AR 15 loading dies again???

[Maximumbob54]

So I saw the other thread and I’m wanting to be more specific in this one. I have read about small base dies, neck vs. full length sizing for the AR, and read pluses and minuses for all of the above. I have read that you must use small base dies and then I have read that most chambers will feed them unless they are seriously tight like in a match rifle. Then I read neck sizing saves brass once it is fire formed in your chamber. Then I read for any AR you must full length resize. Then I even read you don’t need to case trim for an AR unless you again have a match grade barrel as there is almost too much room for headspace issues. Then I try to figure how that factors into the NATO vs. .223 Rem chambers. So what dies are best for what set ups? Or do most AR reloaders have three or four sets of dies that they have gone through trying to see what works best and what works best for them may not be best for you because despite the fact that they say MILSPEC, they are all just different enough??? I’m finding so far in my first year of reloading that way too much of this is boiling down to a mix of witchcraft, luck, and mystery.

 

[m1gunner]

Standard full length dies (I use Lee) : adjusted so the die makes contact with the shell holder while sizing a case. This combo works for every commercial AR I have run into.

Neck sizing, no. Small base dies, not needed.

If you have some custom super spacegun barrel made with an obscure chamber dimension, all bets are off.

The only problem folks have when they start sizing for the AR is the lack of getting the die properly adjusted. If it doesn't touch the shell holder, it won't allow the bolt to lockup when chambering the round.

 

[jepp2]

The difference in the Nato 5.56 chamber and the .223 is in the throat (leade), which is beyond where the brass contacts, so it has no impact on which sizing die you choose.

I load for many different AR's, and have not yet needed to use my SB die set.

For the AR and most all semi autos, you will need to full length size for reliable chambering. You can neck size for bolt actions and get all the benefits.

If you full length size or even neck size, you need to check case length and unless you are using the RCBS X die, the cases will grow in length with subsequent sizings, and you will need to trim from time to time.

I currently size all my 223 brass with a Redding die, but an RCBS, Lyman, Lee or any other would be just as good. You don't need an assortment.

 

[Ron H.]

So I saw the other thread and I’m wanting to be more specific in this one. I have read about small base dies, neck vs. full length sizing for the AR, and read pluses and minuses for all of the above. I have read that you must use small base dies and then I have read that most chambers will feed them unless they are seriously tight like in a match rifle. Then I read neck sizing saves brass once it is fire formed in your chamber. Then I read for any AR you must full length resize. Then I even read you don’t need to case trim for an AR unless you again have a match grade barrel as there is almost too much room for headspace issues. Then I try to figure how that factors into the NATO vs. .223 Rem chambers. So what dies are best for what set ups? Or do most AR reloaders have three or four sets of dies that they have gone through trying to see what works best and what works best for them may not be best for you because despite the fact that they say MILSPEC, they are all just different enough??? I’m finding so far in my first year of reloading that way too much of this is boiling down to a mix of witchcraft, luck, and mystery.

Sir, the Sierra Edition V manual has a very good section on loading for gas guns, including ARs. It answers your questions, and their recommendations work. I'd suggest you get that rather than try to sort out a bazillion different Internet opinions.

Hope this helps, and Semper Fi.

Ron H.

 

[jepp2]

Link for Sierra information

Sierra Semi Auto Section