OK... I forgot! Krag/Springfield guard screw ?

[Char-Gar]

It was one of those things I thought were locked away for ever in my brain. But, it doesn't seem to be there now. What is the tpi on Krag/Springfiel guard screw. They are 1/4 X twenty something. But I forget the something! Anybody still have functional brain?

[Bret4207]

Something makes me think the Krag is 26 and the Springfield is 28.

[docone31]

1/4-28, however.... I found, useing conventional grade 8 machine screws, the start threads MUST be tapered. Straight machine screws jammed at the exit hole.

[Phil]

1/4x25 on the 03, can't recall if the Krag is the same or not right now.

Cheers,

Phil

[Char-Gar]

Well now... Three answer, three different thread pitches? Here is what I know for certain.

1. Krag and Springfield use the same screws. They are interchangable in both length and pitch.
2. 28 is not the right pitch. I have some of those and you have to horse them down and they will go about 1/3 of the way.
3. Brownells lists 1/4 by 25 for their Forster inletting guide screws.
4. Gunparts Corp says 1/4 by 28.
5. Forster guide screws and hand screws go in as pretty as you please.

I need to drill and tap a hole in the bottom of the Krag receiver for a third screw and I wanted to use the same screw as the. I need to buy the tap and wanted the correct size. My screw pitch gage doesn't go any bigger than 30 TPI.

What to do..what to do? Hummm

[RayinNH]

Chargar, I just looked in Joe Poyer's book and I quote:

"...The front guard screw was 1.20 inch long with a slotted fillister head 0.345 inch in diameter. It was threaded on the lower 0.440 inch of its length. The rear guard screw was 1.515 inches long with a slotted fillister head 0.345 inch in diameter. It was threaded on the lower 0.550 inch of its length.

Two types of guard screws were used. The type 1 guard screw had a flat end to circa serial #40,000. After, the tip of the Type 2 screw was beveled slightly. Both were threaded 0.25 inch diameter with 25 threads per inch."

Hope this helps...Ray

[Char-Gar]

Ray.. Thanks that makes sense. It also figures as 1/14 X 25 is not a stardard size (NC=20, NF=28), so that means I will have to pay four times the price for a tap.

[Bret4207]

Chargar- got to ww.mscdirect.com. Good quality stuff, odd taps aren't too expensive.

[Char-Gar]

Bret.. I checked with MSC, ENCO and my local place (Dixie-Tool) and they all have 1/4 by 20 and 1/4 X 28 but not 1/4 X 25. Brownells is the only place I have found and they want over $20.00 for a plug tap.

[RayinNH]

Brownells may be the only game in town. I checked my Travers Tool catalogue, they have 17 different 1/4x thread sizes from 16-80 TPI. Now if it were only 24, 26 or 27 TPI, they have those at $8-10 each...Ray

[Char-Gar]

A fellow has got to know when it is time to give up. I will just use a 1/4 X 28 screw and be done with it. I took a 1/4 X 28 cap/socket screw and turn down the head, so it will make a nice looking installation. Tomorrow I will make an escutcheon and away we go. I already have the 1/4/ X 28 taps. I will have to get a new drill as my carbon bit isn't making much progress on the Krag receiver ring.