I'm looking into a 30 Remington AR purchase. I realize that this cartridge has been discontinued by Remington and that this will be a reloading only job. Is there a production cartridge case that can be converted to this caliber or even a cartridge that uses the same size bolt head?

Thanks for any help here.

Yes, you lathe turn the rims off of 30-30s and cut the extractor groove. I might look at another cartridge unless someone knows of a brass source because ARs use a lot of brass. If it was a bolt action it would be different. Just time consuming is all. Is it a 30 Rem AR?

450 Bushmaster brass
You can make . 30 RAR cases from . 450 Bushmaster brass, but it has to be shortened before forming the neck and shoulder in several steps, and almost surely annealing and neck turning/reaming would be required.

Be aware, if I remember correctly, that the AR for this cartridge was a hybrid. The standard AR15 barrel doesn't have enough meat in the chamber area for a .500 diameter case. It could easily be put on the AR10, but that would be silly as the 308 AR10 is much better.

hard pass

I want to know what brass has a .500 head diameter? 450 Bush is .473. I just barreled a Mauser for one.

quote:

Originally posted by dpcd:
I want to know what brass has a .500 head diameter? 450 Bush is .473. I just barreled a Mauser for one.

Let me clarify that some, probably a better case to form that from is the 7.5x55 Swiss and it does have the larger rim. Now you know many make the 7.5 Swiss from 284 Winchester. The smaller 284 rim doesn't make a difference and I don't believe using 450 Bushmaster brass would either.

All that sounds like a bad idea in an AR 15 platform.
I was thinking the OP wanted to use 30 Rem brass.
Maybe you can use 6.8 SPC brass; I have built those and they use 30 Rem brass.

quote:

Originally posted by dpcd:
All that sounds like a bad idea in an AR 15 platform.
I was thinking the OP wanted to use 30 Rem brass.
Maybe you can use 6.8 SPC brass; I have built those and they use 30 Rem brass.

I don't understand how you can use 6.8 SPC brass with it's a much smaller diameter all around.

No the smaller rim size is not dangerous in an AR, where did you get that from?

I guess the op needs to be more specific about what cartridge this AR is chambered in: the old 30 Remington or the newer 30 RAR.

Some confusion here;; let's recap.
The 6.8 spc is derived from the original 30 REM. Same base size. You can make 6.8s from 30 rems if you had to.
It is NOT anything like the 30 Rem AR; whoever named that I would like to slap. It is quite dead and I never hear about it for the past decade or so.
I didn't say a smaller rim is dangerous in an AR. Not sure where that came from. I used to build 6.8s on ARs.
I am not sure if the OP wants a 30 REM AR, or a 30 REM, AR Rifle. I now think he might want the dead 30 caliber round. The 30 Rem AR cartridge. And thereby, contributing to the confusion, for which I apologize.

I'm thinking the op meant the 30 RAR because the old 30 Remington has a case length of 2.05 so with a bullet it's going exceed the AR15 magazine OAL.

Maybe Remington should have it the 7.62 RAR.

True; I thought he might be shortening it to fit. Remington should not have even invented the new one in the first place.

quote:

Originally posted by dpcd:
True; I thought he might be shortening it to fit. Remington should not have even invented the new one in the first place.

I'm not sure I agree with that. The 30 RAR is the best smaller bore cartridge put on the AR15. They should have had a better name and they should have still continued the rifle, but people are very finicky about their cartridges and rifles.

I've been absent a while and with the shelter-in-place orders and other concerns, I forgot to check this forum. I am indeed talking about the 30 Remington AR (30 RAR) and NOT the 30 Remington of the distant past. I looked for sizing dies on CH4D and they called these by an old name; 30 AR-15. The guy I bought it from finally found the set of dies for it so I did not have to buy dies. I have obtained a small quantity of 7.5x55 brass and this looks like it will work. The 7.5x55 case head is oversized by .002, the body is undersized by .003 to .007 and I believe this is well within fireforming range. I am awaiting an inside neck reamer to finally load some to test. I've found load data in some of my old manuals and I am ready to work up some loads with this rifle. BTW, the Remington brass uses small rifle primer and the 7.5x55 uses a large rifle primer. Anyone see problems? On anything like this I always look for magazines and it seems to me that the 450 BushMaster mag looks like it will work also.