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Q&A for SIG SAUER Sig MCX Upper Receiver Assemebly, M-LOK — 18 Questions & 17 Answers

Name SIG SAUER Sig MCX Upper Receiver Assemebly, M-LOK (4.5)
$1,999.99 $1,639.00 Save 18%
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Q
Rob-O, member, from FL, United States, asked on November 27, 2019

Does this come with front and rear sights?

Expert Answer
A
Answered by Armando R., Gear Expert, from IL, United States, on September 26, 2022

These uppers do NOT include the front and rear sights any longer after revisions made by Sig Sauer.

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Q
Jordan, member, from CA, United States, asked on January 27, 2019

Do the 5 in 300 blackout uppers cycle subsonic and supersonic unsuppressed? If not will the 9inch 300 black cycle both reliably?

Expert Answer
A
Answered by Armando R., Gear Expert, from IL, United States, on September 04, 2019

The uppers should cycle with either ammunition, but when shooting sub sonic the action will cycle much more efficiently and properly with a suppressor.

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Q
MrDoverfield, guest, from CA, United States, asked on March 26, 2018

Will it work with an AR-15 lowers?

Expert Answer
A
Answered by Ethan C., Gear Expert, from IL, United States, on June 03, 2018

Yes, this comes with the adapter and trigger that allows it to work on a standard mil-spec AR-15 lower receivers.

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Q
KiNG LEO, member, from KS, United States, asked on July 25, 2022

what is the thread pitch on the barrel for the muzzle brake?

Expert Answer
A
Answered by Hunter, Gear Expert, from OH, United States, on August 08, 2022

The SIG SAUER Sig MCX Upper Receiver Assembly barrel is threaded for 5/8x24.

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Q
Taylor, guest, from TX, United States, asked on July 09, 2022

Does this upper come with the adjustable gas block?

Expert Answer
A
Answered by Ethan, Gear Expert, from IL, United States, on July 21, 2022

Yes, this SIG SAUER Sig MCX Upper Receiver Assembly includes/features an adjustable gas system that can be adjusted to optimize performance based on conditions such as a dirty gun or running a suppressor.

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Q
JudgeGabranth, member, from NC, United States, asked on April 17, 2022

Is the muzzle break pin and welded?

Expert Answer
A
Answered by Ethan, Gear Expert, from IL, United States, on June 02, 2022

The muzzle device on the SIG SAUER Sig MCX Upper Receiver Assemebly is not pinned or welded.

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Q
g52879, member, from OH, United States, asked on September 13, 2019

is the barrels on these uppers CHF?

Expert Answer
A
Answered by Jonathan D., Gear Expert, from IL, United States, on October 07, 2019

Yes, they are.

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Q
A LEX444, member, from FL, United States, asked on July 31, 2019

What color do these uppers come in?

Expert Answer
A
Answered by Armando R., Gear Expert, from IL, United States, on September 04, 2019

The upper receivers on this page are all black.

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Q
Mykal1970, member, from NC, United States, asked on July 15, 2019

Can the factory original lower (complete to the point that with the installation of the take down pins a ready to fire gun) be bought?

Expert Answer
A
Answered by Armando R., Gear Expert, from IL, United States, on September 04, 2019

We do not sell firearms.

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Q
Thomas, member, from AZ, United States, asked on May 30, 2019

Is the included Sig trigger required for proper functioning, or can I use whatever trigger I already have installed in my lower?

A
Answered by JoeThumbs, member, from VA, United States, on November 27, 2019

Actually, a factory Sig trigger as included with this upper) or an equivalent aftermarket trigger that’s designed to work specifically with Sigs is required. There were reported durability and function issues with triggers that were not specifically designed to work with these, hence why this Sig product includes a trigger.

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