tcoz
02-19-2017, 07:48 AM
I picked up a couple boxes of Hornady 168gr HPBT Match to shoot through my new 20" 10 FCP-SR. Since this is my first .308 bolt gun I wanted to establish some baselines before starting to handload for it using the same bullets.
All things considered I thought the results were pretty good considering who was behind the trigger (me). Going through the first box, five shot groups were an easy 1 to 1-1/4" with no flyers.
I figured I would first establish my load using the same ogive to base measurement as the commercial ammo as a starting point and after finding the load, I would then fine tune the OAL to my rifle. Using the Hornady bullet comparator, I matched my ogive to base to the same 2.170" as the Hornady and I loaded a number of test rounds at seven different charges which I'm going to shoot today.
After loading them I picked up an RCBS Precision Mic and I was really surprised to find that my rifle is 2.250" to the lands which means that the commercial match ammo has a .080" jump which I wouldn't think would be very conducive to good accuracy. I know that commercial ammo is loaded to run in any gun which includes autoloaders so the tolerances can't be tight but I'm just surprised that a bullet jump that long could produce 1 MOA accuracy.
Obviously, I went about it backwards and should have bought the gauge and checked before loading in which case I would've loaded for a .030-.040 jump but I'm thinking that maybe the Hornady HPBT Match bullet isn't all that sensitive to jump. It's a secant ogive so in theory it should be more sensitive and if so, I'm pretty stoked to see what I can do with it after playing around a bit with the seating depth.
I'm curious to hear what others who use this bullet have found.
All things considered I thought the results were pretty good considering who was behind the trigger (me). Going through the first box, five shot groups were an easy 1 to 1-1/4" with no flyers.
I figured I would first establish my load using the same ogive to base measurement as the commercial ammo as a starting point and after finding the load, I would then fine tune the OAL to my rifle. Using the Hornady bullet comparator, I matched my ogive to base to the same 2.170" as the Hornady and I loaded a number of test rounds at seven different charges which I'm going to shoot today.
After loading them I picked up an RCBS Precision Mic and I was really surprised to find that my rifle is 2.250" to the lands which means that the commercial match ammo has a .080" jump which I wouldn't think would be very conducive to good accuracy. I know that commercial ammo is loaded to run in any gun which includes autoloaders so the tolerances can't be tight but I'm just surprised that a bullet jump that long could produce 1 MOA accuracy.
Obviously, I went about it backwards and should have bought the gauge and checked before loading in which case I would've loaded for a .030-.040 jump but I'm thinking that maybe the Hornady HPBT Match bullet isn't all that sensitive to jump. It's a secant ogive so in theory it should be more sensitive and if so, I'm pretty stoked to see what I can do with it after playing around a bit with the seating depth.
I'm curious to hear what others who use this bullet have found.