Barnes change their load data?

[mattri]

Just looking at Barnes' load data page and it looks like they've backed off on some charges.

The 7mm WSM data used to show 66.5 grains of H4831 as max now it's listing 63.9- anyone else notice this?

 

[watercam]

They became very conservative with the change in company ownership (for obvious liability reasons). Their original manual (pre-Triple Shock days) was too liberal for my tastes but that is why we are supposed to start low and work up loads in our own weapons - every one is different!

 

[mattri]

Didn't know they'd changed hands- thanks for the info.

I use their 140 TSX in my 7mm WSM with a load below the old max but above the new. Excellent accuracy and no pressure signs on 6x brass so guess I won't worry about it.

 

[Berger.Fan222]

The forces required to engrave the rifling on copper bullets are much higher than jacketed lead bullets.

In addition, the forces required to engrave the rifling on copper bullets are much more sensitive to the angles at which the rifling engages the bullet in the throat area. Small changes those angles between the test barrels can cause significant increases in pressure with the same charge.

 

[louielouie]

The forces required to engrave the rifling on copper bullets are much higher than jacketed lead bullets.

In addition, the forces required to engrave the rifling on copper bullets are much more sensitive to the angles at which the rifling engages the bullet in the throat area. Small changes those angles between the test barrels can cause significant increases in pressure with the same charge.

QuickLoad does have higher 'initial starting pressure' for Barnes and other solid copper bullets but I'd hadn't heard about leade angle being a factor. Mostly 1.5 deg is used but throat wear changes that over time.