Help with grip screw info on Schofield / Laramie

[Sgt. Saywut]

I decided to try making a pair of 1/8” thick rubber inserts to place under the grips on my Beretta Laramies, so that the grips better fill my large hands.  The original grip screw, which apparently is called a fillister screw, is approximately 1” long, so I’ll need to find a pair that are 1 1/4” long.  The problem is that I don’t know the TPI - it appears to be a fine thread, and most likely is more than the 32 TPI one finds at the hardware store.  Brownells only lists the 1” length, as do Taylors and a couple other vendors, and when we called Brownells, they had no clue what the TPI was, let alone the diameter. 

 

Anyone here who would happen to know, or can offer tips on how to find out?  

[Driftwood Johnson, SASS #38283]

 I don't know, but it is easy enough to find out.

 

Do you have a caliper?

 

Set it open to one half inch and lay it alongside the screw and count the number of threads. Then double it and you will get the Threads Per Inch.

 

Then measure the outside diameter of the screw.

 

If you get a bizarre number it could be a metric screw. If so, set your caliper to Millimeters, open it to one Millimeter and count the threads. Then measure the OD of the screw.

[Sgt. Saywut]

Now why, I ask myself, did I not think of this??

 

Looks to be a 4-48 screw.  Approximately 0.107” diameter, 48 TPI.  Yep. 

 

Thanks, DJ!

[Sgt. Saywut]

Well, turns out it’s very difficult, if not impossible, to find fillister head screws, 1 1/4” long, in 4-48.   Actually, any screws of any kind in that length and pitch, unless I go with a socket head.  No thanks. 

 

So I found a 4-48 die on ebay, and tried it on some 1/8” steel rod.  Turns out, the head would have been too narrow, and I only had a brass 3/16” rod handy, so I tried grinding down part of it to a little bigger than the die’s opening.  Then I cut threads in the rod most of the way back to the intact portion of the rod, and cut off all but 1/8” of the unground rod.  Then I cut a slot in the head, and tried it.   It worked decently. 

 

The funny part is, I was working with a pair of the black plastic S&W grips, which are a bit thinner than the factory wood grips.  Once I put together the plastic grips with rubber inserts, the overall width was approximately 0.2” wider than the wood grips alone.  Thinking to try the inserts and brass screw with the wood grips, I found out the latter has a screw that’s approximately 0.2” longer than the factory S&W screw - with a pitch of 6-40 

 

Pics of the home-made screw and a comparison of the two Laramies.  I need to clean off the bench!