Oh yes, I have been seriously excited over the possibility of a larger boiler room..., but, according to Quickload, there really isn't too much performance difference between COALs of 2.86 and 2.90 inches. About 0.6 grains and less than 40 fps.
In preparation for my next range trip, I loaded up a batch of 178gr BTHP Match at 2.90" COALin for a round of Dan Newberry's OCW testing. I'd really like to use the PTG DBM bottom metal later, but accuracy is more important than convenience, so I'm going to load up another batch with identical components, but at my magazine length limit of 2.86" to see if there really is anything to be gained by being right up there on the lands. I suspect that it is more important to have uniform brass dimension and concentricity, powder charge, and CBTO length.
Speaking of uniform CBTO length (or suprising lack thereof, actually), I took my Hornady Comparator to a box of brand new, off the shelf, FGMM 175gr SMK to see how they compared. I was shocked... They were all over the road, anywhere from 2.208" on the low end to 2.221" high end- a range of 13/1000 inch! By comparison, using the less expensive Hornady 178gr BTHP Match bullets and seating them with my Forster Ultra Micrometer seating die, my total variance for the 25 rounds I loaded for the 2.90" COAL OCW test batch was only 2/1000! I don't have a concentricity gauge yet, but after seeing that range of 13/1000" CBTO with the FGMM, I'm really curious to see how their run-out compares to my neck-turned Lake City brass. Once I get my Lee Collet neck-sizing die in, and process my fired brass with that, I feel pretty confident that my brass will be even more concentric than the FGMM.
'Sorry to run on about this. I guess I'm just hoping that concentricity and uniformity is more important to accuracy than keeping the bullet close to the lands.
Thanks for the offers, FW Conch and Darkker, but I have a pretty good feeling this barrel is going to work well for me. ;-) I really appreciate the your offers and experience!
I'll post an update after my range trip regarding how the FGMM and my handloads at 2.90" and 2.86" all compared.
Acdieter
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