7mm Blaser Mag information

[ebrownw2]

Found the dies in stock at Graf & Sons so went ahead and pulled the trigger on them. Barrel should be here tomorrow. Hated to order any bullets before verifying the twist rate. Do you guys know what yours is?

The barrel I bought has had less than a box of Norma 156 grain oryx factory loads shot through it. He sighted it in and took it to New Zealand where he used it on a huge red stag.

My thinking is that since this caliber was developed as a joint project between Blaser and Norma, and Norma is loading the 156 grain bullet for it, that it probably will perform best with a similar weight bullet. So, I'm mainly looking at the 150 and 160 grain options out there.

[7BlaserMag]

Mine is being built as a semi custom on a trued Rem 700 long action with a 1-8tw Hart barrel. It will have a finish length of 26 inches. Unless you plan on shooting the heavies, I'm sure a 1-9tw will be plenty.

[KZ45]

I started low, and began climbing the ladder slowly with some 160gr. Accubonds, and RL-25. I figured it might be safer to start with a slower burning powder. I measured distance to ogive on the Norma factory rounds, and used that to get my seating depth for the Accubonds. It seemed to work well, and the rounds were plenty accurate, even though I'm not really going to start focusing on that until I get into higher velocities.

At 65.5 grains of RL-25, the velocity was hanging around 2700fps. I'm going to take some out tomorrow, and climb up a couple grains more. I think there's still aways to go, and if this round hits 2925fps, it will be at the speed of the factory Nosler 7mm Rem. Mag., without the belt, less trimming, and possibly longer barrel life. I don't know if this is the ideal powder for it, but I think it will get there, and beyond. I also want to try H4831sc, RL-22, MRP, and IMR4350. I was reading about the new Reloader R-26 on their website, and it sounds like it would be a good one to try, but I can't find it for sale anywhere.

It's a good looking cartridge.

IMG_2413.jpg

[Corjack]

I think Rl 25 should be about right. Possibly try some H1000 and H4831 if you got it.

[KZ45]

I think Rl 25 should be about right. Possibly try some H1000 and H4831 if you got it.

I do. I'll give H1000 a try next.

[7BlaserMag]

Of the powders you listed, per QL, RL22 is going to give you a very slight velocity edge over h4831sc but H4831sc will be by far less temp sensitive. I think H1000 will be a tad to slow for that bullet

[KZ45]

Of the powders you listed, per QL, RL22 is going to give you a very slight velocity edge over h4831sc but H4831sc will be by far less temp sensitive. I think H1000 will be a tad to slow for that bullet

We will have to see. I've seen people post some load data for H1000 with that bullet in the 7mm Rem Mag, and say they had good results The more I read about R26, the more I want to try it with this cartridge. It looks like it has a little faster burn rate than the RL25, without the temp sensitivity. Supposedly you reach higher pressures with less powder. It reminds me of how The R17 works when compared to other powders in it's range. I'm gonna pick up a pound.

Here's what the Blaser case looks like next to a 7mm Rem Mag. A little shorter, but larger in diameter all the way up. Sharper shoulder, and a little bit longer neck. Wild thing is that my once fired cases are about .003, to .005 shorter OAL than when they were new.

IMG_2406.jpg

[SPEEDY]

Love to see the Blaser case necked to either 270 or 264, I've always found tge 7mm a little oddball.
Whats always suprised me is how the 7mm for some reason is the only metric caliber that has ever been excepted in the US.

[9.3x64]

Love to see the Blaser case necked to either 270 or 264, I've always found tge 7mm a little oddball.
Whats always suprised me is how the 7mm for some reason is the only metric caliber that has ever been excepted in the US.

Nothing odd about the 7mm bore.
Exceptional BC & SD characteristics and bullet weights up to 180 grains, excellent for deer.

[7BlaserMag]

Wild thing is that my once fired cases are about .003, to .005 shorter OAL than when they were new.

Your cases are forming to the chamber and you could have a chamber that's a smidge oversized.

You should see what happens to the OAL on some of my Ackley Improved chambered guns, when that should squares off to 40 degrees after it's fireformed, OAL will shorten up 20-30 thou.

[7BlaserMag]

Love to see the Blaser case necked to either 270 or 264, I've always found tge 7mm a little oddball.
Whats always suprised me is how the 7mm for some reason is the only metric caliber that has ever been excepted in the US.

Now that Berger finally offers a heavy .277 bullet with an outstanding bc the 7mm Blaser Mag necked down to 270 loaded with 170gr Bergers should make one he11 of a long range 270 hammer on just about anything you want to point it at.

[7BlaserMag]

Picked it up today. Gunsmith did a load work up with 180 Berger and RL26. Worked the load all the way up to 3100fps with the 180's but that load was giving a very faint ejector mark so he backed it off a .5 grain and shot a 5 shot group of .3 at 3050fps. Not bad for only having 15 rounds down the pipe.

[KZ45]

Man that's awesome. That Berger VLD has an incredible bc of ,673 too. You have that thing going a lot faster than the 7mm Rem Mag 180 Berger that HSM has out.(2845fps) I'm putting together a spreadsheet for 7mm Blaser Magnum load data and plan to post it in the reloading forum when there's info. Hunting season has slowed down the project recently, but I plan on getting back to it soon. We'll have to share information, as that load of yours belongs in the 180s for sure.

[SPEEDY]

Nice looking LR rig that, I prefer something like that over a super duper you bute tacticool rig.

[7BlaserMag]

Man that's awesome. That Berger VLD has an incredible bc of ,673 too. You have that thing going a lot faster than the 7mm Rem Mag 180 burger that HSM has out.(2845fps) I'm putting together a spreadsheet for 7mm Blaser Magnum load data and plan to post it in the reloading forum when there's info. Hunting season has slowed down the project recently, but I plan on getting back to it soon. We'll have to share information, as that load of yours belongs in the 180s for sure.

KZ45, my 7mm Blaser build DOES NOT have a conventional throat design and because of that I'm able to shoot much hotter loads without getting high pressure. My gun has a patented throat design my gunsmith came up with a couple years ago that allows you to load more powder than a standard load but without getting the big spike in pressure. Similar to long freebore, it flattens out the pressure curve, but, unlike long freebore, it has no ill affect on accuracy. They usually get an extra 100-200 fps with this throat design, depending on the cartridge.

My particular load in a conventionally throated 7mm Blaser Mag would probably not be a very good idea.