Last edited by MisterHelix; 10-26-17 at 11:17.
Yes they do and it is for a different bullet as you have noted, with different bearing surface and quite possibly different jacket hardness etc. Their loadings are based on .223 chambers and not the 5.56 NATO variation.
Would you mind sharing your charge weight?
OK, you asked for it! But first I must stress that the loads which I shoot have been worked up with the components that I have on hand and the equipment at my disposal. These might well vary greatly from that which you have access to. Additionally the methods by which I establish a workable and more importantly SAFE charge weight in my rifles are just that mine. I approached this load in 1/10th of a grain increments. Looking for an accuracy node and especially paying attention to pressures. So I must strongly suggest that you follow the established procedures that you are comfortable with and utilize your equipment and knowledge to the best of your ability. I assume no liability for what you or anyone else might choose to do with my loading data.
All that BS out of the way, Using the Hornady 62 grain BTHP, Benchmark powder, Lake City "09 brass and Federal 205 primers loaded to an overall length of 2.255" a charge weight of 24.5 grains (measured on a gemPro 250 scale) gave these velocities for me: 14.5" BCM ELW barrel 2868 ft/secs, 18" Mega barrel gave an even 3000 ft/secs, and the Colt 24" gave 3131 ft/secs. Standard deviations were in the low teens. There is absolutely no bolt swipe on any of hundreds of cases so far, and I must add that case life is shorter, i.e., meaning I am getting about 4 loadings after the original factory pop. Go with God and sin no more.
Thanks 308sako, I appreciate it.
My starting loads were at 23 grains Benchmark, yielding 2675 from a 16" barrel, (LC brass, CCI450's, Lee FCD, OAL 2.25") with the goal of matching POI with the 64 gold dots.
Looks like I probably have a grain or so if I want to push them a bit faster.
Oh, 100 yards will do. I'm pretty close, elevation-wise, though the 62bthp impacts left of the 64gdhp. Kinda weird, but whatever.
Attachment 48225
The group on the left is the 62hpbt, with the 64gdhp on the right. 50 yards. I expect the groups to tighten up when I'm not perching my rifle on the magazine, on top of my pack, trying to avoid putting (another) hole in my chronograph.
Edit: this image is turned on its left side. I don't know why that happens sometimes.
"What would a $2,000 Geissele Super Duty do that a $500 PSA door buster on Black Friday couldn't do?" - Stopsign32v
Thanks for the info. I think I have a box of these in my bullet stash, but haven't gotten around to trying them yet.
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On lateral dispersion... My .300 BLACKOUT shoots the 115 Berger 3.5 inches right and 3/4 inches lower than the Hornady 110 V-Maxes. Velocity and powder virtually identical. I have tried to match jump by controlling seating depth, but nothing helps.
Does everyone remember when Colts with fixed carry handles and HBARs were $1,600?
And now we get FF rails and flat tops for $750.
Inflation what?
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