7mm mag recipe - now with Range(pics) report #2 finally

NormB said:
Jacky,
Those 2 groups have a lot of vertical in them. If you were on a steady rest, this shouldn't be with the right load. Many times increasing the charge will result in less vertical. You say you have no pressure signs and the temperature was warmer, you may want to go up 2 grains and try again.

But as you said, you do have a minute of bear load already.;)

NormB
Click to expand...

This is interesting. I did not know that. I use 62 grains of IMR4350 with the 140 grn Accubonds. Maybe I should work the load up by .5 grain to 62 and chrony each shot. Now I was quite steady on the rest and " a lot" of vertical is really only an inch but thanks for the tip and I may try this next week.

Jacky
 
Jacky, if you are loading for a hunting rifle, it looks like your load is basically good enough. The minor vertical string could just be the result of heating the barrel, or bedding, or the temperature sensitivity of IMR 4350, among other things. For six shots in a magnum hunting rifle to have 1.5 minutes of vertical dispersion is perfectly normal. Interestingly, the 250-yard group shows less than half a minute of vertical spread. I wouldn't worry about it.

Now if you really want to try to tweak up accuracy and velocity, I'd suggest using IMR 4831. As I've posted on the other thread (an many will agree), 62 grains of IMR 4831 with the 160-grain bullet is magic, and should give you higher velocities with less pressure than the load you're using. In fact, 62 grains of IMR 4831 is below maximum. The best news is that IMR 4831 is essentially a slightly slower-burning version of IMR 4350 (same chemistry, just slower burning). If your rifle likes IMR 4350, the odds are that it will like IMR 4831 as well.

In my opinion, IMR 4831 is a preferable choice in the 7mm Remington Magnum over IMR 4350.
 
I may try some IMR 4831 since I have some around that needs to be used up.

As for the groups I didn't have a good rife butt sandbag but I did use one. I think it was more the shooter than anything else.

Jacky
 
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