Tried .310 balls in 30-06

[Float Pilot]

I found some .310 lead round balls in my shop and tried more gallery loads for the 30-06 ( 1903A3 )

9 grains of Unique, 1/2 grain Dacron filler, CCI-200 primer WW brass.
50 yard group was 6 inches. I choronographed it and the balls were going 1930 fps. Which is TOO FAST.

Also there is a long jump from the case mouth to the rifling. So there is some blow back down the case neck of powder and semi-melted Dacron.

Yes it might work at lower velocities, but the jump to the rifling will always be a problem with round ball from this case.

 

[PapaG]

Get rid of the Dacron, substitute kapok out of an old life vest, and try 5 grains of bullseye or red dot. You will be surprised. Also, smear some lube over the bullet.

 

[goon]

Also, Speer makes a "plinker" bullet that is designed for goofing off with .30 caliber centerfires. It's jacketed with an exposed lead nose.

Haven't tried either route myself, but I did load a 7.62x39 with some 60 grain bullets pulled from 7.62 Parabellum ammo once. No recoil and lots of fun!

 

[Salmoneye]

Whoa...

I use .310 Round Balls in .30-30 and .30-06, but my charges are much lighter doses of Red Dot, and I use no filler...

Your charges are far too heavy for the small bearing surface of the RB...