Subsonic Bullet weight floor for 9" AR's?

[spiderthewebguy]

For those of us running 1-8 twist 9" barrels, what is the lightest bullet weight that will cycle most AR-15's in this configuration?

The actual question is, what is the cheapest subsonic load I can produce that will cycle my AR? My presumption is that, more often than not, heavier projectiles cost more. There is already a 'cheapest' load thread, but I didn't find one specifically about cheap, subsonic loads.

Does anyone have data on the floor weight for a subsonic projectile, and recommended powder loads?

*Note: This would be a suppressed rifle, but I know backpressure from suppressors varies widely by make and model.

[morris]

I have used 208 gr but I have read of people trying 147 gr

[BuckySWT]

I've run 208's through my 16" set up suppressed.
Have not tried running them unsuppressed yet, but they were flawless this weekend with the can on.

[dbrown]

[quote="BuckySWT"]I've run 208's through my 16" set up suppressed.
Have not tried running them unsuppressed yet, but they were flawless this weekend with the can on.[/quote]

The 208 will run in my 9" suppressed and unsuppressed. However, unsuppressed the bolt will not always lock back after firing the last round.

[[email protected]]

extremely dependant on your powder choice and gas port size.

[spiderthewebguy]

In my case, the gas port is CMMG's from-factory configuration for pistol-gas.

Does anybody have 9" specific, low-cost subsonic loads they'd care to share? We have a load thread, but it would be nice to have a dedicated subsonic-that-cycles thread, including cost per round based on components.

[bp_968]

In my case, the gas port is CMMG's from-factory configuration for pistol-gas.

Does anybody have 9" specific, low-cost subsonic loads they'd care to share? We have a load thread, but it would be nice to have a dedicated subsonic-that-cycles thread, including cost per round based on components.

Its more then just port placement and barrel length. Make is important too. What works on a cmmg isn't going to work on a noveske.

Some people have no problem with 175gr subs. So far with lilgun it hasn't worked for me. Ive seen 2 other 175gr loads one A1680 and one 4895 and ill try both soon.

[bp_968]

In my case, the gas port is CMMG's from-factory configuration for pistol-gas.

Does anybody have 9" specific, low-cost subsonic loads they'd care to share? We have a load thread, but it would be nice to have a dedicated subsonic-that-cycles thread, including cost per round based on components.

Its more then just port placement and barrel length. Make is important too. What works on a cmmg isn't going to work on a noveske.

Some people have no problem with 175gr subs. So far with lilgun it hasn't worked for me. Ive seen 2 other 175gr loads one A1680 and one 4895 and ill try both soon.

Now that I have a metric ton of 220gr projectiles ill be sticking with those for subs.

[Cotys]

I have shot Hornady 110 grain and 125 grain Nosler Ballistic Tips with no feed problems. It was from an 8" Noveske 1:8 and a GemTech HVT suppressor.

Loads:
Nosler 125 grain BT
17.5 gr Lil' Gun
COL 2.050
Chrono Avg - 2239 fps
Rem 7 1/2 primers

Hornady 110 gr
H110 20 grains
COL - 2.040
Rem 7 1/2 primers
Chrono Avg - 2819 fps
Point of Impact was 18" high and 18" right at 150 yards (compared to zero at 50 yards for sub-sonic loads)