New Old PM9 Owner in GA

[StevePM9]

Took her out for another session today. Misfires are most prevalent on the Barnaul, followed by Tula,
and one Freedom Munition reman.

Got a couple of recoil spring & striker spring sets inbound, from Wulff. Fingers crossed...

[Bawanna]

Never heard of those ammo brands, cept Tula and I wouldn't use it although many do. I'd try some winchester white box or something domestic. 5# trigger is right where it should be, that's what one usually gets using the reduced power spring.

[StevePM9]

Tula and Barnaul are both Russian, different factories. Barnaul seems to load a bit stouter than Tula, in a few calibers I've used--tho Tula has a 150-ish FMJ flat point in .38 Special, that is lights-out accurate in my Model 64, and feels like a +P (like a Seventies +P, not the neutered stuff out there these days!).

Federal is a fairly well known US ammo manufacturer.

Freedom Munitions was a pretty big reman house a few years ago, using main-line reloading equipment, likely old machines from Speer & CCI, up the road from them. They tend to load everything a bit soft, but had a good rep. I think they ran into some HR problems, and have been trying to get back on track AFA ammo production.

At any rate, I don't think I had any of the three Federal loads, fail to ignite. I say "think" because I was on an outdoor range, and I may have ejected some beyond "the red line", or maybe picked em up and fired them in a S&W 469. Today, it popped all the Federal rounds. The Barnaul's were the prime offender, today.

Tonite I punched a disk out of some nylon stock, about 1.5mm thick, and tucked it into the pocket on the slide's back plate--where the base of striker spring guide rod sits. Spacing the rod base forward that distance raised the trigger pull from 5# and change, up to 6# and a couple of ounces. Will that give the striker a bit more oomph? It should. Will it be enough to pop the Barnauls? Time will tell.

I also have some CM40 parts in bound, so I'll be able to do some parts comparing/swapping.

I may (almost definitely will) end up with a heavier pull than I started with, but reliability is king.

[BirdsThaWord]

“Tonite I punched a disk out of some nylon stock, about 1.5mm thick, and tucked it into the pocket on the slide's back plate--where the base of striker spring guide rod sits. Spacing the rod base forward that distance raised the trigger pull from 5# and change, up to 6# and a couple of ounces. Will that give the striker a bit more oomph? It should.”

Interesting idea! Curious to see how that works at your next range outing. I think this would be good “in a pinch” should one find themselves with a weak striker spring and unable to get a new one. Yes, please let us know how that works out.

[StevePM9]

Interesting idea! Curious to see how that works at your next range outing. I think this would be good “in a pinch” should one find themselves with a weak striker spring and unable to get a new one. Yes, please let us know how that works out.

1. With the spacer disk, the misfire rate improved (less misfires), and the misfires became isolated to one brand of ammo--the Barnaul white box "milspec" ammunition.

2. Since that range session, I got hold of some CM40 used parts. The strikers are same part number, between CM40 and PM9, but the used CM40 striker was a wee tad bit longer than the PM9, by cheap caliper & eyeball measure:

Striker Type	Overall Length, mm	Tip-to-Shoulder Length, mm
PM9	41.61	11.40
CM40	41.88	11.68

I came up with a variance in the length differences (.27mm overall, .28mm tip-to-shoulder). Possibly due to slightly curved surface of the shoulder, caliper quality, and operator headspace & timing.

"So how'd it shoot, with the longer striker?!?"

She shot better--out of 24 Barnaul rounds, only five failed to ignite.

3. The Wolff springs arrived--20.5 pound, "xtra power" recoil spring set, and "factory standard 5 pound" striker springs. The recoil springs were noticeably stiffer than the unknown age/round-count springs that came in the pistol, and the striker spring was noticeably stiffer than either the 'original' spring in the pistol (severely wimpy) or the used CM40 spring (which was slightly beefier than the one that came in the pistol).

With the Wolff replacement striker spring and longer CM40 striker, the PM9 cycled and fired a bit over fifty rounds of Barnaul yesterday, 100%, zero misfires.

Summary: Longer striker tip protrusion reduced light-strike misfires on harder primers; stiffer striker spring + longer striker tip protrusion eliminated light-strike misfires.



NOTE: from my interpretation of the Kahr parts pages, the same striker is used in both of these guns, and a slew of other Kahr pistols:

https://shopkahrfirearmsgroup.com/pi...ker-020k9s.asp

I'm not implying "the CM40 comes with a longer striker tip, than the PM9"...just that the striker that came out of this CM40, was longer than the striker that came in my used PM9. Why? Dunno...manufacturing variance, wear from use? The PM9 tip doesn't evince anything to my eye, to suggest a previous owner 'shortened' it.

BTW, my objective was to get full reliability with the most-difficult-to-ignite primered ammo, with the concept that "if she'll
hit hard enough to always pop the hardest primers, I can reasonably assume she'll ignite the softer-primered carry ammo, if I
ever need that."

[getsome]

Dang, my math skills ain’t that good, I’m seeing more small reliable revolvers in my future…..

[StevePM9]

I hear ya. "Selection" brings a lot of factors, reliability being the foundation.

One of my carry criteria is 25 yard accuracy, and this PM9 meets it. I'll putz
around with carry ammo and see if feeding is good--I expect it will be fine,
from how it's performed so far.

I've been wearing a S&W CS9, but the PM9 will take it's place if all pans out.

[BirdsThaWord]

Glad she’s running good for you now! Always a good feeling to turn a dud into a thumper!

[StevePM9]

Yeppers, she's lookin' like a keeper!