Thread: AR15 .300 Whisper / Blackout help

Hey guys,

Have got an AR15 that im trying to reload subsonic 240gr pills for with no luck cycling. Basically ive tried a bunch of powders , (4895 bm2 ,vv110) among others) but some will cycle but dont have enough speed (4-500 fps) and the powder is very compressed (f%ckn jammed) in. tried different seating lengths etc
The powder that everyone seems to be using is vitavouri 110, and which ive brought a shitload of, which fills up the case perfect (9.5 grains) and gives good velocity (1050fps) but it wont fully cycle the action.it kicks halfway. This seems to be the powder that i need to get it cycling.

So whats the answer? do i need to buy another gas block? can i tune my current one to cycle this powder? or do i need to stick to factory loaded 220 grainers?
rifle is a 12" barrel that dan hardy made with supressor etc. can upload a pic if that helps

This is my first ar so my knowledge is limited (read - zero) haha.


cheers guys

do the factory loads cycle OK? I would be keen to see a photo ...

yea factorys cycle sweet no problem a. yea cool ill try post one up

thats it cycling with 220grainers

What's the gas port diameter and what length?

The data I found had 11.2 grains of AA1680 16" barrel 1010 fps for 220smk subs

AA1680 seems to be right between 2205 & 2207 so they maybe worth a try.

Originally Posted by Spanners

What's the gas port diameter and what length?

do I just measure that up with the tape measure?

Originally Posted by Kiwi Greg

The data I found had 11.2 grains of AA1680 16" barrel 1010 fps for 220smk subs

AA1680 seems to be right between 2205 & 2207 so they maybe worth a try.

the 240s seem to suck up just that little bit extra room though aye, even seated right out. its a bastard haha. id realy like to get the vitavouri 110 powder working if i can seeings we got a whole lot of it hahaha. but failing that, more experimentation on powders.

Pistol, carbine, mid and rifle are the standard lengths
Measure it and google the lengths tosee what you have
Will prob be carbine

tried both and neither cycled

carbine length

I think a pistol length gas system is needed for subs

Originally Posted by Beavis

I think a pistol length gas system is needed for subs

what do you mean? it already cycles with factory subs, and other powders that dont give me adequete veloicty, just not with this particular powder that is reccomended and used elsewhere

Sorry didn't fully read the thread. Definitely sounds like the powder could be the issue. Not timing properly or what not. Mate had a similar problem in his SLR except it was the other way around, was ejecting like a crazy c*nt and it was the powder he was using. Try a lighter weight buffer.