with an apparently tight chamber. When using regular dies by the time I got the head dimension squeezed down enough to fit the chamber I've pushed the shoulder back .007" or .008". Using the small base set allows me to keep it down to .002" consistently. But as mentioned dies sets vary even within the same manufacturer just as factory chambers do, you just got to keep working until you find the set up that is good for that particular rifle. I've not had much luck just necking them either.
 
Originally Posted By: sandy hicksSince we are on the subject, I have a set of 300win X diesnthat I bought for use in a BAR. Would you use them in a bolt gun or buy a new set. I have been using them set to just bump the shoulder.

They will be fine for you. No real issues on that set up.

Greg
 
Originally Posted By: MotoHunterI did say "if" you crimp, and taper crimp is more preferred to roll crimp in auto loading rifles isn't it? That's all I was saying. I don't crimp either and have not found a need to as of yet. I have to use small base dies to load for my 7.62 x 51 with an apparently tight chamber. When using regular dies by the time I got the head dimension squeezed down enough to fit the chamber I've pushed the shoulder back .007" or .008". Using the small base set allows me to keep it down to .002" consistently. But as mentioned dies sets vary even within the same manufacturer just as factory chambers do, you just got to keep working until you find the set up that is good for that particular rifle. I've not had much luck just necking them either.

I don't see any real advantage on a taper crimp on the bullets unless they are non-canneleured you might avoid some bullet deformity if you were a bit over zealous on the roll crimp in doing them. I do believe that the roll will be more secure than a taper if you are crimping down in the groove though. In feeding it makes no difference if taper or roll is used when it comes to functioning in an auto.

Historically the 7.62X51 in an auto loader can require the SB approach as they just don't have the camming force. Both of M1A's run fine using standard dies so I while have one on the shelf it is gathering dust. Who knows if I'll need it for my new AR10 I'm doing.

Greg
 
Never had to use a small base until I got my 20 practical. Chamber on it must be pretty tight because running through a SB die is mandatory for proper function on that rifle.
 
I've been loading .223 for 12 years with Lee FL dies. They are far from the best set up, but my rifles have always been able to get .5 MOA or better with them. As long as I am doing my part of course.
 
I've had tight spec'd chambers which called for SB dies - which I ordered specifically with that in mind. For all other AR's, the "need" for SB dies is mostly nothing more than online rhetoric. I have a couple AR's for which I only neck size even, and only need to do a FL every 4th loading (5th gets inconsistent, so I size 4th).

Originally Posted By: Tbone-AZI did disagree with a statement that a deviation of .1gr of powder wouldn't have much of an impact, after saying that weighing the cases for weight, using all the same brands, cleaning the primer hole, and primer picket, trimming, chamfering inside and outside the rim, playing with jump and a couple of other things to get the most consistent and accurate load to work with each rifle and it's whip/harmonics. If the stated goal was to get the most consistent seat, jump, and combustion, and then harmonics/barrel whip to get the best accuracy possible.

Then wouldn't it stand to reason that you also do the very best you can (within reasonable effort) to make sure that the load of powder going in is as close to the same weight as you can manage? shooting through a chrono tells a different story in my limited experience.
Especially if you get into looking at lots and batches for powder and primers?

A guy has to decide where he needs to draw his line, and too many guys arbitrarily draw our line based on the precision of their electronic dispenser. A guy could easily argue +/-0.1grn of powder is a HUGE deviation, or a guy can just as easily argue it's not. So a guy has to determine whether 0.1grn makes a real difference in their loads. I have a scale at work where I can measure my bodyweight down to the hundredth pound, but my driver's license doesn't say 198.73lbs, it just says 199. Drive over scales often only weigh to within 20lbs, so I'm either 180 or 200lbs, that spread makes a difference for my body weight, but doesn't matter much when I'm loading 84-103,000lb GVR. When I weigh charges on my Mettler, I can load to MUCH greater precision than +/-0.1grn - I can load to within fractional kernels. But... On the other hand, with proper load work up, deviation as big as +/-0.2-0.3grn doesn't significantly change the MV, SD, or ES of many of my loads.

The entire industry behind load development is predicated upon finding a load in which 0.1grn becomes insignificant. OCW, Ladder tests, etc all rely upon finding that "window" where relatively large changes in powder charge don't result in proportionately large changes in MV.

So I'd tend to agree with the article - if I have a load which needs tighter than 0.1grn precision, I know it's not the right load for that rifle and bullet.
 
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