7mm-08 load data on the slow side

[std7mag]

@Mlgrace ,

"As I push the loads up I find I must reduce COAL."

That really seems counter intuitive.
Your increasing your pressure by adding to the powder charge.
Then increasing it yet again by reducing your COAL. Effectively reducing your combustion chamber.

The barrel will tell you the powder charge it likes, IE the velocity.

The bullet will then tell you the jump it likes.

All these read on the target.

 

[Mlgrace]

@Mlgrace ,

"As I push the loads up I find I must reduce COAL."

That really seems counter intuitive.
Your increasing your pressure by adding to the powder charge.
Then increasing it yet again by reducing your COAL. Effectively reducing your combustion chamber.

The barrel will tell you the powder charge it likes, IE the velocity.

The bullet will then tell you the jump it likes.

All these read on the target.

I’m reducing the COAL with increased seating depth As you know. All I’m saying is that as I approach higher charges I’m getting better grouping results with a bigger jump.

 

[Wind Gypsy]

@Mlgrace ,

"As I push the loads up I find I must reduce COAL."

That really seems counter intuitive.
Your increasing your pressure by adding to the powder charge.
Then increasing it yet again by reducing your COAL. Effectively reducing your combustion chamber.

The barrel will tell you the powder charge it likes, IE the velocity.

The bullet will then tell you the jump it likes.

All these read on the target.

I've seen conflicting info on this. The graph below would suggest that in that specific situation, pressure decreased with deeper seating until bullet was seated 0.250" jump. I'm typically seating 30-100 thousanths off and dont notice notable difference in velocity/pressure.

 

[Robert N]

I have personally discovered most load data is quite optimistic. My own experiments over the years have proven this out repeatedly.

Direct example: I have a Remington AWR (original Mickey Stocked version) 22” 7mm SAUM. Nosler Load data suggested I could get 3140 fps with a 140 AB…my reality is 3,000 fps and that comes with some nicely flattened primers.

I get 2700 fps out of 160gr. Nosler Accubond factory loads. That stuff should be 2850…

All of which basically says my 7mm SAUM behaves more like a hotloaded 7-08 instead of a 7mm Remington Magnum.

500 rounds of testing later I’ve settled for the 3,000 fps 140gr. Load. Sometimes it‘s just not worth chasing a false expectation.