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[ARCHIVED THREAD] - MK18 (Page 1 of 2)
Posted: 6/8/2006 9:43:08 AM EDT
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Got our new boarding rifles in last week and thought some of you would get a kick out of what the Navy is doing with the M16. The gun uses an old A1 lower, flat top upper with 10.5" barrel. Will try and add a pic if it does not work sorry, not much of a geek. Ross http:///Users/Ross/Pictures/iPhoto |
| There's 17 pages about it right here. And you picture isn't coming up (at least not for me). |
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Did not know there was already so much talk about the gun, 17 pages is a lot. When you leave home for months at a time one can lose touch with what is going on on the net. Redfisher: There is much said by many who know much on there. Although I like the AR platform the MK18 is just a tool to me and the only time I like it better than a standard carbine is when climbing that little caving ladder in rough seas. If some one can point me in the right direction for posting the pic I will try again. |
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That's a 10.5" barrel from what I was able to pick up in the other thread. 10.3" barrels had barely any barrel in front of the FSB and behind the crush washer. Weren't the 10.3" barrels just cut down Colt M4 barrels? All uppers with cut down barrels are the 10.3" and the uppers made specifically for Mk18s were made 10.5" from the factory. You can mount your Aimpoint any way you like. It will work the same any way. The adjustments will not work as intended, but they will still work. It's not uncommon to see one flipped 90 degrees because someone is left handed. 45 is a little strange I must say but oh well... 10.3" from other thread: 
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You don't know why it was mounted that way- maybe ambidextrous access to the on switch or something... The fact is, I'm inclined to believe that the person who had his hands on the Mk18 knew what he was doing more than I'd believe you have any right to say he doesn't. |
That was exactly the reason I thought of. |
Here are the barrel markings under the handguard from that picture with the toes in it   These marking indicate that this is not a cut down M4 barrel, I have yet to measure that barrel and find out exactly it's length, I'll do that tonight when I get home from work |
I'm a lefty and I can access the Aimpoint's controls with no problem. The problem with that mounting is it is extremely difficult to zero. |
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My guess is that the shooter just wanted the aimpoint to the left of his iron sights, for whatever reason it works best for him As for the barrels, The original pic would seem to be a 10.3 barrel, possibly a cut down M4 barrel, Note the flash hider in relation to the bayonet lug  I went home and measured the barrel in the photo with the toes and it measures 10.0" exactly. it would seem to be this one advertised by Specialized Armament, it was sold to me by a spec ops person as a factory Mk18 Mod 0 unit Part #: LE6921SP Description: MODEL LE6921SP, SPECIAL PURPOSE, .223 10in 1/7 (LWT -M4), ENTRY TEAM VERSION OF THE STANDARD LE6921 USING A LIMITED PRODCUTION SOCOM/US GOVT BARREL Note the position of the flash hider in relation to where the bayonet lug would be  Here is a LMT 10.5 barrel, Note the position of the flash hider in relation to the bayonet lug  and both together for comparison  These weapons intrigue me to no end, I guess I'm going to have to find a Colt 10.3" upper now |
Have you ever handled or zeroed an Aimpoint? What kind of experience do you have with an AR other than taking a bunch of pictures with yours and regurgitating the shit you've read here? You have no idea what my experience is, but from judging what you've said and done in the past, you don't have the experience you pretend to have. |
dude...calm down...you went from zero to uncivil in about .02 seconds. My 2 cents...the mounting is certainly non-traditional and would have it's problems, but if it works best for that person, so be it. We have a lot of lefties in my unit that mount their's rotated 90 degrees. Not "by the book", but not exactly morally wrong either. |
I guess if you play chess and you really know how to move bishops then it might not be a problem for you. 
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Chill out Molsen. I didn't try to call you out so don't take so much damn offense to what I said. If ANYTHING, you TRIED to call out the person responsible for mounting the aimpoint. All I did was say I trust the person mounting the aimpoint on a Mk18 MORE than you. You are right, I don't know you or what you do but I'm sure that the guys in charge of the Mk18s know ENOUGH! |
I think he means to say that the sight appears to be rotated90 degrees off from where it is traditional to have it mounted in the ring. Not that the whole thing is canted, just the sight itself rotated. |
Your sight is canted in that it is not mounted properly. My guess is you zeroed it in at 25 yards. And given the method it will work. However, if you have to adjust the sight at longer distances, it will be a pain. I highly recommend you remount the sight where one turret is horizontal and the other vertical. In fact, if I were the WEPS on your ship, I'd have already chewed your ass six ways from Sunday. R, LT dport |
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I was just about to come back in here and reply that I didn't think gunjunky set these up himself- by the way he's made his statements. Now it turns out it was set up that way by Crane. I don't know if Crane is just supposed to slap them together or if they sight in the CQB weapons for 50-100yds or something. But there you go, like I said before, I put more faith in Crane and THEIR weapon than I do in someone just wanting to call people an idiot on an internet forum. If you think about it, a 2MOA or 4MOA dot can be adjusted more than adequately even with each click of either knob moving the dot up or down AND left or right at the same time. NOT a big deal. Look at it this way- one click of the adjustment no longer moves it 1/4 MOA. If you try and make an adjustment at one of the knobs to move the dot up, you won't get 1/4 MOA up. You'll get half of that up and half of that to the left or right. Likewise if you try and move the dot Left, Right or Down, you will always move the dot in one of the other three directions at the same time but a much smaller distance. Hey, it's a frickin' 3 MOA dot most likely and at CQB ranges, who cares? If the knob was put at the top purely for aesthetics, then what does it matter? Crane says it's OK and I'll go ahead and believe them. So, for CQB on a boat- these were given to gunjunky for boarding, right?- they can be sighted in correctly although not easily- but if Crane sighted them in, who cares? ETA: I'm not in the Armed Forces or Law Enforcement Fields. I have no experience in the military except for a little weekend thing the ROTC put on for us down at school in Terra Haute way back in 1995. I scored a 38/40 at the rifle range and was told I ought to join the Army to be a sniper. So, back on topic- I don't need any of the experience you guys have to know how the sight works and why it works and how it is adjusted. I'm saying the set up of the sight is not a big deal because it will still work fine for it's intended purpose. I don't mean to offend anyone here. Let's get back on this Mk18 business so I can get my woody for an SBR back!  |
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I was just playing around and if the adjustments of the turrets on the Aimpoint are 1/4MOA per click, up, down, left and right when it's "correctly" mounted then one click on one knob moves the dot about .17MOA vertical and .17MOA horizontal. So, it's now possible to move the dot 1/3MOA STRAIGHT UP, STRAIGHT RIGHT, STRAIGHT LEFT OR STRAIGHT DOWN with one click of each knob. For instance if you turn the right knob one click and move the dot .17MOA to the right and .17MOA up, you can then move the dot .17MOA up and .17MOA to the left with the other knob placing it .34MOA above the "original" point. |
Crane is smoking something then. I have a feeling they're growing more than just corn out there. Are the instructions you got the M68 FM? I have one laying around home somewhere and I don't recall that. If you're absolute co-witnessing, you can get away with it, until you try to zero at longer range. Then you're going to go nuts trying to figure it out. Because one adjustment will take you to the right and up, and the next will take you to the right, even more, and down. BTW, no ass-chewing required, 'cause I'm not your WEPS. If I were you'd have LaRue mounts for 'em. 
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As much gun BS I've seen and heard in the Navy, I don't trust anyone that mounts a weapon 45 degrees off. Especially, when on the sight itself it is clearly marked on the sight that it is left-right adjustments and up and down adjustments. And I have seen Crane do some stupid shit before.
Actually yes it is. Try zeroing at 100 yards and you need to adjust to the right. You start adjusting one turret to the right and it will take you up as well. You try to negate the vertical movement with the other turret and you take the adjustment back
You can go ahead and believe them.
I haven't seen Crane sight something in yet.
That's obvious.
No you don't, but you have to know how a sight works, and it's obvious that you do not. |
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If you guys know that Crane has a habit of doing things wrong then I'll go ahead and believe you on that one- I just wasn't going to assume they were stupid as others have. Dport- your example of zeroing to 100yds WILL work. From what I remember (I sold my Aimpoint) the left knob is right and left and the top was up and down. When rotated 45 CCW from the shooters perspective, the Right turret is now at 1:30 or so and the Top turret is now at 10:30. The knob at 1:30 now moves the dot up/right and down/left. The 10:30 knob now moves the dot up/left and down/right. If you need to move the dot 1 MOA to the right you will use both knobs. You will turn the 1:30 knob 3 times for up/right and the 10:30 knob 3 times down/right. Mounting it the other way will require 4 turns of only one knob as opposed to 6 turns using 2 knobs. It's not easy, it's not very intuitive and doesn't follow the markings on the sight but it does/can work. I just thought it was silly to call the person who mounted it an idiot. That wasn't fair. Molsen obviously didn't understand there could be a reason for it. His not understanding the reason doesn't man anyone else is an idiot. Dport- are you saying I'm less of a person because I didn't duplicate your career choice? It's starting to seem that way. |
Except that if you mounted it the way God and Aimpoint intended, you can get it level. It's a pain to get it level when canted. So, you don't know if it's 1:30 or 1:32 and 52 seconds. Which makes finding your reference even harder. If it's PERFECTLY mounted at 45 degrees, then you can figure it out somewhat easily, if you can get over the mental aspect of adjusting your sight halfway over and down and then adjusting it again up and over. The problem is it becomes very difficult to know if you're at 45 degrees exactly. Since bullet drop has its effects in the vertical axis and windage has its effect in the horizontal axis it makes sense to aline your adjustments that way. Must be why scope makers have done this for decades. One more point, if you're zeroing at 25m for a 50 or 100m zero it's much easier to zero when your scope is aligned how the manufacturer intended.
I don't recall calling him an idiot.
Where do you get that from? It's obvious you've never been in the military because if you were you'd understand that just because something is issued to you one way doesn't mean it's right. |
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Dport- you never said he was an idiot. That wasn't directed at you. I was stating the reason I got involved (too far I might say) in the way the Aimpoint is mounted. I thought we started by saying the Aimpoint is canted 45 degrees and that it can be done so out of personal preference. Then this sort of turned into an argument about whether it was possible to zero or adjust the sight. That's all I've been arguing. I thought the installer of the sight was being called stupid for mounting it in such a way that it could never be zeroed. I was simply stating it could. It is a silly and counter-intuitive way of mounting it. I've already stated that. I will go so far as to say that I think mounting it 90 degrees as a lefty is really silly because the markings won't make sense and will confuse you like the knockoffs confuse the guys who buy them. |
90 degrees is much easier; I don't see the call for it though. I don't see the advantage, however, I'm a lefty and it is possible to maintain a firing grip while adjusting the intensity. |
My neck is kinda cocked to the side to use the sights anyway
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You did this with a bottom 1/3rd co-witness? |
Joe, I usually agree with you on most things but this is where we disagree. The person who mounted it was an idiot. No matter how you try to rationalize or justify it, he/she is still and idiot. The military is filled with "gun people" who are idiots. I can't think of a single reason why a optic would be mounted like that. I agree that it can be zeroed. I would like to get this topic back on track and figure out the source for a MK18 barrel. |
Yarddogone, what is the hardware [pin] that shows to be under the second slot of the top rail - behind the end cap, side of the 12 oclock rail, bigger than the gas tube roll pin a couple inches ahead of it? It is visable in the photos. |
No, there is more to it. All MK 18 uppers are Colt upper receivers. We have never been provided with any hard proof the receiver is an LMT. We haven't been able to establish weither the barrel is a Colt or LMT. The MK18 posted on the first page is a little bit shorter than a factory LMT 10.5" barrel. Notice where the thread start in relation to the tip of the bayo lug. My guess by looking at the finish that it is a cut down Colt M4 barrel. The 10" Colt barrel is not a MK18 barrel. |
[ARCHIVED THREAD] - MK18 (Page 1 of 2)
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