Aftermarket thumb safety detent

[saltydog452]

The detent, or divot, on my new thumb safety is non-existent.

With no access to powered drill other than a Dremel, your suggestions as to accurately place the detent is appreciated.

Thanks,

salty

 

[Dixie Gunsmithing]

Mark the spot with a pen, and use a center punch to make a mark. Use a round burr, about the size of the detent, to cut the spot. Do a little at a time as to not get it too deep, or too wide. It would be best to place the safety in a vise, while doing the work.

 

[James K]

What gun is it? A 1911 safety if made right shouldn't need a detent.

Jim

 

[saltydog452]

Post 3

James,

If true, why is there a plunger spring, tube, and tips?

Apparently someone, at some time thought these were needful things to have.

sd.

 

[polyphemus]

What gun is it? A 1911 safety if made right shouldn't need a detent.

OP could offer a clue to the question.
Now a M1911 thumb safety has a ramped detent,not just a recessed dimple
ordnance specs and original design call for it,the most obvious reason is to
prevent it from accidentally locking the slide.John Browning designed it as a safety feature and so it remains.The slide stop is a different story Mr. Kuhnhausen notwithstanding, a properly tensioned plunger spring will keep it in
place because it rotates against the plunger to lock the slide,the thumb safety
rotates away from it.
OP please do not use a dremel to do anything,if you have an M1911 pistol you
should return the part because this an intricate milling operation that does not
need to be done.All replacement T.safeties have detents.

 

[James K]

Ooops! I was thinking of the slide stop; many people put detents in them, but they shouldn't need one.

Jim

 

[saltydog452]

It isn't on a pistol. Yet.

It needs to be 'fitted' first. Part of that fitting process is the selective position where 'ramped detent that was mentioned in an above comment is placed. That's the way 10-8 sells its extended thumb safety.

I was thinking of a loooong twist drill bit installad through the plunger tube with the front up against the now installed thumb safety. A couple of slow twists to leave a witness mark on the thumb safety that'd mark where the divot/detent needs to be placed.

Clear as mud? I am terrible at trying to paint a picture with words.

Thanks,

salty

 

[Dixie Gunsmithing]

You may be able to mark it that way, for position. It's according to how good you are with a small grinder, like a Dremel, to recreate the detent. The center punching I mentioned above, is so the burr wont skate off the piece when you start. It will be hard to do it this way, or any other way, without having a mill, or at least a drill press set up with an x-y table and a vise. I would say that if you are steady, keep the Dremel running slow, and take small bites at a time, one could recreate it. Just keep comparing it to the old one and trying it for function.

 

[polyphemus]

The recess dimple itself is not the biggest problem I think the tear drop guide
would be it and a dremel is going to walk all over and ruin your day.
It is possible that just the dimple will work ok,it's your piece.
Here's how you do it without the dremel:the location is critical so you have to make sure of it and then double check.You'll probably need a good quality
hardened center punch,your first mark is very light and you keep on tapping
harder and harder until you have a good pilot hole.
Now you'll need a good quality 1/16" drill bit preferably new and a hand drill,
that's right,again it has to be a machinist grade hand drill,they have minimal
runout.And ever so slowly and carefully you drill the recess,use the plunger as
a depth gauge.
Be sure to secure the work to a vise,good lighting and a loupe will help.
I wish I could help you with the ramp,good luck.

 

[saltydog452]

Thanks all.

sd.

 

[HiBC]

One way is get the Brownells detent drill.It s a long drill that slips through the plunger tube..You can use a pin chuck or fashion a handle and just turn it by hand.No motor necessary.Or,after you fit it,you can just work it,see the shiny line the plunger makes.

That's not necessarily a recommendation.

I've only done four or five of them,I'm not a 1911 ghuru,but of the safeties I've used,none had that issue.

I don't know who made yours,but you might call them.Ask.Sometimes a production part gets a missed operation.Dang dope heads!

It also might just be an angled surface bearing on the plunger.

On a Colt safety,there is a slight detent for "Safety Off"

but for "safety on" its just the contour of the flat plate of the safety body.Its a flat cam.When dropping the safety off,the plunger just goes around a corner.

Off topic to the slide stop..premium slide stops are expensive.I lost a couple to playing the detent game before I figured out a subtle slope with a plunger against it works fine.Remember the mag follower/spring on an empty mag has to be strong enough to overcome whatever "detent" is created. At least,if you want the slide to stay open last round.

I've found second guessing JMB is expensive.So is modding a 1911 part before I completely understand the subtle genius JMB put in it.(which applies directly to Dremel tools!)But,gollygosh,a guy sure learns along the way!!
Fit the safety,see how it works first.

 

[RsqVet]

OK have you otherwise fit the safety? They rarely drop in and doing the file work on the back side is more critical in many ways than the dimple.

And yes the 10-8 safety requires you to spot, and place the dimple. It's meant to be that way, they are opposed to a one size fits all approach.

Spotting, center punch and round burr works well to do this, a small lead in can be cut with the round or a cone burr. Lock it in a vise or you will never be able to do it.