Might as well have a 7mm-08 not a 7mm Rem Mag!
- Thread starter CourtenayBoy
- Start date
Right you are Bruce. And it's a good thing that deer don't read ballistics tables or carry chronographs. I remember when the 7mm STW first hit the streets. I hunted with a couple of pals who had them while I carried my 7x57. We all used 140gr Nosler BTs. They were loading the STW with 80grs of powder to get 3300 fps while 48-50 gr of powder had my 7x57 tooling along at a more sedate 2800 fps. My deer seemed to fall over about the same as theirs, and with a lot less ruined meat. Besides, I could enjoy shooting my 7x57 all day at the range while they were in the "cringe and tug" mode to master all of the sound and fury. Let's not forget the excellent .280 Rem, one of the best all round hunting ctgs there is.
I did this. Used a hack saw to cut a 30" 308 target barrel down to about 24" As I recall, the velocity DROPPED about 25 fps per inch.
The only caliber I know of that gets slower velocity out of a real long barrel is a 22LR.
To the OP. If you use an appropriate powder (and you are), there is a direct correlation to velocity and pressure. You can't measure pressure, but you can measure velocity. Load a batch of ammo (5 round samples) in 0.3 gr increments to at least 4 grains more than you have tried. Different rifles (barrels/chambers) need more or less powder to get the same pressure/velocity as the one in the loading manual.
Shoot 2 rounds over the Chrony and 3 for group.
let us know how it goes.
Be prepared to bring some home, if and when you hit pressure signs. Any change in bolt lift is the sign to stop.
Last edited:
Makes perfect sense to me.
Tikka you say? I had a Tikka 7mag, it was a slug. Couldnt get over 2850 with 160's and I tried a pile of different powders. Barely got 3000 with 150 TTSX, again trying a bunch of different powders. It's been a few years but I seem to recall retumbo and rl 25 giving the best velocites.
Yep H, I suspect he was as I've never had a 24" 7 mag that wouldn't give 3050-3100 with 160s, and a couple did even better than that......approaching 3200...............IMR 7828 and RL 25 are your best friends with a 7 mag.
Yes I was, that being said everytime I started to go over book max those primers would flatten right out and bolt lift was starting to get a bit stiff. But who knows maybe things were fine and I was reading pressure signs wrong...was reading things the best I could at the time.
That happens at 70,000psi, typically. Only thing left to try is more of a slower powder.
uncledillers
Regular
- Location
- Comox Valley
I ran those numbers through quickload (using standard length and case capacity) and 2750 fps was what it predicted.
Yes John, I followed Jack O'Connor for a lot of informative years also and one who has done so, can not help but like him. He told it like it was, in good plain, easy reading English, without the ifs, buts and maybes!
Late in his career he wrote of the many hundreds of game animals he had either shot, or seen shot, with a 7x57 Mauser and told of all the hundreds of head of game he had either shot, or seen shot, with a 7mm Remington magnum, and he stated that he honestly couldn't see any difference in the killing power between either of them!
He wrote that a good hit meant a dead animal and a poor hit meant a wounded animal, with either of them.
Bruce
Late in his career he wrote of the many hundreds of game animals he had either shot, or seen shot, with a 7x57 Mauser and told of all the hundreds of head of game he had either shot, or seen shot, with a 7mm Remington magnum, and he stated that he honestly couldn't see any difference in the killing power between either of them!
He wrote that a good hit meant a dead animal and a poor hit meant a wounded animal, with either of them.
Bruce
I had a 160 gr bullet with 64 gr of IMR 4831 at around 3000fps and a 150 gr TSX up to 3090 fps with 66 gr RL22 with my 7RM. It was a Tikka and shot moa or better consistently. I do believe that 7RM data for some reason is quite anemic...IMHO. Load up carefully...
Just a thank you to all who have lent their time and advice here. My loading bench got packed and the house went on the marea right after I wrote this post so I have yet to get a chance to put anything into action. That being said, we move June 30 and I will be building a new bench and getting back into it. Thanks again
Cheers
Mike
Cheers
Mike
I've loaded for the 7Mag since the mid 60's and started using data available then. It seems that about the time the BAR started being chambered in 7 Mag the loading data changed significantly. M y loads from the past worked well and I have always loaded 1mr 4831 over a 160 for about 3100. All of my rifles liked that load.
