Best .224 cartridge for 12-14” SBR

Baron85

New member
I would like to build a 12-14” sbr in a .224 caliber for coyote hunting during big game season. Where I live you can not hunt predators during big game seasons with anything larger than .224. I currently use a 12.5 6.8spc with a suppressor.

My question is, which of the various .224 cartridges would be most effective in the shorter length barrel. Would I gain anything over 223 with something like 204ruger, 20 practical, 22 nosler, 22x6.8 ect?

I am also planning on building a 20” 22nxs this winter for the longer range stuff but most of my opportunities so far have been 200yds and less.

Thanks
 
I think that you will be fine with the standard .223 round. Anything bigger will just make more noise and flash. Even suppressed.

I had a braked 14" AR at one time and it sure was unpleasant to shoot to say the least. Traded it off.
 
Boiler room plays a part here and a 22X6.8 will give you much of that lost velocity back over the 223. A Fireball is not any better than a downloaded 223 IMHO. I could see no reason to deny myself cheap components. aka brass, and more HP on tap when 556/223 is literally covering the ground in places and FB is no where to be seen anywhere.

Greg
 
I only mention the fire ball, as it is designed for optimum efficiency from a 10" barrel.
With a 52 grain speer HP at 2800 fps it works well on these Colorado coyotes and is not bad on cats or fox.
 
Originally Posted By: GLShooterBoiler room plays a part here and a 22X6.8 will give you much of that lost velocity back over the 223. A Fireball is not any better than a downloaded 223 IMHO. I could see no reason to deny myself cheap components. aka brass, and more HP on tap when 556/223 is literally covering the ground in places and FB is no where to be seen anywhere.

Greg

I was thinking that at some point it won’t matter how much powder you put behind a bullet if the barrel isn’t long enough to burn the powder it won’t gain anything. So your saying the 22x6.8 will out perform at 223 with same weight bullet in a 12” barrel AR?
 
Absolutely. Don't forget you do have powder choices you can match to the barrel and projectile choice.

You want results and to get performance efficiency will takes a hit. Over bore cartridges are a great illustration.

Greg
 
Last edited:
For Coyote hunting i really like my 16 inch guns. Get a mid length gas system.

If you insist on an NFA item, try a 14.5 inch gun with a mid length gas system.

I have found using faster powders, gives fewer malfunctions in over gassed rifles.
 
I just prefer the shorter lengths when using a suppressor. Already have a registered lower so no wait. As far as efficiency, I don’t really care about that as much as I care about a noticeable performance gain. GL, I see you do a lot of testing of different cartridges, powers, barrels ect. What would you guess the velocity gain would be of the 22x6.8 over 223 in a 12.5” barrel using the same bullet?
 
SWAG maybe 150-200 but remember these are done on polygon barrels so that is free velocity. IIRC Ricth may have sold a few. Perhaps they will chime in.

Greg

ADDENDUM:

You got my curiosity up and since I don't have a 12" tube on anything other than a 11" M16 that I have not chronographed I decided to run the numbers on stuff I shot in my rifles in 22X6.8 and 223 that are 24" tubes and then plug in a 12" version with same same loads via QuickLoad.

Realize that this is a COMPUTER MODEL and nothing may match on any of our barrels and chamberngs depending on several factors ad nauseam.

I have shot these loads in my guns but that doesn't mean they would be equivalent though more than likely close in other nor does it imply that that they would be considered safe by others. Both of my test barrels quoted are three groove polygon rifled and history is pretty consistent that they are invariably faster than a similar length barrel with Enfield, standard, rifling. Both used a 50 grain VMAX.

The 223 generated 3476 and a CALCULATED 12" barrel would run 2912. The 22X6.8 showed 3820 on the clock and a CALCULATED 12" barrel running at 3162. Lose per inch will vary on powder choices and not all powders perform in both cases at calculated pressures.

Basically we see a calculated 250 FPS advantage to the 22X6.8 with same barrel length in the 12" over the 223. Stepping up with real world numbers showed in a 24" barrel with judicious powder choices I saw a 346 FPS . Case capacity between the two is about 12% in favor of the 6.8 based round.

 
Last edited:

Anyone say 221 Fireball.

M0QCK0a.jpg
 
Originally Posted By: GLShooterSWAG maybe 150-200 but remember these are done on polygon barrels so that is free velocity. IIRC Ricth may have sold a few. Perhaps they will chime in.

Greg

ADDENDUM:

You got my curiosity up and since I don't have a 12" tube on anything other than a 11" M16 that I have not chronographed I decided to run the numbers on stuff I shot in my rifles in 22X6.8 and 223 that are 24" tubes and then plug in a 12" version with same same loads via QuickLoad.

Realize that this is a COMPUTER MODEL and nothing may match on any of our barrels and chamberngs depending on several factors ad nauseam.

I have shot these loads in my guns but that doesn't mean they would be equivalent though more than likely close in other nor does it imply that that they would be considered safe by others. Both of my test barrels quoted are three groove polygon rifled and history is pretty consistent that they are invariably faster than a similar length barrel with Enfield, standard, rifling. Both used a 50 grain VMAX.

The 223 generated 3476 and a CALCULATED 12" barrel would run 2912. The 22X6.8 showed 3820 on the clock and a CALCULATED 12" barrel running at 3162. Lose per inch will vary on powder choices and not all powders perform in both cases at calculated pressures.

Basically we see a calculated 250 FPS advantage to the 22X6.8 with same barrel length in the 12" over the 223. Stepping up with real world numbers showed in a 24" barrel with judicious powder choices I saw a 346 FPS . Case capacity between the two is about 12% in favor of the 6.8 based round.



That is awesome information! Thank you so much for putting in all that effort. Looks like it would be very worth it to run the larger 22x6.8 even in the shorter barrel. When I get the rifle built this winter I will try to come back and post up the results. Really at those calculated velocity’s might not even need the longer 22 cal AR
 
I like the sound of this plan, but i am weary of brass ruining port pressures. Running over gassed rifles, suppressed and at nose bleed pressure levels will take some taming down to get good reliability and reloadable brass.

Ensure you have an adjustable gas block and a fancy buffer spring.
 
I definitely run adjustable gas blocks on all my suppressed ARs. Haven’t had a need to play with buffers or springs yet but know it’s on the table as an option
 
I would look at a barrel that is chambered in .223 Wylde. I run a 10.5" SBR w/ a Spec War Can. It is a beast and I can shoot predators at 200+ yds with no problem. I have shot out to 3oo yds but not that often. You can run .223 or 5.56 ammo and I have had no issues with pressure. I use an adjustable gas block and I adjust the gas so that it functions w/ the can only. If I take the can off, it will not cycle. No need for springs/buffers outside of standard carbine.

Bonus: the ammunition is cheap and always easy to find. Even now, I can still pick up components for it. If you lose the brass - no worries!

TC
 
I've been playing around big time with polygonal twist barrels like BHW and bullet lubes, they can really send a bullet, you must disregard every loading manual out there but it can be done.

My BHW 16" 233 is shooting 53gr TSX over 3500fps with HBN lubed bullets, and that was the last I checked, I've increased the powder charge from there.

I'm loading 26.9gr H322 with 53gr TSX, 26.6gr benchmark with HBN 65gr SGK. I just lubed some 50gr Vmax and the Hornady copper seemed to pick up the lube really well, they will slip out of my fingers dry and I cant even get enough H322 in the case to give pressure problems.

I would think a 12" poly twist SBR barrel and lubed bullets would shoot faster than your average 16" 223. These loads might damage a gun with a land and groove barrel but the poly twist barrels just shoot faster and faster the less friction you have and the faster burning powder you use.
 
Back
Top