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AR dies vs standard 223 dies

Cshultzy999

Supporter
Supporter
Minuteman
Feb 7, 2019
74
15
South West SoDak
I’m going to start reloading 223 primarily to shoot out of ar15’s and I was wondering if the specialty AR dies are going to be better for my application than just standard Hornady or rcbs dies. I shoot gas guns pretty precisely and I wasn’t sure if I would be sacrificing accuracy with the AR dies and I wasn’t sure if standard die-made rounds would feed correctly. Kind of a noob question I understand
 
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Shoot and loaded more than a few for my AR’s. AR15 dies weren’t around when I started. My standard 223 dies work just fine. Wouldn’t bother with “AR15” dies.
 
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Never heard of "AR15" dies before, I just used standard .223 dies and they work fine.
 
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With rare exception, they make it hard to even know what the dimensions of dies are compared to chamber or ammo specs.

If a die is called an "AR" die, and they tell you the dimensions, then you could at least make an informed decision.

Something along the lines of the old diagram that Forester used to show like this one at least tells you what to expect.

1671148855361.png
 
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I’m going to start reloading 223 primarily to shoot out of ar15’s and I was wondering if the specialty AR dies are going to be better for my application than just standard Hornady or rcbs dies. I shoot gas guns pretty precisely and I wasn’t sure if I would be sacrificing accuracy with the AR dies and I wasn’t sure if standard die-made rounds would feed correctly. Kind of a noob question I understand
..TBH, the only way to definitively answer that is to take measurements from a fired case from YOUR chamber and compare it to a sized case from whatever die you purchase. The critical areas to measure on the fired case is the shoulder bump and the case web. You want the die being used to be able to bump the shoulder to the fired cases measurement PLUS an additional .002-.004 more depending on die adjustment. The die should also be able to do same with the case web, meet the fired case measurement PLUS additional to ensure it chambers properly in your AR platform.

In rare cases, getting both the amount of shoulder bump desired AND the case web sized down at the same die adjustment setting didn't occur FOR A SPECIFIC BARREL, i.e, the user had to screw die down more to size the case web down, but ended up with more shoulder bump than they desired. YMMV, so the only way to determine it is via testing and measuring. Off-the shelf die sets (both .223 and "AR" ) are relatively inexpensive compared to some of the niche specialty brands/models, so I'd go with the off-the shelf first before jumping to the more expensive ones, either type will still be 50-50 until you test them. in reality, you could go thru a couple of off the shelf types and it could be less costly than a single niche product (that could not work for YOU and YOUR chamber).
 
From RCBS...."RCBS AR Series Die Sets feature a Small Base Sizer Die designed for semi-automatic firearms. The Small Base Sizer guarantees the cartridge will rechamber in AR-platform firearms. The AR Series Die Set also feature a rifle Taper Crimp Seat Die."
 
Agree, small base die is what this is and may include crimping die or a combo die. No need IMO for crimping. I do use a small base die but seems like others don’t and no need probably. They’re the same price usually so I figured it couldn’t hurt. Definitely not adding the step of crimping .223 or .308 if it’s an extra die. Never had a problem.
 
The RCBS SB dies work great for range brass , some ARs have generous chambers and some don't . They bring oversized bases back to spec .
 
If you don't own a 223 die set, there's nothing wrong with buying your first 223 dies in a S/B- AR die set as long as the set isn't much more $ than a standard set.

If you already have a set of 223 dies, I wouldn't go out and buy the S/B set unless you really NEED them.
 
You don't need small base dies in 99.9% of ARs, and they are NOT a "might as well use them" sort of thing. They can be a detriment to accuracy and are best avoided unless you actually need them. And if you're using some rack grade barrel and not a custom match barrel specifically intended to have a tight chamber, you don't need to use small base dies.
 
You don't need small base dies in 99.9% of ARs, and they are NOT a "might as well use them" sort of thing. They can be a detriment to accuracy and are best avoided unless you actually need them. And if you're using some rack grade barrel and not a custom match barrel specifically intended to have a tight chamber, you don't need to use small base dies.
"You don't need small base dies in 99.9% of ARs...."

When do the .1 percent need it ?

detriment to accuracy ?...

Can you explain your theory on this statement ?
 
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"You don't need small base dies in 99.9% of ARs...."

When do the .1 percent need it ?

detriment to accuracy ?...

Can you explain your theory on this statement ?

Nice change from what you first posted. At least you decided to attempt to be civil.

Obviously the 99.99% statistic is carefully measured across thousands of rifles. Or it's an internet statistic made up on the spot to get a certain point across. You pick.

If you don't understand how a cartridge fitting a chamber loosely is a detriment to accuracy, there are plenty of online resources to help you figure it out.