AR dies

I bought a set of RCBS FL 308 dies for my AR 10. Today I was looking at the Cabelas catalog and they AR dies. Do I need them instead ? What's the difference ?

Remember this is my first AR and wanna do it right from the jump.

I have never seen AR dies but its the old FL SB thing if your ar feeds and functions fine with the FL dies you are good to go. IF it hangs a lot or has trouble cambering a round you would need small base same for any semi auto rifle.

In AR style platforms it is recommended that you use small base dies however people do use the regular FL dies. I personally use SB dies for my AR's. The SB die will bump the shoulder back and the size the body diameter smaller. For expample a normal FL die will bump the shoulders back .002" below SAAMI minimum where the SB die will bump the shoulder to .003" below SAAMI minimum. Now one of my AR's fired brass measures .005 above SAAMI min and the other AR's fired brass measures .002 above SAAMI min. When sizing my brass I do not fully resize my brass. I bump the shoulders back a total of .002 from the fire formed size. So headspace wise I would be fine using the standard FL die, but the kicker with the SB dies is that the body will be sized to a smaller diameter. If you have more questions let me know or you can even call me and I can explain more over the phone or Skype.

Here is my video that explains small base dies:

https://www.youtube.com/watch?v=V-Ej2lq_7BI

Here is my video that kind of goes with the small base die but shows the RCBS Precision Mic tool that I use to measure headspace:

https://www.youtube.com/watch?v=02p5BNhEh1w&feature=mfu_in_order&list=UL

Thanks Reman, that is good info.

I dont use SB dies and have never had a problem. I would stick with the regular dies and just bump the shoulder back .003" to be on the safe side. That way if you ever get a bolt action 308 your still fine.

I have never used SB dies and have never had any problems with my FL dies....it's nice to know they exist in case I do someday.

WoW Rich I seen your post AR dies scared the crap out of me thought you lost your AR then read your post

The only dies I have for my AR are the ones that Lee sells. I have had no problem with them.

I do see that RCBS sells a new to the market AR Dies that are suppose to be for the AR. Not exactly sure what makes them AR specific except the demintions which, besides the base being small, shouldn't they all be the same specs? I guess it changes according to the type chamber your AR has....

Hughie wrote:WoW Rich I seen your post AR dies scared the crap out of me thought you lost your AR then read your post

Lol, not lost