7mm Magnum velocity

[TackDriv3r]

I am in the process of gearing up for deer season and loaded some RL-22 and 140 Bergers VLD. I have a Sako 7 Magnum with a custom Brux 26 inch pencil thin barrel and made 6 loads in .5 increments from 66.5 to 69 grains as a work up to find accuracy / velocity with some good case fill for consistency. I started close to max as manuals indicate and up to under max pressure as Quickload indicates. At the range I set up my Oehler 35 and settled down to shoot my first string of 3 rounds, mean speed average was 3275 fps with 14 ES and 7 SD. Group was .267 MOA, 2nd group was at mean velocity of 3302 fps with 67 grains with 15 ES and 7 SD but groups opened up slightly to .4 MOA, 3rd group shot a mean of 3323 fps and no pressure signs on bolt or brass. Groups opened even more to .5 MOA. I know that I never have shot a 7mm Magnum with this kind of speed and I decided to stop right there. I chose to go back to 65.5 grains and work up to 66.7 grains and find that sweet spot. Just being wise not to continue to shoot the rest of those loads and pulled out all the bullets.

 

[snert]

I am in the process of gearing up for deer season and loaded some RL-22 and 140 Bergers VLD. I have a Sako 7 Magnum with a custom Brux 26 inch pencil thin barrel and made 6 loads in .5 increments from 66.5 to 69 grains as a work up to find accuracy / velocity with some good case fill for consistency. I started close to max as manuals indicate and up to under max pressure as Quickload indicates. At the range I set up my Oehler 35 and settled down to shoot my first string of 3 rounds, mean speed average was 3275 fps with 14 ES and 7 SD. Group was .267 MOA, 2nd group was at mean velocity of 3302 fps with 67 grains with 15 ES and 7 SD but groups opened up slightly to .4 MOA, 3rd group shot a mean of 3323 fps and no pressure signs on bolt or brass. Groups opened even more to .5 MOA. I know that I never have shot a 7mm Magnum with this kind of speed and I decided to stop right there. I chose to go back to 65.5 grains and work up to 66.7 grains and find that sweet spot. Just being wise not to continue to shoot the rest of those loads and pulled out all the bullets.

That is a smokin fast 7Rem mag load. Good move.

 

[nvbroncrider]

Nosler manual claims 3340 with 140's and RL22 in a 24" barrel. Your 26" tube should give you an extra 50fps or so.

 

[rifleman700]

I am in the process of gearing up for deer season and loaded some RL-22 and 140 Bergers VLD. I have a Sako 7 Magnum with a custom Brux 26 inch pencil thin barrel and made 6 loads in .5 increments from 66.5 to 69 grains as a work up to find accuracy / velocity with some good case fill for consistency. I started close to max as manuals indicate and up to under max pressure as Quickload indicates. At the range I set up my Oehler 35 and settled down to shoot my first string of 3 rounds, mean speed average was 3275 fps with 14 ES and 7 SD. Group was .267 MOA, 2nd group was at mean velocity of 3302 fps with 67 grains with 15 ES and 7 SD but groups opened up slightly to .4 MOA, 3rd group shot a mean of 3323 fps and no pressure signs on bolt or brass. Groups opened even more to .5 MOA. I know that I never have shot a 7mm Magnum with this kind of speed and I decided to stop right there. I chose to go back to 65.5 grains and work up to 66.7 grains and find that sweet spot. Just being wise not to continue to shoot the rest of those loads and pulled out all the bullets.

What brass are you using? That is a lot of velocity / pressure for a mid range load. I would not go above the 3300 fps. Just because you don't see pressure signs does not mean you don't have high pressures. VELOCITY=PRESSURE. Adjust your case capacity option in QL and then adjust powder charge to show velocity you are getting and you will get a better idea of pressures. Powder lots can vary but pressure never changes for that given powder.

 

[nvbroncrider]

I'd say your right there.

 

[TackDriv3r]

What brass are you using? That is a lot of velocity / pressure for a mid range load. I would not go above the 3300 fps. Just because you don't see pressure signs does not mean you don't have high pressures. VELOCITY=PRESSURE. Adjust your case capacity option in QL and then adjust powder charge to show velocity you are getting and you will get a better idea of pressures. Powder lots can vary but pressure never changes for that given powder.

I am using Norma brass and CCI 250 Magnum primers. QL has been weird with H20 capacities for this caliber except other calibers. Even if I use default and my measurements for H20 case capacity, weighing factor of .33, temp of 90 degrees and it still shows mild pressure ( high 30k to mid 40k)with speed from 3,046 to 3,144 with default and after adjustment. I did not touch the Burning rate Ba factor yet,,, after I changed the Ba factor from .3934 to .4234 to match the chrono velocity of 3280 fps and pressure shows 54,591 with 66.5 grains and max pressure is 61,000. Hope I was doing the adjustments correctly. If I am wrong, please correct me. Thanks.

Side note, Nosler manual says 67.5 grains RL22 is max. I have not gone over yet, I am getting good speed possibly because I have a fast barrel.

 

[nvbroncrider]

I am using Norma brass and CCI 250 Magnum primers. QL has been weird with H20 capacities for this caliber except other calibers. Even if I use default and my measurements for H20 case capacity, weighing factor of .33, temp of 90 degrees and it still shows mild pressure ( high 30k to mid 40k)with speed from 3,046 to 3,144 with default and after adjustment. I did not touch the Burning rate Ba factor yet,,, after I changed the Ba factor from .3934 to .4234 to match the chrono velocity of 3280 fps and pressure shows 54,591 with 66.5 grains and max pressure is 61,000. Hope I was doing the adjustments correctly. If I am wrong, please correct me. Thanks.

Side note, Nosler manual says 67.5 grains RL22 is max. I have not gone over yet, I am getting good speed possibly because I have a fast barrel.

Plus you got 2" of extra barrel that will give you another 50 fps as a general rule. Your doing just fine. If your accuracy is falling off at that point you don't have enough room to hit the next node so run with it.

 

[TackDriv3r]

Plus you got 2" of extra barrel that will give you another 50 fps as a general rule. Your doing just fine. If your accuracy is falling off at that point you don't have enough room to hit the next node so run with it.

Exactly what I was thinking, seems like its the safest highest accuracy node.

 

[nvbroncrider]

If you want more than that punch it out to a 7mm Mashburn Super Mag

 

[TackDriv3r]

If you want more than that punch it out to a 7mm Mashburn Super Mag

No need for more punch, the 7 RM has all you need. Plus I have a new .300 Win Mag build coming next month. The Mashburn Super Mag is bad ass.

 

[nvbroncrider]

No need for more punch, the 7 RM has all you need. Plus I have a new .300 Win Mag build coming next month. The Mashburn Super Mag is bad ass.

Yeah I got one 3050 with a 24" tube and 175's is some serious medicine.

 

[TackDriv3r]

Yeah I got one 3050 with a 24" tube and 175's is some serious medicine.

That is a smoking fast heavyweight.

 

[AckleymanII]

Now what is weird, go to 200yds and 300yds with those same loads and find out what shoots the best. Every 7 mag that I have owned shot the best with the bullet touching the lands with the 140g, and the accubond touching lands and 140 tipped triple shock .050 off the lands is simply fantastic. Figure on loosing a tad bit of velocity in cold weather, thus the hotter load will be ok. R#22 loves the cci 250, and the 120g tipped triple shock with 71-73g of R#22 is nothing short of unbelievable, fast and bug holes to clover leafs. 120g tipped triple shock will penetrate like a 175 cup and core bullet, deer will not stop them, and most elk do not either.

 

[TackDriv3r]

Now what is weird, go to 200yds and 300yds with those same loads and find out what shoots the best. Every 7 mag that I have owned shot the best with the bullet touching the lands with the 140g, and the accubond touching lands and 140 tipped triple shock .050 off the lands is simply fantastic. Figure on loosing a tad bit of velocity in cold weather, thus the hotter load will be ok. R#22 loves the cci 250, and the 120g tipped triple shock with 71-73g of R#22 is nothing short of unbelievable, fast and bug holes to clover leafs. 120g tipped triple shock will penetrate like a 175 cup and core bullet, deer will not stop them, and most elk do not either.

I have used 140 Accubond and RL 19, shoots bug holes like this,,,

 

[AckleymanII]

I forgot that I shot R#19 in one rifle till my brother scarfed that rifle up, 67g of R#19, Win brass, fed 215, 140g Tipped triple shock, shot bug holes at 3300, bullet off the lands .050. Lot#'s vary, start low and work up.

 

[nvbroncrider]

That's perfect right there. Can't complain one bit about it.

 

[TackDriv3r]

I forgot that I shot R#19 in one rifle till my brother scarfed that rifle up, 67g of R#19, Win brass, fed 215, 140g Tipped triple shock, shot bug holes at 3300, bullet off the lands .050. Lot#'s vary, start low and work up.

Yes, it shot that fast in mine a few weeks ago with same charge weight.

 

[AckleymanII]

I would really have reservations on a 140g berger at 3200 in a 7 mag as these bullets are more explosive than the old 140g Nosler ballistic tips.

 

[tominboise]

What is the intended target of your load? Deer, elk, coyotes, rocks?

 

[Breakshunter]

I have shot 5 elk in the last few years with 140 Berger’s in a 7stw at just above 3300fps. None took another step but it is hard on meat. Dang do they shoot great outta that old sendero rifle though!