Browning X-Bolt Speed – Nosler 168g ABLR w/ IMR 4831 Groups – Updated 2/2/23

As you may know, I have been working up hand-loads for my moose hunt and finding the Nosler 168g ABLR reaching over 3000 fps with IMR 4831. But the question is, with what accuracy or groups?

Well, I shot this group below and it looks like a tight 3/4″ except for the flyer. I shot the third shot in the upper right target and extrapolated its position on the string below. Why I shot that upper right target? Because I wanted a smaller target as a focal aim point.

But it needed to be repeated in the second target below for me to validate it. The trigger is a heavy 4 lbs. but I was able to get used to where it breaks. The thin mountain barrel does heat fast and after 3 shots to warm it, it begins to string. 

I repeated the same shots a week later with all the same components at 100 yards. The first 3 shots group 3/4 ” from a cold barrel and the 4th shot drops an inch. I know that a lighter trigger may also help. But overall, I was very pleased with the cold shots for hunting purposes.

Tests continue Using my Labradar

I loaded some 168g ABLR’s with hot H1000 Powder to compete with the IMR 4831. See below low left and right 100 yd 3 shot cold barrel groups with extreme spread of 78 fps an 2 inch groups. The IMR 4831 wins!

I did shoot 168 ABLR today for a third bench rest group for the IMR 4831 and Statistics. Below this group was 1 1/4 inches. Shown below with associated Labradar Stats with Extreme Spread of 14.34 fps and a Std Deviation of 8.17. Very nice indeed!

Labradar Report for IMR 4831

Device ID LBR-0028541                                      
                                                             
Series No 4                                             
Total number of shots 3                                 
                                                             
Units velocity fps                                         
Units distances yd                                         
Units kinetic energy ft-lbf                                
Units weight grain (gr)                                    
                                                             
Stats – Average 2937.25 fps                                 
Stats – Highest 2946.69 fps                                 
Stats – Lowest 2932.35 fps                                  
Stats – Ext. Spread 14.34 fps                               
Stats – Std. Dev 8.17 fps                                   
Shot ID V0 V25 V25 V50 V75 V101 Ke0 Ke25 Ke25 Ke50 Ke75 Ke101 Proj. Weight Date Time
1 2933 2893 2893 2852 2814 0 3207 3120 3120 3034 2953 168 2/2/2023 13:01:22
2 2932 2882 2882 2841 2801 0 3207 3098 3098 3011 2925 168 2/2/2023 13:02:44
3 2947 2907 2907 2868 2829 2788 3238 3151 3151 3067 2984 168 2/2/2023 13:04:08

 

Interestingly, I did note that a drop in outside temperature affects ignition and velocity. Last week I shot at 37degrees F and MV avg was 3003. Today at 26 degrees F,  MV avg was 2937 a drop of 70 fps. At 600 yards that equates to a drop of 4 inches on a moose. I’ll keep that in mind!

More Soon…

© Copyright 2023 All Rights Reserved.