7mm rem mag speed

[bstomper]

I have done the first portion of the Scott Saterlee 10 round load development for my 7 mm rem mag. I am using H1000, federal case, federal 215 primers and 175gn Accubond LR. I found a real nice node with speeds of 2719, 2722, and 2715 at 63.8, 64.0 and 64.2 grns and they grouped sub MOA. Is 2700 FPS a considered a slow speed for the 7 mm in 175 grain bullet.

 

[BallisticsGuy]

Kinda depends on the bullet. Construction, composition, bearing surface all have an effect. Based on the published data, you're right around max and getting what I'd expect, if not just a tickle more.

 

[55stone]

I dont have a lot of time with a 7mm RM but i just went through load development with 160gr. accubonds and 2 different powders. started with RL22 which was fast around 3000 but didnt group well. now with H4831 im getting an average of 2830 and around 1/2 MOA at 100 yards. havent had time to stretch its legs yet.

 

[bstomper]

Thanks guys. From my research I thought that the speed was in the ball park also for that grain but just wanted hear from some others with more experience.
My next plan is to load up 5 more at 64 gns and stretch it out some and see what they do. I will also chronograph the speed to see what the extremes spread is and if that looks good I will adjust the seating depth to try and tighten up the group.

 

[JJMoody]

Deleted

 

[bstomper]

I have also done the same development with the same case, primer and powder but the 165 gn Sierra gamechanger and got a nice node at the 2930 FPS speeds. Groups are slightly bigger though. I will definitely keep working on this.

 

[airohunter]

My load is 69.5grains of Retumbo pushing 175gr ELDX and I am able to get 3035fps

 

[Jud96]

I would push to find a higher node. A 7mm-08 nearly does that with a 175 and 26" barrel. There shouldn't be any reason you can't reach at least 2950fps safely with H1000 and 175s.

 

[L.Sherm]

Im getting right at 3000 fps with 180 Berger and 215 primer and H1000 in my nephews 7 mag. It's got some freebore not alot I dont know how much.

 

[bstomper]

I've taken it up to the manuals max of 64.5 and only hit 2812 fps. My Coal is 3.370. Instead of the 3.290 the manual says. With the extra room in the case could I go a bit above the book max for powder charge. I haven't seen any pressure signs. The primers are a bit flat but then again so are the lower charged ones.

 

[bstomper]

Would the extra case volume because of the longer seating cause lower speeds. Should I go higher with charge weight. Or redo the text at 2.290"

 

[Jud96]

Would the extra case volume because of the longer seating cause lower speeds. Should I go higher with charge weight

Yes, the more case volume you create, the more powder it will take to get up to pressure. I would just slowly work up 0.2gr at a time until you feel the bolt lift get stiffer and/or ejector marks on your brass. Manuals are excellent starting points and references, but their max loads could either be dangerous in your rifle or a squib load. It's best to start low like you did, and work up until you find pressure in your rifle with your bullet, powder, brass, primer, seat length combo.

 

[JJMoody]

What's your distance to the lands in your rifle?

 

[JJMoody]

Book coal may not mean as much in your rifle. Speaking of that, I don't recall seeing any specs on your rifle. My knee-jerk says you're at the low end of velocity, but without knowing certain specifics, I could be very wrong. Barrel length, action, barrel make, custom/factory job etc... tell us about her, man!