Does anyone know the reason most ring mfgs undersize their rings of all sizes? For instance a 30mm ring is probably more like 29.8mm.
I know this is gonna create a bunch of different opinions but I lap my rings. I know what you're gonna say... "high quality rings dont need lapping" yadda yadda yadda... spare me please. I own badgers, I own Seekins, I own ARCs, Spuhrs, TPS, USO, etc.. The only set I've ever owned that i didnt felt needed lapping was the ARCs but I generally dont like how the top cross bolt design can obscure the numbers on the elevation knob sometimes forcing you to lift you head off the rifle to check your dope so I am not a huge fan of them for that reason.
This all goes back to like 2011. I was fortunate enough to place top 5 in a big match (this was before PRS/NRL) and was able to pull a brand new high end optic off the table. I got home and bought a set of high quality rings from the same MFG as the scope itself and went to mounting it all up once the rings came in. Didnt think much of it but went out the following week to discover the parallax was all bound up. I reached out the the MFG and the rep walked me through a process of elimination and he determined the rings were out of spec causing the parallax to bind once the rings were tightened. This rifle had a Surgeon action BTW. He sent me a new set of rings and guess what? Same problem. He described that when you put the bottoms halves on the rail and tighten them down that you should be able to set the scope in the bottom halves and it should feel like the tube is riding on ball bearings. This was definitely not the case. When I set mine in it would almost lock up once you put any finger pressure on the tube. On closer observation I discovered that when I gently would set the scope on the bottom halves that you could almost see a sliver of daylight between the bottom of the ring and bottom of the tube. I was able to find a guy on here at the time that was loaning people a lapping bar if they paid shipping. So I had him send it and ordered myself some compound. First thing I did was put calipers on the bar itself... 34mm exactly! Set the bar in the bottom halves by themselves..day light underneath. I proceeded to lap those rings and removed about 30% of the existing surface of them (all the material removed was from the sides and it was totally even). I cleaned them up and dropped the tube in.. it was slick as snot just like the rep said it should feel like. Torqued the caps on and everything worked as it should and the scope did great for many years after.
Ever since then I do the same thing. Drop the scope in the bottom halves and see how it feels. They almost always will bind up but not always am I able to see daylight under the tube. I run mostly Defiance deviant actions now so it's not a base issue. Today I received a new optic and a new Badger unimount for one of my ARs. Same thing as always so I guess I'll lap this thing too but it has brought out some extra thought on the subject.
I've owned a ton of scopes over the years and i know some of them are more prone to having parallax issues from rings or other factors than others but what about tube damage from the rings? I see so many guys with gouges or marks on their tubes nowadays and although probably in most cases isn't hurting anything on most scopes, it just seems so unnecessary...this leads me to my question. Why don't ring MFGs make thier rings to exact specs? Why do some put weird bumps (older USO rings) or recessed channels (badgers) in their rings that ultimately seem to put more of a mechanical lock on the tube rather than rely on friction alone? I've been lapping all my rings that exhibit anything like this ever since 2011 and I've never had one slip and havent had an issue with parallax since. Ring marks on the tubes are almost non existent now as well. I can usually get away with not lapping my Spuhrs (which I mostly run nowadays) but they definitely arent as slick as a lapped set feels so they're not exactly perfect either.
Anyway, can someone shed some light on this thats knowledgeable with why they all seem to be slightly undersized? Is it to create that extra lock to prevent slipping?
I know this is gonna create a bunch of different opinions but I lap my rings. I know what you're gonna say... "high quality rings dont need lapping" yadda yadda yadda... spare me please. I own badgers, I own Seekins, I own ARCs, Spuhrs, TPS, USO, etc.. The only set I've ever owned that i didnt felt needed lapping was the ARCs but I generally dont like how the top cross bolt design can obscure the numbers on the elevation knob sometimes forcing you to lift you head off the rifle to check your dope so I am not a huge fan of them for that reason.
This all goes back to like 2011. I was fortunate enough to place top 5 in a big match (this was before PRS/NRL) and was able to pull a brand new high end optic off the table. I got home and bought a set of high quality rings from the same MFG as the scope itself and went to mounting it all up once the rings came in. Didnt think much of it but went out the following week to discover the parallax was all bound up. I reached out the the MFG and the rep walked me through a process of elimination and he determined the rings were out of spec causing the parallax to bind once the rings were tightened. This rifle had a Surgeon action BTW. He sent me a new set of rings and guess what? Same problem. He described that when you put the bottoms halves on the rail and tighten them down that you should be able to set the scope in the bottom halves and it should feel like the tube is riding on ball bearings. This was definitely not the case. When I set mine in it would almost lock up once you put any finger pressure on the tube. On closer observation I discovered that when I gently would set the scope on the bottom halves that you could almost see a sliver of daylight between the bottom of the ring and bottom of the tube. I was able to find a guy on here at the time that was loaning people a lapping bar if they paid shipping. So I had him send it and ordered myself some compound. First thing I did was put calipers on the bar itself... 34mm exactly! Set the bar in the bottom halves by themselves..day light underneath. I proceeded to lap those rings and removed about 30% of the existing surface of them (all the material removed was from the sides and it was totally even). I cleaned them up and dropped the tube in.. it was slick as snot just like the rep said it should feel like. Torqued the caps on and everything worked as it should and the scope did great for many years after.
Ever since then I do the same thing. Drop the scope in the bottom halves and see how it feels. They almost always will bind up but not always am I able to see daylight under the tube. I run mostly Defiance deviant actions now so it's not a base issue. Today I received a new optic and a new Badger unimount for one of my ARs. Same thing as always so I guess I'll lap this thing too but it has brought out some extra thought on the subject.
I've owned a ton of scopes over the years and i know some of them are more prone to having parallax issues from rings or other factors than others but what about tube damage from the rings? I see so many guys with gouges or marks on their tubes nowadays and although probably in most cases isn't hurting anything on most scopes, it just seems so unnecessary...this leads me to my question. Why don't ring MFGs make thier rings to exact specs? Why do some put weird bumps (older USO rings) or recessed channels (badgers) in their rings that ultimately seem to put more of a mechanical lock on the tube rather than rely on friction alone? I've been lapping all my rings that exhibit anything like this ever since 2011 and I've never had one slip and havent had an issue with parallax since. Ring marks on the tubes are almost non existent now as well. I can usually get away with not lapping my Spuhrs (which I mostly run nowadays) but they definitely arent as slick as a lapped set feels so they're not exactly perfect either.
Anyway, can someone shed some light on this thats knowledgeable with why they all seem to be slightly undersized? Is it to create that extra lock to prevent slipping?
