M40a1 Scope Mount

[grunt0311]

I have noticed that on most of the M40a1 scope mounts that there is a gap between the rings. Has anyone ever lapped their rings to make the rings touch? Im thinking of doing that to mine as this bugs me that there is a gap like there is. On my M40a3 this does not occur. Id like to make this right and lap them. Also I have noticed that the USMC M40a1's didn't have the gap. What tools do I need to lap the rings? I haven't lapped any rings before but have an idea on how to do it. Any suggestions will help. Below is a picture of the gap that Im talking about. Thanks.

 

[scatsob]

Lapping is not going to take that gap out. And they would have to be "lapped" perfectly in the vertical direction only otherwise you will destroy the rings.

 

[LeoC8541/2112]

What he ^ said. Plus I built a bunch of M40A1 and A3's at Quantico and never saw one without a gap. NEVER! If you lapped them you wont make them right; you will make them wrong. We used feeler gauges to even out the gap for looks but the purpose of the gap is to have space to create tension on the scope tube. If your going to Jack them up then sell it to me and I will put it on my rifle. I'm not saying that a set never slipped thru the cracks and a top half never touched the bottom but I never saw it happen while I was there.

 

[rlm8541]

There are allot of repro's out there. The ones I have seen from US Optics all seem to have had this gap. I can't make an assessment as to why they did this because it would only be an assumption.
It took me years to locate a real set and they cost me dearly. They do not have this gap.
Twomanattack made a run of A1 ring/base mounts several months back that did't have the gap as well. They come up from time to time for sale.

Hey Redmanss.....I should have frased differently...I agree with you in regards to there being a "Gap". and for anyone who has ever had any experience in build rifles or mounting glass, there will always be a small gap. I also understand what grunt0311 is refering to in regards to the "excessive" gap in the rings. I also spent 5 years in STA and all of them had it as well.....Just not as much of one as you see un the Repro's.
When you spending $1000's of dollars to build something as historically and as aesthetically accurate as you can. These attention to detail things me alot to some.......that is all.

 

[Redmanss]

I don't know what USMC M40A1s you were around, but every single one I was across five years in STA platoons had gaps in them. Quit fretting over aesthetics and shoot the damn thing!

 

[totenkopf]

Wrong. If you have a real Unertl mount and real Unertl10x scope there will be NO, I say again NO gap. USO mounts and are out of spec, therefore you'll have a gap. If you put a real Unertl 10x in a USO mount you'll have a gap. USO mounts also leave more scope marks because of this ring ID error. Unknown? Measure the ID of a REAL Unertl mount vs a USO and you'll see. Measure the tube dia of a USO MST100 and a Real Unertl 10x....

Mark

 

[TWOMANATTACK]

Alot of good information here, but the reality is, the rings should have a gap. The ones we made did not, however they can be fit to do so. We made the models from an original USMC issued mount. However we did flaw them so we know what mounts are real deal and what mounts are replicas. Unertl did the same thing when they did the T series scopes and offered mounts. They stamped Unertl on the side of them. We were not so bold in our flaw. The USMC mounts from RTE were hand fit to every USMC issued rifle. The front and rear lug had to be fitted to fit the action and action screws properly. YOU WOULD BE SURPRISED HOW MANY M40A1 BUILDERS DONT REALIZE THIS! At the RTE shop the rear lug was taken down to fit the clip slot in the rear and the front portion sometimes was also adjusted. I own several USMC issued mounts, I even have one that was still in the original box with original screws. I may post pictures if I can get them emailed to me, but for now you will have to take my word for it. This mount has the gap when installed on a USMC marked Unertl. In some cases the gap is necessary in order to tighen the rings tighter. This is another fitting issue. If you look at a true USMC unertl mount you will see a couple of tale tale signs its an original. One thing you should see some electro penciled numbers on each ring. These dont always match. Dont stress they were reused. Next thing you will notice is the they have shallow round lines carved into them, lines that show they were ground down on a round sanding wheel. Look carefully, they are there! Alot of times they dont get noticed because of years of CLP and dirt have filled them. But they are there. When we made the mounts we took fitting into account. Our mounts were not drop in ready. Clip slots will vary depending on who did them. We made the rear lug oversized. We also made the rings close so the builders can HAND FIT them to the scope. I hope that helps. We are going to do a run of M40A1 mounts early next year. I was only going to build 8 but I have had an overwhelming interest in them. The first 8 sold for $415 each. If you need one, let me know ASAP! I am collecting $$$ now. I may build 20 of them rather than 8 if I get enough interest. I will be posting in the for sale section also, but you heard it here first. This picute is a KNOWN USMC issued rifle that PMO had after the M40A3 was in service. Look at the gap... As the rifles were sent back for fitting the gaps would get a bit larger in order to get more torque on the bottom mount screws

other side

 

[bildoe308]

Alot of good information here, but the reality is, the rings should have a gap. The ones we made did not, however they can be fit to do so. We made the models from an original USMC issued mount. However we did flaw them so we know what mounts are real deal and what mounts are replicas. Unertl did the same thing when they did the T series scopes and offered mounts. They stamped Unertl on the side of them. We were not so bold in our flaw. The USMC mounts from RTE were hand fit to every USMC issued rifle. The front and rear lug had to be fitted to fit the action and action screws properly. YOU WOULD BE SURPRISED HOW MANY M40A1 BUILDERS DONT REALIZE THIS! At the RTE shop the rear lug was taken down to fit the clip slot in the rear and the front portion sometimes was also adjusted. I own several USMC issued mounts, I even have one that was still in the original box with original screws. I may post pictures if I can get them emailed to me, but for now you will have to take my word for it. This mount has the gap when installed on a USMC marked Unertl. In some cases the gap is necessary in order to tighen the rings tighter. This is another fitting issue. If you look at a true USMC unertl mount you will see a couple of tale tale signs its an original. One thing you should see some electro penciled numbers on each ring. These dont always match. Dont stress they were reused. Next thing you will notice is the they have shallow round lines carved into them, lines that show they were ground down on a round sanding wheel. Look carefully, they are there! Alot of times they dont get noticed because of years of CLP and dirt have filled them. But they are there. When we made the mounts we took fitting into account. Our mounts were not drop in ready. Clip slots will vary depending on who did them. We made the rear lug oversized. We also made the rings close so the builders can HAND FIT them to the scope. I hope that helps. We are going to do a run of M40A1 mounts early next year. I was only going to build 8 but I have had an overwhelming interest in them. The first 8 sold for $415 each. If you need one, let me know ASAP! I am collecting $$$ now. I may build 20 of them rather than 8 if I get enough interest. I will be posting in the for sale section also, but you heard it here first. This picute is a KNOWN USMC issued rifle that PMO had after the M40A3 was in service. Look at the gap... As the rifles were sent back for fitting the gaps would get a bit larger in order to get more torque on the bottom mount screws

other side

Count me in....I'll take one set twoman.....sending email.....

 

[grunt0311]

I wasn't going to post anymore on this thread since theres really nothing I can do about this problem. But I will have to agree with totenkopt and TMA that on the real Unertl mounts there is no gap or if there is it is really small gap. On the USO repo mounts that I have and have seen on most a1 rifles that there is a gap and it is much bigger than the Unertl mounts. If I had some feeler gauges I would measure the gap. Now that TMA is making some more Id like to get some but unfortantly its the holidays and cash is low. Going have to come up with some quick. I could use 2 of these mounts.

 

[Tickle]

Alot of good information here, but the reality is, the rings should have a gap. The ones we made did not, however they can be fit to do so. We made the models from an original USMC issued mount. However we did flaw them so we know what mounts are real deal and what mounts are replicas. Unertl did the same thing when they did the T series scopes and offered mounts. They stamped Unertl on the side of them. We were not so bold in our flaw. The USMC mounts from RTE were hand fit to every USMC issued rifle. The front and rear lug had to be fitted to fit the action and action screws properly. YOU WOULD BE SURPRISED HOW MANY M40A1 BUILDERS DONT REALIZE THIS! At the RTE shop the rear lug was taken down to fit the clip slot in the rear and the front portion sometimes was also adjusted. I own several USMC issued mounts, I even have one that was still in the original box with original screws. I may post pictures if I can get them emailed to me, but for now you will have to take my word for it. This mount has the gap when installed on a USMC marked Unertl. In some cases the gap is necessary in order to tighen the rings tighter. This is another fitting issue. If you look at a true USMC unertl mount you will see a couple of tale tale signs its an original. One thing you should see some electro penciled numbers on each ring. These dont always match. Dont stress they were reused. Next thing you will notice is the they have shallow round lines carved into them, lines that show they were ground down on a round sanding wheel. Look carefully, they are there! Alot of times they dont get noticed because of years of CLP and dirt have filled them. But they are there. When we made the mounts we took fitting into account. Our mounts were not drop in ready. Clip slots will vary depending on who did them. We made the rear lug oversized. We also made the rings close so the builders can HAND FIT them to the scope. I hope that helps. We are going to do a run of M40A1 mounts early next year. I was only going to build 8 but I have had an overwhelming interest in them. The first 8 sold for $415 each. If you need one, let me know ASAP! I am collecting $$$ now. I may build 20 of them rather than 8 if I get enough interest. I will be posting in the for sale section also, but you heard it here first. This picute is a KNOWN USMC issued rifle that PMO had after the M40A3 was in service. Look at the gap... As the rifles were sent back for fitting the gaps would get a bit larger in order to get more torque on the bottom mount screws

other side

I think you may find this thread interesting. Check out the forum bolt action rifles " Thank you Leo Conring." It's my rifle and I think you may have a comment or two.

Thanks.....Tickle