The Hi Power Walking Trigger Axis Pin

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JayPee

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Lots of owners of the various Hi Power pistols, the Browning, FEG, and FM Hi powers have run into the problem of the trigger axis pin walking out the side of the gun during firing. Once it starts this, tapping it back in only lasts for a few shots before it starts to walk again. So here is an explanation of how and why this happens and a few remedies I’ve used successfully to cure this problem in my Hi Power pistols. First, here is a photo of the pin we’re talking about.
PICT0590-2A_zpsybnte4nu.gif

The problem begins with a need to remove the trigger, and with a misunderstanding of what holds this pin in the gun. If you look down into the frame at the trigger, as in the next photo, you’ll see that the trigger spring rides under the trigger axis pin in a groove put there just for that purpose. Seeing this, many owners conclude that the pin is held in the gun by the spring riding in the groove made for it in the pin’s shaft. 'Fraid not. The trigger spring has nothing to do with holding the trigger axis pin in the frame. The slot is simply a place for the tail of the spring to get neatly tucked away and routed back towards the rear of the trigger body. As in this photo.

PICT0687_zps0xy4oazk.gif

Hang on to your hats because Mr. Browning was smarter than all of us. The trigger axis pin is held in the frame by a tight squeeze fit of the pin into the slightly undersized right side hole in the frame. And this is where the mistake is made - The pin is driven out in the wrong direction. It must never be removed by driving it out from left to right, because that enlarges the hole and destroys the squeeze fit. The same applies to installing it from right to left. The pin must always be installed rounded end first from left to right, or from slide stop side to ejection port side, and it must always be driven out from right to left. When the pin is driven in or out improperly, the damage is done to the hole in the frame, not to the pin, so it does no good to replace the pin. You have to fix the hole. Really? How the heck do you fix a hole?

Well, the fix given by Browning is to degrease the right side hole and paint a coat of modeling enamel into the circumference of the right hole, let it dry, and then reinstall the pin from left to right. Now, sometimes one coat isn't enough, and you may even have to go to a thicker substance to return the hole to its factory dimensions if the damage is bad enough. A friend of mine uses fingernail polish, and I once fixed a rather bad case with a coat of construction adhesive. But remember to let it dry....you aren't gluing the pin back in the hole, you are just restoring the tight squeeze fit between the pin and the hole.

I haven’t had a lot of luck with the modeling enamel working well unless you use multiple coats, and I would prolly go directly to the construction adhesive if I was going to use this technique again. The one I repaired with construction adhesive has done a lot of shooting for five or so years and has never moved. But whatever substance you use, remember to let it dry at least 36 hours. You want it hard as a rock when you drive the pin back in.

OK, now let’s talk about a non-factory authorized repair. There is another way first mentioned on the 1911 Forums several years ago by a couple of very smart gents, and it works extremely well. In fact, it's my favorite. First the trigger and pin are removed and the frame is laid on its right side. Then a roll pin punch of an appropriate diameter is passed through the left side trigger axis pin hole so that the "ledge" of the roll pin punch is resting on the "ledge" of the inside lip of the right frame hole, with the "tit" of the punch projecting down into the hole. Once the punch is positioned, you simply tap it lightly in order to peen the inside lip of the hole. I usually do this three or four times around the circumference of the hole, or just enough to give the hole a good, solid, bite of the pin. Like I said, it's permanent and works very well. I've done it to three PJK-9HP's in the past couple of years and haven't seen any "walking" of the pins since. But remember, tap the punch LIGHTLY.

I don't know if you want to try and repair the hole in a gun that is still in warranty, so I'd probably call the manufacturer and get some guidance on it. But if this is a problem for you, I've used both of these techniques and they work very well. Hope this helps.
 
modeling enamel
Modeling enamel??

I'm sorry, but I would just use blue lock-tight on both sides as the pin is installed, let it cure 12-24 hours, and be done with it.

Enamel paint has nowhere near the adhesion or flexibility necessary.

Peening the hole from the inside is also a viable option.

I have used a hollow end nail-set punch on the outside with good results on other loose roll-pin problems.

It leaves a circular crimp matching the hole on the outside, and is nearly invisible if done correctly.

rc
 
The intent is not to glue the pin back in, but to reduce the circumference of the hole back to factory specs so that the tight squeeze fit is restored between the pin and the right side hole. The paint/polish/adhesive solution works well, it just comes across as a little cheesy
 
I have seen several of the Israeli import High Powers with roll pins for trigger pins. Not elegant but effective.
 
Blue Lock-Tight will not 'glue' it back in perminently.

It will just keep from walking out.

It can still be easily removed in the future if necessary.

Not trying to argue with you, or with paint.

But the paint is much more likely to harden and chip out, or debond over time.

rc
 
Yes the roll pin was used in military service and was even used by the factory for a time long ago. The military armorers usually said heck with finesse and just peened the solid pins in place, but that causes problems in removing it later on. We have a contributor on another forum who bought a surplus Hi Power with the pin peened in place and he's having a devil of a time with it.
 
We live and learn. Now I wonder why they went to all the trouble to put that groove in the pin if it doesn't serve any purpose. But I guess Saive and Browning never thought of holding the gun together with modelling enamel.

Jim
 
For years on these type issues I used a tiny bit of epoxy glue, then I discovered Loctite. Works good; lasts long time. So did the epoxy glue but it was a bit of trouble removing sometimes.
 
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