Poor man's Blackout - 100gn subsonic .223 Rem

[KenH]

That 100 grain bullet is interesting. Playing with Quick Load in .223 brass, 6.3 grain of Little Gun, OAL = 2.20, 16" barrel, with a 7.5" carbine gas system it gives about 6,000 psi at the gas port for a 1086 fps bullet speed.

I don't have a clue if that will cycle a 5.56 with carbine gas system or not, but on my 300BO with 4.5" pistol gas system it takes almost 8,000 psi to cycle with LBO. With suppressor it will cycle down to 7,000 psi (as calculated by QL).

Ken H>

[Whistler]

KenH: I've done the same thing and my figures are conclusive with yours.

I also ran a competition load for 160 power factor. 9.5gn N110 gives a fill rate of 51%, 1600 fps out of a 18" barrel at 23k PSI chamber pressure and 4.2k PSI muzzle pressure. Sure, the comp won't have much to work with, but it will nonetheless be an interesting low recoil load.

[KenH]

My SIL purchased a box of subsonic .223's during Thanksgiving but darn if I can remember manuf or bullet weight. They were just barely subsonic with at least one breaking sound barrier by the sharp "crack" heard. They wouldn't even lift the bolt on my AR15, even with a suppressor mounted. They sure were quiet with suppressor. The gunshop that sold them said they would cycle an AR just fine and be whisper quiet with NO suppressor. With suppressor they were pretty quiet, but no suppressor they were pretty loud. Not like a full power load, but still pretty loud.

I'd read on a 300BO forum about .223 subs and they all said "can't be done with standard AR15 rifle" to fully cycle. I expect if using a pistol gas system and those 100 grain bullets it might be done, perhaps with an extra light bolt setup.

With that 100 grain bullet it would have a good bit more energy than a .22 LR.

Ken H>

[Lloyd Smale]

im in. I foolishly bought a suppressor for the 5.56 that is about useless because theres nothing I can shoot subsonic out of my ars. this might be just the ticket!

[KenH]

Lloyd, does the suppressor not cut the noise a good bit on supersonic loads? They're still loud with my 5.56, but can shoot ok with no hearing protection. Using mid range loads around 1800fps for plinking they are quite pleasant to shoot with no hearing protection, and those mid range loads punch holes in paper 'n cans just as good as full power with full cycling and LBO.

You're right, subsonic I've not been able to get to even lift the bolt on the AR15, but are almost air rifle quiet, and well less than .22LR

Ken H>

[Lloyd Smale]

shooting mine is about half way between a 22lr and a 22mag rifle is. Thats with the suppressor and super sonic ammo

[Whistler]

Some sloppy work in MS Paint gave a visual on seating depth. Compared to the .300 Blackout this is a breeze, especially since this will be a plainbase and coated no-groove bullet.

[KenH]

What powder is used in that top cutaway to have a full case and still subsonic?

[Whistler]

It is just a visualization of the seating depth at mag lentgh OAL. I did not alter the powder in the photo, just the bullet.
...and subsonic is not the sole purpose of this bullet.

[Smoke4320]

A 223 to approx a 243 in bullet weight
Using some softish lead might make a good hog killer
You would be nearly doubling the common 223 weight for much higher energy level plus some good expansion possibilities

[KenH]

Per QL it looks like about 2200 fps using 3031 powder for the 100 grain bullet. That's 1100 ft/lb energy at muzzle. Plenty for hog killing I'd think - at close range anyway.

[Smoke4320]

KenH. Thanks for those figures
With that energy level would make a decent short range deer load as well " with proper shot placement"

[Lloyd Smale]

to you guys that shoot a lot of 22 cal cast bullets. Do you think a hp option would help make this bullet expand or is the nose just to small to make a pin for or to small to produce expansion?

[Smoke4320]

Lloyd previous conversations with NOE he said he needed a .20 nose to make a HP pin
Now that was at least a year ago so maybe he has figured something out since then

[Smoke4320]

A 100 gr slick sided bullet would make casting that small dia a lot easier as there is more heat being added to the mold and the slick side should make for fast release

[dverna]

It is an interesting concept. A bit off topic...but I wonder if a swaged bullet made of soft lead would work better? Something like a .22RF HP bullet but 100 gr. It should expand a bit even at subsonic speed and BBL would be a simple lube for it. It would deliver 270 ft-lb at 1100 fps - good enough for varmints and coyotes.

Not sure if PC would allow such a bullet to reach 2200 FPS...any thoughts? It would not be suppressed, but a "cruise missile" profile is good at penetrating game and 1100 ft-lbs is not too shabby.

If it could be swaged in a Rock Chucker I would be interested. Casting .22 bullets that long makes me wonder how consistent they would be.

Don Verna

[Whistler]

Since Mihec is not responding to PMs and has several hanging group buys that were supposed to be "fast", I am contemplating other options.
How are the turnarounds on NOE?

I checked Mountain Molds and Accurate Arms, but they can only do .18" flat points, which basically means this design would be a wadcuttter. I believe the RN/spitzer shape is important for feeding in an AR15.

Perhaps Lee would be an option if we get +10 to split the $175 tooling cost, but I am a bit concerned about their +.003" tolerance. A .228" would have to be sized both before and after coating I think...

[Whistler]

Gonna give NOE a try since the turnarounds seem outstanding and only 10 are required.

http://noebulletmolds.com/smf/index.....html#msg16369

[Smoke4320]

Get 10 to commit and Noe will run quickly

[Whistler]

Please sign up in the NOE forum if you guys are interested. I believe we can come up with 10 pretty quick.