Velocity ladder with 165 gr. Sierra Gamechanger and the 7mm08

[Cornivorus]

This is with Imr8208xbr powder, looks I have a good node there. I'm just wondering if I can get it up to the next level or if I should just be happy with this?

 

[jjmp]

So where are you on your chart node ?

 

[Cornivorus]

So where are you on your chart node ?

Can you rephrase the question for me?

I think I'm going to re run this from 40.7 on up to 42 just to verify everything.

 

[Hand Skills]

What is your barrel length?

2688fps is right in the ballpark - how is accuracy at 40.9gr?

 

[Cornivorus]

What is your barrel length?

2688fps is right in the ballpark - how is accuracy at 40.9gr?

Barrel is 22.4" and I haven't checked for accuracy there yet. I've just been exploring the limits some to see where I can safely get to and looking for the nodes. But 40.9 is right where I was going to start with accuracy testing.

 

[Cornivorus]

For comparison this one was my original test

This one is after I rerun the test starting with 40.7 and going up to 42.1

I am starting to see some signs of pressure at 42 gr., just flattening the primers and slight ejector swipes showing, but no sticky bolt at all. It looks like the node is still there though.

 

[jlteague]

For what it's worth , if I'm seeing pressure signs at 42 I wouldn't go past 41.8. I would start my accuracy testing at about 41.5 going up by 1/10 grains cause I will always give up a little velocity for accuracy. Good luck with your experimentations.

 

[Dell]

Wha

View attachment 141283

This is with Imr8208xbr powder, looks I have a good node there. I'm just wondering if I can get it up to the next level or if I should just be happy with this?

Whats your recommended max load?

 

[Dell]

For what it's worth, if it were me, I'd play with the mid 2688 FPS velocity. That's a really good flat spot. Shoot 5-10 with that load and see what your Extreme spread is. Looks like the 40.9 grains might be a winner.

 

[Rflshootr]

If your accuracy isn't there, you'd have to go to a little bit slower powder like 4064 to get a little more velocity. I'm surprised you're getting 2700+ with that short of a barrel and a 165. If you get the accuracy you desire, then I'd be happy with it.

 

[Cornivorus]

For what it's worth, if it were me, I'd play with the mid 2688 FPS velocity. That's a really good flat spot. Shoot 5-10 with that load and see what your Extreme spread is. Looks like the 40.9 grains might be a winner.

Yes I'm with you on this, I plan to run some more at the 40.9 and see how accuracy is. I was hoping for a little more velocity, but if that's where the accuracy is I'm good with that.

As for the recommended max, well I could not find any published load data with this bullet and powder combo so I'm winging this based on similar components.

 

[Cornivorus]

If your accuracy isn't there, you'd have to go to a little bit slower powder like 4064 to get a little more velocity. I'm surprised you're getting 2700+ with that short of a barrel and a 165. If you get the accuracy you desire, then I'd be happy with it.

I may try some Ramshot Big Game, it's a little slower than 4064 and it's one powder that I can find some published load data for this bullet too.

 

[jjmp]

Mid2600+ is very nice for your factory bbl length ,espically with that new 165 Sierra bullet , I've settled on 2780 with Sierras tipped 160 Match Kings ,in my 27 inch 708 bbl ,enjoy your Fine 708 Tikka ! Cheers

 

[Rflshootr]

I may try some Ramshot Big Game, it's a little slower than 4064 and it's one powder that I can find some published load data for this bullet too.

From what I see H414 and (same as) W760 should also give you some pretty good velocities. You should be able to use 168 data for the 165's as well.