Again, your needs and the OP's (and mine) may be different. The OP is talking about a .300 Winchester Magnum in Weatherby Vanguard rifle. That rifle weighs under 8 lbs. Most precision rifles are much more than that, and most shooters aren't shooting the likes of .300 Win Mags. Some are, but still, their rifles are significantly heavier. There's a quite a bit of difference in shooting an 8lb .300 Win Mag versus a 15 lb 6.5 Creedmoor with a compensator or whatever may be screwed on the end.

Don't want to lap? Don't. But saying to "never ever ever" lap is just short sighted, inconsistent with advice from experts, and from the perspective of sport shooting that is entirely different than that engaged in by someone shooting a sporting rifle like the OP's. Your sport and the one engaged by someone using a Vanguard or other hunting rifle are different. Your rings fail, you loose a match. The OP's fails, and he may loose out on a guided elk hunt and loose a small fortune.

I've shot a 7saum off and on for the last several years. Previous to that shot a straight 284 w/o a brake.

Honest question asking before and after. That comes from my years as repair tech, always wanted to see a result. If I didn't see a result, I was wasting my time and more importantly my customers money.

I’m sure there are circumstances, particularly with an older rifle and rings, where ring lapping may cause some benefit. However, after personally touring a number of firearms manufacturers and looking closely at their manufacturing processes, I feel quite confident that any receiver, sporting rifles and precision rifles alike, are held to better tolerances than a typical lapping rod. I can totally see lapping rings on an older rifle, but I just don’t see any benefit with a modern rifle using top notch rings. A receiver will be straighter than a lapping rod as will rings and bases.

Sinclair lapping tool, which is what I've used, is advertised to have a tolerance of +/- .0005". That's probably far better than the best rings made.

Again, these discussions almost reveal two schools: either always do it, or never do it. But the real answer is usually somewhere in between. You lap if you need to. Someone who shoots on a course with a heavy, low recoiling rifle, may never see the need to lap. Someone hunting deer, elk or bear with a light, heavy recoiling rifle, and who may need a quick follow up shot, may have a greater need for properly lapped rings than the other type of shooter.

quote:

Originally posted by Micropterus:
But saying to "never ever ever" lap is just short sighted, inconsistent with advice from experts, and from the perspective of sport shooting that is entirely different than that engaged in by someone shooting a sporting rifle like the OP's. Your sport and the one engaged by someone using a Vanguard or other hunting rifle are different. Your rings fail, you loose a match. The OP's fails, and he may loose out on a guided elk hunt and loose a small fortune.

I guess it depends on the experts, because the experts I know in shooting sports recommend using quality rings/mounts and not lapping.

Each year I try to shoot in the an ELR (Extended Long Range) match. Some of us don't yet have magnums, but the majority of the competitors have some flavor of 7mm, 30-cal, or 338-cal magnum rifles. Having sighted in a 300 Wby Vanguard for my boss, and having a fair amount of time between various 338 LM rifles, I can state even a heavy comp 338LM rifle recoils more than a light 300 magnum. Lots of round are fired in ELR matches. In the train up, sight in, and competition weekend of one ELR match, the ELR shooter may fire more rounds in one weekend than the average hunter does over decades with a given rifle. In extremely windy conditions such as this year's Nightforce ELR match in Wyoming, the ELR competitor does a lot of follow up rounds.

There is a lot of futzing around with equipment at PRS, field, and ELR matches. I've seen a lot of scopes mounted, moved, remounted. I don't recall ever seeing rings with lapping wear marks.

Yeah, a guided hunt costs a lot of money. However, there is a lot on money involved in match shooting. Performing well for some competitors means substantial sponsorship money. Maybe even a reasonable portion of their livelihood. Prize table earnings are a big deal, too. I've seen cash payouts of $1k to $5k in matches to the top dog. Prize rifles worth $3k to $5k are common -- many of the winners immediately sell them. High end optics are common -- top of the line S&B, Vortex, Nightforce. Laser range finding binos and spotting scopes, too. Selling these items serve to keep many shooters going. Lots of equipment & cash changes hands after big matches. If a shooter's equipment fails, they don't have a chance at this money.

I'm a long ways from a top dog in matches, but on occasion I remove my shooting asshat. This year I won a Thunderbeast 338 suppressor and a Grayboe stock. Prior years have resulted in a 30-cal TBAC can, a Grayboe stock, a Manners stock, barrels from Proof and Bartlein, LWRC 223 upper, Falkor Defense AR10 rifle, JP rimfire upper, 3 JP silent capture springs, a handful of full-sized IPSC AR500 targets, a few JP bolts, a fleet of rear bags, some Hornady ammo, some bullets, a rifle sling, a Triggertech trigger, JP scope mount, Warne scope mount, Warne toque tools, some ammo carrying devices, rifle DOPE systems, a few hundred in cash here & there, and a bunch of smaller do-dads.

So even at my level, there's money in the competition games. Money that I would have lost out on if my equipment didn't perform. This year's TBAC can and Grayboe stock were won with rifles using NF scopes and unlapped NF rings/mounts. The rifles used in these comps have taken a pretty fair amount of shakes -- between what's required in stages and from fellow competitors kicking over staged rifles.

*****
I few years ago I forgot to close my Pelican hard case after practice. Pulled the case out of my SUV at home, and the rifle did a 24" drop onto the concrete driveway. 18 pounds of rifle landed squarely on the left turret of a NF NXS 3.5-15x F1 -- the turret which controls parallax and illumination. The turret cap flew off and a few parts scattered about. That scope had a few thousand rounds of 308 and 6.5CM on it by that time, mounted with unlapped NF rings. Mailed the scope to NF the next day for repairs. Interestingly, when I held the wayward parts on the scope, both parallax and illumination still worked. A quick bore sighting in may basement indicated that it zero had not changed.

NF replaced the left turret cap and polished a few parts. Their CS guy said the scope was in perfect working condition. That scope was eventually rotated to an AR10, and now resides on a AR15. I suspect if anything would have left a ring mark on that scope's main tube, that was it. There are no ring marks on this scope, and the rings were not lapped.

****
Sinclair's lapping tool may be built to .0005" specs. Lapping compound wears both the rings and the lapping tool. Who knows how long the lapping tool will remain in spec.

All I can add is from the perspective of someone that:

Doesn't shoot for long range accuracy, PRS, and similar disciplines.

Is currently learning CNC machining.

I've been taught, that when machining holes to tight tolerances (in the past few days, anywhere from +/- .005 to +.002/-.000)
I should measure the diameter before removing the part from the vise. Reason being if I remove it from the vise, then find
it out of spec, attempting to put it back in the vise, and get it within tolerance is a recipe for potential failure.

If a couple thousands of an inch is worth it to you, to lap the rings, then don't ever remove the scope from the rings, or
then, the rings from the rifle. Because your hands won't be able to repeat such small amounts of precision.

Just buy quality rings. Warne fan here.

Congratulations. Impressive history. Yet none of it alters the fact that one should lap if they need to. Quality rings are no indicator that lapping won't be necessary. I've had to lap quality rings, including so called "matched rings". And most of the custom rifle builders I know of, including the ones that build rifles far in excess of the costs of what you are I are accustomed to, Rigby, Heym, H&H, even Dakota, lap their rings when installing scopes. It's part of the perfection in their products.

Lapping is necessary when it's necessary. You stating "use quality rings" and you won't have to lap, with all due respect, it flies in the face of my own experience, and the plethora of posts on places like Snipers Hide (which I suspect you're familiar) and other sites, like 24HourCampFire where real high end gunsmiths often post, that all conclude that sometimes lapping, even sometimes high end rings, is necessary.

I think a lot of people in the never-lap camp are actually afraid to lap because they don't really understand the process. They don't understand the absolute minute amount of material that's removed during lapping. Often times these people see a symptoms of a less than perfect ring and simply torque it down more, thinking they are fixing the problem, when in fact, they are minutely damaging their scope. In fact, when you lap a ring properly, you can retorque it down to the recommended in/lb and still have better grip than before. Quality horizontally split rings are not going to close completely around a scope tube when torqued properly. They aren't supposed to. Most of the time, when a scope is properly mounted in a horizontally split ring, there is a gap between the top and the bottom rings when torqued to the proper spec. That gap gives you a huge margin for lapping given the amount of material actually removed, one you will never use up. In fact, that gap won't be noticeably less once the rings are properly lapped. So "throwing them out of spec" with proper lapping is such a remote possibility, that it's not really a thing. (Indeed, if there are rings out there that can't be lapped for fear of throwing them out of spec, I probably wouldn't use them.) When I see a scope in a set of quality rings where the rings have been tightened to a point where there is no gap between top and bottom ring, that is a pretty good indicator that whoever did it didn't know what they were doing and possibly damaged their scope. Look around next time you are on the course and see how many rings have been torqued down to the point they touch on both sides. A shooter that does that generally tells me one of two things: he didn't know what he was doing, or he had rings that needed to be lapped and didn't and compensated for it by over torquing.

Lapping simply ensures as close to a perfect fit between scope tube and rings as possible so you don't have to over torque to keep the scope in place. You do it when you need to. And the amount you pay for rings is no indicator that it isn't needed.