Custom Screw Threads

[Moe]

Anyone order an Encore barrel from say SSK or Reeder with custom screw threads? Lets say 8-32 instead of the bastard 8-40 size? Seems like this would be simple at the time of ordering then when different sizes are needed they would be available at your local hardware store!!
Thoughts?

[skb2706]

I am assuming you are referring to scope screw threads. Although they may be a 'bastard' thread pitch they are a standard. If you buy the mount the correct screws normally come with it. If the holes are tapped differently you now have a new bastard problem.
The quality of hardware store screws is far inferior to the quality of 'Torx head' or 'Allen head' machine screws that commonly come with scope mounts from such places as Leupold, Burris and Weaver.
An 8-40 screw pitch obviously has more threads in the same given length as a 8-32. More threads = more holding strength particularly if you are working with a very short overall screw.

[cnTndr85]

Hi Moe,
  I had a custom Encore barrel from Dave VanHorn that used 10-32 screws for the forend, and I have drilled out the factory 8-40's on my 26" 22-250 and threaded them for the 10-32's as well. Its easy to do and works well and I prefer the larger screws for the forend.

  skb2706, Moe is most definately referring to the forend screws here, for whatever reason T/C decided to use an 8-40 screw for the Encore forends instead of the larger 10-32's that are standard for the Contenders and G2's..... and the standard scope/sight screw threads are 6-48 for both the Contender and Encore.
Mark

[Moe]

Yes I definatly meant forend screws on an Encore. Scope screws are fine.

[haroldclark]

Hey Cntndr,

Is the retapping something that someone that is not a machinist do at home with a hand tap?

I have heard guys talking about a "bottom out tap" to get the threads deep and to the bottom.

Is there such a thing?

Harold

[Moe]

Harold, yes it is called a"bottom tap". It doesn't have a point on the end allowing threads to be tapped all the way down to the bottom of the hole.

[haroldclark]

thanks Moe

Harold

[cnTndr85]

Hey Cntndr,

Is the retapping something that someone that is not a machinist do at home with a hand tap?

I have heard guys talking about a "bottom out tap" to get the threads deep and to the bottom.

Is there such a thing?

Harold

Hello Harold,
Yes this can be done by someone that is not a machinist(I'm not one) If you have a drill press set the barrel up in v blocks or vise and make sure you have it level both directions(I level off the barrel lug) so that you're not drilling off center of the original holes, use a #21 drill bit and drill the old threads out making certain that you dont go any deeper than the original hole, then use a 10-32 taper tap to start the new threads, and finish them with a bottoming tap. Go easy with the bottom tap so you dont break it off in the hole when you contact the bottom, use a good cutting/threading oil, and make sure you keep the tap square with the hole(I use a Tap-Rite guide from Brownells).
  Moe is correct in regards the the bottom tap.
Mark

[haroldclark]

Thanks for the info on tapping.  I was in the hardware store today checking out their taps.  The little store didn't have any bottom taps for 10 - 32.  I suppose one could grind off the point on a pointed one.

However, I will shop around for the real thing.

I have 4 Encore barrels at the present time with another in the workings of my mind and I have lost a screw already.  I like to keep the screws with the forend.

Thanks again.

[HHI-7420]

Harold C., if you haven't tried tapping before be cautious. Once you start, only turn the tap a quarter turn and then back up before trying another quarter turn. This clears the little metal chips out of the tap's cutting surface and allows you to proceed. Use plenty of cutting oil also.  Pat

[Moe]

Harold, bottom taps aren't generally at the hardware store, not around here at least. I get them from work. May have to do a little digging to find one. Industrial tool suppliers may have one or can get one. Might even call a machine shop, they may have one or certainly know where to get one.