Thumb safety fitting problem

[batoy1911]

Bought 2 EB thumb safeties recently. One for my Norinco and one for my ARMSCOR widebody.

The one I installed on the Norc fit really nicely. The one on my ARMSCOR would not completely go into the "off" position to engage the plunger. At first I thought the inner side of the paddle was hitting the plunger tube so I trimmed that part of the safety to clear the plunger tube. Still the dimple on the safety is a hair short of going way down to allow the plunger to rest in the recess. As a result the safety is easily knocked up into the "on" position. The safety seems to function well blocking the sear from moving though. I'm usimg Wilson Sear, EE disconnect and Koenig hammer. I tried the original Norc safety on the ARMSCOR, all's well. Tried the original ARMSCOR on the Norc, works ok too. I swapped EB safeties between the 2 guns, both safeties work OK with the Norc and both have the same problem with the ARMSCOR. What gives? TIA... batoy

 

[Eric F]

Some times the hole for the safety is slightly out of position. I have seen very few safeties drop right in with out a problem. You may need to grind a little more off to get it to work. I suggest getting a file and doing 2 or 3 swipes at a time.

 

[Riss]

I am having the same problem with my Sistema in getting the EB wide safety fitted. Simply will not go in. CAN get the one that I broke to go in though. The new one almost goes, about 1/16" short of going in. Took a small mallet to the first one and promptly smashed it in two. Figured the next step will be to strip the grip safety and sear etc out of the gun and start putting things back in along with the new safety to see which piece it is binding on. Not really looking forward to that.

 

[BBBBill]

This is a little more info than you asked for, but others might benefit.
The safety must be fit (as needed) to the frame, the slide, and the safety detent plunger as well as the sear.

First, examine your safety to insure that the pin is straight and square to the body of the safety. I've seen some pretty bad ones come out of the package. You may have to stone the back of the shield (flat portion that rides the outside of the frame) to eliminate any casting irregularities that will prevent it lying flat and/or scratching your frame. Do not remove the radius at the root of the pin.

Then, strip the frame of all parts so that you can insert the thumb safety by itself and observe any interference. Insure that you remove the safety detent plunger assembly. You want no possible resistance from anything except the frame itself. Fit to frame to insure that it is seated fully and smoothly moves fully from on safe to off safe. You may find the the notch on the underside of the safety lug is too narrow and binding on the frame window. Relieve the face of the lug to widen the notch ever so slightly with a safe side needle file if needed. Remove only enough to allow the safety to clear the "window ledge" and drop all the way down. .0005" -.001" is plenty.

Then install the hammer/sear/disconnector and fit the safety to the sear to insure no (absolute zero) movement of the sear/hammer while on safe. Insure that the safety is fully blocking the sear while in the up position with the slide on. Do not fit the safety to the sear with the slide off as the safety can sometimes overtravel upwards without the slide resulting in a poor fit to the sear when fully assembled. Check fit of the safety upper blocking surface in the slide notch while on safe.

Then remove the hammer/sear/disconnector again, reinstall the detent plunger assembly, and fit the forward face of the safety to the detent plunger for proper "feel" when moving on and off safe.

 

[batoy1911]

I am having the same problem with my Sistema in getting the EB wide safety fitted. Simply will not go in. CAN get the one that I broke to go in though. The new one almost goes, about 1/16" short of going in.

Hi Riss,
Yes the EB wide thumb safety is what I'm using too. It will not go in fully because the part that blocks the sear probably has not been trimmed to the proper height yet. No, don't use a mallet. You'll have to see how much metal needs to be removed at the proper place and use a file. You'll have to remove the grip safety to see where you need to remove metal from.

Hi BBBBill,

Thanks for the info.

First, examine your safety to insure that the pin is straight and square to the body of the safety.

The new EB TS is good on all these.

Then, strip the frame of all parts so that you can insert the thumb safety by itself and observe any interference. Insure that you remove the safety detent plunger assembly. You want no possible resistance from anything except the frame itself. Fit to frame to insure that it is seated fully and smoothly moves fully from on safe to off safe.

Yup did all that. Safety is flat and square in the frame and movement is smooth.

You may find the the notch on the underside of the safety lug is too narrow and binding on the frame window.

I do suspect that this might be the case though I don't feel any binding moving the safety up and down while in the frame with everything removed. I am just not sure if its a narrow notch or a shallow one. I'm almost tempted to remove some from that part but opted to ask here first.

Then install the hammer/sear/disconnector and fit the safety to the sear to insure no (absolute zero) movement of the sear/hammer while on safe.

Yup did that too. No sear movement at all when safety is on verified both visually and by listening to a click as advised by tuner in some other thread.

Then remove the hammer/sear/disconnector again, reinstall the detent plunger assembly, and fit the forward face of the safety to the detent plunger for proper "feel" when moving on and off safe.

Don't want to do this right now. I'd first try and see if the notch is where metal hit metal prematurely. I may have a thicker than usual frame. The ARMSCOR is cast while the Norc is forged BTW.

Thanks for the replies, guys. Any actual experience with ARMSCOR/RIA and EdBrown Wide Thumb Safety incompatibility?

 

[krs]

There's no incompatibility, just incompetence.

Read BBBBill's post carefully. ALL new thumb safeties need to be fitted by careful filing of their contact surfaces and NOT by hitting it with a mallet!

Take the gun apart. Put back the trigger parts, disconnector, sear and hold them in place with the sear spring and the mainspring housing, but leave off the grip safety so you can look in and see where the new safety is making contact prematurely. File there, on the safety, very carefully.

It's a little filing then try it out, then a little filing then try it out sort of thing that takes patience and no small amount of skill.

 

[Riss]

Mallet (little brass tapper) was used as it had been a very tight fit on the pin through the grip safety. Missed on one strike and cracked the MIM part. Errors on all sides. Did not know enough of fitting part FIRST. Did not use correct tool. AND did not purchase a steel part. No wonder the stainless steel and hardened steel ones were all out of stock.

 

[batoy1911]

There's no incompatibility, just incompetence.

The 2 EB Safeties have been properly fitted to the sears in both the Norinco and ARMSCOR. Both block the sears on each of the 2 1911s and there's no sear movement with the safety "on" on the two. The problem is the EB safety on the ARMSCOR would not fully go down to the "off" position to engage the plunger properly thus there is much less tension to hold it in the "off" position.

Observation #1: The original Norinco safety when installed in the Norinco 1911 travels past the plunger detent when I press hard on it such as using a thumb over safety grip during live fire. Conclusion: the notch on the part of the thumb safety that goes thru the "window" on the frame and blocks the sear is deeper than spec OR the "window" on the frame for that part to go through is wider than spec.

Observation #2: The Norinco safety fits the ARMSCOR better than it fits the Norinco in that it firmly stays in the "off" position and not beyond no matter how hard I press down on it. Conclusion: ARMSCOR window in spec, Norinco safety in spec, Norinco window is wider than spec OR ARMSCOR window is small than spec, the notch on the Norinco safety is deeper than spec and the ARMSCOR window is smaller than spec.

Observation #3: Both EB safeties fit the Norinco perfectly. Both are a hair shy of going down fully to the off position in the ARMSCOR. Conclusion: if I trust the EB safety to be in spec, the ARMSCOR has a smaller window than need be (at least at the bottom part where the safety is stopped by the frame when in the off position), the Norinco "window" is in spec, and the Norinco safety has a deeper notch than usual.

I tried to deepen the notch on the EB safety at the bottom part where it hits the frame when in the off position and the EB safety is now closer to the full off position, is held by the plunger with more tension and no longer easily flipped into the "on" position with a light flick.