9mm cast bullet + s&w 5900 series = poor accuracy

[rp85]

hello;

using cast bullets in my 9's. having accuracy issues only with the s&w 5906 and 5903.

bullets sized are from the lee 358-125rf and 356-1242r. sized bullets to
.356, .357, and .358".

accuracy still poor, 4-6+" at 12 yards. accuracy is good with my rugers, browings, sigs. @2" groups. lube is 45/45/10 recluse.

using 3.3 grains of hp38 because accuracy goes out the window with all pistols with an increase of powder. never had a failure to feed, fire, or eject in any of my 9mm pistols with this load.

o.a.l for 358-125 is 1.030" and o.a.l for the 356-124 is 1.135"

any suggestions thanks for any input.

rp

[sgabel1]

I have a S&W 6904 and have found the same issues. I found that the best powder was Alliant Blue Dot. The fast powders did not work well for me. The best cast bullet were Lyman 356402 run through a .358, they drop at about .358 from the mold. They like to be driven at fairly high speeds. I had key holing when I dropped the velocity. I have also tried 358345, 358212,358242. Which are 115 gr, 140 gr, 120 gr respectively. The 120 gr 358242 round nose would be the second choice. Again the powder is key I think. I have tried Bullseye, Red Dot, Power Pistol, Unique, & Clays . Power pistol was OK but had big muzzle flash. Hope this helps.

[MtGun44]

Typically if accy is poor, go larger. If larger does not help, try a better lube. What lube
are you using? Test NRA 50-50 if you are not using it.

Seat a boolit after measuring it with a MICROMETER. If you are using a caliper, you do
not have adequate accuracy to do this project.

Crimp as normal, then pull the boolit (most us inertial puller) and remeasure the diam
of the boolit. If the same diam as you started with, good. If not, try a larger expander
ball.

Last thing to try; harder alloy or heat treat a few.

Bill

[primersp]

i have an 5906 it shoots well with rcbs 124 tc sized at 356,5 good accuracy no leading problem to chamber cartridge with an 357,5 bullet, sorry i have only these olds saeco dies no 357 to try .

[Wal']

Slug & size is King...... I also went with the Alliant Blue Dot in my HP Browning 9mm after using the faster powders & keyholeing.

But again size...size .....size.

[joec]

I'm using 4.0 gr of BP-38 in my 9 mm with 125gr .356 Dia Bullets and fairly good accuracy to about 15 yards. By that I mean with in a 3" circle with standing and holding the gun. Probably better from a bench rest but not me.

[sig2009]

I have owned a couple S&W's and I can tell you both were as innacurate as yours and that was with factory ammo. I sold them both and never looked back. Lousy product!