Eric
9 May 2008, 16:05
Item Reviewed: Brownells HK Style Flip Up Sight
Backup iron sights (BUIS) are mandatory for a weapon that uses some type of battery powered optic and preferable as a backup to other optics as well. Even though great advances have been made in the battery life of Aimpoint, EOTech and similar optics, there is still a chance that they may fail and thanks to Mr. Murphy, they will fail at the worst possible time. Luckily, the AR15/M4/M16 with a flattop upper and 1913 rail makes adding a BUIS simple.
Brownells is one of the best known names in the firearms industry and they continue to offer more and more accessories for this weapons system. I’ve been using their new HK Style Flip Up Sight for a while now.
When I first picked up the sight I noticed that it was fairly hefty. Components were cleanly machined from 4140 steel and 6061 T6 aluminum. The matte black finish is evenly applied. The four position drum has a .160” aperture for close-range engagements, as well as three .070” apertures for 100 yards, 200 yards and 300 yards, which are calibrated for M855 62 grain ball ammo.
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31381.jpg
Installation was simple and secure. I appreciated the slot milled into the mounting nut on the left side. This allowed it to be tightened down with a coin or screwdriver, instead of a hex wrench. The cross-bolt on the underside of the unit engages a slot in the 1913 rail, adding more stability. When using a carbine with the correct “F” height front sight base, zeroing was straightforward. However, we’re still stuck with numerous manufacturers that are using rifle front sight bases that are the incorrect height. This caused the front sight post to nearly be screwed all the way out.
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31501.jpg
I’ve had the opportunity to use this BUIS on a few different weapons, with either an Aimpoint or EOTech optic in place. It was also used as a stand-alone rear sight, with no optic in place. This BUIS is easy to deploy and it solidly folds into the up and down positions. While there isn’t a provision to lock the optic in the up position, I didn’t experience any issues with it folding back down until I intentionally did so.
I’m more accustomed to peeking through a more traditional type rear aperture, yet I found that I didn’t have any problems finding the front sight with this unit. The majority of my shooting was done with the larger aperture, which is a bit smaller than the larger A2 type aperture. I did use the 100 yard aperture a bit, but have no use for the 200 and 300 yard settings. Windage adjustments are made by way of a standard A2 style knob on the right side of the BUIS. Each click is a half MOA of adjustment.
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31451.jpg
Overall, I liked this BUIS a lot. However, I can think of a couple modifications that would make it even better for my use. The mounting nut protruded too far, which occasionally interfered with the rapid grasping of the charging handle. I’d like to see the same style of nut used, but just a lower profile one. I’m also a big fan of A1 style detent adjustments on iron sights. While these require the use of a tool or FJM bullet-tip for adjustment, there are less likely to get knocked or otherwise moved out of adjustment. I don’t think that most users will utilize the 200 or 300 yard settings on a BUIS. Perhaps the apertures could all be set on the same plane, using a full size A2-size aperture (.200” I believe), the .160” aperture and the smaller .070” aperture.
It looks like Brownells has added another good option to the backup iron sights that they already offer.
http://www.brownells.com/.aspx/sid=51853/sku/360_Series_Flip_Up_Rear_Sight
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31491.jpg
Backup iron sights (BUIS) are mandatory for a weapon that uses some type of battery powered optic and preferable as a backup to other optics as well. Even though great advances have been made in the battery life of Aimpoint, EOTech and similar optics, there is still a chance that they may fail and thanks to Mr. Murphy, they will fail at the worst possible time. Luckily, the AR15/M4/M16 with a flattop upper and 1913 rail makes adding a BUIS simple.
Brownells is one of the best known names in the firearms industry and they continue to offer more and more accessories for this weapons system. I’ve been using their new HK Style Flip Up Sight for a while now.
When I first picked up the sight I noticed that it was fairly hefty. Components were cleanly machined from 4140 steel and 6061 T6 aluminum. The matte black finish is evenly applied. The four position drum has a .160” aperture for close-range engagements, as well as three .070” apertures for 100 yards, 200 yards and 300 yards, which are calibrated for M855 62 grain ball ammo.
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31381.jpg
Installation was simple and secure. I appreciated the slot milled into the mounting nut on the left side. This allowed it to be tightened down with a coin or screwdriver, instead of a hex wrench. The cross-bolt on the underside of the unit engages a slot in the 1913 rail, adding more stability. When using a carbine with the correct “F” height front sight base, zeroing was straightforward. However, we’re still stuck with numerous manufacturers that are using rifle front sight bases that are the incorrect height. This caused the front sight post to nearly be screwed all the way out.
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31501.jpg
I’ve had the opportunity to use this BUIS on a few different weapons, with either an Aimpoint or EOTech optic in place. It was also used as a stand-alone rear sight, with no optic in place. This BUIS is easy to deploy and it solidly folds into the up and down positions. While there isn’t a provision to lock the optic in the up position, I didn’t experience any issues with it folding back down until I intentionally did so.
I’m more accustomed to peeking through a more traditional type rear aperture, yet I found that I didn’t have any problems finding the front sight with this unit. The majority of my shooting was done with the larger aperture, which is a bit smaller than the larger A2 type aperture. I did use the 100 yard aperture a bit, but have no use for the 200 and 300 yard settings. Windage adjustments are made by way of a standard A2 style knob on the right side of the BUIS. Each click is a half MOA of adjustment.
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31451.jpg
Overall, I liked this BUIS a lot. However, I can think of a couple modifications that would make it even better for my use. The mounting nut protruded too far, which occasionally interfered with the rapid grasping of the charging handle. I’d like to see the same style of nut used, but just a lower profile one. I’m also a big fan of A1 style detent adjustments on iron sights. While these require the use of a tool or FJM bullet-tip for adjustment, there are less likely to get knocked or otherwise moved out of adjustment. I don’t think that most users will utilize the 200 or 300 yard settings on a BUIS. Perhaps the apertures could all be set on the same plane, using a full size A2-size aperture (.200” I believe), the .160” aperture and the smaller .070” aperture.
It looks like Brownells has added another good option to the backup iron sights that they already offer.
http://www.brownells.com/.aspx/sid=51853/sku/360_Series_Flip_Up_Rear_Sight
http://img.photobucket.com/albums/v503/AR15forme/Brownells/IMG_31491.jpg