Function of semi-auto (CW9) with different loads

[Cloudpeak]

I just started working on loads for my new Kahr CW9. I shot the 105 gr Lee SWC loads (3.5 Gr. W231) that are so accurate and function well through my CZ Compact. They just didn't have enough power to function the slide. The Kahr seems to have plenty of "spring power". These loads turned the gun into a single shot. The bore also leaded to where is was pretty hard to get clean (LLA).

So, I loaded up some loads with varying charges of W231 behind some Rainier 115 grain clad bullets. Only the 4.4 and 4.5 grain loads (the highest I went) functioned in the Kahr and accuracy wasn't all that good (1.03"-2.0" and 1-2" below POA). Then I shot a few 124 grain Lee TL RN rounds loaded with 3.7 grains of W231 that I had developed for my M&P (lubed with LLA). These functioned 100% and shot a group of .535" and shot to POA. All loads fired offhand at 7 yards.

I'm kind of surprised that the Lee RN load with a 3.7 gr charge of W231 functioned well and the 115 gr clad Rainer with a higher charge (4.5-4.5 grains) would not function as the bullet weights are pretty close. I guess the Lee loads generated higher pressures that allowed CW9 to function properly???

As far as leading goes, it seems that I've had a bit of leading with all of my pistols using LLA when the pistols are new. My 1911 barrels now clean up with only 3 or 4 passes with a Chore Boy wrapped brass brush through the bore. The M&P and CZ also are now much easier to clean. I guess, with enough lead rounds down the bore, the bore smooths to where cleaning is very much easier. The fact that the bores on my pistols, especially the 45 1911's, got much easier to clean as the round count increased kind of snuck up on me. Have you noticed this as well? How many rounds would yo say it generally takes, shooting lead rounds, for the bore to polish to where it's easier to clean?

Thanks, Cloudpeak

Cloudpeak

[9.3X62AL]

All of my new or new-to-me handguns get 100-300 rounds of jacketed bullets--often in factory loads--to polish the bore out a bit and also to see if something BAD happens with a new gun. Only once, so far--but factory loads in a gun that chokes makes the warrantee process into a much shorter conversation with the maker. A significant portion of my handgun brass has been acquired in this way--by running Winchester White Box or Remington UMC ammo through the guns and then re-stuffing them.

[HeavyMetal]

For every action there is an equal, and opposite, reaction.

125 created more recoil than 115's hence the slide moved easier. I have also noted that gun maker's seem to sight the 9's in with 125 grain loads rather than the lighter stuff.

Guess the line of thought is this is the ammo most likely to be shot in them. Thats way 38 snubbies are sighted for 158 grain RNL, it's was the standard police round.