Rifle Scopes Trijicon RMR usable on scope with 50mm objective?

[xk319]

Can't find an answer anywhere. I have fears of the objective bell infringing on the RMR's windowed view. I'm talking the RMR piggy backed on the scope just behind the turrets, with the RMR rotated to about the 2 o'clock position so the view is between the 12 nd 3 o'clock dials on the scope. Just worried about the bell getting in the way. I know the knobs won't.

Any help is appreciated.

 

[salmonaxe]

Re: Trijicon RMR usable on scope with 50mm objective?

Yes

 

[xk319]

Re: Trijicon RMR usable on scope with 50mm objective?

I love this place. Thanks for the help.

 

[smokshwn]

Re: Trijicon RMR usable on scope with 50mm objective?

This is a far better way to mount the RMR or any micro red dot for that matter.

Burkett Offset Mount


It mounts the RDS in line with the bore so you don't have to compensate for being off in two planes.

 

[salmonaxe]

Re: Trijicon RMR usable on scope with 50mm objective?

I dunno. Better is very subjective. When I see that mount, I think of how I'd end up smacking it into a barricade. On mine, being tucked in between two already existing protrusions of the NXS adjustment knobs makes it add very little to the profile.

The position on the burkett is good for rolling 45 and maintaining cheekweld. Mine it's either a roll and heads up position or an off the jawbone hold. Which have worked fine for me. This setup does work way better than the Larue minireddot ring for the SPR series of mounts. I have one on my other SPR.

 

[xk319]

Re: Trijicon RMR usable on scope with 50mm objective?

And the burkett won't work for me in my application because of rail space. I'm using this on an m1a I hunt with. I'm using an old style split rail arms mount and 4.5-14x50 Leupold. I hunt in pretty varied land, something can pop up 20 yards from you or 200 yards from you. I only have two small rail spaces to mount the scope, those are taken up by the rings, so the RMR must go on the scope.

I could go with a SMITH or SADLAK mount and use a burkett, but I love the original arms mount too much. Also, I like the compactness provided on Salmonaxe's setup, tucked between the two knobs. Exactly what I'm looking for.

 

[smokshwn]

Re: Trijicon RMR usable on scope with 50mm objective?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: xk319</div><div class="ubbcode-body">And the burkett won't work for me in my application because of rail space. I'm using this on an m1a I hunt with. I'm using an old style split rail arms mount and 4.5-14x50 Leupold. I hunt in pretty varied land, something can pop up 20 yards from you or 200 yards from you. I only have two small rail spaces to mount the scope, those are taken up by the rings, so the RMR must go on the scope.

I could go with a SMITH or SADLAK mount and use a burkett, but I love the original arms mount too much. Also, I like the compactness provided on Salmonaxe's setup, tucked between the two knobs. Exactly what I'm looking for. </div></div>

For discussion sake, how do you plan on zeroing the rds to get good function from 20-200yrds with the mount you have indicated?

 

[xk319]

Re: Trijicon RMR usable on scope with 50mm objective?

I suppose I don't understand the question. But by asking it I'm assuming you think there would be some trouble using the mount I have indicated? This will be my first experience with variable power scope/rmr combination. Do you have some advice or see something incorrect in my setup? Any help is appreciated.

 

[salmonaxe]

Re: Trijicon RMR usable on scope with 50mm objective?

I'm not sure what he's talking about either. Based off of some rough ballistic math, a 50yd zero would cross over at 200yds and be less than 2" offset at any given point in between 10-200yds. Would be a pretty effective zero for something like the RMR. (Based on a rough 175gr load 2550ft/s with a sight height of 3")

He did state something about the optic not being on the same planes or some such. Not really getting that. The way the optic is mounted it can be a little odd to zero. Not crazy, just have to think about the angle it's at as you make corrections to the adjustments. Besides that, you just have to consider what your cheekweld will be when you zero. If you're going to roll the rifle or cant your head. If you roll the rifle for a zero done where the rifle was oriented square up and down, it will change the POI. Zero the way you shoot.

 

[brand692]

Re: Trijicon RMR usable on scope with 50mm objective?

Here is how my FastFire is attached to my 56mm OBJ scope.

No impedance whatsoever. In fact, I'd like to get it lower. Sorry, only pic I have on PB and I'm traveling all day today.

Honestly, IMO, the mini RDS is a sub 100y sight anyways. If you are shooting at 200, might as well use the scope. If you end up with anything but the 3.5-4.0 MOA versions, 200yds is really not applicable. Even the 4 MOA version projects a 8 inch dot at 200. To me, that's huge. <span style="font-style: italic">(That's what she said-Michael Scott)</span>

Like Salmonaxe said, it's critical with an offset mount to zero how you shoot.

ETA: That Burkett mount, while innovative, seems to have very limited application. As in only to platforms with extended front rails. I have no idea how you would go about using that with a bolt gun or M1A unless you had it in a chassis.

As a M1A owner, I can tell you with almost absolute certainty, that you will be happier with a Sadlak, ARMS 1 piece, or SEI mount. And even with one of those, you still would not be able to use that Burkett mount without issue. It would be in the way of ejecting cases unless, again, unless you had a forward rail or a rail system that replaces the front hand guard. Plus that thing hangs WAY off to the side. I imagine in a hunting rig it would get caught on stuff all the time.

Honestly, if you are shooting 20-200 yards, a different optic might be in order. One with less magnification. Like a 1-4 or 1-8. Then you would have the bases covered without buying a $600 RMR + $? For a mount that may or may not work. You could walk around with it at the lowest mag for your close up shots and dial it up for the 200yd shots.

YMMV

 

[xk319]

Re: Trijicon RMR usable on scope with 50mm objective?

Yeah, in all honestly a 1-8 or 1-4 would be nice for me. Really somethign like an NXS 2.5-10x32 would catch any situation I could encounter. I could always stick an rmr on that if I felt I really needed it.

A shop close to me said they might be getting in some of the new S&B 1-8x and Leupold CQBSS scopes soon, like a couple weeks. Who knows how much those are gonna cost though. I don't really have a limit in scope cost, buuuuut man.....those things are ridiculous on the cost last I saw.

 

[smokshwn]

Re: Trijicon RMR usable on scope with 50mm objective?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: xk319</div><div class="ubbcode-body">I suppose I don't understand the question. But by asking it I'm assuming you think there would be some trouble using the mount I have indicated? This will be my first experience with variable power scope/rmr combination. Do you have some advice or see something incorrect in my setup? Any help is appreciated. </div></div>

I don't have an answer for you, but yes I assume there can be problems finding a zero that will compensate for both the height over bore offset as well as the distance to the side of the bore.

As to the Burkett mount being limited, yes I can understand the limitations on the M1 but then again even mounting a scope is somewhat limited on that platform. The Burkett rocks on any AR platform or any bolt gun with the room on the rail,

 

[salmonaxe]

Re: Trijicon RMR usable on scope with 50mm objective?

Just FYI, I was able to hit a 6" steel plate with my piggybacked Burris Fastfire 2 (in the second picture) with no issues. It's been a while so I'm not certain of the range. I want to say it was 150yds since I remember the dot completely obscured the steel. But it could have been 100yds. (I never shoot my steel with a rifle closer than that since none of it is setup specifically for close engagement.)

This stuff isn't magic. Horizontal offset shouldn't be much more than how much it is physically offset. And with the reddot compensating for it at a given zero distance I don't think it varies that much. Looking at JBM calculations, it seems to shift windage at max, the amount of the offset. (Comparing non offset numbers to offset numbers.)

Plus if one zero's with the rifle rolled so that the center of the optic is perfectly vertical through the bore, this offset will not matter.