Home Forums Reloading Big Game Rifles RAR or Predator .223 mag length question

For those that have a Ruger American in .223, what's the max OAL your flush fit magazine allows?

If you have a .223 Predator with the AR style mag, the P-mags for my AR allow about 2.325" or 2.330" OAL, does that jive with what you see?

Might want to check your measurements on that Jim. Pmags are pretty consistent about allowing 2.260" OAL and no more. I don't think there's a factory AR magazine in existence that allows a 2.330" OAL; longest is the stainless ASC mags at a claimed 2.315" which is often more like 2.300".

Thanks for the info. I was just measuring it with the inside to inside jaws of a dial caliper stuck in it so figured there would be some error, plus you're not going to get reliable feeding with a bullet rubbing both inside walls.

Gathering data for a new toy and weighing different factors - likely OAL with various longer bullets vs. mag constraints etc. I can always single load a bolt action but was looking for something that would allow long bullets and stay inside magazine constraints while still getting close to the lands. So far the likely candidates keep leading me to a .22-250 or .243/6mm of some kind, both of which generally come with 2.8" or slightly longer magazines but keep their OAL's touching lands below that even with the longest high BC bullets.

Still keeping a RAR or Tikka .223 in the running though, so if anybody can measure the inside of the standard rotary mag or point me to a post where this was revealed I'd appreciate it.

2.300" according to cotis in this thread (scroll down a ways). https://www.24hourcampfire.com/ubbt...49238/all/Latest_on_Ruger_American_223_m

Thanks, that helps a lot in the decision process. That thread also alludes to the problems of trying to fit long 75 grain bullets into the factory mag. Kind of counter intuitive to manufacture a .223 with a 1:8 twist for very long bullets, then give you a magazine which won't let you seat them out.

Something to know about AR mags, and most double stack mags in general - you can load one or two fairly long rounds and get away with it, but when you have more than 4 or 5 in the magazine, problems with OAL as well as odd bullet shapes start showing up real quick.

With the RAR rotary mags, you can get away with one round that's loaded long, but with two they better be mag length. Also, the RAR actions don't lend themselves well to single loading; they really do best when fed from the mag.

On 75gr 223 bullets - if you're restricted to AR mag length or even 2.300", the Hornady 75gr BTHP and new 73gr ELD work great, but the 75gr ELD (and old 75 Amax) are longer and do not work very well. You'll have the ogive into the case neck with the 75 ELD.


Someone here a couple years ago was making different back plates for the RAR 223 rotary mags that allowed longer OAL. I don't know what came of those or if you could get one, but it's probably a better option than trying to long load in AR mags. IIRC the Predator model is still available with flush fit rotary mags as well.

I filled the back of the magazine with epoxy, took the mag halves apart, and then used a router to rout out the internal rotary mag (back half) another .3" or so. I have no problem loading to 2.5" in the RAR with my altered mags.