Developing a load from scratch

[Tater1985]

Does anyone think that starting at 66gr is a bad idea with a bullet that's only .010" off the lands?

For reference I had shot some HSM ammo loaded with 168gr bergers. I measured them to be .080" off the lands and the advertised velocity (never shot through chrono) was 3067fps. The primers in these loads were smashed pretty dang flat, but that's a pretty hot for factory.

[moombaskier]

You'll be fine. My load is 72grs with the 168 at .010" jump in a factory Rem 700 action. DON'T start at 72! If you have a chrony use it during the work up. I'll bet that 66grs will chrony at 2800fps or less. Just start at the 66grs and enjoy the practice.

[rscott5028]

I would use a .5 gr step size.

[Tater1985]

Sorry for the super long wait, but here is the update on the loads. Just shot them today.

Reloaded first loads @ 2.714" (.011" off the lands)

3 shot groups at 200 yards off bipod out of my truck bed.

66.0 gr
2831, 2775, 2748
2785 avg
1.81"

67.0 gr
2836, 2830, 2749
2805 avg
1.88"

68.0 gr
2885, 2945, 2895
2908 avg
2.93"

69.0 gr
2943, err9, 2854
2899 avg
6.06"

70.0 gr
2979, 2912, 2953
2948 avg
3.88"

[MachV]

Your results go right along mine with H1000 with any length that would fit down the mag. I switched to Retumbo and the groups closed up as the powder increased,they fit down the mag and dont mind the cold but do get a little fickle above 95*....

[Tater1985]

Originally Posted by MachV

Your results go right along mine with H1000 with any length that would fit down the mag. I switched to Retumbo and the groups closed up as the powder increased,they fit down the mag and dont mind the cold but do get a little fickle above 95*....

Groups closed up! I'm no crack shot by any stretch of the imagination, lol. If I shoot sub MOA groups at all, I'm doing good, especially since these were all laying in the bed of my truck and shooting off a bipod. They my tighten up if I were to shoot off of bags at a bench.

I wonder if I can get the 70gr charge to tighten up to what the 66gr and 67gr was shooting by playing with seating depth? I would still like to find what the max charge is for this load, I'm not showing any pressure signs yet at 70gr.

[kaseyfied]

U should be able to get under an moa to be effective at longer range.. 1.88 is not really long range accurate.. it may even open up more at longer distance.. shouldnt matter if ur off a bipod or shootin bag i do both.. mostly bipod now as thats how we hunt in the field.. just as accurate if u use a rear bag.. i would keep playing with it u def should be able to get those within 1 inch or better at 200.. i have a lapua that off a bipod shoots .33 inch groups all day at 300.. keep workin at it
. I agree try retumbo.. my 7mm loves retumbo!!

Kasey