Thread: 308 Subsonic powder alternative to Trailboss

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.

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.