Mkiv misfire

[NIADT02]

Hi
Got myself a new toy. A Mark IV tactical. Brand new out of the box. So I fired 100 CCI rounds through it many needed at least 2 strikes, some even had 6 strikes. Put the other rounds into another gun and they went no problem. All the strikes look hard enough and I’ve never had misfires before with any guns. Striped the gun and cleaned it, with same problem. Striped it a wee bit further and still having the same problems. I know it’s new but never had any issues with a mkII.

The only bit it haven’t taken out of the bolt assembly is the wee lever, spring and pin on the side at the front, which I believe to be the firing pin, quite simply as I don’t know how. Any advice or tips please?

Thanks

 

[hittman]

22LR guns and ammo can be finicky. Try a different brand ammo first.

 

[Mobuck]

That wee lever sounds more like the extractor. How much was the rim dented on the rounds that didn't fire? Possibly as simple as the bolt failing to completely close?

 

[blume357]

My only suggestion is lube the heck out of it... bolt and such until it is dripping and then try it some more and if that doesn't solve the problem send it back to the factory for them to figure out.
These critters should fire pretty much all 22LR ammo... yes you will get a bad round from the cheap stuff every so often but not like you describe.

 

[Uncle Howie]

It sounds to me like the firing pin channel in the bolt may have some debris in it, slowing down your firing pin(?).

See if you can find a video showing disassembly of the bolt, it's not difficult. I'm most familiar with/MK II series, but the bolts are substantially similar. (***Use care, though- small parts under firing pin.)

Once the bolt is out and stripped, thoroughly clean/degrease the firing pin, firing pin channel, and all related parts.

Once it's degreased, I would take a cotton swab and run it along all surfaces of the firing pin, firing pin channel, etc. Check for any burrs left from manufacturing.

I can easily imagine a burr on a stamped firing pin (don't know whether they're still stamped), or in the firing pin channel. If you find a burr somewhere, stone it off. Lube/reassemble, and I'll bet you'll be back in business.

The "the wee lever, spring and pin on the side at the front" sounds like the extractor, as Mobuck said. Probably a red herring, for this problem. Also spring-loaded parts (prone to flying springs!), so I'd leave that for now, until you have more experience taking down your pistol…

Here's a schematic for your pistol, in case you don't have one handy:
https://www.gunpartscorp.com/gun-manufacturer/ruger/auto-pistols-ruger/mkiv
Pay attention to part #61, "Firing Pin Stop." Be SURE this pin is in place upon reassembly.

Let us know how you come out!
———
Edit: Possibly related- is your chamber scrupulously clean?

If you drop a cartridge into the chamber of your disassembled barrel, does it drop right in? (A lot of us call this the "plop test.")

If you had a dirty chamber, I could possibly see the cartridge not seating fully until the firing pin "taps" it into place. Withouth the rim seated against the barrel, the firing pin might not crush the rim of the cartridge properly…

 

[Laserbait]

My MKIV 22/45 LITE was cranky like that at first. Once it got past 500 rounds, it was flawless. and it's been flawless for at least 4000 rounds. It's easily as reliable as either of my MKII's.

 

[Mobuck]

Hose it with WD40 and blow it out with 150psi compressed air. That may fix the problem.

 

[fallsinhole]

First check the plug screws in the top of the receiver to make sure they are not interfering with the bolt travel, with the bolt out check the inside of the receiver with your finger for any burrs!! Bolt out, remove the action spring assy, in the side there is a thru pin that holds the firing pin in place, as you remove the pin cover the top of the bolt with your hand so as to not lose the firing pin and return spring assembly! Clean the channel with a solvent and check for any burrs!! If you have emery paper or fine sandpaper dress both sides of the firing pin to remove any high spots!! Clean all parts and re-assemble!! Make sure the action spring on top of the bolt is down tight in place!! Pay attention to how the parts fit!! DO NOT remove the part on the front side of the bolt, it is the extractor!!! Let us know how you make out!!

 

[peachhead]

My MKIV 22/45 LITE was cranky like that at first. Once it got past 500 rounds, it was flawless. and it's been flawless for at least 4000 rounds. It's easily as reliable as either of my MKII's.

This
I shot a LOT of standard velocity CCI through my mk 4 when I first got it. Had some issues like that at first, they eventually cleared up.