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CMMG F Marked Front Sight Base Assembly, AR15 Color: Black, Gas Block Journal Size-Diameter: .750 in, $6.00 Off w/ Free Shipping

CMMG, Inc F Marked Front Sight Base Assembly, AR15, 55DA338
CMMG, Inc F Marked Front Sight Base Assembly, AR15, 55DA338
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CMMG, Inc F Marked Front Sight Base Assembly, AR15, 55DA338

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Questions & Answers
is this predrilled for the taper pins to attach to the barrel?

It is not pre-drilled

by clint, Verified Owner, June 28, 2019
See 2 More Answers
Can this fsb be mounted with a set screw instead of the mil spec tapered pins? I see a hole above the sling swivel... �

Thanks! I posted that question over a year ago and have since mounted 2 fsbs using the taper pins. There are a few good videos on YouTube showing exactly how to do it. You could remove the sling loop rivet and tap that hole as well.. that's the hole used to drill the gas hole above it.

by Tom, Verified Owner, October 30, 2025
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
AR front sight base by Marc, March 23, 2024
Authentic milspec article for your A2/A1 rifle. .750 diameter for the modern carbine barrels. Very-very nice.
3/3 found this helpful
Helpful Positive Review
ignore the other fools reviewing this by M, March 19, 2022
I recently purchased a friend's cmmg FSB just like this one that he got off optics planet. I saw a few reviews about how the product has no holes. When you do a fixed sight build, the pins must be put into the individual build and drilled. Yes, you s...
Read More...
35/37 found this helpful
Helpful Positive Review
Great Product by Justin, Verified Owner, January 25, 2017
Solid construction and nice finishes. Nice weight to it and seems very sturdy. Nice that it includes the front sight post. Would recommend any time. Also shipped very fast. Optics planet never disappoints
7/7 found this helpful
Helpful Positive Review
CMMG Front sight assembly by Builder Lee, August 15, 2023
This sight base comes complete with sight post, spring, detent also with sling loop attached. This is for virgin barrel assembly and must drill for tapered pins. Seems mil spec and matches the nitrate barrels.
2/2 found this helpful
Helpful Positive Review
Very good basic M4 gas block/sight base. by Doug T., Verified Owner, December 22, 2024
Overall I'm very pleased with this gas block/sight. Good machining and finish. Good price. The only negative is the tapered pin holes are not drilled, not sure why they don't do this. This took a couple hours of measuring, setting up, 1 broken bit,...
Read More...
1/1 found this helpful
Helpful Negative Review
Should have read the reviews by Dan, January 13, 2022
I am usually good about reading reviews but it looked simple enough. As mentioned there is no way to "fasten" the block to the barrel without taking it to a machine shop, sort of defeats the price point. Overall construction is good and solid but I ...
Read More...
7/20 found this helpful
Read All 9 Reviews
Color:
Black
Gas Block Journal Size-Diameter:
.750 in
Size:
One Size
Gun Make:
AR Platform
Gun Model:
AR-15
Additional Features:
F-Marked
Condition:
New

Code: 2CM-RGB-CMMG55DA338-55DA338

MPN: 55DA338

UPC: 815835012773

List: $75.99Save $6.00
$69.99

Product Info for CMMG F Marked Front Sight Base Assembly, AR15

"F" marked front sight base assembly for .750" gas journals. Includes front sight post and sling loop.image

Features of CMMG, Inc F Marked Tri Sight Base Ass:

  • F marked
  • Front sight base assembly
  • For .750 gas journals
  • Sling loop

Package Contents:

  • CMMG, Inc F Marked Tri Sight Base Ass

Specifications for CMMG F Marked Front Sight Base Assembly, AR15:

Manufacturer: CMMG
Color: Black
Gas Block Journal Size-Diameter: .750 in
Size: One Size
Gun Make: AR Platform
Gun Model: AR-15
Additional Features: F-Marked
Condition: New

Package Contents:

  • CMMG F Marked Front Sight Base Assembly, AR15

CMMG F Marked Front Sight Base Assembly, AR15 Orderable Models

List of Orderable Models

  • CMMG Front Sight Base Assembly, F, AR15, Black, 55DA338 , MPN: 55DA338 , UPC: 815835012773 , Code: 2CM-RGB-CMMG55DA338-55DA338

CMMG F Marked Front Sight Base Assembly, AR15 Unavailable & Discontinued Models

List of Unorderable Models

  • USED, CMMG Front Sight Base Assembly, F, AR15, Black, 55DA338 , MPN: 55DA338-EDEMO , Code: 2CM-RGB-CMMG55DA338-55DA338-EDEMO-RE-C
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Last updated 2026-10-09 UTC.