Kahr P45 recoil spring wearing out after 850 rounds
I'll start with the letter I sent Kahr on my problem:
I bought a Kahr P45 in August 2006. I realize it's well out of the warranty but I
wanted to relate what I think is a design issue.
After about 850 rounds of midrange loads (standard commercial), and my 200gr flat point
reloads (actually a bit lighter than commercial) I started getting periodic failures to
extract. They became more prevalent as time went on, and when I tried my carry
load - commercial Hornady XTP 200gr hollow points, the FTEs became an every-shot thing.
The cases were being left about halfway out of the chamber. It appeared that extraction
had been premature before the case had unsealed, and the extractor had stripped over the
I suspected a worn recoil spring, contacted Kahr, and was sent a new spring under warranty.
The new spring was a full 1/4" or more longer than the old one. No question it had lost
Sure enough, my P45 functioned perfectly until today when I started getting an occasional
FTE with standard loads - about 8 out of 100 or so. This time the case made it completely
out of the chamber, but was stuck partially into the rear back of the magazine lips, angled
up at 45 degrees or so. The slide had to be pushed very firmly to its extreme rear before
the case could be pivoted out. Almost as if the weak spring allowed the action to function
rapidly enough for the slide to catch the case on the way back into battery.
I figure it's been about 900 rounds or so, although I haven't kept an exact count.
I've ordered a couple of recoil springs, as well as an extractor and two striker springs just
for good measure.
The spring failure may be due to taking a set over time, or incorrect alloy mix.
It appears that the spring must be replaced every 800 rounds or so to prevent FTEs - not good
in a defensive handgun. The P45 is my every day carry piece and is excellent in all respects
except this rather serious situation.
Do you know about this problem? Have you gotten any other similar complaints? Any plans to
employ a better quality recoil spring?
A possible solution might be a concentric recoil spring arrangement like the Para-Ordnance
P10 and others.
NOTE: Hornady XTP 200gr is my carry ammo and usually functions perfectly.
Has anyone else here experienced this? If so, how often do you replace your spring to
ensure reliability? I'm guessing it needs to be done every 800 rounds or so, unless
and until Kahr does something about it. I'll repost and give their response if/when
I get one.
FYI, my practice loads are Starline brass, Ranier Ballistics 200gr copper-coated flat
points ahead of 5.3gr of Bullseye and Winchester primers. These have somewhat less
recoil and velocity than than the Hornady XTPs. I do NOT use "hot loads" in the P45 - it's
necessarily a lightly-constructed handgun and IMHOP is simply not meant for maximum
loads. Reloading data given for informational purposes only - your mileage may vary.
New recoil springs appear to have solved problem
Got the new recoil springs from Kahr yesterday, and thought at first they'd sent me the wrong ones.
They were over an inch longer than the ones I was replacing! Taking into account the 1/4" of
shrinkage I was seeing on the originals, that's still over 3/4" longer to start with.
The new springs had the same number of coils, but they were spread out over a longer length.
I miked the originals in several places and got .043" diameter. The new ones miked at .045".
.002" is a small difference, but over 22 coils it was enough to make the difference I felt.
I wondered how the heck I was gonna get the thing into the gun, and sure enough it was a real
pain. Literally. The muzzle end kept wanting to sproing out. Finally I found I could compress some
coils onto the chamber end of the guide rod at first so there weren't as many at the muzzle end.
Slide operation is noticeably tougher - a good thing, but would it shoot? Just went through 50
of my midrange reloads and a mag of my carry ammo - Hornady 200gr XTPs - with no burps
whatsoever. I limp-wristed a few on purpose with no burps.
Ran out of time so will continue later. But no further posts on my part about this will indicate
I'm satisfied. It's obvious that Kahr has gone to a completely different spring design, and for the
better. Unless you count what I'm now going to call "Kahr Recoil Spring Thumb".
Additional recoil spring testing - Good news/bad news
The good news is I ran another 50 rounds through without any FTEs or burps of any kind, including deliberate
limp-wristing to see if I could induce a failure. Even on my worst day I wouldn't hold the piece as loose as I
tried - and it cycled no problemo. Cartridges included a wide variety of mid-range loads - commercial
PMC FMJ, Federal FMJ, my flat point reloads, Mil Ball 230 FMJ, Hornady 200gr XTP JHP carry loads, etc.
The bad news (possibly) is when I stripped the piece for cleaning, the spring had shrunk back down to the
same length of the worn-out springs! This means the spring lost an inch in just 100 rounds. Maybe normal
and expected - I intend to find that out.
Since I had no failures, there is absolutely no question that my FTEs were again caused by a worn-out
recoil spring. I've been trying to get through to the Kahr tech people to ask some very pointed questions
about the spring redesign, whether they've tested one to failure, and what their results were.
So far, their line has been constantly busy. I emailed over a week ago - no response. I'll keep trying
until I get through and post what I find out here.