5.56 subsonic help please

[madbear]

i have an ar 15 low pro upper that i will be setting up as a side charge. it has an adjustable gas block.

i would like to use this with my suppressor & turn the gass off for a single shot.

does anyone have sub load data for this setup with sierra 80 gr. hpbt match. if not sub load how about a good load that might be hearing safe.

thanks;

madbear

[Jaxshooter]

I don't know what brand supressor you have for your AR but the can on my SBR is quiet with regular 55gr Lake City ammo. I shoot it with no ear plugs or muffs. All you can hear is the bolt and a report like a .177 cal air gun. My buddies cannot beleive how quiet it is.

[jmorris]

I also run supersonic ammo that I feel is hearing safe. If you feel the need to plug shooting a .22 rimfire rifle you would think its too loud though.

.223 subsonic is a waist of time. A .22lr costs a lot less an is pretty close. On the other hand, I have a suppressed 458 socom that is as quite as a subsonic .223, just a lot more usefull. A 600 grain bullet or even a 405 has a lot more energy than anything you can push down a .223 barrel.

[bobmysterious]

My AAC M4-2000 manual advises to not use subsonic ammunition. I'd imagine there is a possibility of a baffle strike, which would really be a drag. Just something to keep in mind.

[madbear]

thanks for all the advice guys. this is a from 1 suppressor that i built with omega style baffles. it is my first can & i have only been turning metal for about 1 1/2 years so i want to be super careful about what i run thru it. will be using the "old tire test fire" method to start out! i was hoping to use a 22 lr upper for this but the $ just isn't here this time of the year. i did thread my wife's 10-22 so maybe i'll use that for the test fire then if all goes well i'll graduate to my ar15s.

maybe i should try some sub loads without the can just to see if i get any keyhole prints on paper first. man this is getting a little scarry! LOL but hey we wouldn't be where we are without steping outside the box now & then.

madbear

[ziebart]

Look up trail boss powder. You can fill the case and never be over pressure. With subsonic you need to work down or you can get a round stuck in the barrel.

I would also be very careful to ensure you bullet stabilizes.

[redial]

Previous Accurate Powder manuals included subsonic loads. The newest ones don't and I don't have an old one to reference, but you might try to locate some of their data.

That said, I hesitate to run SS 223 ammo through my cans, given the increased likelihood of baffle strikes. I do that with 22LR instead.

Mark

[sschultz]

Hodgdon has an article in their new magizine about this. they recomend trail boss. I have made a few rounds with other powders but there was to much issues with the powder not going off because the shift of the powder in the case.

Schultz

[ben b.]

FWIW: It doesn't matter how you "feel" about it, CF rifles with std ammo and silencers are NOT hearing safe and the test data backs that up. It is your hearing, so obviously do as you like, but do so with knowledge that silencer-equipped CF rifles with std ammo, especially ARs, are NOT "hearing safe".

[gunther]

If you are gonna shoot subsonic 233 try starting out around 5.0gr of powder and cream of wheat as a filler. Be cautious.

[perrysho]

MAD BEAR,

Damnifiknow, what your trying to do.

Bullets going thru the sound barrier then droping below do a lil tumbling act,

Bullets need enough speed and/or velocity to stabilize in flight.

Be safe and cover your back side, JMO your in an area most folks don't know do-do about. Nor do I.

In the 70s shot silhouette With a 264 Win, learned a lot about bullet flight and velocity.

Maybe play a lil high speed and wide open then go back to your slo-mo.

Have fun be safe, ( Count your fingers on a regular basis and wear good high dollar safety glasses.)

Perry