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Installing a New Locking Cam in a FN-Browning HP.

10430 Views 15 Replies 8 Participants Last post by  FartinLutherKing

The question of, "How Do I Install a New Barrel Cam in a BHP" comes up from time to time.

So, here's how to install a new barrel cam or locking cam as FN call's it.

First: Tap the broken cam pieces out of the frame.

Second: Position the new cam in the frame making sure it is oriented properly (the cam has a front, back, top & bottom). With the cam properly positioned in the frame, place the assembly in a large machinist vise and upset both ends of the cam.

Third: Remove the assembly and, using an anvil & hammer carefully work the ends of the cam to flow metal into the recesses on each side of the frame. NOTE: The metal of the cam must be flowed gently with light hammer taps to avoid work hardening and causing brittleness of the cam.

Fourth: File both ends of the cam flush to the side surfaces of the frame. Finish with 320 grit emery cloth, polish and reblue.

Note: You may need to finish with a finer grit than 320 prior to polishing, and that will just depend on the level of finish the pistol has that's being serviced.
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Hello Johnny:

Man, that's the 64,000 dollar question.

I wish I knew, because I buy atleast 6 of 'em!
I was able to buy one from the ex-browning gunsmiths in missouri about 8 or so years ago. Think it ran about $27 or so. Might try them. The last two I made from scratch from a grade 8 bolt. Remember to put spacer on the inside while peening to prevent collapsing. The right amount of feeler gauges works ok. Good luck Bill
I got lucky and found one today, used. Waiting for delivery, should have it in a few days.

Update: Received the barrel locking pin today. This one measures (side oval) .197" x .313" not having my gun and can not confirm if it different.

If someone would please measure the end of the take down pin that sticks through the right side of the frame. This way I have a reference in the photos I have, so I can determine if the size is correct.


Hi David,

If you mean the pin on the slide stop (dunno its proper name) it looks to be .152" on the end where it steps down and .197" where it goes through the frame.

If you're looking at a photo of a stripped frame, the hole for it would be a smidge bigger than .200". (My calipers don't measure inside holes that small)

Hope this helps a bit.


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Mr. blue68f100,The part you are installing is called a cam pin. It's a sloppy fit in the frame and must be swedged into the frame from both sides. It's not really a very easy procedure and it sounds like you might want to get some help on this one. Please make a post if you need someone to guide you thru it. Good luck, Bill
Browning wanted $300 to repair the gun, so I'm having them return it (what I paid for the gun). The replacement part I have was removed from some guns that were being destroyed. Looking at it, it should just drop in. If the fit is snug like it should be, I will solder it in place, if not I will weld it. The place where I got the part from said that he welds them on the Left side, this is hidden by the slide release. I would like to use the solder for not to burn the bluing off. I think it will look ok with the oval rings on the side plates of the frame. What ever I do I will test it and keep a close eye on it for signs of cracking and coming loose.

I bought a Sig P229R SA/DA SRT to be my shooter now. It is larger and heavier than the BHP. But it is a very accurate gun even with a shorter barrel.

What I need to know is how to check the barrel fit to the lug and frame.
Mr. blue68f100, I think what you're trying to do just won't work. A new cam pin has extra material on the ends so you can swedge it in to the frame,a used one doesn't have this material as it has already been swedged and ground off. Welding is out as it will make the part hard and brittle. Either buy a new part or make one yourself, but I don't know your abilities. I've done three, one factory and two I made myself. Took about 4-5 hours on first one and about 3 hours on second one. After you get it in, you have to make sure that the slot in the barrel lug doesn't bottom out on the cam pin and that the barrel rests on the frame rails or repeated hits will break the cam pin again. In the auto repair business we would call this problem a "gotcha". This problem surfaced in the early 50's so fn made the cam pin smaller instead of bigger, go figure! For the life of me I can't figure out why they designed this type of "bastard"arrangement other than to keep anyone from doing it themselves. If you need help, feel free to post your e-mail address and maybe we can help you out of a jam. Good luck,Bill
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Bill, I did not know my email was blocked, clear now.

I have an unusually high mechanical ability, design as well as mfg. I have a end mill in my garage + all of the necessary tooling. Plus I have welders too. I will not rush into this knowing the barrel is locked in with this cam. I will know more about the fit when my gun is returned this next week. I really would like to reserve the high gloss bluing on this gun, but the repair will take presidence. Safety first.

Thanks for all the info about the cam.

What is the main cause for these cams to fail? Low strength steel, improper fit (to frame, to barrel).

Since the failure was caused by fatigue, points to low strength steel, or loose/improper fit. With less than 8000 rounds of reduced loads, leads me to material selection. The fit to the frame was very good.
Mr. Bluef6800, What ever happened to your cam pin project ? Bill
I just got my BHP back last week. It took Browning greater than a month to send it back after requesting it to be returned.

I have started fitting the replacement part today. It looks like the replacement is slightly larger than my original one. This will make fitting easier and better. The interface is almost perfect for a thermal fit. I have removed the bell at one end (slide lock). So I will slide it in from right to left. With a little luck I may get this back together friday.
I have my BHP back together now. Will not be able to test it, till the 1st part of next month. The barrel fit was good as is. This part is a harder than the original, can tell the difference with a file. The only question is how it will it hold up.
Bob Reed said:
Hello Johnny:

Man, that's the 64,000 dollar question.

I wish I knew, because I buy atleast 6 of'em!
Check with Bill Laughridge at Cylinder and Slide.
Update: Received the barrel locking pin today. This one measures (side oval) .197" x .313" not having my gun and can not confirm if it different.
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