Borrow scope lapping tool???

[audiopro74]

[desertrider]

I'm not going to knock lapping rings as a waste of time and effort, because there are situations when it may be the best option, but have you already eliminated all other variables causing the misalignment you're experiencing?

Do all mounting screw holes in the receiver align properly?

Are you using a one piece scope base or two piece?

If you're using a one piece scope rail, does it sit flush with no gaps?

Are you using name brand rings? (Beware of cheap, poorly machined rings)

Remember, you are combining several different systems, probably all manufactured in different facilities on different machines. All provide an opportunity for different tolerances between each other.

There's a good chance that if you eliminate all tolerance inconsistencies between the mating parts it may not be necessary to lap your rings.

[audiopro74]

[desertrider]

I'm in the same boat right alongside you right now.

I recently bought a used 700P (PSS?) in .308 and I'm in the process of scoping it right now. I'm using a bunch of old components that I happen to have on hand.

Rem 700 action - Leupold MK IV one piece steel rail - Badger Ordnance steel rings - SWFA SS 10x42 scope.

I know I will have a tolerance stacking situation since there is a very slight gap between the receiver and rail at the back of the receiver. I'll bed the rail to correct that this weekend though.

Once I'm satisfied with the rail bedding, I'll use some green plastigage on the ring surface to look for any abnormalities in fit once the cap screws are torqued.

[audiopro74]

I'm in the same boat right alongside you right now.

I recently bought a used 700P (PSS?) in .308 and I'm in the process of scoping it right now. I'm using a bunch of old components that I happen to have on hand.

Rem 700 action - Leupold MK IV one piece steel rail - Badger Ordnance steel rings - SWFA SS 10x42 scope.

I know I will have a tolerance stacking situation since there is a very slight gap between the receiver and rail at the back of the receiver. I'll bed the rail to correct that this weekend though.

Once I'm satisfied with the rail bedding, I'll use some green plastigage on the ring surface to look for any abnormalities in fit once the cap screws are torqued.

[sigstroker]

The plastigage thing is for bearings, which are supposed to have a certain clearance. Scope rings aren't supposed to have any clearance.

[audiopro74]

The plastigage thing is for bearings, which are supposed to have a certain clearance. Scope rings aren't supposed to have any clearance.

True, but it will give you a good idea of mating surface. Run 2 strips. One on each edge.

[sigstroker]

Did you read somewhere this was a good idea? The point of lapping is to have even contact along the whole surface of the ring. The plastigage won't tell you anything about that because if there are high spots, you won't be able to tell. Those high spots won't compress.

[audiopro74]

[desertrider]

Did you read somewhere this was a good idea? The point of lapping is to have even contact along the whole surface of the ring. The plastigage won't tell you anything about that because if there are high spots, you won't be able to tell. Those high spots won't compress.

I've never read of using plastigage for this application, it's just something I've done to see if the mating surface is uniform.

If the flattened plastigage isn't uniform in it's spread I'd attribute that to imperfections in the machining of the rings.

At that point I'd consider lapping the rings, especially if I've done everything in my control to ensure proper fit starting at the receiver and working up.

I'll be mounting up my scope this weekend. Over the years I've mounted several scopes and have never found it necessary to lap a set of rings yet. That's been my experience, I'm no world class marksman, but I shoot reasonably well.

[MarikinaMan]

I’m in West LA. I’ve got the Wheeler tool kit.

75 bucks cash deposit, get 65 back on return. Shipped at your cost. Pick up ok.

I’ve lapped a few rings. All of them showed high and low spots. Some more than others. You clamp down on imperfectly mounted or made rings, never seen perfect ones, you run the risk of torquing the scope tube. What happens when it’s torqued? Tracking can be affected. “can” not do sho.

Some designs, like some vertical splits rings from Warne and Aero Precision don’t benefit from lapping due to the way they clamp down.

[desertrider]

I agree with you on the above point, especially if you have a matched set from a reputable manufacturer.

Not being a professional on this subject, I believe that if you paid good money for a set of matched rings and find that there is uneven pressure being applied to your scope tube, it is most likely a result of tolerance stacking where something else just isn't fitting together right.

So if you choose to lap the rings to accommodate the inconsistency of the poorly fitted parts, you no longer have a matched set of rings. You've just modified them to fit the combination of tolerance inconsistencies in your build.

Like I wrote in my first reply, sometimes lapping may be the best option for some situations though. For instance, what if the problem is with the receiver? The cost to have a 'smith strip your gun down to just the receiver and match the surfaces would be a heck of a lot more than the cost of a lapping bar for your rings. That's for damn sure.

If that were the case, I'd spend the coin and get a good lapping kit. Personally, I'd buy the Kokopelli Accurizing Kit and be done with it. http://www.kokopelliproducts.com/acckit.htm

[desertrider]

75 bucks cash deposit, get 65 back on return. Shipped at your cost.

I was typing my reply when Markina Man replied.

For only ten bucks plus shipping, that might be your best bet audiopro.

[smoothy8500]

If planning to use shims, Plastigage would make sense in determining the "gap" when installing the one-piece rail on the receiver. Bedding the rail with some sort of epoxy is easier though.

[Spyder]