243 AR Build

[CBDR]

Question: Pros & cons of having a 243 AR built?
Primary use: hog hunting max range 400m.
I do not reload. Off the shelf Hornady Black is my go to.
I have 2 small frame AR platforms a 5.56 & a 6.5 G.
Future ammo availability is a concern, no wildcats.
Trying to keep it light & short.
Feedback welcome

R/
CBDR

 

[Makinchips208]

Great idea! Can I recommend 308 if future ammo availability is a concern?

 

[Sh33pdog]

I've wanted to do a 243 in my Mega Arms build, even got a spare upper for it too (just no barrel yet). But the issue I've found is for 243, the FASTEST twist I can find is 1:10, sometimes 1:9, and for the bullets I've got on hand (90gr+) those twists just aren't what I'm looking for. Additionally, to seat those long bullets into a 243 case, you're going to be either pushing them so far into the case you'll miss out on case capacity or they will sit so far out of the case, they will easily exceed the 2.8ish COAL. So 6mm CM is eventually what I'll do when I find a 20" bbl for it with a 1:8.

With 6mm CM gaining in popularity, I would really sway you towards that setup. I can find 6mm CM on the shelves, but can't find the more "common" ammo like you used to be able to. Price-wise, its all too damn expensive tbh, but typically you're only going to find the higher end ammo like Hornady or etc, and its like $30 a box. For hogs, I would think you'd want a heavier 6mm bullet anyways. I think 243 ammo is more readily found in the mid/light-weight bullets meant for deer/antelope etc.

Good luck either way!

 

[Smith1]

If it’s just for hogs I’d go .308 also. I’m doing a .243 ar10 now, but I hunt coyotes and want the speed

 

[cloverleaf22]

If it’s just for hogs I’d go .308 also. I’m doing a .243 ar10 now, but I hunt coyotes and want the speed

Yeah, I'd be hesitant to go with a 243 in an AR platform if I didn't really want/need the velocity because of barrel life concerns.

 

[Sogan]

This company does a .243 in a small frame AR. Heard good things but im just now starting my research for one. Pricey but seems pretty sweet.

SF10 Small Frame .243 Winchester - F4 Defense

Common Use: Hunting * SUB 1/2 MOA Guarantee * The SF-10 is compact, lighter, and more dynamic version of the AR10. The 243, a 6mm cartridge necked down from the .308 case, was introduced by Winchester in 1955. This potent 6mm cartridge is suitable for game ranging from prairie dogs to mule...

www.f4defense.com

 

[Long Range 338]

243 is a great little cartridge and great for long range as well, the limiting factor has been factory barrel twists and ammunition. If you aren't looking for heavy for caliber bullets but just good hunting ammo for fairly cheap the 243 is gonna be a real winner.

6CM is what the 243 should have been for long range factory setups. Great for long range shooting and a good variety of factory ammo. Downside is the factory ammo for 6CM is a lot more than for the good old 243.

 

[LRRPF52]

Just go Grendel and stay inside the AR-15 frame would be my recommendation. One of the only affordable factory cartridge options I’ve seen on the shelves has been steel cased Grendel even at local big box stores.

You pay a lot of weight penalty for a standard AR-10-ish receiver set and BCG just to get into .243 Win gasser. That F4 SF10 option would be slick though.

 

[Bigtrucknut]

I absolutely love my LR243. Use it for long range shooting and PRS. I shoot primarily handloads using IMR4895 and SMK 95 grain bullets @ 2960 fps with sub-MOA groups with recoil so light that I can spot myself and make extremely fast follow-up shots. I ordered the barrel with 1:8 twist in order to shoot 95 grain bullets. Below is a link to my post on some of the LRs I've built.

308 AR10 Build Info/Picture Thread

Not sure how I'm doing. This is a JP PCS-12 born a 308 but now a 6,5 Creeeedmooore. Conversion was HELL during COVID, and when you make silly mistakes and re-order takes half a year. But now it shoots, thanks to a South African and a Swede. Spuhr mount, Acro 2ndary, S&B 3-27, Ase Utra...

www.snipershide.com

LR243:
-Aero Precision M5E upper and lower receivers
-X-Caliber 24" chromoly barrel, .243 Win, 8:1 twist, AR-10 HBAR profile, rear fluting, .0935" gas port, rifle-length gas tube
-Aero Precision BCG
-SLR Rifleworks steel adjustable gas block
-Rifle length buffer with tungsten weights (8.85 oz), AR15 buffer spring (to reduce forward impulse)
-Aero Precision charging handle
-AR-Stoner Precision (3-port) muzzle brake, 5/8-24 thread
-Geissele SSA-E trigger
-Timney 45/90 ambidextrous safety
-15" AP M5E Gen 2 M-Lok handguard
-Magpul PRS 308 Gen 2 stock, MOE grip
-Vortex PST 6-24X scope (MOA), Nightforce 20 MOA base/rings

 

[Sogan]

I absolutely love my LR243. Use it for long range shooting and PRS. I shoot primarily handloads using IMR4895 and SMK 95 grain bullets @ 2960 fps with sub-MOA groups with recoil so light that I can spot myself and make extremely fast follow-up shots. I ordered the barrel with 1:8 twist in order to shoot 95 grain bullets. Below is a link to my post on some of the LRs I've built.

308 AR10 Build Info/Picture Thread

Not sure how I'm doing. This is a JP PCS-12 born a 308 but now a 6,5 Creeeedmooore. Conversion was HELL during COVID, and when you make silly mistakes and re-order takes half a year. But now it shoots, thanks to a South African and a Swede. Spuhr mount, Acro 2ndary, S&B 3-27, Ase Utra...

www.snipershide.com

LR243:
-Aero Precision M5E upper and lower receivers
-X-Caliber 24" chromoly barrel, .243 Win, 8:1 twist, AR-10 HBAR profile, rear fluting, .0935" gas port, rifle-length gas tube
-Aero Precision BCG
-SLR Rifleworks steel adjustable gas block
-Rifle length buffer with tungsten weights (8.85 oz), AR15 buffer spring (to reduce forward impulse)
-Aero Precision charging handle
-AR-Stoner Precision (3-port) muzzle brake, 5/8-24 thread
-Geissele SSA-E trigger
-Timney 45/90 ambidextrous safety
-15" AP M5E Gen 2 M-Lok handguard
-Magpul PRS 308 Gen 2 stock, MOE grip
-Vortex PST 6-24X scope (MOA), Nightforce 20 MOA base/rings

What kind of weight are we looking at here without the mount and scope? Cost too, if you dont mind sharing that

 

[CBDR]

I've wanted to do a 243 in my Mega Arms build, even got a spare upper for it too (just no barrel yet). But the issue I've found is for 243, the FASTEST twist I can find is 1:10, sometimes 1:9, and for the bullets I've got on hand (90gr+) those twists just aren't what I'm looking for. Additionally, to seat those long bullets into a 243 case, you're going to be either pushing them so far into the case you'll miss out on case capacity or they will sit so far out of the case, they will easily exceed the 2.8ish COAL. So 6mm CM is eventually what I'll do when I find a 20" bbl for it with a 1:8.

With 6mm CM gaining in popularity, I would really sway you towards that setup. I can find 6mm CM on the shelves, but can't find the more "common" ammo like you used to be able to. Price-wise, its all too damn expensive tbh, but typically you're only going to find the higher end ammo like Hornady or etc, and its like $30 a box. For hogs, I would think you'd want a heavier 6mm bullet anyways. I think 243 ammo is more readily found in the mid/light-weight bullets meant for deer/antelope etc.

Good luck either way!

Thank you guys for the feedback. Several good points were brought to light. Smooth feeding issues is not something I want to revisit.
The jury is still out.
R/
CBDR

 

[Dildobaggins]

Like another person said on here, I might go with a 6.5 grendel. I have an Aero build with a criterion barrel. Took a deer at 300 yards with it, using Open tip match ammo. Feeds flawlessly ammo is a little scarce. I use it for varmint. If you want a large frame ar I'd go with a 308 win. Ammo availability would be my greatest concern. Online I see alot of 308 win for sale at reasonable prices for what's going on right now. I don't see much 243.

 

[Biggie1976]

You can do the 243 wsm in AR15 platform too. Company called Dtrch has a lot of stuff out

 

[TACC]

I had an extra AR10 upper so I got a KAC 19 inch 243 barrel put in it.

Shoot only factory ammo and it is lights out.

 

[Makinchips208]

The 243 in an ar platform is 342 WSSM.
Dtech
Cool idea but I have zero experience with this.

Dedicated Technology - Custom AR-15 Upper Recievers.

Dtech Custom AR 15 Uppers made by Mike Milli - ar 15 upper recievers, 243 WSSM, Custom Barrels, Float Tubes and much more!

www.dtechuppers.com