Are the 1/2 lug made every year and how do you think how many 1/2 lugs are made to the number of whole lugs. Winded for sure. When did they quit making half lugs?
1/2 lug? Are you talking about the 6" light contour barrels? Those were not common . I have only seen 4 and I did gun shows for 5 years with a friend and saw a lot of guns come through. I have one and a friend has a very early production. They are nice guns with a classic profile. The 6" Security Six is also a nice gun with a similar profile.
I always thought my full lug 6" was a bit muzzle heavy, but it does help with recoil from hot .357s. I'd gladly trade it for a half lug which I think look better too.
They do offer half lugs in batches on occasion. In 2013 Davidsons had a new batch of the 4" GP100 in .357 half lug with fixed sites. There is another brand new batch available right now at the florida armory website for $799.00. If a distributor requests a batch in enough quantity Ruger will gladly supply them. Ruger still has the injection molds for all the half lug barrels.
http://www.floridaarmory.com/Ruger-GP100-.357Mag-4inch-Stainless-Half-lug.html
If you are willing to order 50 at a time, Ruger will make ant barrel, caliber and sight combination. A local security company just got 100 GPs 38spl half lug fixed sights.
Keen eyes will notice this brand new model 1711 has an ETCHED not roll marked barrel, thus debunking the old spare parts throw together batch theory. Pine Tree Castings keeps ALL the molds available and ready to put in production.