Hey folks! I’m going to be reloading for an AR for the 1st time … I’ve always just reloaded for bolt guns and lever actions in the past. It will be chambered in .204 and has a 1 in 10 twist 24” barrel on it. WOA upper to be exact!

Anything different I need to do or be looking for when building my AR rounds? Help a fella out would you!?!? Lol

My advice would be to use stainless mags which allow 2.3" oal, vs standard aluminum which are normally 2.26". Also note that Pmags don't work well at all without internal modifications. There can be feeding issues but I'm betting WOA has it figured out.

Funny, just an hour ago I was looking at 204 barrels online. I haven't had one together in years since my Shilen tubed laser beam burned out. That thing was a pdog slaying sun of a gun.

I don't have a 204 AR but do have a two 223s, two 300 blackout and a 6mm Creedmoor in ARs that I load my own ammunition for.

Have you had any issues with factory ammo cycling your AR? If you have not shot factory ammo in your rifle and will only be shooting your own loads, don't assume that cycling issues are caused by the ammo you load. Sometimes you need to make adjustments to the buffer spring or adjustable gas block (not all ARs have an adjustable gas block). A dirty AR will also have cycling issues.

If you have too light of a load it may not produce enough pressure to cycle your AR. That would be a rare issue though and I would not expect that to happen in any reasonable 204 load. Even with subsonic 300 blackout loads I don't have issues with cycling as long as the gas block is adjusted appropriately.

Pmags are all I currently have so I hope they will work. When you talk OAL are you referring to tip of bullets I’m assuming and not the ogive?

Over all length, base of case to tip of bullet.

Pmags will limit oal, and the shoulder of a 204 is longer than 223 so that plastic rib inside the mag will interfere. It can be filed off and made to work but it wouldn't be worth it to me, given the oal restrictions.

You asked for advice, mine is to buy some asc or other stainless mags. Loading the ammo is basically the same as a bolt gun, set the shoulder back 4 thousandths to ensure easy chambering and extraction of live rounds.

Build yourself a 20 Practical. very close to the .204 balistics. Uses .223 mags. Free brass from ranges and very easy to reload.

Pmags were problematic in mine, for the reasons 204AR mentioned. I've been using the C Products SS mags (223) with success.

That's what I did(20P), already had too many AR mags to keep track of. Haven't had a feed issue with any mag,GI,plastic or brand with the 20p.

My 204 Ruger AR shoots great either at Hodgdon's overall length of 2.240" or Berger's of 2.260" I just weigh each charge carefully and shoot. It's very accurate with a variety of powders.

My Shilen 24” laser beam cycles good without doing any extra. I use the steel mags to rather than the tapered Pmags. I haven’t seen a need for small base dies in any AR yet.