6mm ppc

[tackb]

morning gents ,

can anyone give me a good load for a sako 75 in 6mm ppc with 70g hpbt sierra bullets or the 74g berger flatbase ?

thanks in advance

Russ

[phaedra1106]

28gr Varget

[tackb]

cool , i've got bucket loads of varget !

[phaedra1106]

Couple of useful sites,

http://data.hodgdon.com/main_menu.asp

http://www.lapua.com/en/products/reload ... odata/5/47

http://www.alliantpowder.com/reloaders/ ... ulletid=99

[tackb]

thanks but i have all the books and sites etc i was just after a head start with whats working for you guys ?

R

[Laurie]

Nearly everybody on the bench rest competition scene uses Viht N133 in 6PPC under 66-68gn flat base bullets. While Varget will work - as would many, many others - it's too slow burning and bulky for such a small, space constrained case. Prior to N133, most Americans used Hodgdon H322. Hodgdon introduced Benchmark, another small grained fast burner to wean people off N133, but without success. Their latest entry to try and get the benchresters back onto a 'US powder' is Australian made (Thales / ADI) IMR-8208 XBR, a very fine grained powder indeed, but a little too slow burning it seems, so none of the top US competitors will use it.

Here's what QuickLOAD says for the 70gn SMK in 6PPC-USA (the commercial CIP specified version) in a 24-inch barrel.

28gn (which is around what all the BR crowd use in the cartridge, but they run some hot loads at times!)

H322: 3,260 fps 56,439 psi
Benchmark: 3,136 fps 54,0723 psi
N133: 3,177 fps 56,770 psi
Varget: 2,997 fps 42,884 psi

28.0gn produces slightly compressed loads with the 70 at the CIP COAL of 2.193" with all powders other than N133 which is moderately compressed.

CIP PMax is 58,740 psi, and one should ideally run at 55,000 of more psi, Varget's low 40 thousands definitely on the inefficient side. QuickLOAD also calculates that only 89% of the Varget load will be burned in this combination compared to 99-100% for the others.