M*CARBO Brotherhood

Thoughts On An Offset Mount?

All Things SUB-2000!

I am thinking about trying this low profile 45° mount. Has anyone had any experience with this type?

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@Jimmy. I have one, works okay, just don’t use it anymore because difficult to get a cheekweld with a 45 degree cant.

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I currently use one of these on mine with a reflex sight. It’s not bad if you turn your S2K at a 45 degree angle to get a better sight picture. Only problem I have is folding it my reflex sight rubs against the buffer tube. I will probably be switching to the MCARBO one when it is released.

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@Jimmy I bought one on Ebay to use on my Sub and it would not clamp down tight enough to work on the Sub picatinny rail (longer set screws would probably make it work) but I also learned that canting the Sub to use a red dot is not for me.

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Thanks for the input, I should have mentioned I was planning to put either a light or a laser on the mount. (I am eagerly awaiting the mcarbo mount for my red dot!!)

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I found that the edge of the mount’s picatinny rail rubbed up against my Mcarbo bolt tube cover. I decided against shaving off a mm with a dremel in favor of slightly bending the whole thing. Fit great and the tines that go on the Subs rail are flush. It works good for a light but I tried a Vortex Sparc red dot and the extra width of the sight pushed against the bolt tube cover again grrr. Bent it just a smidge more and got it to fit and, although it was actually comfortable having your face upright to look along the barrel to get a good sight picture, the red dot could not adjust down far enough to put it on target. I had a bit more luck with the laser. I bought a Protec laser/flash light RM230LSR for $70 at Gander. The on/off switch is easy to get to (a bit too easy to push so watch it in your case or bag). Good luck.

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I had just been perusing the internet and found www.bigdaddyguns.com. There were a few Barska Offset mounts available for under $20. They would definitely ‘fit the bill’ for comfort on the SUB-2000! I know that this would not agree with the ‘tinkerers’ of the group? LOL It seems that some adventurers spend more money and time fabricating parts because of his/her rash decisions? I am to blame as well…

[Mounting A Scope]

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@Jimmy Here is a really secure offset mount for the S2K that I would recommend.

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@dave67 Did you ever try that mount with an optic or just lights and lasers? I am suspicious of the M-Lok on the S2K and its ability to remain stable and hold zero for an optic, and wondered about your experience if you had used it for one.

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@JoeFridaySays I did install it and it was solid but I quickly realized that I did not want a canted optic so it was never used. I have seen on this forum that the high rise m-lok optic mounts have issues because the optic is so high above the mounting point that recoil can loosen it. This mount is low and optic sits right above mounting point so I don’t think there would be “holding zero” issues. It is a nice well made mount and I will find a use for it.

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@JoeFridaySays I have the Magpul mount which weighs 0.7oz. and a TRS-25 dot which weighs 4.0oz. on my sub. Agree with @dave67 response. It’s lite enough that the forearm doesn’t flex. Off set dot takes some time getting use to for me.

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I was using the TRS-25 before giving the SeeAll a trial run and moving it to another firearm. How hard was it to zero from the offset position? Obviously the elevation and windage relationship to the bore is different from when it is mounted directly above the barrel and that just gets worse with greater range.

@JoeFridaySays All I know is with the 45 degree mount the gun is meant to be canted or tilted at a 45 degree angle which would not change zeroing as if it were mounted on top the gun…you are just rotating the whole gun 45 degrees so optic is still over top of barrel. When you say “offset” are you still holding the gun vertical and just moving it over to get a view through the optic? Something I just remembered, the mount comes very close to bolt tube cover when closed. Can probably not leave the optic mounted and close the Sub, will need a QD mount. Also interferes with my sling mount when mounted all the way back.

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@dave67 Thanks. I was referring to the fact that with an offset mount optic, up is no longer really up and right is no longer actually right when it comes to adjusting windage and elevation. As explained in the link below, with a 45 degree right offset mount a one MOA elevation adjustment UP will now actually move the point of aim roughly ¾ up and ¾ right as opposed to simply one full MOA up. Similarly, a one MOA adjustment of the windage RIGHT will now actually move the point of aim roughly ¾ right and ¾ down as opposed to simply one full MOA right. There is math to calculate all that and the article has the equations, but I barely passed algebra in high school and remember darn little of it now. As I recall, you are similarly math challenged. :grin:

http://www.thescopesmith.com/Procedure%20to%20sight-in%2045%20degrees%20offset%20red%20dot%20sights.pdf

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@JoeFridaySays Ok, I was not good in Algebra but besides that…In the picture he shows it looks like his red dot is mounted on the scope and that changes everything in relation of red dot to barrel. He talks about just a little tilt of the rifle as well, not a 45 degree cant. The mount I showed you puts the red dot right over barrel when rotated 45 degrees so all of his calculations I don’t think really apply. Now this is just me thinking out loud so if I don’t make sense then please let me know, I’m always interested in learning something new.

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@dave67 There is logic in what you say since from the perspective of the optic UP should always be up and RIGHT should always be right no matter where it is mounted. The issue is whether it ultimately is over the barrel and that is where the problem arises since none of the mounts are truly directly over the barrel though many are close. And apparently this one is close enough as you had no trouble zeroing the Red Dot which was my question to begin with.

There also is another thing called the “crossing effect” that I do not pretend to fully understand. Supposedly a bullet’s path deviates from straight ahead by however much lateral offset the sight has and keeps going on that line. A sight with a lateral offset of 1" right of bore line adjusted to produce a “dead on” POI @ 25 yards will give a POI of 1" right @ 50 yards and 3" right @ 100 yards. That may not apply here, however, since the entire firearm is canted when sighting; i.e. the sight is not used with a lateral offset but is basically over the barrel when sighting.

Maybe smarter folks than us will weigh in and edumacate us on the subject, eh?

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@JoeFridaySays So this is something that can be talked about all day but I guess until you mount the optic where you want it and zero it one will never really know. I always bore sight my optics at home before I even go to the range, saves time and ammo.

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@dave67 I need to break down and buy a 9mm bore sight laser but the prices are all over the place and so are the reviews so it is hard to know what works accurately and what doesn’t. Any recommendations?

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@JoeFridaySays I use the SiteLite Ballistic Targeting System, does everything from .22 to 12 ga. I had to buy a separate .17HMR bore laser from Sight Mark and that cal. is not in this system. There is a program you install in your computer and after typing in all gun and bullet info plus your preferred zeroed distance and distance you have to work with it prints out ballistic info and target. Put bore laser on laser spot and adjust red dot/scope cross hairs to the cross hash marks and it is bore sighted. Target in picture is .223 bore sighted to 100 yds. but I only had 21 yds. to do it in at my house. I paid $95 for it about 5 years ago.

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I use this mount and reflex sight on my S2K. Works great. The mount is aluminum and the color matches the S2K pretty well. When folded the mount just barely touches the buffer tube due to using the MCARBO buffer tube sleeve

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