Do you need to lap a scope,what are the advantages and disadvantages if you don't lap the rings ??

there are many advantages to lapping, the biggest of which is that your scope will survive even the cheapest of rings without a scratch. i personally wouldnt say there are any true disadvantages to not lapping as 99% of the rings out there are not lapped and work just fine. i would say its like getting another option in a vehicle, it might help but its not really necessary to essential function. albeit i still lap all my rings only out of precaution. but of all my rifles i have only ever found that proprietary type rings like sako optilock, ruger's half moon dovetail and cz's lug + dovtail needed lapping but thats because ive found them to often have a lip on the rings edge. especially with rugers cast rings. so if you have access to tool steel and a lathe go ahead and make a set but otherwise you should be fine unless your rings have some obvious flaw.

I lap all my rings when the rings let me. Some rings, you just can't. But with leupold std rings, you can.

When I lap, I get no ring marks, second, they hold better. I had trouble holding a scope on a 300RUM, and lapping fixed the issue. It takes off torque on the scope also. Lots of work, but worth it IMO>

a disadvantage would be rust after you expose the coated metal. another one i suppose is removing too much material that you run out of hold on the screws. how many gajillons of scopes have been mounted without lapping and with 5$ rings and still doing fine.my personal preference is to use one piece scope bases when possible . there are some scope rings that dont benefit or need lapping like the buris zee signature because it has a plastic insert or warne style rings that close on a scope more like a clam shell. if your worried about ring marks just use a thin coat inside the rings with liquid electrical tape. lapping does have benefit but i dont do it anymore.

Thats why you can cold blue. I do. Works great.

Those POS burris won't hold a scope worth a crap over a 300win mag. Been there and done it. Sure, for the 3 day a year gun hunter, just about any ring will do.

i install several dozen scopes per year. All of the rings are lapped. Worst rings of all are the cheap made in China crap. i no longer install them.

If it was me I'd go with the Burris Signature Zee rings with the inserts. Do a search on google, or other forums and you will find how highly people think of them.
IMO they are the best I've used in that price range. I like them a lot better than the Leupold rings I've used. A local shop has also started really pushing them, as their gunsmith loves them. I just don't think you can beat them for the price. Since they have the inserts, you don't need to lap them, and you won't get any ring marks on your scope. Plus, if you need to shim them, which you usually don't but just in case you do, you can get offset inserts.

home cold blueing rarely holds up. you still need to keep bluing oiled as it has only basic rust protection... moisture is gonna get in those rings i dont care how tight.on heavy hitters i use warne tactical rings. leupold prws are good ones too. wouldnt bother lapping those but i guess everyone has there own rituals for accuracy.

Well, its held up to weeks after weeks in newfoundland and other place of non-stop rain and snow. Never had a problem in decades.

What one has to understand is, what blueing is. Its a chemical reaction. Not just for looks. Everyone oils thier guns. At least I hope they do.

But I understand your point of view too. The 3 day a year hunter, it makes no difference either way.

If you don't check them for alignment after lapping, you have really done nothing!