Does it need to Break-In again?

[kenduc999]

Just got a chance to run my MK9 at the range for the first time since getting a new factory barrel from Kahr. I also bought a new recoil spring assembly, and had it installed when I went to the range. I put 200 rounds of 115gr FMJ through it and had 3 FTE. I attached some pics of the failures. They were all both with the same mag (I had forgotten to pack my other one). I have never had any problems before the barrel/recoil spring swap and now am thinking it may have been a bad move. I had approximately 1000rds through the gun before I changed the recoil spring and barrel out, with no failures. Does the gun need to have another "break-in" period? or should I be looking at a new extractor (it has some slight dings in the edge)? Thanks for your help!

http://i39.tinypic.com/300ceic.jpg
http://i40.tinypic.com/352hk6p.jpg

should I re-install the old recoil spring and see if that cures it? it is WAY stiffer than it was with the old spring unit...

[O'Dell]

It probably does need another break in, but I'm curious why you changed the barrel and recoil assy in a perfectly functioning pistol?

I'm thinking that the 'much stronger' recoil spring may have changed the timing of the recoil cycle.

[OldLincoln]

I don't have the gun, but it seems to me that if the slide fully retracts the round should fly. The new barrel should not require break in although you will want to polish up the ramp and chamber throat as well as the ejection path.

A new recoil spring is stiffer and the only new thing that should really affect things. So what will prevent it from fully retracting? First is under lubed recoil spring guide which needs grease rubbed into it and a couple drops of oil into the inner spring guide. Next is low powered rounds as in target reloads, followed by running the slide a bit dry.

I'd suggest addressing these items which are easy and try again.

[Ikeo74]

^^^^ As OldLincoln said the barrel by itself should have no effect on ejection, but the new recoil assembly definately changes everything back to a break-in condition. However it probably won't need the full 200 rounds. Go back to full power loads for a while until the new springs limber up. By the way, thats a nice looking gun with the walnut grips!:)

[kenduc999]

It probably does need another break in, but I'm curious why you changed the barrel and recoil assy in a perfectly functioning pistol?

I'm thinking that the 'much stronger' recoil spring may have changed the timing of the recoil cycle.

When I got the gun (used, unknown round count) it had pretty severe pitting throughout the whole bore. I sent the barrel back to kahr, and they gave me a bright shiny one for free. As for the recoil spring I wasnt sure how many rounds had been through it when I got it, and I had shot about 1,000rds through it. I have heard they need to be changes at 1,500 - 2,000rds, so I figured I was close anyways, and since I had to wait for my new bbl to show up, may as well get a new recoil spring assembly, and new grips! thanks for the tips! Ill try some higher power stuff the next time out.

--I'll try and take some better pics to check out how the grips look! I refinished them as soon as I got them, I didnt like the semigloss that was on them, and they needed to be slightly fitted anyways, so I sanded them to fit, and re-oiled with Teak Oil. I love that finish on wood, very resistant to water/sweat, and it gives it a nice dark tone. I'll have better pics tomorrrow :)

[TominCA]

I'm going to guess that the new springs are doing it - but take the gun apart and then reassemble without the recoil spring. Carefully and slowly work the slide back and be especially alert near the end of the cycle to notice any "extra" friction as the slide comes fully back. If you have a bad barrel lug cut out or an out of spec barrel the gun will get a lot of friction as the barrel is jammed up against the slide.

I had a (still have) a p380 that would run around 40 rounds or so - get dirty ahd hot and then start to act up with normal power ammo. I did the abov and notice a lot of fricton as the barrel jammed against the slide at the last approx 1/4 inch of the recoil stroke. I checked the barrel surface and found three "bumps" on the bottom of the barrel forward of the lug. They were abviously tooling marks. Out came the Dremel (a smart person would have used a flat file, Dremels are dangerous around guns in amature hands) and took them off. I also put a little green glow polish on the surface and green glowed the slot inside of the barrel lug with a q-tip in the dremel just to give everything a little more play. Worked great after that! But try the old spring first - and see if it works better - If the old spring fixes the problem I'd just polish up the barrel a little and try again.

Hope this helps.

[kenduc999]

Well I tried working the slide without the recoil spring, adn I didnt notice any binding. But of course that didnt stop me from breaking out the Dremel and polishing spots with wear marks (things that were touching). I also worked the slide about 500 times with my had, and it seems to have smoothed out a bit. After working the slide, I took out the spring and soaked it in some CLP, and a bunch of gunk/grease came out, maybe it really did need a break in! its re-lubed and ready to go back to the range for another test run. Ill try some more carry ammo through it, and see how she runs.

Here are the pics of the grip (2 weeks late...)

http://i40.tinypic.com/2aevf5.jpg
http://i40.tinypic.com/15hclt.jpg
http://i40.tinypic.com/jgpedz.jpg

The holster is from jlaudio on this board, it is AWESOME.

[jocko]

take the old recoil spring with ytou to the range, if the gun doesn't snap out of it in 50-+ rounds or so with the new recoil spring in it, then go back to the original spring that was in it and retest. If it works OK, then u can assume it is recoil spring related and quite possable more rounds are needed to get it going right. I woul dnot think a new barrel would require anything but again u can'thurt that barrel by polishing the feed ramp and barrel lug even. Check to see if the reoil spring is on correctly to. open end always towards the front of the slide, count the coils to be sure they are the same springs. length will be different as one is brokien in and pre set the other is not yet..

nice gun, nice grips, nice holster.

[Ikeo74]

New springs = New break in. It might not take the full 200 rounds though.

[kenduc999]

Thats where the problem was, I DID put 200 rds through it, and it was still having the issue. I have not tried it since the recent "spring therapy" though, and I will bring the old recoil spring with me to the range...maybe I can sneak out tomorrow....:D