7mm rem mag speed

[bstomper]

So here's where I'm at with the accubond lr 175gn
H1000
3.370" coal. Max magazine length
federal 215
Max charge at SAMMI length 3.290" is 65.5 gn
I loaded up to 67 gn in .2 gn increments with fastest speed of 2840fps with no pressure signs. I didn't load higher than 67 because I thought I would probably see pressure signs by then. But I didn't.
Found a node at 2774, 2778,2781 at 65.6, 65.8, and 66.0 gns. Still to slow for my liking. Should I keep going.

Here's what I have for the 165 gn gamechangers.
Same length
Same powder
Same primer
Max load at SAMMI spec is 69.9gn
I loaded to 70.4 and hit 3010fps. Didn't have a sticky bolt but thought I could see some marks on the back from the ejector at 70.4 so I stopped there. Found a really nice node with 2918, 2912, 2915fps at 68.6, 68.8, and 69.0gns and another one at 2987 and 2988 at 69.6, 69.8 gns but the the next one shot at 2942 at 70.0. Don't know what happened there.
What's your suggestions.

 

[Jud96]

So here's where I'm at with the accubond lr 175gn
H1000
3.370" coal. Max magazine length
federal 215
Max charge at SAMMI length 3.290" is 65.5 gn
I loaded up to 67 gn in .2 gn increments with fastest speed of 2840fps with no pressure signs. I didn't load higher than 67 because I thought I would probably see pressure signs by then. But I didn't.
Found a node at 2774, 2778,2781 at 65.6, 65.8, and 66.0 gns. Still to slow for my liking. Should I keep going.

Here's what I have for the 165 gn gamechangers.
Same length
Same powder
Same primer
Max load at SAMMI spec is 69.9gn
I loaded to 70.4 and hit 3010fps. Didn't have a sticky bolt but thought I could see some marks on the back from the ejector at 70.4 so I stopped there. Found a really nice node with 2918, 2912, 2915fps at 68.6, 68.8, and 69.0gns and another one at 2987 and 2988 at 69.6, 69.8 gns but the the next one shot at 2942 at 70.0. Don't know what happened there.
What's your suggestions.

If you want to shoot the 175s I would continue slowly working up. I would work up to 68.5 or so. You should hit pressure there and find a node in the low to mid 2900 FPS range. For the 165s, I would load 5 each in the middle of the two nodes you found. I would load 5 at 68.7 and 5 at 69.7 and test those through the chronograph. Whatever has the lowest ES and SD is what I would settle on. If both loads have an ES under 20 and single digit SDs, then I always pick the faster load. You could also load some up after testing velocity and see what node shoots better on paper to help you decide.

 

[bstomper]

Thanks Jud96. That's the route I was thinking I should take. I will post my results later today.
So just to be clear, during the first round of testing when I'm looking for a node, obviously it would be better if I can find one with 3 shots that are similar in speed but could I also use a 2 shot group. And what kind of ES am I looking for in in these groups during this initial testing

 

[Jud96]

Thanks Jud96. That's the route I was thinking I should take. I will post my results later today.
So just to be clear, during the first round of testing when I'm looking for a node, obviously it would be better if I can find one with 3 shots that are similar in speed but could I also use a 2 shot group. And what kind of ES am I looking for in in these groups during this initial testing

The more charge weights that have very similar velocities, the better. If you have a node that's 1.0 grain wide, that's awesome. Most of the time you find nodes that are 0.4-0.8gr wide. Nodes that are wider are going to be more forgiving, but small nodes can still be good too. When testing five equal charges from the middle of the node, I like to see ES under 20fps. Obviously the lower the better. If you don't get ES lower than that, then try a different primer or go to another node.

 

[bstomper]

Here's the results on the Sierra gamechanger 165's. The temp and bp are not accurate. I forgot to change it but the the rest is the important stuff for now. I have the grains in the name spot. The groups were not real tight but the 68.8 were definitely tighter. I'm not sure why the speeds are greater than yesterday but maybe it's beca I switched out the shell holder in my press for a different one and it made some sort of slight adjustment in the crimp. Not really sure but I like what it did.

 

[bstomper]

If I remove the worst in each group it changes thing dramatically.

 

[Jud96]

Here's the results on the Sierra gamechanger 165's. The temp and bp are not accurate. I forgot to change it but the the rest is the important stuff for now. I have the grains in the name spot. The groups were not real tight but the 68.8 were definitely tighter.
View attachment 153123

View attachment 153124

Those are good numbers other than one random velocity in each string that messed up the ES. I don't remember if you said or not, but what chronograph are you using? And what primers?

 

[bstomper]

I'm using the Caldwell ballistics precision. It's by no means a top of the line chronograph.
Primers are the federal 215 match. I have some CCI 250's that I may give a try and see what happens. If I did try them would I have to start low in charge weight and move up or could I just try them with this load.

 

[Jud96]

I'm using the Caldwell ballistics precision. It's by no means a top of the line chronograph.
Primers are the federal 215 match. I have some CCI 250's that I may give a try and see what happens. If I did try them would I have to start low in charge weight and move up or could I just try them with this load.

Honestly that flyer could be from your chrono. I use to use a Pro Chrony but it would randomly not read some shots or give oddball velocities like yours did. I now use a Magnetospeed sporter that I picked up for like $160. It's considered one of the most accurate and consistent chronographs. As far as the primers, the CCI's are also magnum primers, I would start a grain lower than your nodes and work up again just to be safe.

 

[SHDeersniper]

I get 2914 from Black Hills 162 Amax in a 26" Bartlien

 

[Canhunter35]

What's ur load doing on the target?

 

[bstomper]

Groups aren't real great but I know I pulled a few shots. I know that I am only a 1 moa shooter, maybe a bit better so take that into consideration in the grouping. The red dot is 1" diameter

 

[bstomper]

 

[zr600]

Did your shoot two groups on each target? Or is that one 5 shot group on each target?