Fireforming dasher brass

[Chaotik]

Although I have shot at F class targets at 600 yards with acceptable accuracy, I am going to my first 600 yard tournament next month, and will need a lot of rounds for all the days of competition. I may not get a chance to reload during the event.

My question is: I fireform (using a false shoulder method) with 29.5 gr of varget. The subsequent cases are then loaded with my regular dasher load.... 32.6 gr of varget. I have heard that it really takes firing a couple of times (at least) until the case is completely fireformed, and I may not have a chance to fire the case more than once. How can I expect this to affect accuracy at 600 yards?

It is interesting that my initial fireforming load of 29.5 gr varget at 100 & 200 yards is rather accurate, and typical MOA is usually under 0.5.

Thanks in advance.
-Bob

 

[dkhunt14]

I have shot great groups at 1000 after the form. I use around 30 grains of Varget and a 107 Bullet in the lands hard. I also put the false shoulder on the fireform cases to help hold the headspace. It forms them good enough that I have to bump them when I load them again. I have shot some of my best groups on the next firing. They are not quite sharp in the corners but are pretty much formed. Matt

 

[Delaware_Ken]

Good Morning,

After one trip thru the barrel to fire form, instead of just blindly shooting rounds off, I used a 600 yard F/class match to fire form 60+ rounds for the second time. The results, 596, 30X. It was my first try at shooting F/Open vs. F/TR, and good enough for me to make HM. Still my best shoot ever.

Ken