Range Report 6.5x47 / IMR 8208XBR / Velocity variations

gvanhyning

Sergeant
Full Member
Minuteman
Went to the range on Friday with some new loads built up. I’m shooting 6.5x47 Lapua and have been looking at alternatives to RE15 for 123 Scenar’s. I put together some loads with IMR 8208XBR and while the overall results look quite promising, I have some numbers with shot groups that are not what I expected. So here is the gun and load info, I’d be interested in some feedback and thoughts.

The gun is a Remington 700 chambered in 6.5x47 Lapua. Action is trued by GA Precision, trigger is Jewell, barrel is a 24” Rock Creek SS 5R with Badger Ordnance oversize recoil lug and FTE muzzle brake. Scope base and rings are Badger Ordnance and scope is a Schmidt & Bender PMII 4-16x50 with P4F reticle. Action is bedded in an AICS chassis with ViperSkins.

The load’s I worked up and reviewed in QuickLoad. I started with 35.0 grains of IMR 8208XBR and increase increments of .2 grains. Bullet is the 123 grain Lapua Scenar seated @ 2.164" measured with a comparator. All shots were through a CED M2 chronograph.

Velocities
35.0 gr - 2790 2810 2803 2798 2805
168esn4.jpg

35.2 gr - 2888 2885 2888 2880 2891
x547lf.jpg

35.4 gr - 2832 2820 2839 2840 2830
futjqe.jpg

35.6 gr - 2832 2831 2828 2837 2840
5xuzxg.jpg

35.8 gr - 2919 2910 2924 2920 2916
2drt5ko.jpg

36.0 gr - 2869 2872 2870 2862 2875
epp1c1.jpg

36.2 gr - 2894 2884 2894 2886 2884
k3lvfp.jpg

36.4 gr - 2894 2892 2932 2909 2903
33ek5tt.jpg


All groups are 5 shots. All pics should be rotated 90 degrees but the damn smartphone is smarter than me. The reason I made this post is to get feedback about velocities and the unusual steps, i.e., 35.0 gr group to 35.2 group had a big jump and then slid back down. The same happened between 35.8 and 36.0. All shot groups were loaded separately so everything stayed in order. The brass did have about 8 shots. I have put portions of these loads together again with brass that has only 2 shots and will check it on the range this week. I would be interested in any all thoughts.
 

mudvayne

Sergeant
Full Member
Minuteman
Feb 23, 2011
168
2
37
Washington TX
Re: 6.5x47 / IMR 8208XBR / Velocity variations

When I was testing my x47 with h4350 it did the same thing. I settled at 41.7gr with a 130 berger @ 2940 fps. H4350 shot by far better than R15 did for me. I had diagonal stringing with moderate loads.

What is happening with the velocity drop is that until you get a compressed load your pressures will vary slightly. Once the pressure is just right, the velocity will maximize and groups seem to tighten up a bit