.243 Win with W540 powder

[sledgehammer001]

So, a friend gifted me 8lbs of 1980s W540 summer of 2021. December of '21 I acquired a Mossberg Patriot in .243 Win.
Bought a Lyman 245496 single cavity used.
I had an unopened 1lb of Unique, but with things being in short supply, I didnt really want to burn it all on the .243 so I started searching for data on using 540 under cast .243 and found nothing.
After finding an older burn rate chart I deduced a safe starting load. Today was range day for me. These were my preliminary results....
All brass was trimmed to length, chamfered, and full length sized using Lee Pacesetter dies. Primed with CCI 200.
Expanded the necks to just start a gaschecked boolit, using Lee's Universal Expander die.
Using Lee dippers, I started with 0.3(2)=0.6cc
0.7(1)=0.7cc
0.3(1)+0.5(1)=0.8cc
0.3(3)=0.9cc
I have not weighed those charges yet, but will post data a.s.a.p.
Boolits were Lyman 245496, gas checked then with Sage's copper checks, PC'd, sized to .243" (testing .243" before I open the die up) through a Lee pushthrough die.
Crimped with the Lee Factory crimp die.
No chrony data as I don't have access to one. Pics are numbered according to CC of powder. Range: 27 yards, fired from a bipod off the bench.
Case necks are all sooty, no pressure signs on the primers so more, hotter loads to come. Will update when I have the next batch downrange.

[Ford SD]

540 powder
A versatile propellant that works well in 12 gauge 1 1/4 oz. and 1 1/2 oz .,20 gauge 1 oz. and 28 gauge
3/4 oz. loads. As a high density propellant, 540 is an excellent choice to maximize velocities with minimal recoil in
these loads. Suitable as a handgun propellant in 38 Super, 9mm, 40 S&W and 10mm loads.


I have used it in 45 ACP as well

Not marketed as a rifle powder

Data can be found in some of the old Winchester Free handouts

[cabezaverde]

Same as HS-6.

[sledgehammer001]

Yes. But searching turned up nothing using HS6 with that boolit in the .243 so I started from scratch. Once I settle on a load, I'll update the final data, maybe help the next shooter

[sledgehammer001]

540 powder
A versatile propellant that works well in 12 gauge 1 1/4 oz. and 1 1/2 oz .,20 gauge 1 oz. and 28 gauge
3/4 oz. loads. As a high density propellant, 540 is an excellent choice to maximize velocities with minimal recoil in
these loads. Suitable as a handgun propellant in 38 Super, 9mm, 40 S&W and 10mm loads.


I have used it in 45 ACP as well

Not marketed as a rifle powder

Data can be found in some of the old Winchester Free handouts

Love it in 45acp under a 225gr cast. I have an old Winchester pamphlet that I'll use for 12ga loads. It's on my list to do.