LMT almost my idea of a perfect fixed sight, EXCEPT..... [Archive]

Opie

11-25-08, 02:04

I can not stand the huge thumbscrew. I use a PRI big latch on my charging handle and I still have trouble racking the charging handle without banging my hand on the LMT.

Has anyone found a solution to this? I am thinking about taking it to the smith and see if he can change the bolt out.

FWIW I never remove the LMT so quick detach is not important.

Thanks, Brian

Robb Jensen

11-25-08, 06:16

I can not stand the huge thumbscrew. I use a PRI big latch on my charging handle and I still have trouble racking the charging handle without banging my hand on the LMT.

Has anyone found a solution to this? I am thinking about taking it to the smith and see if he can change the bolt out.

FWIW I never remove the LMT so quick detach is not important.

Thanks, Brian

Remove the big knob and cut the threaded portion and use a McMaster blackened nut.

http://img.photobucket.com/albums/v408/gotm4/04b4f97b.jpg

chrismartin

11-25-08, 07:02

Happen to remember the thread pitch on the McMaster nut?
I need to do this mod!

Robb Jensen

11-25-08, 07:05

Happen to remember the thread pitch on the McMaster nut?
I need to do this mod!

www.http://www.mcmaster.com part #91581A345

chrismartin

11-25-08, 07:08

Sweet! Thanks!
That thumbscrew is WAY too big and very much in the way of my light mount.

NinjaMedic

11-25-08, 08:46

GotM4, what length barrel is hiding under that MK18 rail?

ST911

11-25-08, 12:38

I can not stand the huge thumbscrew. I use a PRI big latch on my charging handle and I still have trouble racking the charging handle without banging my hand on the LMT. Has anyone found a solution to this? I am thinking about taking it to the smith and see if he can change the bolt out. FWIW I never remove the LMT so quick detach is not important. Thanks, Brian

We need a LT front BUIS.

RD62

11-25-08, 18:44

Rob,

What's the best method of removing the LMT factory nut?

-RD62

Robb Jensen

11-25-08, 18:48

Robb,

What's the best method of removing the LMT factory nut?

-RD62

You can install the sight in a padded vise and use a Big-Ass™ screwdriver to remove it (it's staked on).

usmcvet

08-18-10, 22:24

Okay this is an old post but I need some advice from those of you who have done this modification.

I have a brand new TRX Extreme Battlerail on my upper and I pulled out my LMT front and rear BUIS set. The rear is good to go on my BCM flat top upper.The front is way too loose on the VTAC/Troy! It fits just fine on the upper, soo looks to me like the Troy is out of spec a little.

My question is will this modification allow me to tighten up my front sight so it fits?

Thanks

liaisons

08-18-10, 22:55

www.http://www.mcmaster.com part #91581A345

Thanks gotm4... same one work for the rear LMT BUIS?

ra2bach

08-19-10, 14:43

is it possible to move the sight forward one notch?

decodeddiesel

08-19-10, 14:48

Thanks gotm4... same one work for the rear LMT BUIS?

Not gotm4, but yes.

decodeddiesel

08-19-10, 14:49

Okay this is an old post but I need some advice from those of you who have done this modification.

I have a brand new TRX Extreme Battlerail on my upper and I pulled out my LMT front and rear BUIS set. The rear is good to go on my BCM flat top upper.The front is way too loose on the VTAC/Troy! It fits just fine on the upper, soo looks to me like the Troy is out of spec a little.

My question is will this modification allow me to tighten up my front sight so it fits?

Thanks

Probably not. You are being limited by the actual sight body to rail interface. Changing out the nut, which is essentially just a tightening mechanism wouldn't change that.

usmcvet

08-19-10, 15:13

Thanks Guys. I tried the sight on the very front of the rail and again back where I will want it when I put my SureFire X300 on the rail. Kinda a PITA to think I need to buy a new front sight. Any one have a DD FS for sale or trade cheap!:meeting:

Col_Crocs

08-19-10, 19:58

GotM4, what length barrel is hiding under that MK18 rail?

IIRC from an old thread, that's an m4 barrel cut down to 12.5.

RyanB

08-20-10, 00:31

That sure looks like 12.5.

As to the LMT sight, I have no use for target sights on a carbine.

usmcvet

08-20-10, 06:58

Thanks for sharing but I am talking about the front sight.

That sure looks like 12.5.

As to the LMT sight, I have no use for target sights on a carbine.

jsebens

08-20-10, 07:06

Okay this is an old post but I need some advice from those of you who have done this modification.

I have a brand new TRX Extreme Battlerail on my upper and I pulled out my LMT front and rear BUIS set. The rear is good to go on my BCM flat top upper.The front is way too loose on the VTAC/Troy! It fits just fine on the upper, soo looks to me like the Troy is out of spec a little.

My question is will this modification allow me to tighten up my front sight so it fits?

Thanks

Funny you should mention that; I had to send 2 TRX Extreme rails back to Troy before they sent me one that was in spec. Whole process took just under a month.

usmcvet

08-20-10, 07:13

Jake

Thanks for the info. How did you determine they were out of spec and get them to agree. I emailed them before posting but have not heard back yet. I am sure I will. I've had good response from them in the past.

Have you seen the new QD attachment they have for your rail? It will fit in one of your cooling holes.

jsebens

08-20-10, 07:17

I used a set of calipers and the specs (available online) for the Picatinny rails. Turns out the first TRX Extr. rail was well under the minimum spec for the width of a Picatinny rail. The second one was improperly assembled; they'd neglected to glue in one of the helicoils by the barrel nut. The third one looked to be to spec, and I immediately sold it..."Troy" is now a four-letter word to me.

usmcvet

08-20-10, 07:27

Thanks Jake,

I will hunt down a pair of calipers too. I know it is too narrow just from moving my FS from rail to upper but I will verify it too. Again thanks for the help.

cop1211

08-20-10, 16:02

I just went with the Larue rear and Troy fixed front. I also didnt like the huge knob on the LMT.

markm

08-20-10, 17:22

We need a LT front BUIS.

The Daniel Defense front fixed BUIS is awesome.

http://i210.photobucket.com/albums/bb201/trixiebud/CIMG3505.jpg?t=1282343038

usmcvet

08-20-10, 18:52

I think DD is the way I am going. I bought the LMT new/used for this rail. DD here I come. I just read it is designed for use with an X300. I had the LMT rear from my SBR and wanted to modify the nut to a smaller one. This gun will not have an optic for a while. It is not in the budget right now so the adjustable LMT rear is helpful for now.

The Daniel Defense front fixed BUIS is awesome.

http://i210.photobucket.com/albums/bb201/trixiebud/CIMG3505.jpg?t=1282343038

bkb0000

08-20-10, 18:59

the LMT fronts are great.. not any different than a number of good options, however.

as to replacing the big knob- i do this, too, but i don't order anything special for a replacement. i'll use acorn nuts or takeoff knobs from other mounts... your hardware store will have something that'll work.

M&P45

08-20-10, 19:08

Solution to the knob...

http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=320

usmcvet

08-20-10, 19:57

the LMT fronts are great.. not any different than a number of good options, however.

as to replacing the big knob- i do this, too, but i don't order anything special for a replacement. i'll use acorn nuts or takeoff knobs from other mounts... your hardware store will have something that'll work.

The first.thing I bought here was an LMT rear from you. I need to switch out the front sight or mod it to fit my brand new Troy rail which is not mil-spec it is too narrow and the LMT will not tighten up enough. It rattless.

bkb0000

08-20-10, 20:37

The first.thing I bought here was an LMT rear from you. I need to switch out the front sight or mod it to fit my brand new Troy rail which is not mil-spec it is too narrow and the LMT will not tighten up enough. It rattless.

have you contacted troy? better to get one that's correct than limit your options in the future by having to modify all your shit

usmcvet

08-20-10, 20:44

have you contacted troy? better to get one that's correct than limit your options in the future by having to modify all your shit

I emailed them two or three days ago. Another M4C member, in this thread I think, said he sent two back before he got one right.

It is like getting a present as a kid but the wrong sized batteries and not being able to play with your new toy.

The modular rails are mil spec the LMT clamps on perfectly.

RyanB

08-20-10, 23:12

Thanks for sharing but I am talking about the front sight.

My bad. I didn't even know they made a front sight. I got confused by the comparisons to the rear sight above.

billybronco

08-24-10, 20:32

help me out folks......i know i read that a vise and BFS could be used to remove the original nut but i'm not having any luck.

is it really possible or would i have better luck taking a hacksaw to it?

thanks

bkb0000

08-24-10, 20:35

twist hard.. all you're doing is un-staking it as you twist. it's hard, but it works fine.

don't hacksaw it unless you have another screwbolt that matches perfectly. and then i wouldn't hacksaw, i'd sawzall with a new metal blade. MORE POWER.

eta ... but then after getting out the sawzall, i'd remember that a dremel is probably a cleaner way to do it.

silly carpenters...

billybronco

08-24-10, 20:56

thanks for the quick response bud!

usmcvet

08-27-10, 19:37

Jake

How long did it take to get an answer back from Troy? I emailed them last week and called today. Nothing yet.

Funny you should mention that; I had to send 2 TRX Extreme rails back to Troy before they sent me one that was in spec. Whole process took just under a month.

jsebens

08-27-10, 19:42

I got someone on the phone the first time I called.

usmcvet

08-27-10, 20:01

They must be rocking and rolling. I called around two and was told the person I needed to speak to was at lunch.

jsebens

08-27-10, 20:03

A late lunch is fairly common...most customers would call ON the lunch hour, so most CS reps take a late lunch so that they're around when you call.

At any rate, I hope they take care of this for you.

usmcvet

08-27-10, 20:07

They have been great in the past.

usmcvet

08-30-10, 16:34

Well I know folks are busy but no contact twelve days later sucks. I've had no response to my email and several phone calls.

I just spent forty bucks to buy a set of calipers and the rail is out of spec it is 8.31 and should be 8.35. The modular accessory rail is dead on at 8.35.

I just tried to leave them another voice mail and the mail box is full. The good news is I can add another tool to the tool box.

http://www.brownells.com/.aspx/lid=12631/GunTechdetail/Picatinny_Rails__Weaver_Rails__What_s_The_Difference_

jsebens

08-30-10, 16:39

To be fair, the Picatinny spec is a spread of values; the width of the rail at its widest point should be anywhere from .830 to .840 inches. Having said that, while you are within the range, you're definitely close to the minimum.

Their inability to answer the phone is an entirely different issue.

usmcvet

08-30-10, 16:56

So + /- .05

decodeddiesel

08-30-10, 17:23

Well I know folks are busy but no contact twelve days later sucks. I've had no response to my email and several phone calls.

I just spent forty bucks to buy a set of calipers and the rail is out of spec it is 8.31 and should be 8.35. The modular accessory rail is dead on at 8.35.

I just tried to leave them another voice mail and the mail box is full. The good news is I can add another tool to the tool box.

http://www.brownells.com/.aspx/lid=12631/GunTechdetail/Picatinny_Rails__Weaver_Rails__What_s_The_Difference_

That is some serious hot garbage. I hope you get this worked out.

usmcvet

08-30-10, 17:29

I am hoping it is just a bad week or so. I have a bunch of Troy gear and it all GTG the rail is my only issue.

Clem

06-08-12, 14:25

Sorry, I know I'm resurrecting this old thread, but I was hoping someone could give me some advice.
I was trying to take the big knob off the rear sight to replace it with a mcmaster nut, but it seems that I've stripped the bolt.
I used a big screw driver to turn the big knob counter clockwise and met resistence obviously. But when I tried to muscle it some more, the whole bolt now turns with the knob. Looks like the recessed part where the bold head is seated has stripped.
Is there anything I can do to fix this? I sent an email to LMT to see if they can fix it, but I haven't heard anything yet.
Should I just cut the bolt and replace it with one of these?
part#91251A349 (http://www.mcmaster.com/#socket-head-cap-screws/=hw3hbv)

usmcvet

06-08-12, 17:06

It it is the right length and diameter go for it.