Opinions on my OCW.

[Dobbs02si]

Alright, I finally got the Axis "budget precision build" to the range today. The cartridge is 7/300 wsm with 180 bergs over h1000. I don't have a chrono, so this is my method until I get one(if I ever do).

The numbers. Small decimal numbers are vertical deviation from POA. the charge weights are below. These were measured with calipers so human error could be a factor.

My main goal when shooting groups was to keep the vertical as close as possible, so horizontal could be suffering from that. Given that, the worst group was .61 vs the best at .37.

Anyways. My thought is to revist 64.8-65.7 in .2s or .3s. Any thoughts to sway my decision? Thanks in advance.

 

[Supersubes]

65.5

 

[Deleted member 113831]

65.5

 

[Dobbs02si]

So 65.5. Any reason to at least go .2+/- before seating, or just rock on? Thanks again.

 

[dustingaunder]

I’d try 65.5 at distance and see how it does.

 

[Supersubes]

So 65.5. Any reason to at least go .2+/- before seating, or just rock on? Thanks again.

The method usually calls for 2% increments, which would be 1.3 grains in your case. You’re showing a 1 grain spread that printed exactly the same POi. .2gr will show you literally nothing on either side of 65.5. You could load 65.5 and do seating depth. I’d add some distance as well, the resolution is better with the results. Some things to note. The velocities in the window are important. A new barrel speeding up or virgin brass to fired brass loads can bust you out of that.

 

[Deleted member 113831]

So 65.5. Any reason to at least go .2+/- before seating, or just rock on? Thanks again.

As far as the charge weight, you are good to go at 65.5 according to what you are showing us.

65-66 being that stable is a HUGE node for a round as big as that.

It also looks like you may have lucked out with your seating depth being good as well. Shoot 10 rounds (two 5 shot groups) at the same point of aim at 200. That should tell you a lot more about how it's gonna do.

 

[Dobbs02si]

Well, both of those variables will be in play. It's a lilja 8 twist 3 groove and minus the 2 sighters, those are the only rounds down the tube. Virgin sorted win brass as well. Alright, I'll work seating and stretch it out. I've got 500yd within an hour drive so I will stretch it out.

On more question, why would the brass shorten .005-6 on the first firing? I've always run new brass and they have always grown. Given my other rifles have factory chambers, and I cut this one my self. Just out of curiosity I guess.

 

[Supersubes]

Well, both of those variables will be in play. It's a lilja 8 twist 3 groove and minus the 2 sighters, those are the only rounds down the tube. Virgin sorted win brass as well. Alright, I'll work seating and stretch it out. I've got 500yd within an hour drive so I will stretch it out.

On more question, why would the brass shorten .005-6 on the first firing? I've always run new brass and they have always grown. Given my other rifles have factory chambers, and I cut this one my self. Just out of curiosity I guess.

Depends on the combo, but when the shoulder blows out radially (along with the rest of the body), it can cause the overall case length to recede slightly.

Do you have a chrono?

 

[Dobbs02si]

I do not have a chrono. I feel like it would make this process easier, but I don't shoot enough to justify the puchase.

 

[Dobbs02si]

Well another good day at the range with more data. As was said earlier, the .010 jump was it. .015 shot the same, anything less than .010 opened up considerably.

Also stretched it out to 500yd with 65.3gr and original .010 jump. Only shot one group of 5, but it measured 1.8" with the largest spread being vertical. I would be willing to bet it's in the brass, but I will keep tuning.

I know its only 500yd, but with verified zero and perfect 2.1 dope to 500. Would it be safe to call that 3025 on velocity? Older berger 180 hybrids at .674bc in an 8 twist. Newest box(unopened) claims .680?

Thanks for the look and advice.

 

[Dthomas3523]

I’d look into borrowing a chrono if possible. That will give you more of an idea how stable/large if a node you have.

 

[Dobbs02si]

I agree, but everyone I shoot with are hunters, and I load for them. I wish I had a chrono because no one else I shoot with cares THAT much about it. I just do it the hard way by verifying drop with what I HOPE is an accurate bc.

 

[chevy_man]

I agree, but everyone I shoot with are hunters, and I load for them. I wish I had a chrono because no one else I shoot with cares THAT much about it. I just do it the hard way by verifying drop with what I HOPE is an accurate bc.

That's what my Dad did for years. He finally broke down and got a $100 Caldwell Chrono. It's not fancy, but it gives you a picture. Bluetooth so it records to your phone and you don't need a printer or to see the screen.

His dope and load development got much quicker and easier to figure with a good starting number. Especially important when he was screwing with wildcats and had no good manual data.

A Labradar is on my list. I don't like the magnetospeed mounting (I have dozens of guns that may need chrono'd) and the radar does everything.

 

[Dobbs02si]

I've heard nothing but good about the labradar, I just can't talk myself into it. Now the magnetospeed comes and goes on my 'to buy' list. I would have to make an mlok/swivel stud mount extension to keep it off the barrel to be happy with it. That might be my xmas present to me this year haha.

 

[Dthomas3523]

I've heard nothing but good about the labradar, I just can't talk myself into it. Now the magnetospeed comes and goes on my 'to buy' list. I would have to make an mlok/swivel stud mount extension to keep it off the barrel to be happy with it. That might be my xmas present to me this year haha.

Few things to keep in mind:

Labradar can be finicky. Great when it works

Magneto works 100% or close to it

Even keeping the magneto off the barrel won’t alleviate POI change. I’ve tried 3 different mounting systems. If the bayonet is near the muzzle, POI will move away from the bayonet location. I going to try having it about an inch away from barrel and turning the sensitivity up.

 

[Dobbs02si]

Wasn't aware of that, but it makes sense. Takes my mind to a rifle from the late Shelly Davidson that used magnets to tune the barrel. If the POI moves up as you say, I bet it would fall right in line with with his thinking..