Posted By: wapitirod
Why lap or linebore rings - 06/13/2012 5:58 AM
I decided to write this as I was lineboring a set of rings on a Super Redhawk. I will show some pics of the rings half way through the process and then finished. The problem is that almost all rings no matter how good will be out of whack when you get them mounted and they will put undue stress on your scope. There are two methods you can do yourself or have any competent gunsmith do. The first is lapping which only requires a piece of 1" or 30mm polished steel round stock, the harder the metal the better. You can also buy an actually lapping kit if you would rather. This process is simple, you just apply either some lapping compound purchased from a gunsmith supply store or you can use valve lapping compound from your local auto supply store which will be less expensive. The other method is cost prohibitive unless you do alot of rings and that is to linebore the rings with a special reamer. The reamers can run around 100.00 or more but I prefer them as they work faster and are more precise.
This is the reamer I use, it's turned with a wrench and you start with the rings lightly tightened and then slowly tighten the screws after each couple of turns of the reamer, you don't want to try and take too much material at once.
These are the rings after about 15 minutes of working on them. The pic isn't the best but you can make out the dull spots which show where the low spots are and exactly how the rings were putting uneven pressure on the scope as the high spots which are shiny are all that were contacting the scope.
This pic is the rings finished with the maximum amount of material I felt good about being removed. It's hard to make out but the front ring top and bottom are stamped with a small "1" on the same side to allow for proper reinstallation, the rear ring is marked with a "2".
The final step is to torque the screws, there are a couple of things to note here. Always torque in a cross pattern and do it in steps, with four screws like this go diagonal otherwise go straight across. If you have vertical rings always tighten the bottom screw first or it can take tension off the clamping force on the base. With #6 screws I'll start with a regular screw driver and just go to where there is tension on the screws, then using the same pattern I go around the screws again with a torque driver set to 10" inlbs and then a final torque of 15inlbs. If I have #8's I go to 20inlbs but more important than actually torque is even pressure on all the screws. Some of the screws supplied with rings and bases can leave something to be desired but the specs above I've used on both steel and aluminum rings and with cheap and good screws. You don't need a 300.00 Snap On driver like mine but if you do very many scopes I recommend and inexpensive driver like the one from Wheeler engineering, it's not as precise but it will give equal torque.
Something else I'll mention is it's not necessary to put loctite on rings. If they are torqued correctly the rings themselves act against the screws with spring force which keeps them from backing out. I do loctite bases with red loctite but I don't use the liquid. Loctite has two new versions which are much less messy and the red is just a little less strong than the liquid and although it holds very well the screws can usually be broke loose without heat. The two types are a solid stick and a gel both use a screw feed system like deoderant. With bases start your torque sequence in the middle and work outwards toward the ends. If any of you have done heads on an engine it's the same principle otherwise it can cause warpage and always go back over everything on last time. I hope this helps answer some questions and give you some helpful information.
This is the reamer I use, it's turned with a wrench and you start with the rings lightly tightened and then slowly tighten the screws after each couple of turns of the reamer, you don't want to try and take too much material at once.
These are the rings after about 15 minutes of working on them. The pic isn't the best but you can make out the dull spots which show where the low spots are and exactly how the rings were putting uneven pressure on the scope as the high spots which are shiny are all that were contacting the scope.
This pic is the rings finished with the maximum amount of material I felt good about being removed. It's hard to make out but the front ring top and bottom are stamped with a small "1" on the same side to allow for proper reinstallation, the rear ring is marked with a "2".
The final step is to torque the screws, there are a couple of things to note here. Always torque in a cross pattern and do it in steps, with four screws like this go diagonal otherwise go straight across. If you have vertical rings always tighten the bottom screw first or it can take tension off the clamping force on the base. With #6 screws I'll start with a regular screw driver and just go to where there is tension on the screws, then using the same pattern I go around the screws again with a torque driver set to 10" inlbs and then a final torque of 15inlbs. If I have #8's I go to 20inlbs but more important than actually torque is even pressure on all the screws. Some of the screws supplied with rings and bases can leave something to be desired but the specs above I've used on both steel and aluminum rings and with cheap and good screws. You don't need a 300.00 Snap On driver like mine but if you do very many scopes I recommend and inexpensive driver like the one from Wheeler engineering, it's not as precise but it will give equal torque.
Something else I'll mention is it's not necessary to put loctite on rings. If they are torqued correctly the rings themselves act against the screws with spring force which keeps them from backing out. I do loctite bases with red loctite but I don't use the liquid. Loctite has two new versions which are much less messy and the red is just a little less strong than the liquid and although it holds very well the screws can usually be broke loose without heat. The two types are a solid stick and a gel both use a screw feed system like deoderant. With bases start your torque sequence in the middle and work outwards toward the ends. If any of you have done heads on an engine it's the same principle otherwise it can cause warpage and always go back over everything on last time. I hope this helps answer some questions and give you some helpful information.
