777 Question

[xcop]

I just made a good deal on a lot of shooting supplies from a guy who was selling off all his stuff. Included in the purchase was a new container of 777 powder in fffg. I have been shooting ffg. I have a good accurate load figured for the ffg, and was wondering how much I should reduce the charge to get the same equivelent charge from fffg. Or should I not use it at all?

 

[cayuga]

There is not a lot of difference in the velocity between the two. The 3f will give you a little more but not as much as one might think. Although I think it ignites easier and peaks a little sooner in the power spike. If you are shoot 100 grains of loose 2f, then give 90 grains of the 3f and see how close you are.

 

[sabotloader]

xcop

i would agree with all the points Cayugad has posted - but you might end up right back where started - but start 100 lower and work back up...

 

[Critter]

I use 90 of FFg and 80 of FFFg in my LK-93 and get almost identicle POI at 100 yards.

 

[Confederate rifleman]

Give 'er another 10

I shoot rather low charges I max at 90 gr, but my chronograph tells me that keeping the same weight of charge but changing granulation gives a roughly 100 fps difference in favor of 3f. I used to shoot 70 of 3 under a 240 hornady XTP and got 1750 fps. Keeping 70 gr but of 2f gave 1675 fps. Adding another 10 gr of 2f got me back to the mid 1700's and slightly better accuracy too.