Cast bullets in 9mm AR-24

[Kmrere42]

Hi,

Been having some problems with my pistol.  Winchester WB 9mm 115gr will hold in the black on a B2 50 ft target if I do my part.  Cast bullets have been a completely different story.  I have tried 115gr round nose, 125gr truncated cones and 147gr flat points and all will keyhole.  I have been using tightgroup for my powder and with light to moderate charges.  There is some leading but not enough to choke the barrel. The strangest was the 147's with 3.3gr powder, most hit sidewise and the 3 that didn't did show some tipping.  Barrel dia is .3565 and the bullets are sized .356 and .357.


Any thoughts...



Paul

[Cat Whisperer]

One major cause of keyholing is the bullet is not spinning fast enough for it's length.  Try higher velocity to make it spin faster to stabilize.

Another, would be the bullet is too small in diameter.  Cast bullets generally work much better if they are .001 to .002 over the grove diameter.  Slug the barrel and measure the diameters.

[Nobade]

See if a .358" bullet seated in a case will easily chamber (With the barrel off in your hand). If it will, use those. 9MM runs pretty high pressures, so bullets need to be pretty hard. Water quenched wheelweights work well here. Use real bullet lube, not the lousy crayon stuff commercial bullets come with. See if you don't come closer to finding happiness by doing this.