4566 frame peening from guide rod.

[18DAI]

I took down my 4566 duty gun for cleaning Sunday night. I'd fired 80 rounds through it that afternoon. I noticed that the little hole in the frame where the plunger from the guide rod sits was peened.

Peened to where there was two burs formed on either side of it at the top. This is the original guide rod that came in the pistol. The recoil spring is a 16lb factory spring. Round count on the gun is unknown as I bought it used and have put around 3500 through it.

I did notice that when stripping the gun the guide rod is already out of its "notch" in the barrel and already free as I pull the slide off. Gun functions fine though.

Is this indicative of an issue with the pistol or just normal wear? Anything to be concerned about or watch out for? Thanks! Regards 18DAI

 

[bgrafsr]

I think you need to get a new recoil spring.

 

[Fastbolt]

It isn't uncommon. I've even seen it happen in newer production guns. I've never bothered to remove the burrs as long as the guns were running normally. When I've seen it happen it's been sort of like flamecutting in revolver top-straps, meaning it reached a point and stopped looking any worse.

I'd replace the recoil spring for GP, though, since it's used and with an unknown round count.

Is the guide rod one of the older staked collar types? If so, can you gently turn the collar (head) with your thumb and forefinger while holding the body still? If so, replace the guide rod, as the staking has become loose.

A few years ago they started sending out the newer 1-piece machined guide rods (with the removable plunger & spring), but I was still getting some of the original staked 2-piece units sent as spare parts. One thing to look for on the older units is for the front end to start to become peened and almost mushroom-shaped (hardening problem), making it hard to easily move within the slide's hole, causing unwanted resistance.

 

[18DAI]

Thanks fellas!

Hi Fastbolt! It is one of the late production "one piece" guide rods without the staked head. This was a 2001 "standard" LE 4566. Decock only with spurless hammer.

The recoil spring is relatively new. I put it in late last year, so it has less than 500 rounds on it.

I wouldn't have noticed anything wrong except for the fact that the last two times I took down the pistol, the guide rod and spring fell away as I took the top end off the frame.

In examining it closely, I saw the peening. I also checked the guide rod thoroughly and did notice that the pin protrudes more from this guide rod than it does on an older staked head 4566 rod. Dunno if that is causing more peening or not. Thanks again! Best regards, 18DAI

 

[Fastbolt]

Thanks fellas!

Hi Fastbolt! It is one of the late production "one piece" guide rods without the staked head. This was a 2001 "standard" LE 4566. Decock only with spurless hammer.

The recoil spring is relatively new. I put it in late last year, so it has less than 500 rounds on it.

I wouldn't have noticed anything wrong except for the fact that the last two times I took down the pistol, the guide rod and spring fell away as I took the top end off the frame.

In examining it closely, I saw the peening. I also checked the guide rod thoroughly and did notice that the pin protrudes more from this guide rod than it does on an older staked head 4566 rod. Dunno if that is causing more peening or not. Thanks again! Best regards, 18DAI

The new plunger is a bit larger & wider in part of the profile than the older style. Both were is-use for some years before I suspect they eventually ran out of the old-style.

Not an uncommon occurrence, though. The guide rod not quite hanging onto the "nail nick" under the barrel, or the minor peening around the plunger hole in the frame.

If the burrs are ever obviously rubbing/catching on the plunger head, as an armorer I'd lightly de-burr them. Don't get carried away. It always takes less than you think it does when you're dressing burrs & removing metal.

I've also seen some of the new plungers develop a bit of a peened wire-edge around the shoulder/edge of the tip, which is easily dressed, if needed (don't get carried away with this, either). Kind of like how the plastic plungers in the CS guns can get ragged edges after enough times in & out past the slide stop assembly pin.

One of the black nylon guide rod plungers in my CS guns is pretty worn and "fluffy", but it works just fine so I haven't "fixed it." It doesn't offer the same stiffness/resistance, and the potential for the rolled wire wedge, that a steel plunger developed in the gun when I changed it for a while (just to see the difference). There's always the potential for some variance in these things among a lot of different guns.

 

[Fastbolt]

I know they were still making the old-style guide rods for at least the 4566TSW's about 5-6 years ago, as someone with whom I spoke at the company discussed the process for how the staking was still being done (at that moment) by someone on a hand-operated press.

The dimples were done in 2 stamping "sets", with the rod body rotated between stampings, which is why some dimples appear unevenly spaced or over-lapped, it seems.