Thread: 308 Subsonic powder alternative to Trailboss

Anyone got any powder alternatives for Trailboss using Robert walkers 151’s

Unique 8 grains

Vihtavuori n32 c tinstar use 9.5gr with 190 grain sub x

I have found AP 70 and Unique are very similar to trailboss in most cases and are not overly position sensitive.I loaded 13 Gr unique in 303 and 45/70 with cast bullets and now use 11 or 12 Gr trailboss. AP70 is also sold as Universal and is touted as equivalent to Unique.
As always find data you can trust before using any load.

For Cast bullets, Red Dot, Green Dot have been widely used in 30 cal. ADI have published data for AS30N, a Shotgun/Pistol powder. Some other Shotgun powders are very close to AS30N, which is very close to Red Dot. 10gn is a useful start point to work up or down from. Subsonic tends to run below 10gn. Below 10gn, any such powder, be sure projectile leaves your barrel. 7.0gn is kinda getting down there. Its also useful with cast to consider 13gn as likely to be a max load. Generally 13gn in 30 cal and 303B will give you between 1400 and 1800fps. Accuracy tends to deteriorate quickly after 1400fps. Higher velocity in cast is feasible with accuracy but tends to require a specific combo of lead hardness, gas check and bullet lube. Twist rate really comes into play. Starting out I wondered why my 303B was not registering any hits on a large piece of cardboard at around 35m. The big Grey cloud between muzzle and target turned out to be 215gn of too soft lead vaporizing at something around 2200fps over a 45gn charge of RL19. A published load for a Woodleigh lead bullet BTW.

Anyway. Lots of options for you. While you get your sub load sorted, try a load around 1200-1400fps. You may be surprised how quiet, accurate and hard hitting it can be.

Have fun.

The good thing about Trailboss is it is bulky. Other powders aren’t so bulky so looking for alternatives really that are more readily available.

There's no other powder with the characteristics of trail boss. Personally I've never had great results with it certainly not enough to make me change from unique and red dot plus it burns dirty compared to them. The bulk aspect of it is seen as a plus by some compared to 7 or 9 grains of pistol powder, it's impossible to double charge a case with it but if you're inattentive you could with red dot etc. They are far more cost effective than TB.

AP 70 with a bit of dacron to hold powder against the primer works really well. A heavier bullet would be better .

15gr of AS50n in my 30.06 180gr cast gives about 1500fps. I tried Dacron once. Never again, very dirty result in barrel. It's bloody plastic!!
I always worry about double charges. Not only do I look in the charged cases with a torch, but I drop I pencil in the case too now. A double charge or empty case becomes very obvious then.

Originally Posted by Oldbloke

15gr of AS50n in my 30.06 180gr cast gives about 1500fps. I tried Dacron once. Never again, very dirty result in barrel. It's bloody plastic!!
I always worry about double charges. Not only do I look in the charged cases with a torch, but I drop I pencil in the case too now. A double charge or empty case becomes very obvious then.

Yup, forget the Dacron, fillers are not required.

I tried 8.0 grains of AS30 with my 151HP yesterday velocity was 1275fps average for 10 shots accuracy was not great but the rifle I used is not a cast bullet fan
The stats are quite good ES 29fps SD 8 FPS A double load 16 grains is just below the case shoulder, So easy enough to spot an overload,
Will drop to 7.5 grains for the next trial.
My barrel is not SAMMI spec it is a 1970's NRA Fullbore Black Mountain speced for the 144 FMJ.

Originally Posted by Muddyundy

The good thing about Trailboss is it is bulky. Other powders aren’t so bulky so looking for alternatives really that are more readily available.

Procedure when you're loading takes care of any issues with bulk or lack of it and the associated risk of double charging. i.e. grab a pill with one hand, take a primed empty case and drop a charge of powder in it and at the same time place the pill on top and seat it. Very hard to double charge if that's your procedure - easier if you are loading a tray of cases with powder at the same time.

The benefit of the faster powders is there is virtually no delay in lighting the entire powder charge and it doesn't really matter where the powder is in the case - no need for fillers. Downside is the pressure curve is fairly abrupt which is where the dangers of the double charge come in, but if your procedures are good on the bench you can prevent this issue from happening. Trailboss is designed to get around the loading density thing by being so bulky - but it's tending to be on the dirty side and a lot of people have gone away from it for this reason plus some rifles just don't play with it. Google 'The Load' with Red Dot powder, and you get quite a bit of info on using Red Dot with all sorts of pills in the .308 case.

Originally Posted by No.3

Procedure when you're loading takes care of any issues with bulk or lack of it and the associated risk of double charging. i.e. grab a pill with one hand, take a primed empty case and drop a charge of powder in it and at the same time place the pill on top and seat it. Very hard to double charge if that's your procedure - easier if you are loading a tray of cases with powder at the same time.

The benefit of the faster powders is there is virtually no delay in lighting the entire powder charge and it doesn't really matter where the powder is in the case - no need for fillers. Downside is the pressure curve is fairly abrupt which is where the dangers of the double charge come in, but if your procedures are good on the bench you can prevent this issue from happening. Trailboss is designed to get around the loading density thing by being so bulky - but it's tending to be on the dirty side and a lot of people have gone away from it for this reason plus some rifles just don't play with it. Google 'The Load' with Red Dot powder, and you get quite a bit of info on using Red Dot with all sorts of pills in the .308 case.

I have both Red dot and AS30 their denstiny and burn rate are very similar, I am using up the AS30 first and then compare results with Red dot as I have more Red dot and don't want to waste it
doing load development, AS30 should be easier to source than Red dot at present.

There's a lot of red dot about it seems, not sure about AS30 but yes they are very close in performance. I see it's in stock at Bronco's on the website where AS30n is listed as out of stock...

P.s. what length and twist is the black mountain barrel? That 10gr might be perfect for a faster twist barrel I'm thinking...

Originally Posted by No.3

There's a lot of red dot about it seems, not sure about AS30 but yes they are very close in performance. I see it's in stock at Bronco's on the website where AS30n is listed as out of stock...

P.s. what length and twist is the black mountain barrel? That 10gr might be perfect for a faster twist barrel I'm thinking...

Sorry I'll correct that - the 8gr of AS30 don't know where I got 10 from. Probably thinking Red Dot...