175gr Sierra HPBT Handload Quirk

Discussion in 'Reloading' started by alex.sevilla.98, Jan 6, 2013.

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  1. alex.sevilla.98

    alex.sevilla.98 Member

    Sep 16, 2010

    I decided to move up to the 175gr Sierra's (Matchking) for my 308. I've used M118LR in it before with moderate success, but not at <400 yards and in. As I understand it, they 175s do not stabilize at these short ranges, so I decided to work up some loads of my own to see whether I could get good results. For testing, I used Lake City Pull Down brass, Varget Powder and of course the Matchkings from Sierra. All shooting was done from the prone, off a bipod, at 300 yards. I've previously worked up loads for the 168s at 100 yards with good results, but terrible results beyond...something like .6MOA at 100, to 1.5MOA beyond. That, and the stabilization issue was the reason for me deciding to test at 300 yards. Okay, here were my results:

    40.0 grains = 3.060"
    40.5 grains = 2.300"
    41.0 grains = 1.244"
    41.5 grains = 2.114"
    42.0 grains = 1.498"
    42.5 grains = 2.791"
    43.0 grains = 1.050"
    43.5 grains = 2.048"
    44.0 grains = 1.254"

    These are non-corrected 5 shot group sizes. After each string, I let the barrel cool down for about 5 minutes with the bolt removed to allow for max air flow. Temperature was 45*, humidity was 76%. There was little to no wind (merely 1-2 mph when it was howling).

    My question is: has this happened to anyone else??