300 Blackout subs...700 Tactical.

[Artos]

Merry Christmas Gents!!

Need some input for this dedicated sub gun. Shooting 220 Sierra Matchkings.

I sorta chased my tail on this gun the other day but found a couple of mistakes that I think caused the problem.
First of all I grabbed the prepped brass that I use with the super 110's for my 12.5" sbr. These had magnum primers & I had a couple of misfires on the 700. I would get 5-6 rounds in 1" in the 1050fps range & then out of nowhere a 3-4" flyer would appear and the FPS would drop by 100fps. Starting over with Federal small match & going back out. I'm using a Bruno measure so I'm not concerned about powder drop.

I come from a benchrest background & almost all my turn bolt rigs like the bullets engaged with lands. My main question is I am also seating this bullet with a slight jam into the lands, but I started thinking that all my other rounds have a full to compressed loads & wondering if a light case load doesn't like this approach. I'll obviously play around with the seating depth / other powders but just wanted some input on what is working in your rigs in the 16" tube range & if you have any thoughts. This sub biz is all new to me.

Best...

[ace4059]

The only advice I can give you on subsonic rounds is to start loading on the high side and work you way down to subsonic.
My cousin was used to loading regular rounds and started at the "minimum" for subsonic rds and had a few bullets that did not clear the barrel. I've noticed in a new loading data book I have, they do not even have a minimum starting load listed.

What powder are you using?

[Artos]

The only advice I can give you on subsonic rounds is to start loading on the high side and work you way down to subsonic.
My cousin was used to loading regular rounds and started at the "minimum" for subsonic rds and had a few bullets that did not clear the barrel. I've noticed in a new loading data book I have, they do not even have a minimum starting load listed.

What powder are you using?

Thanks...It hated H110/296 as that is what I use for my super sonic & 110's, but again the case is full & shoots sub MOA on the 12.5" aac SBR.


My only other suitable powder on hand at the time was W680 & it was trying to group. I now have some AA1680 & Lil Gun to try. I got some starting loads from friends but will indeed start higher. Never had to unstick a pill yet & don't want to start!! I really hope the 680 will work as I have a lot of this discontinued powder and it is in the same rates. Plus it meters so well.

I figured there would be a lot of folks shooting this rig...I did swap out the Hogue stock for an HS & dropped in a Jewell trigger.

[ace4059]

For my 9.5" AR I use H110 with a 125gr hornady sst bullet for hunting. Great results that cycle flawlessly. I tried Lil'Gun and did not like how it cling to the inside of the powder dispenser, cases, and it did not meter consistently for me. I use the lil gun now for 150 copper washed 150gr bullets for plinking only. I run those at about 1400fps and they are just enough to cycle the semi auto.

Go thing about the 700 is you do not have to worry about the round cycling the BCG. You may have good luck with 4227.
I wonder if trail boss would work? That might be a quiter load suppressed but I have not seen any load data for the 300 blk out and trail boss powder.

[Artos]

Thanks,

I use a bunch of H110/W296 (same powder really) in my AAC 12.5" with 110gr TSX & amazingly shoots sub MOA & have already killed a doe & other critters with it...could not be happier @ around 2400fps. I however did not feel the joy with subs in the sbr AR with the bolt slap. That is why I got the 700.

Regardless, it was indeed the magnum primers...the discontinued W680 worked just fine with Fed 205 match primers & shot around moa with just a little testing. Was pressed for time (hunting season) and didn't mess with the other powders I brought along or seating depth. Going to skim bed the stock & do fine tuning later.

Happy New Year...




For my 9.5" AR I use H110 with a 125gr hornady sst bullet for hunting. Great results that cycle flawlessly. I tried Lil'Gun and did not like how it cling to the inside of the powder dispenser, cases, and it did not meter consistently for me. I use the lil gun now for 150 copper washed 150gr bullets for plinking only. I run those at about 1400fps and they are just enough to cycle the semi auto.

Go thing about the 700 is you do not have to worry about the round cycling the BCG. You may have good luck with 4227.
I wonder if trail boss would work? That might be a quiter load suppressed but I have not seen any load data for the 300 blk out and trail boss powder.