vmax, how far from the lands?
Been shooting my browning a bolt 22-250 a little bit lately with some 55g vmax and H380 and W760 powder. Been getting .75" 3 shot groups from a bench at 100 yards with the better loads, on up to 1.5" or so for the not so good ones. I think if I tinker with my seating depth, I should be able to get it down to at least 1/2". Its been kinda windy lately, usually 10 mph crosswind, but it doesn't seem to have much effect on the good loads still.
I have found both nodes for each powder, so now I need to find the sweet spot for the seating depth. Anything above or below these charge weights and groups open up considerably. Right now, these are printing .6"-.8", with them all doing 2 in and 1 out.
With H380 my node is very short from 37.5g-37.8g and is around 3525fps.
With W760, my node is a bit longer from 37.9g-38.8g and again right at 3525-3550fps.
I am .010" off right now, but I am seeing somewhat of the typical 2 in 1 out, its not bad, but noticable. My OAL is 2.490" at the moment which puts me roughly .010" off. I started them at 2.5" which was at the lands, but back down to 2.490" shortly after I had a bullet get stuck.
So I guess my question is where do you guys set your vmax's typically off the lands to get them shooting the best??
I read an article on the VLD's saying to jump in .040" increments. I know the vmax is a totally different bullet but was thinking of doing something along those lines. I was thinking .040" at a time would be to much, but they say your rifle will defintaely show a preference for 1 of the lengths, then you could fine tune in .005 or .010" increments.
So I was thinking of going 2.450", 2.410", 2.370", and 2.350" which is the SAAMI oal with each of the 2 powders.
I think I'll concentrate around 37.5g of H380 and 38.5g of W760 and try those 4 different seating depths in groups of 3 next week and hopefully I can get it shooting dime size groups which I"m pretty sure its capable of doing.
Cases are fully prepped Winchester, weight sorted to within 1g, (out of 200 I got 100) trimmed, chamfered, debured, primer pockets cleaned, flash holes deburred, powder weighed on the dot every time. Am using Winchester Larger rifle primers. Did minimal testing with a few fed210's and my rifle definately showed a preference towards winchesters.