Thompson Encore iron sights

[WilliamDahl]

I'm wanting to add iron sights for a .45-70 barrel for a Thompson Encore that I own. The barrel doesn't come with sights, only with holes drilled for a scope. I believe that there are two holes tapped in the front sight area. What I'm curious to do is put one of the aftermarket AR-15 front sights into the front-most screw hole and put a peep sight on the rear. Something like this for the front sight:

http://www.brownells.com/userdocs/products/t_923015001_1.jpg

So, does anyone know if the sight screw thread for the ARs is the same as the screw threads for the Encore barrels?

[unclebill]

i dont know
but i like the idea!

[WilliamDahl]

Some of us with old eyes have trouble focusing on the front and rear sights. The advantage of the aperture / peep sights is that you don't have to focus on the rear sight. You just put your eye up close to it and it is so small that if you can see through it, all you have to do is put your front sight on the target. Combining an aperture / peep rear sight with a ring and crosshair front sight seems like it would be a good idea for us old eyed folks.

Odds are that they use different screw threads, so I'll probably have to either tap the barrel with another hole, find a front sight ramp that fits the existing screw holes and that I can tap for the AR's threads, or have a barrel band custom made for the end of the barrel that I can then tap for the AR's threads. I've got some hex bar stock that would be of sufficient size to create a barrel band for an Encore heavy barrel, but I don't have a lathe or milling machine to cut the center hole. I'm thinking that I could cut it a bit smaller than the barrel diameter, heat up the barrel band to make it expand, and then slip it over before it cools off and shrinks. The only question for this would be how much under to cut it. Anyone gunsmiths out there want to relay what various manufacturers use for barrels that are installed this way into receivers?

[dave22250]

The site holes are usually no. 6 or no 8 thread see if thread size is the same,don't know about the AR.

[Hammerhead]

Chances are it will end up too low. They make a version of that sight that fits in a ramp dovetail.
KNS sights at Midway (http://www.midwayusa.com/find?currentMWCatID=9472&dimensionids=4294846210&statuses=Available&statuses=In+Stock&statuses=Backorder+OK&statuses=Special+Order&statuses=Not+Available&statuses=No+Backorder&statuses=Coming+Soon&statuses=Other&minPrice=&maxPrice=&sortBy=1&itemsPerPage=20&PreviousCategoryDimensionId=1049&promotionId=&userSearchQuery=)
http://media.midwayusa.com/productimages/440x330/primary/137/137119.jpg
I had one on a 10/22 and found the cross wires to be too narrow to see well with my 52 year old eyes. I should have bought the duplex style with wider wires.