.257 Roberts Question

[ArmedGinger]

Has anyone heard of a .257 Roberts round being loaded with a bullet that is .247 in diameter?

Guy came with with a factory box of Nosler Custom Trophy Grade that he bought from wholesale sports. Said he thought something was off with them.

When we measured the diameter of the bullet it was .247 in diameter.

The neck measured .280 yet our reloading data shows it should be .290.

 

[Willy Tincup]

Is your caliper or mic out of whack by .010"?

 

[ArmedGinger]

Is your caliper or mic out of whack by .010"?

Don't think so, we measured a box of 257 Roberts from our shelf and they measured .256 with the same set of calipers.

This is why I am confused. I cannot find any bullet with a diameter near that diameter of what was in those Noslers.

But every round in that box was .247-.248 when we tested them.

You could take one of these Nosler rounds, put it down the crown of a barrel chambered in .257 Roberts, and it wouldn't even touch the lands and grooves.

 

[Al-Sway]

Did you pull the bullets and measure them at the maximum diameter, or did you measure them where they showed outside of the case neck? The only diameter that counts is what is further down.