RCBS "AR" Dies?

[Averageman]

Is anyone using these and are they worth the additional money?
These were the ones I had in mind SMALL BASE TAPER CRIMP DIE SET - AR SERIES http://www.rcbs.com/Products/Dies-by-Category/AR/Small-Base-Taper-Crimp-Die-Set-AR-Series.aspx
Would this mean if you wanted a crimp, this would be sufficient rather than going with a regular RCBS 5.56 full think set up with a Lee crimper die?
I'm new again to reloading and a bit in the dark here.
Thanks.
A/M

[bigedp51]

I have this die set, BUT I buy a lot of once fired Lake City brass and I size these cases once with the small base die. For .223/5.56 cases fired in my AR15 rifles I use a standard Forster full length die with the high mounted floating expander.


RCBS AR Series Small Base 2-Die Set with Taper Crimp 223 Remington sale $37.29
http://www.midwayusa.com/product/621875/rcbs-ar-series-small-base-2-die-set-with-taper-crimp-223-remington


Forster Bench Rest 2-Die Set 223 Remington
http://www.midwayusa.com/product/184923/forster-bench-rest-2-die-set-223-remington

Below my .223/5.56 AR Series small base full length die equipped with a Forster expander and spindle assembly to reduce neck runout.

http://i122.photobucket.com/albums/o254/bigedp51/IMG_2140_zpsea657d9e.jpg

[Averageman]

At the moment I have several thousand commercial brass that I would like to learn on. I would take it then that going with the RCBS AR die would be fine until I begin running Military brass?
Thanks bigedp51.

[bigedp51]

My AR series small base die sizes further down the case and will make the case .0005 to 001 smaller in diameter. This may cut down on case life because it reduces the case to minimum SAAMI dimensions. I'm reloading for three different AR15 rifles using once fired Lake City brass that was fired in many different rifles and possibly in machine guns with a even larger diameter chamber.

So if your brass was fired in your rifle a small base die can or might be over kill, meaning the small base die will make the case smaller in diameter than needed. As a example I can take a Lake City case sized in my AR series small base die and wipe all the lube off and run it into my Forster .223 die with no effort without it sticking in the die. In a semi-auto rifle the thumb rule is to bump the shoulder back .003 to .006 and the resized case diameter should be .003 to .005 smaller than chamber diameter for reliable chambering and extraction. (ball park thumb rule)

My advice would be to buy the standard Forster die with the high mounted floating expander. This type expander system greatly reduces neck runout, the expander enters the case neck while it is still held and centered in the neck of the die. Meaning the expander will not pull your necks off center.

http://i122.photobucket.com/albums/o254/bigedp51/Sizer_Die_011_zpst2zm6m7y.gif

Bottom line, buy a standard .223 die and if you have problems then buy a small base die.

As a side note I bought Forster expander and spindle assemblies for all my RCBS dies because of the reduced runout.

Also the hardness of your brass plays a good deal on how long your reloaded brass will last and react when reloaded. At the link below you will see Lake City followed by Lapua has the hardest brass and Federal and Remington has the softest brass. Add this to variations in dies and I think having both type dies is a good idea. I also have a standard Lee full length .223 die that sizes the case smaller in diameter than my small base die does.

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests
http://bulletin.accurateshooter.com/2014/05/how-hard-is-your-brass-5-56-and-223-rem-base-hardness-tests/

I have a Wilson case gauge and a JP Enterprize .223 case gauges, the Wilson gauge only checks shoulder location. "BUT" the JP gauge also checks case diameter and I use it as a final "plop" test for my reloaded rounds. And with a standard full length die all my cases will drop/plop into the JP gauge. The only reason I use a small base die for the first sizing is for brass spring back. If the once fired case was fired in a machine gun it can "spring back" more and need to be sized smaller in diameter with a small base die.

JP Enterprises Case gauge cut with chamber finish reamer .223
https://www.amazon.com/JP-Enterprises-chamber-finish-reamer/dp/B0063HTD7U

[Eurodriver]

I have a Krieger and have found I get issues without using the RCBS small base sizing die. I have only 2 loads, max, on any of my brass (I use LC exclusively) but I am getting sub MOA at 600 yards so I do not feel that sizing the brass too far harms accuracy if the other tenets of precision reloading are followed.

[bigedp51]

I have a Krieger and have found I get issues without using the RCBS small base sizing die. I have only 2 loads, max, on any of my brass (I use LC exclusively) but I am getting sub MOA at 600 yards so I do not feel that sizing the brass too far harms accuracy if the other tenets of precision reloading are followed.

We live in a plus and minus manufacturing world and dies vary in diameter along with the type chamber you have.

Look at line "C" below and the variations in chamber diameters.

http://i122.photobucket.com/albums/o254/bigedp51/223-556_zpsf4f56449.jpg

I'm retired and worked part time in a Gander Mountain Sporting goods store and received a good discount on what I bought there.
Long story short, I bought 7 different type and manufacture .223 die sets. My "standard" Lee full length die sizes the case diameter smaller than my small base die does and none of these 7 dies will size the case the same diameter and shoulder location the same when the die touches the shell holder.

On top of this the three AR15s I'm loading for have a chrome, melinite or bare steel chambers and vary in size.

Look at the link and information below and see how much a full length die can vary. My Forster die has the largest body and neck diameter and my Lee die has the smallest body and neck diameter.

http://i122.photobucket.com/albums/o254/bigedp51/overworked_table2_zpsvgj7lnlt.jpg

Are Your Sizing Dies Overworking Your Rifle Brass?
http://www.massreloading.com/dies_overworking_brass.html

[Averageman]

Thanks Ed,
I went with the standard RCBS dies I found on the shelf locally.
I should be trying it out this coming weekend. I will look in to some LC Brass ASAP.

[markm]

I've always just run the Dillon carbide die. It's a small base die, and the Carbide's hardness makes sizing a little smoother.

[bigedp51]

I've always just run the Dillon carbide die. It's a small base die, and the Carbide's hardness makes sizing a little smoother.

markm

How many times can you reload a case using a small base die and have you ever had a case head separation when using a small base die.

My RCBS AR series small base die only makes the case .0005 smaller in diameter than my standard RCBS .223 die.

I'm not criticizing anyone for using small base dies, I'm on my second sizing after using the small base die once and I'm using the standard .223 die now. I'm just curious as to your case life and what brand of brass you use.

[bigedp51]

Thanks Ed,
I went with the standard RCBS dies I found on the shelf locally.
I should be trying it out this coming weekend. I will look in to some LC Brass ASAP.

Once Fired .223/5.56 Military Brass (I'm lazy and buy the Cleaned, Deprimed & Swaged brass)
http://www.brassbombers.com/Lake-City-Only_c42.htm