Chrono'ed identical loads last Sat. in my 300 win, 75.5 gr RL 22 Fed 215M and 180 Accubond. I shot partial full length re sized brass groups and neck sized bras groups. The neck sizing was done by a Lee collet die, the rounds from the neck sizing were 50 fps faster than the pfl re sized. Is this the norm? Thanks

Wow!! 50 fps difference, that is a lot! Are you going to try to verify this with a second set of measurements??

- mike

I have never heard of anyone doing a similar experiment but the velocity difference is probably due to some of the load's energy being used up in expand your brass, after full length resizing, back out to fit your rifle's chamber. And 50 fps doesn't seem at all out of line to me...Rusty.

That is the norm.

I've run this test numerous tiimes of FL cases vs NS'd cases with same load. The NS'd cases always are faster. The reason is simple.; it takes energy to expand the brass case. That energy is then not being used to push the bullet. Thus with the NS'd cases all of the powders energy is used to push the bullet. Quite simple really.

Larry Gibson

That is waht I thought. I just thought that 50 fps was alot. Thanks