Hi all
I’m hoping someone will give me a little guidance on front sight install.I have a Stag upper with an YHM co. folding front sight.I have been leery of malfunctions with it and today was having failures to feed and failures for bolt to lock back on empty.Rifle has less than 300 rds. thru it. Weapon was clean,lubed and ammo was known good.Load was 25.9g. WCC-844,62 g. FMJ green tip,WW SR primer,WCC brass.
Anyway i want to remove the YHM sight and reinstall the original that Bravo sent along when i bought the upper from them. Is it hard to do? What potential pitfalls should i be aware of? Is the flash hider difficult to remove? Special wrench or anything? Gas tube roll pin? Looks like the gas block pins go in from left to right. Any help will be greatly appreciated. Thank you…Macon
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The clamp on sight/gasblock can move and restrict or shut down the gas from the port – this could very well be what is happening, you should be able to see if it has moved… it does not take much, an 1/8 inch can do it.
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The flash suppressor may or may not be permanently attached… if the barrel is under 16" without the FS, it is probably permanently attached – If it is, removing them can be above the average person’s pay grade, best to let a shop handle it.
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If it is not permanently attached, it threads off lefty-loosely just like you would expect.
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If you have the original sight that came off that barrel, it will be a cinch to put back on… just line it up and tap the pins in – I am not going to say which way they go in, because not all pins are installed the “right” direction, but they are tapered and you can figure it out pretty easy.
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The gas tube should come out of the block with minimal problem… but they can get stuck to the point that you may tear it up getting it out – the roll pin is nothing fancy, a proper “pin punch” makes the job a lot easier. I would think about having a spare roll pin on hand when you do the job (all of a few pennies).
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Removing the clamp on sight will tell you a lot, you should be able to see the “print” of where the hole was and get an idea if it was lined up or not… you can have the barrel and front sight indexed and pinned if you want to keep that sight, a small pin or set screw from the bottom (directly opposite the gas port) lines everything up most ricki tic, and keeps things from moving around.
Did you read This?
Just let is know if you into problems… pictures always help too 
Your problem may be magazine related. How many different mags are you using? Magazines with weak springs and cheap knock off followers will cause a failure to feed, usually from one side of the magazine and the bolt won’t lock back because the spring pressure is too weak to engage the bolt catch.
“ammo was known good.Load was 25.9g. WCC-844,62 g. FMJ green tip,WW SR primer,WCC brass”
Reload? Maybe a bad batch? Try some factory loaded and see if that changes anything.
Hi all
K.L.Davis
Thank you for your response.The barrel is 16".I removed the Phanthom flashider,the YHM front sight assm and installed the original sight assm.[my pins go in from left] i then reinstalled flashhider,cleaned and relubed bolt/carrier assm. and went for a test. I took 6 mags with 2 rds. each.I failed to lock open after the second shot every time. I went back to the house,recked -lubed-cleaned bolt assm. removed and reinstalled factory front sight assm. went back out for test.Then it started pouring rain.I fired 2 rds. from each of 3 mags. First mag. failure to lock.2nd. mag…locked open after 2nd rd. 3rd. mag. failure again. I am now “officially clueless”…not to mention frustrated. I e-mailed Bravo ,where i got it, Paul suggested i call Stag Arms. So i guess that will be my next step.
H.
I tried 6 different mags. Some from Midway,Colt,Adventure Line ,ect. I cannot feel any extra friction of the bolt dragging on any of them. Also as i ease the bolt back the spring pressure always raises the bolt catch instantly.
Anyway…thank you for your response.
AMMOTECH
Thank you also. I did not try any factory ammo at this time. I did try 3 different handloads though. This was not ammo that “someone” loaded for me.It was loaded by me for this test,on a single stage loader with all rds. visually inspected after powder dump and at each stage of the process. .All rds. felt,… sounded normal although i did not take my chrono to check velocity. Due to weather and work,tests with the carbine have been very limited but it has not performed to my expectations since i had it built and seems to have gotten worse. Anyway thanks again to all that helped.
Macon due
Try some factory ammo and inspect the entire gas system for leaks.
try a different bolt carrier? gas key on tight?
Failures with both gas blocks/Front sights…
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Loose Carrier Key
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Out of spec gas port
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Out of spec gas tube
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Damaged gas rings
Sounds like short stroking. So we can rule out mags and gas port alignment. The above is all I could think of, what else guys?
Did you catch the link to this in my first post?
I’d put money down that his gas key is loose or a screw is broke.
K.L.
Yes i read it,a couple of times actually.There is/was actually a little 'brownish…rusty looking stuff on the barrel behind the gas block with the YHM co. sight. But the carbine malfunctions the same with either block and with the 6 different mags. I called Stag Arms and they want it sent in and issued me a call tag. So i guess that will be the route i go. Thanks to all who have helped!
Macon Due