Subsonic load with AA#9?

[redmo]

Anyone have subsonic load data for accurate #9? I have searched and only found recipes for super. I was hoping to get it to work with Nosler 190s in AR. I loaded up lowest load data provided by accurate and they performed but we're supersonic at about 1210 fps. About to try ladder down but have read some have had problems with full function if low enough for subsonic. Thanks!

[certifiable]

8.2gr No9 with 220gr SMK & 220gr Nosler CC got me 1030 fps in a 16" AR, 8.0gr was 1030 with a 225gr BTHP. Can't help you with the 190 nosler though

[dellet]

Hornady also has data, but I think it is also 1200 fps on the low end in a 16" barrel.

I use #9 a lot in my 8" SBR, you will need to tweak these in longer barrels

Nosler 190
8.2 @ 2.175

Sierra 190
8.4 @ 2.145

[redmo]

Good info, thanks. I will give these a try. The 300blk in particular that I am reloading for is an 8.5.

[John A.]

Mine is also is an 8.5 inch barrel.

KAK barrel actually.

For me, 9.1 gr and 240gr matchkings started getting supersonic and I needed almost all of that to cycle my gun.

Even with a standard buffer and spring, I never got full function (bolt lock back), but I did get cycling.

In order to get the bolt to lock back on an empty mag, I had to use a sprinco reduced power buffer spring with the #9. This also allowed me to drop the charge a little to keep it subsonic easier.

That is my limited experience with #9.

[TobyJ]

I'm going to try #9 for some 220 RN leatherheads, in my 8.5" with GMT-300blk.

7.8gr of lil gun at 2.06 COAL gets me just over 1000fps, and good cycling...no FTF, all eject well, but bolt doesn't always hold open with 30rd pmags. I have opened the gas port from .09 to .098, to see if that helps. This is with a standard carbine spring, and a modified buffer...I run a law tactical folder, and I modified the buffer so that it and the bolt carrier extension weigh what a carbine buffer alone would.

So I'm going to try 7.8, 8.1, 8.3, and 8.5 gr of #9 at the same COAL (gives me about the same bullet in the case as a 208 AMAX loaded to 2.25), and see what happens. I really like the lil gun load, and it is LOTS quieter than the same fps from 1680...but based on research, and what Dellet has written, it sounds like #9 might be even quieter still. If not, I'll go back to Lil gun and be happy.

Back to the OP about the 190cc's, I had good luck with those over 8.3 of lil gun, at 2.20 COAL...right around 1025 fps, low es and sd, fed and ejected no problem, but still wouldn't lock bolt back 100% of the time. I will be trying those again with the larger gas port, as well.

Looking at Hornady's 9th, the 190 Nosler CC looks a lot more like the 195 BTHP, than it does the 190 interlok BTSP, and for that bullet, they show that it takes a little less #9 to get the same velocity as lil gun, so it would seem that 8.2 of #9 is a pretty good start.

TobyJ

[John A.]

Yeah, the only thing that 1680 has going for it is slow burning and builds pressure even after the gas port making it cycle well.

But it's loud and dirty.

And did I mention, loud? H4198 is even more loud to my ear than 1680.

I am very happy with the way #9 sounds. But has taken a lot of work getting it fully functional in my gun. I could live without bolt hold open for most things as long as it cycles reliably, but having it so that it will lock back is always a good thing too, but I had to use a reduced power buffer spring to get to that point, at least without going supersonic to get there.

[TobyJ]

Yeah, the only thing that 1680 has going for it is slow burning and builds pressure even after the gas port making it cycle well.

But it's loud and dirty.

And did I mention, loud? H4198 is even more loud to my ear than 1680.

I am very happy with the way #9 sounds. But has taken a lot of work getting it fully functional in my gun. I could live without bolt hold open for most things as long as it cycles reliably, but having it so that it will lock back is always a good thing too, but I had to use a reduced power buffer spring to get to that point, at least without going supersonic to get there.

How does that Sprinco spring work with supers...or have you tried that? And I'm assuming its the 'yellow' spring, correct?

TobyJ

[John A.]

I fired a box of supers through the upper when I first built it just to "proof" everything and just to have some brass to reload while I was waiting on my chop saw and jig. But I haven't shot any since swapping the spring. To be honest, I'm not even certain if I have any supers left.

I went into the blk for a dedicated suppressed upper that I could use for short range whitetail brush hunting and primary HD gun to protect my families hearing if God forbid I ever have to use it in such a manner.

My main reasoning for not being interested in 300 blk supers, is that 7.62x39 costs a third of what blk costs so, if I want x39 performance, I just pick up one of the SKS or AK's.

Yes, I am referring to the yellow spring Sprinco.

[TobyJ]

Thanks...I'm leaning toward a primarily sub only rifle, but want to remain able to shoot supers, ideally without messing with an adjustable block.

I opened my port to .098, and now my 8.3 of lil gun under Nosler 190cc's works fully, including BHO. Supers (125gr TNT over 17.3gr of lil gun) also functioned fine.

Then, I tested AA#9 under the 220 Leatherhead down to 7.8gr, and got function on all, and BHO at 8.3 and 8.5. The 8.3 avg'd 1069, with an ES of 16 and an sd of 8, so that's the load I'm going to work up further. I'd like to drop the avg more into the 1025 range, so I'm thinking I'll add some COAL, and see what happens next. Will also check accuracy, as well.

Then, I'm going to load some up with 7.8gr of lil gun (similar fps) and see if I can tell if one is quieter than the other.

As an aside, 7.8gr of AA#9 was just under 1000fps, feed and fired fine, but no BHO.

TobyJ