Slow Barrel???

[Dano1]

Well,

I went out and did some shooting today and decided to Chrony my 7mm Rem Mag Sendero. I needed to find out the Velocity to match it up to the New Leupold Varmit Hunter's Plex in my new scope.

I was Very supprised to find out that while shooting "book" Max 150g Sierra GameKing with 62g H4831SC. I was only getting 2750fps (5 shot average). I had a Ruger No1 and fired the same load in it and got 2960fps (5 shot average) that's over 200fps.

Has anyone here ever seen something like this. I know there are variations from one rifle to another, but I've never seen that much diffrence between two rifles and the same load.

Accuracy was ok, but not the best. I've gotta wonder if something is up with the bbl. I've never quite been happy with this rifle, it's never felt right when shooting it, meaning balistics and stuff, For crying out loud, my .30-06 AI will shoot a 165g bullet at 3125fps.

I love Remington 700's, I'm just thinking of rebarreling the thing and using a better bbl, and maybe a diffrent cartridge.

Any thoughts???

Dan

 

[Ballistic64]

That does sound a little slow for that load.Im getting almost 2900 with 168SMKs using 62gr of RL19 in a 24" barrel.Id almost be more suspect of the chrono?

 

[Dano1]

It's not the Chrony, I fired a known load over it with my .30-06 AI and it was right on.

It also was consistant from shot to shot with each rifle. Variation was maybe 25fps max.
It's just that the 7mm Sendero was shooting very slow. According to the book, I should be getting 2900-3000 FPS with this load, Sierra says I should be shooting 63.2g of H4831 to achieve 3000FPS.

I'll re-test it when I get another chance, but I'm still wondering why so slow.

I used to shoot Moly bullets, but I stripped the bbl and cleaned out the moly. It still holds copper. I've never been able to get it all out of this bbl. I also bought this rifle used several years ago and I frankly don't know it's past history. There could certainly be something there.

I'm leaning toward using it as a builder for another cartridge. I've been interested in a .300 Win Mag for a while. Might be time to build one of those.

Dan