280 Ross

[Halger280HVMag]

Bullets.
The Halger bullets are all .287" very uniform.
One box of Woodleigh bullets measure .286 with variations.
The second box of Woodleighs go .286.5" to .287"
The J&J bullets are a very uniform .287"
The Kynoch example is .287" below the crimp groove, and .286 above.
Also there, is a bullet cast by myself. and the resulting slug upset in the bore of my rifle.

 

[Halger280HVMag]

No not quite!

The 100 Gr. flat base spitzer delivered 3900 Fps.
No squeeze bore in my rifle.
There was some squeeze bore development. mostly went into to some PAK anti-tank guns.

Very cool. Was it Halger that was claiming 5000 fps with something like a tapered 9mm to 7mm barrel?

 

[diopter]

Bore riding bullets.
Just like Swiss GP11 which is 0.306" above crimp groove and 0.3075"± at widest part of boat tail.

 

[Halger280HVMag]

I would appreciate details on construction and method of your bumping die.
I have lathe and mill.

When I had my .280, I machined a bumping die to bump Sierra .284 bullets up to .287. It worked, but in the end I started using .284 Nosler partitions, which worked just as well in my rifle.