Trail Boss

[dylan5588]

Hi all, Has anyone used this powder for subsonic .243 loads? if so do you have any load data? and accuracy expectations.

Adrian

[bewsh]

Only Blu Dot

some data:

 

 

 

[dylan5588]

Only Blu Dot

some data:

 

 

 

Many thanks Bewsh, I have seen this data, Looks like you are restricted to one bullet to achieve sub sonic, I will carry on looking into this further, I have seen a post on Hodgdens site which says "mark the case where the bottom of the bullet reaches when seated, fill case to this level, weigh powder, then use 70% as a starting load". But this sounds a bit hit and miss to me, but it is on Hodgdens site.

Adrian

[Laurie]

I take it you've gone into Hodgdon's 'Reloading Center' website? If you use the menu driven option, there is one Trail Boss recipe - Winchester case, WLR primer, 100gn Speer BTSP, 2.650" COAL. Starting load 8.0gn 1,045 fps, 27,300 CUP pressure; maximum load 15.3gn, 1,603 fps, 39,100 CUP from a 24-inch barrel. With the nominal speed of sound at 1,126 fps at 59-deg F ambient air temperature that gives you a bit of leeway as Trail Boss gives MVs that increase directly proportionately with charge weight in my experience or 76 fps / grain powder charge increase.

 

A shorter, flat-base bullet might be advisable for rifles with 1 in 10-inch twist rifled barrels rather than a 100gn boat-tail design as used by Hodgdon. Miller gives the 100gn Hornady BTSP at 1.08" OAL, an Sg of 0.98 at 1,100 fps under standard conditions in 1-10" which says it won't work. If your barrel is a 1-9, it'd rise to 1.21 - still lower than ideal but it would stabilise this particular 100 BTSP.

 

People I know who've used the 70% of the volume that reaches the bullet base formula say it works, although it was probably developed with lead bullets in mind.

[dylan5588]

Thank you Laurie, as always sound, precise, detailed advise, I was a bit concerned about the low (8gn) amounts leaving a lot of empty space in the case, but after seeing how bulky the powder is (like mini washers) i can see how it will take up the space.

Adrian