.223 Subsonic twist rate?
 

Will I be looking to shoot heavy/long bullets for subsonic .223? The rifle will be a bolt gun. What twist rate, 1/7? Barrel length?

Thanks,

Paul

Hart offers a 6" twist barrel. That's the fastest I know of from any manufacturer. Sierra makes 90 grain Matchkings which should give fair wind and drop performance. I would expect that combination to work subsonic though I haven't tried it.

I'm curious though why you'd choose a subsonic 223 Rem over a subsonic 300 whisper. I would expect the performace to be inferior in every respect except maybe for having less recoil. The 223 case has way too much chamber volume to give high expansion ratio and low velocity dispersion. A 221 Fireball would be better, but still more case capacity than optimum.

Hey Lou,

I'm not choosing it over .300 Whisper, I"m including it along with .308 for use with my .30 caliber can (when I buy it). I plan on threading every barrel that I buy for my Savage that is .30 and under. I know that subsonic .223 will not be as quiet as it could be out of a dedicated .223 can and most of the time, I'll be shooting supersonic with the can in place but I was hoping that I could buy a barrel in a twist rate that would allow good performance either way.

I didn't understand part of your answer . Could you elaborate?

Thanks,

Paul

Subsonic 223 is a total waste of time. You'd be better off with a suppressed .22 rimfire. It will be safer and more reliable, not to mention a lot more fun to shoot.

I've seen this type of response several times and it always chaps my ass.

I recently started playing with subsonic .223 in a variety of bullet weights, from 40 gr. up to around 75 gr (using different rifles, with appropriate twists for the various bullet weights). I have been using Trailboss powder, as it fills the case to not quite 2/3 full.

Initial testing is good. I'm half thinking of punching a few milk jugs full of water to see if something like a V-Max or Nosler Ballistic tip will actually fragment at subsonic velocities. If so, this would be a much better round on small critters than any .22LR solid or HP. This also gives me the option to tailor the load specifically to my rifles, rather than check multiple makes and lots of .22 LR for one that gives optimal velocity from a given barrel.

Well said.:grin:

I corresponded with a guy who's "22 whisper" was a 22 hornet that he used to shoot whitetails through the lungs.He claimed it was very effective by virtue of the long bullets tendency to yaw at impact.

I'm running 68gr horn match over 4.8gr of IMR SR 4759, REM 7 1/2 primer WIN brass, out of a 20" 1/8 twist AR 5.56 chamber with the gas system closed. This load cronys in at 1010 clean barrel, after a few shots speeds increase to around 1040 works great for bustin squirles at 100yds. Oh by the way 4.8 gr of 4759 dose not soak up alot of case space. If your scared go to CHURCH!!

It all depends on what you are trying to do. Even with 60 grain 22lr in the mix, there are better options for some applications in a .223 caliber rifle though, I'd be tempted to stick with a .221 Fireball.

I have done some shooting with my 223s and not nailed a load yet. It is fun and cheap to plink with. I have also used the 22lr conversion in some of my ARs and sub-sonic with acceptable results.

Does anyone make a .223 reduced capacity case for subsonic use? Is there any way of easily and safely reducing the capacity of the standard case?

1 in 9 works on rimfire 60gr bullets at subsonic speeds. I was recommended a 1 in 7 for 80 and 90 grain at supersonic speeds. If you are wanting those, I would suggest a tighter twist for subsonic than 1 in 7".

I asked JD Jones about it recently, as I was interested in a 22 whisper. He said they have made a bunch on the 22 hornet as well as the 5.7 FN round. He also was quick to point out the 22 SSS rimfire ammo with the right twist makes a lot of sense for less money.

I'm looking for the right bolt action 22 hornet, and have hopes to exceed the accuracy and range of the 22 SSS. Now if I can just come up with an old BRNO in 22 hornet for the right price....

I have not tried .223 subsonic but I shoot a 5.7x28 with 60gr. Vmax over 2.7 gr of Hodgin Clays. I fire it through a 22lt can from a Ar57 works great:nanabang:

What he was referring to is the tendency to see larger velocity dispersion in a case that has a small percentage of the volume filled by powder and/or bullet. It is why the 300 Whisper is good for subsonics. It has a very small case and with the larger .308 bullets there is very little open space when it is loaded, making it ideal. If you shoot .308 Win subsonic, which is definitely possible, you will see a larger variation in the velocity from round to round. For this reason, you'll have to load to a lower average velocity to make sure all rounds are subsonic and will get some vertical stringing because of it at longer ranges.

I haven't even gotten my 300/221 fully pieced together and I'm already dreaming about the next one. TC contender 1/6.5" twist .22 K-Hornet, shooting 90gr SMK's ... beautiful. Would the would this case support the 90gr pills. What is the program that everyone uses for calculating muzzle velocities off case capacity, powder, bullet weight etc? And a ballistics Calculator? Anyone got any pictures of such a round? I imagine it would be mostly just for plinking and/or varmint.