K38 strain screw threads- not same as other K frame?

[Evan Price]

I picked up an early 4- digit serial number 5-screw K38 as a stripped barreled frame with cylinder. I'm reassembling it from my spares.
The problem I'm having is the strain screw won't thread in the frame. The threads look good in there, no damage, but they are looking like a finer thread than the normal K frame screw. I know the older models use a strain screw with a longer threaded shank and I have a correct (i believe) screw, it appears to be the same thread as the newer style strain screw.
Was there ever a different screw i don't know about or did someone customize the screw threads?

 

[robertrwalsh]

To the best of my knowledge (remembering from S&W factory armorer revolver school) the screw threads should be the same, unless somebody deliberately diddled with it. Could the lead-in be damaged, turned under slightly maybe?

 

[BC38]

Those fine thread are really easy to get cross-threaded. Someone may have done just that at some point in the past. Have you tried following the threads all the way around the hole looking for any crossovers?

 

[fleabus101]

The early post war K frames have the earlier minimum diameter strain screw.
To be brief..order an early pre war stain screw. off ebay for a early M&P.. Victory model..earlyK22 outdoorsman..etc
The pics will show a longer threaded body on early strain screws. The later 50s up are larger diam dimension screws that dont fit like early pre war screws.
I you have problem I'll mail you one..
My 14XX PRE 17 post war K 22 has the same small diameter strain screw type..
I may be mistaken..but I think Hondo44 covered this in my question about this issue earlier. search my strain screw questions in an advanced search..
Randy..