McMillan action cocking piece

[AlNyhus]

I'm working on a McMillan BR action. It's a steel action with a square tang from the '80's by my research. The exact sequence of events is a bit murky but years ago, the nose of the cocking piece somehow got broken off (the part that goes into the cocking helix cut of the bolt). The original cocking piece and the broken off piece has gone missing so I don't have anything to go by for fabricating a new one.

Before getting too far into this, does anyone have any ideas as to where I could source a new one? McMillan's is unable to help. Any 'smiths or builders that might be worth a try for a replacement? I'll post some pics up of the shroud and pin a bit later, too.

Thanks in advance! -Al

 

[DaveTooley]

Contact Lazzeroni. They used McMillan actions. You might get lucky or at least pointed in a direction. Or try these folks. Not sure of the status of the company.

Home - McMillan Firearms

WELCOME TO ARMALITE RIFLES

www.mcmillanfirearms.com

 

[Alex Wheeler]

I would be looking at what cocking pieces are still available for other actions and see if any are similar enough to retro fit. I have made a roller cocking piece from scratch and it was very time consuming on manual machines. Like more than the actions worth lol.

 

[AlNyhus]

A Hall looks pretty close except for the rear. The McMillan has a rear rail that guides it along a notch on the back of the shroud.

 

[jackieschmidt]

Al, do you have a picture?

 

[DaveTooley]

Al
I just remembered I have a 416-338 Lapua I built on a McMillan action. I'll send you pics and measurements when I get to the shop. I need to finish that rifle.

 

[AlNyhus]

Here's some pics of what I've got to work with...the pile of stuff that followed me home home a couple days ago. . At one time years ago, someone attempted to make a new cocking piece....that's what's pictured. If the original broken one was available to look at it would be easier but that's evidently gone "walk about", as the Australians would say.

As you can see, these two surfaces of the home brewed cocking piece aren't parallel to the firing pin...so the pin won't thread into the cocking piece when it's in the shroud:

The rear guide through the shroud actually doesn't fit too badly:

Why the nose wasn't carried to the bottom of the cocking cam helix cut....who knows???

Looking forward to everyone's thoughts and input. -Al

 

[DaveTooley]

This is what mine looks like. Let me know if you think they are the same and what dimensions you need. The recess in the shroud is approx .812".

 

[DaveTooley]

Might be able to track down the gunsmith that worked there.

That part was cast BTW

 

[AlNyhus]

Dave...that one is surely very similar. The recess length on this one is .750, the recess width is .525 and the depth is .450 measured from the side flats.

Thanks!!!!!!!

 

[DaveTooley]

Mine is .500" wide.

 

[DaveTooley]

PM sent

 

[Tucker65]

AlNyhus, I would think with some time spent on a milling machine you should be able to mill out a replacement that would work if you can't find one. Dave has one that shows you what they are supposed to look like. You just need the correct dimensions to fit your assembly. Not sure how hard the piece would need to be as far as heat treatment but Nitride treatment might work for that.

 

[AlNyhus]

Have milled a replacement cocking piece. Any thoughs on where the hardness should be? I'm not exactly sure what material it was that I used as it came from the scrap bin at the race shop. It's not cast. -Al

 

[spike-55]

Just make sure its a "Hemi" piece and it will be fine Al lol!!!!!
stan

 

[WSnyder]

Any thoughs on where the hardness should be? I'm not exactly sure what material it was that I used as it came from the scrap bin at the race shop. It's not cast.

I measured an R700 unknown origin that was handy. I got Rockwell A78 and C48. Looking at that it might suggest to me that it might be case hardened. Good luck with the mystery metal