What filling you are using on subsonic ammo loading 308win

[viking78]

I have one Hodgon Clays powder pound, and i thought to start to reload subsonic ammo with that powder.
I have shot few packages Lapua subsonic factory ammo, but that is pricey as hell, so thought to start to make my own sub ammo.
Have done quite a lot reloading, but going to subsonic area, is unknown and new, and scary area.
I have heard a lot of those detonation failures, so kind of newbie and want to have a good information of this, some one who has done it a lot.
Few question, do i need to open the flash hole, or just leave it as it is?
What filling you use on subsonic ammo, as a filler, that is one thing what i have been thinking to use.
Something that would burn would be best, nothing that will get and stuck inside the supressor.
And have you done it with Lapua Scenar bullets, or is Sierra MK better choice, is has a bit softer jacket, than in Lapua brass is.
8gr seem to be the load what some of people has used, but what barrel and lenght that is good?
I have Tikka ctr with 20" barrel 11" twist.

I have one 100-pcs of Nosler 168gr Hornady A-Max, that would be nice bullet for fox and predators, but will it work on subsonic speed?
V-Max is too light for subsonic?
I have those too.

Thank you guys

 

[DGT]

I use 11gr. Trail Boss behind a 200gr. Lapua subsonic bullet.
This gives me 1050 fps in a 24" barrel and the bullet stabilizes just fine in my 11" twist barrel.
No filling needed with Trail Boss or VV Tin Star.

I know this is not what you are asking but consider getting a can of Trail Boss.

The Lapua 200gr. bullet is designed for subsonic loads and will not stick in the bore and stabilizes well in standard twist barrels.

 

[MrSmith]

Seconds on Trail Boss.

I tried 8 grains Titegroup and the velocities were all over the place, but it was just a 4 round quickie sample. ES over 200.
Tried 9.5 grains Trail Boss, 4 rounds, avg 1028 fps, ES of 15
Tried 10.0 grains Trail Boss, 4 rounds, avg 1062 fps, ES of 7
I'm happy with that.

.308 Rem 700, 20" Tier One barrel, 10 twist
245 grain RNFP coated from Missouri bullet Company, stable at this velocity
Mil case, 2.010", no filler, .005 off jam, "medium" Lee crimp

In the Reloading Depot forum there is a dedicated thread on subsonics. Check there for more information. Lots on the .308

Thank you,
MrSmith

 

[mdmp5]

Trail boss has such low density that a few grains will fill most of the case. The powder looks like little cheerios

 

[spife7980]

I have no experience with subs in large cases with little powder but I would rather get something a bit bulkier to fill it , such as trailboss, before I went putting poly fill or anything in a case that will then have to go through my barrel and can.

 

[towerofpower93]

Third, fourth, or whatever I am, ref Trailboss (or Tin Star) being THE powder for this application.

Can’t remember my load in .308, but go to Hodgdon’s website and you can find their data, which will be just into the supersonic realm. Work DOWN in charge weight with a chrono, a target 5yds downrange, and no suppressor on.

When you get to your desired subsonic velocity, stop and ensure you have round holes in the target. Done.

There is also some Hodgdon info about how to find a starting load with TB if you are using a different bullet than the one they list in their data. Basically has to do with measuring how far into the case your projectile will be and then using the remaining space as ‘100% full.’ TB doesn’t like to be compressed and a full case almost always generates more velocity than you want, so I think they say something like starting with 80% fill. Can’t remember exactly, but if you find the literature to which I am referring it’ll be obvious.

ETA load data:

Trailboss 10.6gr

Hornady 208gr AMAX

3.063"/ogive: 2.330"

Win LRP

3rds

Avg: 1023
ES: 12.3
SD: 7.5

20” Rem AAC-SD 1:10 unsuppressed

 

[BigTex]

Another vote for TrailBoss, 10.5gr behind a Hornady 220gr RN is a good one.

 

[viking78]

Big thanks for all of you guys, this kind of help is what i was looking for

 

[Thistle]

I like 10.8 grains of trail boss.
I use a 180 grain flat base bullet and a magnum primer.
Steyr SSG with an AAC can, very quiet.