Velocity for Rams, using 7mm 175 SMK?

Bill the Lurker · Post by **Bill the Lurker** » Thu Mar 13, 2008 1:29 pm

This is all new to me, so asking for help from experienced users.
Is there a rule of thumb regarding needed velocity using 175gr 7mm SMK for Rams?

Started some load work on my new 7mmBR. I am gettting decent groups of 5 (at 100M), with 175gr moly SMK running 2325fps.

Do I need to look for more velocity?
Am I there?
Pressure LOOKS good, primer pockets seem tight yet, but only have like 3 loadings on this R_P brass.

Pretty sure I have the c-p-t load figured with 130SMK.

Thanks for any ideas,
Bill

Silo65 · Post by **Silo65** » Thu Mar 13, 2008 2:22 pm

Using you

yankee · Post by **yankee** » Thu Mar 13, 2008 3:25 pm

The bottom line is you won't know for sure how they group at 500 M till you try them. So next time you go to a match arrive early or the day before and spend some time at the different distances. Take along some different loads and give them a try. Check with the match director and see when the best time is. I have used the 175 7mm at about 2450 and they did a great job.
You hear stories about velocity and energy at 500 M. There have even been studies done. Hornady had a pamphlet printed years ago. Again the bottom line. Each bullet is different and constructed different and hits the target at a different angle and at a different velocity. They all hit the target and transfer the energy differently. We are not even talking about different targets, stands and all that. Try them and see how they do.

carl425 · Post by **carl425** » Thu Mar 13, 2008 8:22 pm

I look at Silo's calculation a little differently. I've always heard that 1 lb of momentum is the minimum required to reliably knock down the ram. It seems to me that 16% over minimum reliable is a good place to be.

Before switching to the 6.5x47 Lapua, I shot 7mm 168's at 2350. Every ram I ever hit went down.

If it groups well, I'd go with it.

timfinle · Post by **timfinle** » Fri Mar 14, 2008 1:48 pm

My thoughts are that first you must hit the target. If your rifle groups best with what you stated as your load, use it. If you speed up the velocity and the group grows in side, don't use it.

I shoot a 140 grain bullet (smk) at 2550 and have only lost one ram. My friend shoots a 123 and he has only lost one that I remember. Bullet construction can have a lot to do with how well the rams topple. I have heard that the A-max is a great bullet when hitting rams with a small grain weight because they hold together real well and push on the animal longer.

Here is an experiment I did a while ago. I pushed a 120 smk to 2900 ft/s and shoot it at the rams. Hit the ram pretty close to center. I fired from the bench and guess what? The ram did not fall. The hit looked like a big splat. Then I shoot a 120 smk at my usual velocity of 2700 ft/s, hit in about the same place (different animal), with no big splat and the animal fell. If you push the velocity to fast some of the bullets will just come apart on impact.

I think your load and velocity are going to work great for you if it is the most accurate load for your rifle.

Jerry G · Post by **Jerry G** » Thu Mar 20, 2008 9:35 am

I think you need about 35Lbs-Ft/Sec. If you can't come up with a program that gives you that information, 1100 lbs of energy on the target is about as low as you want to go.

The two different measurments don't have a lot to do with each other. I would use the Lbs-Ft/Sec if you could. It gives you a better picture of target knock down power.