I just joined this site the other day. I already have found tons of useful info. I have not reloaded in some time but due to the increase in Federal Premium 25-06 bullets I broke out the Rockchucker a few weeks ago. I worked up a load for my 25-06.
I just purchased a Thompson Center Venture chambered in 270 Win, a box of Hornady SST bullets and some IMR 4831. I checked my old trusty Speer # 13 manual which listed a max load of 58 grains and a velocity of 2967 (if I remember correctly) . I then pulled up the data on Hodgdon's website. They list max as 55.8 with a velosity of 3002 fps. I then called Hornady and they said they listed the max at 56.2 grains and I did not ask what velocity they listed.
I started with 55 grains and worked up to 57 grains. 56.5 grains was my best group. It shot a 5 shot group around 3/4 of an inch. I noticed no pressure signs at all until I hit 57 grains. The primers flattened out. The only way you could tell where the primer stopped and the case started was the color difference. I figured it was a little to hot. 56.5 grains is the magic load in my gun. I guess I could try to dial it on in but I deer hunt with shots generally less than 200 yards. I figure I am right where I need to be.
I am stumped on the differences in the loading data. I called Speer and they stood behind their max load. Hornady said it is way to hot and I should stay below 56.2 grains. My question is how can 55.8 grains of IMR 4831 have a velocity of 3002 fps but the 58 grains is only listing 2967 fps.
Anyone have any ideas??
Thanks!
Darin
I just purchased a Thompson Center Venture chambered in 270 Win, a box of Hornady SST bullets and some IMR 4831. I checked my old trusty Speer # 13 manual which listed a max load of 58 grains and a velocity of 2967 (if I remember correctly) . I then pulled up the data on Hodgdon's website. They list max as 55.8 with a velosity of 3002 fps. I then called Hornady and they said they listed the max at 56.2 grains and I did not ask what velocity they listed.
I started with 55 grains and worked up to 57 grains. 56.5 grains was my best group. It shot a 5 shot group around 3/4 of an inch. I noticed no pressure signs at all until I hit 57 grains. The primers flattened out. The only way you could tell where the primer stopped and the case started was the color difference. I figured it was a little to hot. 56.5 grains is the magic load in my gun. I guess I could try to dial it on in but I deer hunt with shots generally less than 200 yards. I figure I am right where I need to be.
I am stumped on the differences in the loading data. I called Speer and they stood behind their max load. Hornady said it is way to hot and I should stay below 56.2 grains. My question is how can 55.8 grains of IMR 4831 have a velocity of 3002 fps but the 58 grains is only listing 2967 fps.
Anyone have any ideas??
Thanks!
Darin