• ODT Gun Show & Swap Meet - May 4, 2024! - Click here for info

Am I dumb or just unlucky?

Bennyboy

Default rank <3500 posts Lifetime Supporter
ODT Junkie!
262   0
Joined
Feb 2, 2013
Messages
3,224
Reaction score
3,316
Location
Commerce
Okay AR15 guys, need some advice. Here’s a little backstory:

My last purchase AR was a Ruger AR556. They do NOT have an F-marked sight base but according to all sources, they ARE F-marked height. They come with a proprietary Ruger flip-up BUIS in the rear that looks like a Magpul rip-off. Sights in perfect, works great, all is good.

Then, I tried to mount a Milspec carry handle on it. The gun shot super high (like a 2 foot at 50 yards) even with front post adjusted all the way up. Oh well, order a taller post, install it, adjust it all the way up (level with the ears on FSB). Gun shoots better but still high (~4” at 50 yards). Think “WTF” remove carry handle, reinstall Ruger flip-up (which must be shorter than Milspec sights), co-witness with Vortex Sparc, all is fine.

Fast forward till now. My newest AR is a Colt 6720, which does not have an F-marked sight base (apparently used barrel assemblies from 6520s which had A2 uppers) and a Magpul brand flip-up BUIS. Everything I read online says it’s no problem, Colt installs taller front posts at the factory to make up for it. I get it out yesterday and shot it for the first time. Windage is perfect, shot really high. I adjust post all the way up (level with the ears again) and yep, still shoots high. Roughly 4”@50 yards just like the Ruger.

I was gonna order a DD A1.5 read sight and a MRO or Aimpoint but now I’m not sure the irons will even work. Any higher on the post and it will be higher than the ears on the FSB. I need a shorter rear sight. Are there any good options? I could shave it and free float it but hate to cut a new rifle.

Am I dumb or unlucky? How can I be the only person noticing this on these rifles? Any suggestions?
 
Did you make sure that the carry handle rear sight was lowered? Those have elevation on them as well.

Are you putting the top of the front post in the center of the rear sight hole?
Yes, elevation all the way down on carry handle, post centered in peep.

For the record, I’ve sighted in dozens of guns over the years, these two have been the only problems.

Also, I think the taller sight post would work on a rifle length gun, but on a carbine, the shorter sight radius puts the post higher than the ears. I can find “commercial” carry handles that are shorter than Milspec but not any good flip ups and/or fixed that don’t block the whole rail.
 
Yes, elevation all the way down on carry handle, post centered in peep.

For the record, I’ve sighted in dozens of guns over the years, these two have been the only problems.

Also, I think the taller sight post would work on a rifle length gun, but on a carbine, the shorter sight radius puts the post higher than the ears. I can find “commercial” carry handles that are shorter than Milspec but not any good flip ups and/or fixed that don’t block the whole rail.

Lol sorry sometimes simple things can be missed, like the old IT line "is your computer plugged in?", which solves the problem for many calls. I think the best choice just might be to chop it and free float, depending on what purpose the rifle is for.
 
Random question, where do you guys mount your rear BUIS (specifically Magpuls)? Mines screw was in T2 from the factory, I moved it back to T1. I’ve always mounted them as close to the rear as possible.

I’m just looking at everything guys .
 
Okay AR15 guys, need some advice. Here’s a little backstory:

My last purchase AR was a Ruger AR556. They do NOT have an F-marked sight base but according to all sources, they ARE F-marked height. They come with a proprietary Ruger flip-up BUIS in the rear that looks like a Magpul rip-off. Sights in perfect, works great, all is good.

Then, I tried to mount a Milspec carry handle on it. The gun shot super high (like a 2 foot at 50 yards) even with front post adjusted all the way up. Oh well, order a taller post, install it, adjust it all the way up (level with the ears on FSB). Gun shoots better but still high (~4” at 50 yards). Think “WTF” remove carry handle, reinstall Ruger flip-up (which must be shorter than Milspec sights), co-witness with Vortex Sparc, all is fine.

Fast forward till now. My newest AR is a Colt 6720, which does not have an F-marked sight base (apparently used barrel assemblies from 6520s which had A2 uppers) and a Magpul brand flip-up BUIS. Everything I read online says it’s no problem, Colt installs taller front posts at the factory to make up for it. I get it out yesterday and shot it for the first time. Windage is perfect, shot really high. I adjust post all the way up (level with the ears again) and yep, still shoots high. Roughly 4”@50 yards just like the Ruger.

I was gonna order a DD A1.5 read sight and a MRO or Aimpoint but now I’m not sure the irons will even work. Any higher on the post and it will be higher than the ears on the FSB. I need a shorter rear sight. Are there any good options? I could shave it and free float it but hate to cut a new rifle.

Am I dumb or unlucky? How can I be the only person noticing this on these rifles? Any suggestions?
Call ruger they have good customer service should make it good
 
Back
Top Bottom