9 MM semi automatic

[Beekeeper]

Lets see if I can say this correctly and not make a mess of it!
I have a KAR CW-9 semi automatic that I bought as a house gun.
I bought it 2 years ago, fired 5 rounds through it to make sure it would accept cast and put it in the bedside table.
Today I took my new next door neighbor to the range with me.
He is a straight pistol shooter ( and a Darned good one too) so I took the little KAR along to shoot a few and kinda stay with him as it was his first day there.

The Kar shoots better than I can but I am not a pistol shooter period.
Problem is when I got home and started to clean it I found a lot of leading.
The boolit is the Lee 356 120 gr. SWC, has one lube groovesized to .356
Used DGL lube.
The rounds were loaded 2 years ago and have been in the night stand drawer ever since.
On a 9 MM should I use something like Bens Red instead of the DGL lube?
Look in a diferent direction?
As I said I am not a pistol shooter at all and want to get this right the first time (or maybe 2nd)


beekeeper

[Thumbcocker]

My SWAG is boolit too small. Read the sticky by Mt. Gun .44 . Good info there.

[Piedmont]

Yes. Too small. I run .358" in a Kahr K9. Only got around to slugging it this year after owning well over a decade. Funky polygonal rifling but a throat tapering from .359 down to .355. I have been running .358" boolets all these years.

[rintinglen]

+1 on sizing .358. My initial experience was similar to yours, using store bought cast. Making My own 358-242 122 grainers and the leading all but disappeared once I sized them @.358.

[bobthenailer]

I have 2 Kahrs a PM9 & a CW45 they both shoot cast bullets excellent and with no leading even from the PM9s polygon rifled barrel but i did shoot 150 rounds of break in fmj ammo and 50 rounds of fmj with the cw45 with convential rifling before using cast bullets, and i now use cast 99.9% of the time for pratice. i usually shoot from 100 to 150 rounds at one time at the range and each gun has over 1000 rounds through them with cast bullets. I size my bullets to .357 & .452 dia and hard commercial lube

[blackpowder man]

My Kahr CW9 likes .358 sizing too.

[GREENCOUNTYPETE]

I slugged a new 9mm 2011 production and found it was .357 in the groove and slugged an old 40+years old 9mm and found the groove .354

i think you will find most newer 9mm to have a groove closer to .357 , it makes me thing that some were along the line many manufactures started using the same barrel stock for 9mm and .357/38spl

also guessing that the extra room helps to keep pressure lower , and they see that as a safety

i have heard Taurus does this with 45

[Shiloh]

+1 on sizing .358. My initial experience was similar to yours, using store bought cast. Making My own 358-242 122 grainers and the leading all but disappeared once I sized them @.358.

+1

Retested the 125 gr. RNFP. The .357 boolits were slightly better. After tweaking the seating depth, the ones sized at .358 were better than the .357 sized boolits.
Gonna stick with .358

Shiloh