7mm rem mag speed

[bstomper]

Haha.
One 5 shot group on each target unfortunately.

 

[zr600]

Maybe play with seating depth to try tightening it up, or maybe let a more experienced shooter shoot it, or further distance. There seems to be a lot of vertical in them groups.

 

[bstomper]

I was shooting off my bipod. I will repeat the test and use my sand bags to shoot off of. That should work better.
When adjusting the seating depth what increments should I use 0.010"? Shorter or longer?

 

[zr600]

You could do .010 there's a lot you could do. Did you have a rear bag when you were shooting off your bipod if not that could be some of the grouping issue there too.

 

[Canhunter35]

Bstomper, I see we r both saskatchewanites.
Flat spots aren't necessarily indicated by low muzzle velocity spreads. Group size indicates the node, sometimes it comes with a tight es, sometime not.
You're getting a lot of vertical stringing, is ur barrel free floated and if it is does the stock touch it when you rest on the bipod?
I've only recently been loading for a 7rm I had built, but 69.5gr of h1000 sounds about right for 2950fps and probably is on or near the node.
But measuring es for a 1moa load is rather meaningless, your group size will exceed your hit potential before variations in muzzle velocity will.

 

[DJ Fergus]

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.

You can always go back to that load if you want and it's fine speed if that's where it groups best but I run 2860 fps in two different 7mm rem mags with 26" barrels & 180 elds. I run retumbo. 69.5 in one and 69.9 in the other. I think you will find a really wide node somewhere around 2860 up to 2900. There's probably another node up around 3000 to 3040 fps but I don't think every 7 rem mag can get there with 175-180s. 2860 with the 180 elds gets me to around 1700ft/lbs energy between 700-800yds. 1700ft/lbs was an old rule of thumb for being minimum for elk.

 

[DJ Fergus]

How much freebore you have can make a difference in how fast you can run it and if you can get to desired node.

 

[bstomper]

You could do .010 there's a lot you could do. Did you have a rear bag when you were shooting off your bipod if not that could be some of the grouping issue there too.

No I wasn't using a rear bag, I forgot to take it to the range, but I'm going to retest tomorrow using one. I'm sure it will help a great deal with my groups.

 

[bstomper]

Well lots has happened since my last post. Because of the poor grouping I had been having eversince I started reloading and the fact that I'm nearing 2000 rounds through this gun, suggestions from some others made me decide to get a proffesional opinion on the condition of the barrel. long story short, the gunsmith checked the whole gun over and it all checked good. He said the rifle was in great shape. while keeping with the long story short theme. It came down to the barrel was too clean. Before I started reloading my own ammo, I cleaned the copper fouling out of my barrel and continued to clean it each time I came back from the range, thinking I was doing a good thing for my gun, apparently I wasn't. It was suggested to me to stop cleaning the barrel and let the copper fouling build up and my accuracy would return. Well thats exactly what I did and thats exactly what happened. Accuracy is back and I have continued to work on my loads. I have found a node at 2891 fps with Nosler ABLR and 68.4 grains of H1000. Four test shots at this charge weight gave me an average muzzel velocity of 2891 fps, extreme spread of 2fps and a standard deviation of 1fps.
I owe much of my sucsess to the help of you guys and especially Jud96

 

[DJ Fergus]

Glad you got it figured out. I used to over clean them myself. I've saw fresh cleaned barrels that settle down after 3-4 shots and some that may not settle until 30 or 40 shots. For the same token, I had a factory barrel that would foul out after 40 shots. That particular barrel would only produce about 35 accurate shots between cleanings.

I reduce my hot loads or use factory rounds to foul a clean barrel.

 

[bstomper]

 

[zr600]

What bullets were these with?

 

[L.Sherm]

Looks like 175 ABLR

 

[DJ Fergus]

Bstomper, that looks like a dandy load you've got worked up. Im sure everyone gets tired of my over zealous for the 7mm rem mag and I know that there are other cartridges that are great. 7mm rm has always been easy to load for me with 160-180gr bullets & recoil isn't bad. I have a brake on one of mine but it's probably not necessary.