I finally found a replacement for my Unique/7.62x54r accuracy load

[texassako]

I had an old 1# bottle of Hercules Unique that no other powder could compare with in my M28-76(7.62x54r), even current production Alliant Unique. It was slow, but it was always very accurate. My very first test of Vectan A0 and Ba9 had the A0 close, like some other powders, and Ba9 actually matching the old Unique accuracy. Even better was this was done in a light rain with a variable gusty wind, and every charge grouped like this instead of just one. The load: Lapua 7.62x53r brass, NOE 311331, sized .313", TAC1 lube w/ tumble lube overcoat, 3.04" COAL, and the targets pictured are the 10.5 and 11 gr loads of Vectan Ba9.

137546

[pworley1]

Nice groups. I have been wanting a range report on those powders. Thanks for posting.

[1911cherry]

Congrats ,and by the way- that is a fine rifle.

[Motor]

I noticed M28-76 and also "sized to .313" I like em on the big side too. :)

Nice shootin.

Motor

[texassako]

I noticed M28-76 and also "sized to .313" I like em on the big side too. :)

Nice shootin.

Motor

Yeah, I changed my sizing procedure on this one last fall since testing showed .311 was not as accurate as the bigger sizes, but I still needed to seat the bullet way out there. The .313" is about as big as the chamber will take and still have room to release the bullet. The mold drops .311", I run them through a Lee .313" to seat the check, and lube with TAC1 in my 450 with a .314" die so it is not sized at all. My 450 was sizing the long 311331 slightly off center. Using the smaller .311" bullet lets me seat it out closer to the rifling.

[tomme boy]

These rifles may have a tighter bore, but the throats are huge and long on them.

[truckjohn]

These rifles may have a tighter bore, but the throats are huge and long on them.

Pretty typical when you have a 308 groove with a D or F spec-chamber...
You get a LONG throat....

In general - you want to size the bullets for proper fit in the throat - not necessarily the groove dimensions... and so you get a big 'ole fat bullet that *looks* like it ought to be way too big for the barrel - but it shoots great....

Interestingly enough - that super duper long throat doesn't make them shoot badly....

Thanks

[Ken in Iowa]

Pretty typical when you have a 308 groove with a D or F spec-chamber...
You get a LONG throat....

In general - you want to size the bullets for proper fit in the throat - not necessarily the groove dimensions... and so you get a big 'ole fat bullet that *looks* like it ought to be way too big for the barrel - but it shoots great....

Interestingly enough - that super duper long throat doesn't make them shoot badly....

Thanks

I had an early 30's M27 with the 'F' chamber. The throat was very short and the bore had a .310" groove diameter. If you ran into a long one, it probably had the D166 modification.

Poundcasting some of my Finn Mosins revealed throats of .314 to .316. I choose one, a Tikka 91/30 for cast shooting. Per Texassako's lead, I bought a 311331. I hope to ring it out in the next few weeks.