Need a favor from someone with a Legacy MCX - Page 1

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[ARCHIVED THREAD] - Need a favor from someone with a Legacy MCX

Posted: 6/20/2018 5:36:43 PM EDT

Take a look at your gas plug. Are the + and - holes different sizes? Mine look like the same size.

This is the non-Cabelas MCX with the gas piston that has the M16 gas rings on it.

Posted: 6/21/2018 3:30:44 PM EDT

[#1]

I have an earlier 2xxx serial number one. The 2 gas port holes are definitely of different sizes...the difference is easily seen with the naked eye. With it in the - position, the gas goes through the smaller hole. FWIW, my MCX functions 100% in the - position with the empties ejecting about 6 feet out. In the + position the recall is noticeably sharper and the empties go out much further. This is with no suppressor mounted.

Posted: 6/22/2018 12:24:55 AM EDT

[#2]

Well, maybe I'm blind. My two look the same.

I've messed with it on the range before, didn't notice much difference in ejection.

Posted: 6/22/2018 10:35:47 AM EDT

[#3]

I looked at it again this morning. Maybe one is larger? You be the judge.

I've probably shot a thousand trouble-free rounds. 99% of them suppressed and on the (-) position.

Attached File

Attached File

Photos obviously taken with a moldy potato.

Posted: 6/23/2018 12:27:55 PM EDT

[#4]

A hundred and change views, and no other opinions?

Posted: 6/23/2018 10:05:12 PM EDT

[#5]

Paging the MCX master @coregon

(I had it up a few posts, but realized that it was case sensitive)

Posted: 6/24/2018 1:13:18 PM EDT

[#6]

I was always under the impression that changing gas settings closed off one of the holes.
The other let both holes open. Could be wrong.

Posted: 6/24/2018 2:49:03 PM EDT

[#7]

Looking at it, it doesn't look like it allows both holes to be opened. The gas port in the block is dead center, and not quite large enough to allow gas into both holes at a time. At least by my visual inspection.

Posted: 6/24/2018 7:46:49 PM EDT

[#8]

You could be right.
Live always wondered why they didn't give it more then two settings.

Posted: 6/24/2018 8:23:57 PM EDT

[#9]

Quote History

Quoted:
You could be right.
Live always wondered why they didn't give it more then two settings.

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FAL-style gas would be titties.

Posted: 6/24/2018 9:06:18 PM EDT

[#10]

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Quoted:

FAL-style gas would be titties.

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As would caliber options or at least licensing out to 3rd parties so others could do it.

The MCX could be the caliber king if Sig played their cards right.
For the same space as an AR and another upper I can carry a MCX and 4 caliber exchanges

Posted: 7/12/2018 9:50:26 AM EDT

[#11]

@JAG2955

Sorry, just seeing this - not sure why the @ tag didn’t notify me. I’m not convinced that’s ironed out...

I’ll snap some pics today of some Legacy parts.

Posted: 7/12/2018 9:54:22 AM EDT

[#12]

Thanks! I had given up on it. But I'd love to know if something is wrong with mine. It would give me a great reason to buy a new MCX.

Posted: 7/12/2018 6:36:55 PM EDT

[#13]

Posted: 7/12/2018 11:18:42 PM EDT

[#14]

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https://media.giphy.com/media/UxREcFThpSEqk/giphy.gif

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Sorry

I have a 7-day old baby at home, so timing is something I should know better than estimate.

I PROMISE ill get you some pics on tomorrow (7/13)

Posted: 7/12/2018 11:23:08 PM EDT

[#15]

Quote History

Quoted:

Sorry

I have a 7-day old baby at home, so timing is something I should know better than estimate.

I PROMISE ill get you some pics on tomorrow (7/13)

View Quote

Full time stay-at-home dad here. An almost two year old and another due in two months. I guess I'm a glutton for punishment, as well as being well-versed in the ways of Sesame Street.

I FULLY UNDERSTAND.

Posted: 7/13/2018 5:10:01 PM EDT

[#16]

Quote History

Quoted:
Full time stay-at-home dad here. An almost two year old and another due in two months. I guess I'm a glutton for punishment, as well as being well-versed in the ways of Sesame Street.

I FULLY UNDERSTAND.

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Quote History

Quoted:

Quoted:

Sorry

I have a 7-day old baby at home, so timing is something I should know better than estimate.

I PROMISE ill get you some pics on tomorrow (7/13)

Full time stay-at-home dad here. An almost two year old and another due in two months. I guess I'm a glutton for punishment, as well as being well-versed in the ways of Sesame Street.

I FULLY UNDERSTAND.

Yep. 3YO daughter and now 8-day old son, so trying to get my sleep back up to a pre-SERE level

Pics incoming - ill apologize in advance of the iPotato pics...

@JAG2955

Posted: 7/13/2018 5:13:57 PM EDT

[#17]

I snapped several pictures of several different configs/generations of MCX, just for the comparison. Ill detail below, but let me know if you have any questions.

First off - what config if your rifle/barrel/plug that you posted? I ask because every caliber/barrel length is going to be different. Some more discernible than others.

L to R:
9" 300BO Legacy
11.5" 556 Legacy
6.75" 300BO LVAW
16" 556 Legacy
6.75" 300BO Virtus
5.5" 300BO Virtus/Rattler
16" 556 Virtus
9" 300BO Virtus

Attached File

Closer look at the Legacy plugs:

Attached File

Closer look at the Virtus plugs:

Attached File

Note:
1.) Some plugs are very, very well used and others are brand new pulled from brand new pistons. You can see on the used plugs which setting is used the most.
2.) Some ports are more easily discernible between the size, others are much less discernible to the eye - changes could be as simple as tapering into the port or just a slight change in diameter
3.) When comparing plugs, make sure you are comparing apples/apples - as the different length barrels and calibers will have different size ports.

Posted: 7/13/2018 5:19:40 PM EDT

[#18]

Closer views of the plugs:

9" 300BO Legacy and 11.5" 556 Legacy:

Attached File

6.75" 300BO LVAW and 16" 556 Legacy:

Attached File

6.75" 300BO Virtus and 5.5" 300BO Virtus/Rattler:

Attached File

16" 556 Virtus and 9" 300BO Virtus:

Attached File

Posted: 7/13/2018 5:21:43 PM EDT

[#19]

It should also be noted that I counted the number of MCX rifles/parts I have while I was getting these pictures. There's going to have to be an intervention

Posted: 7/13/2018 5:52:59 PM EDT

[#20]

@coregon, mine was from a 16" legacy 5.56 that was cut down to 11.5".

And LOL, my plug's holes are waaaayyy smaller than any of those. Almost looks like I got. .300blk plug somehow.

Still functions great, but, damn.

Posted: 7/13/2018 5:58:08 PM EDT

[#21]

Quote History

Quoted:
@coregon, mine was from a 16" legacy 5.56 that was cut down to 11.5".

And LOL, my plug's holes are waaaayyy smaller than any of those. Almost looks like I got. .300blk plug somehow.

Still functions great, but, damn.

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I'm willing to bet they aren't much different than the 11.5" Legacy 556 I posted above (at least, the way mine originally started out) - however, mine are eroded quite a bit.

Posted: 7/13/2018 6:06:35 PM EDT

[#22]

Thanks for your help. I really appreciate it.

I guess what what I need to do now is to shoot is suppressed and I suppressed in both + and - and see if there is difference in ejection or recoil.

Posted: 7/13/2018 6:07:16 PM EDT

[#23]

And what's up with the rings on your 11.5 legacy?

Posted: 7/13/2018 6:24:45 PM EDT

[#24]

Quote History

Quoted:
And what's up with the rings on your 11.5 legacy?

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That gun has been rebuilt since Virtus was released, so that's not a "Legacy" gas port. Probably should have noted that, but your comment spurred my memory.

Posted: 7/19/2018 9:40:18 PM EDT

[#25]

Quote History

Quoted:
Thanks for your help. I really appreciate it.

I guess what what I need to do now is to shoot is suppressed and I suppressed in both + and - and see if there is difference in ejection or recoil.

View Quote

Mine is a 16" cut down to 11.5" and I haven't noticed any difference in ejection between gas settings.

In fact that that brings up a good question for @coregon under what conditions should I change from - to +?
i haven't seen any difference between suppressed and unsuppressed.

Posted: 7/19/2018 10:28:42 PM EDT

[#26]

Quote History

Quoted:
Mine is a 16" cut down to 11.5" and I haven't noticed any difference in ejection between gas settings.

In fact that that brings up a good question for @coregon under what conditions should I change from - to +?
i haven't seen any difference between suppressed and unsuppressed.

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Quote History

Quoted:

Quoted:
Thanks for your help. I really appreciate it.

I guess what what I need to do now is to shoot is suppressed and I suppressed in both + and - and see if there is difference in ejection or recoil.

Mine is a 16" cut down to 11.5" and I haven't noticed any difference in ejection between gas settings.

In fact that that brings up a good question for @coregon under what conditions should I change from - to +?
i haven't seen any difference between suppressed and unsuppressed.

You really shouldn't have to mess with it. You should be shooting suppressed or unsuppressed in the "-" position. The only time you MAY have to change to the "+" would be an extremely dirty gun and/or extremely light loads.

FWIW, I dont know that I have ever switched my gas setting, in any caliber, in any configuration - other than just demoing how to physically do it. Other words, i've never had a reason to change the gas.

Posted: 7/20/2018 9:45:34 AM EDT

[#27]

So, I actually did shoot a few rounds the other day in both + and - positions. That's when I noticed the blowback from my new Raptor charging handle (see my other thread).

In fact, that wound up being the tattletale for letting me know that yes, one hole is slightly bigger than the other. Brass ejects slightly farther. Not by much.

And I switched back to my OEM charging handle, but haven't shot it again. Never noticed ANY blowback before.

I love this gun, and I REALLY want a Rattler pistol. I'm about to start selling my body.

Posted: 7/25/2018 1:20:50 PM EDT

[#28]

Quote History

Quoted:
So, I actually did shoot a few rounds the other day in both + and - positions. That's when I noticed the blowback from my new Raptor charging handle (see my other thread).

In fact, that wound up being the tattletale for letting me know that yes, one hole is slightly bigger than the other. Brass ejects slightly farther. Not by much.

And I switched back to my OEM charging handle, but haven't shot it again. Never noticed ANY blowback before.

I love this gun, and I REALLY want a Rattler pistol. I'm about to start selling my body.

View Quote

If you love your MCX, you'll put it down after buying a Rattler. No joke.

I have 14+ MCX rifles and every configuration you can think of and love them all - my favorite for a long time has been the 6.75" guns with several different cans. However, my Rattler with SRD762-QD gets more play time than any other and has for a while.

[ARCHIVED THREAD] - Need a favor from someone with a Legacy MCX

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