A good friend wants me to build him a 243 ar10. He has looked at the Remington r25 and doesn't like it, too long and too heavy. He wants it as short and light as possible but for it to still be accurate, it's going to be a hunting rifle, shots will very rarely be 300 yards. Most will be 200 or less.
I found that black hole weaponry has made to order 243 barrels that are 16" so here come the questions.......

Does BHW make quality barrels that will be accurate?

What twist rate is best for 243 in a 16" barrel, the options are 1/8, 1/9 & 1/10 ?

What length gas system carbine or mid?

If it is a light profile would it be OK to have it fluted?



Thanks guys, before it's brought up I have tried to convince him to get a different caliber but he is dead set on the 243

Yeah, I tried the .243 20" barrel setup in one of my Armalite AR10's...purchased new as a .243.  Great shooting cartridge, and I still have a bolt gun in that caliber for which I reload.  I ended up shooting my 20" .308 Armalite AR10 way more even though it's not as "fast" and "flat" as the .243.  I swapped the .243 barrel for a 16" pencil Armalite .308 to get a carbine AR10 and love it.  The .243 barrel is sitting in the closet and will probably remain there.  I love .243, but it's mainly in a good bolt rifle.  I agree with you trying to talk him out of it.  Not a bad AR10 cartridge, but there are better semiauto cartridges out there for the big AR's.

Edit:  I'll add something else here.  His wanting a 16" barrel .243 is not generally considered anything close to optimum for that cartridge.  Even in the new Ruger Precision Rifle in that caliber, a 26" barrel is the way to go.  I'm not saying that one needs a 26" barrel to make .243 work, but it's very obvious it's a longer barrel cartridge for good performance.  Anything less than 20" in an AR10 .243 is probably a waste.  If he wants 16", the .308 is a cartridge that does quite well in a shorter platform.

I have an armalite ar 10 .243.  Mine is accurate but a tad heavy.  Really notice it when lugging it around all day.

Muzzle blast will be terrible! For .243 I would not go shorter than 20" mirrors on your vehicle will not like 18 1/2" or shorter in that caliber.

I think going to an 18" barrel will be OK with him. I don't think he will want to go 20, that being said I think the r25 he looked at had a 24" barrel so 20 might work but I think 18 would be preferable if the cartridge will perform at the ranges above and be accurate

BHW does make very accurate 243  barrels that will fit the bill for your needs. Their site has so many choices it makes your head spin. If he won't go past an 18" I would go carbine if it were my build but the blast, as noted, wil be a bit heavy IMHO
Greg

I would think a longer gas system would be better. They don't even offer carbine length in an 18" barrel length. Probably for good reason. It is a really overbore cartridge. Rifle length would make sense. It would be a crazy amount of port pressure at carbine. If it were a 5.56 based round and not .308 based then I could understand carbine or mid (like 6x45).

I would probably go with 1:8 twist to make up for the barrel length.

You are right on the gss. A mid would be better.  I think too much about smaller capacity  rounds.  I would also go 1:8 on the twist.  I find myself clicking that on anything over s 6X45.

Greg

Rifle would be even better.  1/8" 18" light profile with rifle length gas would make a great hunting rifle.  Pair it up with a 2A Arms receiver set and a lightweight rail and stock.  The 1/8" twist would also allow him to use 105gr rounds if he ever decided to stretch its legs.

I think on the big frame light is always good.

Greg

On my Armalite, all the research I could find about .243 AR10 seemed to indicate that 20" was about optimal for a semiauto.  Even though .243 uses the .308 parent case, it has some decently different ballistic characteristics and requirements from what I've learned in my limited exposure with bolt and semiauto .243 and loading for that cartridge.  I would really encourage the OP's friend to not go less than 20" for a .243 AR10, and frankly, I'd really suggest going to another caliber in the bigger AR platform.  In that platform I'd go with 6.5 Creedmoor or .260 Rem or the tried-and-true .308 before doing another .243.  I'm keeping my .243 bolt gun.

I had a DPMS AR 10 243. Heavy pig. Sold it. Have him lift one if he can find one. Think he will change his mind after lifting it.

I have a 15 lb AR15.  I also have one that's sub 4 lbs.  AR10s are no different, just because one is heavy doesn't mean they all are.

I agree fully with Josh here. If you pay attention to weight you can make a AR-10 pretty trim