I recently got a new colt 6920 and mounted an eotech and a midwest industries carbine length drop in rail. I really don't like seeing the fsb in the eotech and I'm thinking about cutting it down. I bought a magpul buis to take it's place. I'm just wondering if you guys think it would be stupid or look bad to cut down the fsb with a 7 inch handguard? It would be visible obviously but I'd do it right so it wouldn't look hacked up. Would using the buis mounted on the rail a little further back from where the original front sight post is make a noticeable difference?..I may eventually go to a longer free float handguard but right now just don't have the money.
Shave the fsb?
- Thread starter Kach33
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Thank you ugaarguy. I tried finding some pics but all I found were the shaved sight, I couldn't find any with the carbine length hand guard on it..I don't think it looks bad either, I just wanted to know what you guys thought since I'm fairly new to the ar platform..what about the fact the buis will be mounted a little further back than the original front sight, will that be a noticeable difference or not recommend?
1911 guy
Member
Have you thought of swapping gas blocks to a low profile with a rail to clamp the sight on it?
I have looked at low profile gas blocks but figured shaving it down is the same thing but cheaper and less work..I know they're not too expensive but I didn't wanna pay for something I could easily do myself...I actually didn't know they made low pro gas blocks with a rail on them though. Would the heat melt the polymer front sight?..I really don't think the less than an inch the sight will be moved back from stock will really make a difference but I just wanted to ask
1911 guy
Member
Unfortunately, most polymer sights say not to mount them on railed gas blocks. So unless you want to buy another (metal) sight, shaving the block may be your best option.
Ok that's what I figured, it came with a magpul rear sight so I bought the front to match in perpetration for doing this. If I had to buy both I probably would have went with the metal troy industries sights ..thanks for the help. I think I'm gonna go ahead and do it. I know it's common when people add a longer hand guard. I just wanted to make sure it wasn't gonna look ridiculous with the 7 inch hand guard since it would be showing
ApacheCoTodd
member
Save it.
Being a Colt outfit, I would without question, remove the FSB and save it in the case of a future upper/barrel sale.
Get an add-on block. Cutting yours wouldn't look at all bad, but I'd pull it and save it all the same.
Being a Colt outfit, I would without question, remove the FSB and save it in the case of a future upper/barrel sale.
Get an add-on block. Cutting yours wouldn't look at all bad, but I'd pull it and save it all the same.
Is that something I could figure out the right way to do it myself by watching YouTube videos or something? Like I said I'm new to the ar platform, as far as doing some at home smithing, I've fired them plenty. I've read things about the gas block being hard to line up and the differences between screws and pins..it's a little overwhelming at times lol.. I'm sorry if these are stupid questions but I just don't want to get over my head on something I thought I could do myself.
Sam1911
Moderator Emeritus
If you aren't planning to make this your "always and forever" change, why not? If this is just to get you through the next competition season while you scrape together the funds for a more cohesive build, that would be perfectly workable. I don't think I'd bother to put BUIS on it, myself, until you get a decent float tube set up. As it is you'll just have a super short -- even shorter -- sight radius and the short carbine gripping length with a whole lot of "useless" barrel space sticking out the front.
You could always sell that MI drop-in handguard set to someone who wants to keep the M4 style sight arrangement and have a chunk of the price of the float tube of your choosing.
You could always sell that MI drop-in handguard set to someone who wants to keep the M4 style sight arrangement and have a chunk of the price of the float tube of your choosing.
ApacheCoTodd
member
The pins holding it on need to be removed by driving them from the left side (as held when firing) out the right side.
If you don't get a proper punch from say, Brownells, just take it to a good shop and have them drift the pins for you. You don't want to use a flat tipped punch as it can "mushroom" the end of the pin making it very hard to then get out.
Pretty straight forward and I'm sure there are vids about the internet for it.
It's worth saving the sight for the barrel.
If you don't get a proper punch from say, Brownells, just take it to a good shop and have them drift the pins for you. You don't want to use a flat tipped punch as it can "mushroom" the end of the pin making it very hard to then get out.
Pretty straight forward and I'm sure there are vids about the internet for it.
It's worth saving the sight for the barrel.
Look into the lo pro gas blocks with the flip ups made into them. There rail height when folded and you don't lose any sight radius. It also sounds like your going to try to shave the gas block while its on the gun. Just get someone knowledgeable to swap the parts for you even if it cost some money. It's better than scratching up your rifle.
desidog
Member
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- 2,595
Chances are, if you cut it it will look bad...so, if you cut it, make a dissipator out of it, with a longer free float handguard to cover your cut down fsb. You can either use an fsb with a rail, or get a second fsb with a flip up sight to retain the handguard...that's what i did.
Sam1911
Moderator Emeritus
Wow. That's harsh.
It sure doesn't HAVE to look bad. FSBs are pretty rough castings as it is. It isn't that hard to improve on what you've got.
henschman
Member
I say cut it. No point replacing it with a low pro. There is nothing stronger than a factory pinned gas block. This is more of a concern if the gas block is going to be exposed, like you're talking about. Yes, moving the front sight rearward will give you a slightly shorter sight radius (not really a good thing) and will change your click values slightly, but if the irons are going to be strictly for backup in the event your EOTech fails, it's not really that big of a deal. If that's what you want to do, go for it.
ApacheCoTodd
member
If you go the "cut it" route. Gratifying results are easy enough. Get your initial cut taking the two uprights off close to but not even with the horizontal bar (holding the gas tube), file within a reasonable profile and finish with emory tape across the top and perpendicular to the bore. Wrapping the ends of the emory tape around a dowel or screwdriver handle and drawing the tape side to side with your hands (end of the tape) always below the bore and at an angle.
Steel "black" and Bob's your uncle. The courser your final finish - the better the results of blacking it cold.
Steel "black" and Bob's your uncle. The courser your final finish - the better the results of blacking it cold.
Jesse H
Member
I'd wait until you have funds for a longer rail, then shave down the fsb.
In the meantime shoot the gun with the Eotech and fsb. You'll get used to it if you shoot with both eyes open and focus on the target instead of the dot. My duty gun is a carbine length with a fsb and Eotech, I even keep the back up sight up.
It's not difficult cutting then smoothing the fsb down with a dremel tool. Just go slow and let the tool do the work. It doesn't have to be pretty if it's covered with a 10 to 12" rail.
In the meantime shoot the gun with the Eotech and fsb. You'll get used to it if you shoot with both eyes open and focus on the target instead of the dot. My duty gun is a carbine length with a fsb and Eotech, I even keep the back up sight up.
It's not difficult cutting then smoothing the fsb down with a dremel tool. Just go slow and let the tool do the work. It doesn't have to be pretty if it's covered with a 10 to 12" rail.
Normally, I'd advise cutting the FSB and rockin' the optic without BUIS- except you have an Eotech, which are notorious for their short battery life.
Check to see at what height your Eotech is mounted. If it's at true co-witness height- that is, when you look through your iron sights, you are looking through the middle of the optic, you might find you will like a change to a one third lower co-witness. With a one third lower co-witness, the optic sits higher and when looking through the iron sights, they line up through the lower third of the Eotech. I like the lower one third set up better because the front sight doesn't intrude in the field of view as much.
But I must admit, after shooting my AR pistol with an RDS and no front sight, I don't like going back to having a front sight. If you still don't like having the front sight in your FOV, shave the FSB and don't worry about what anyone thinks about how it looks. I think carbine length handguards look goofy on a 16 inch carbine, fsb or no fsb. What I think of how your carbine looks doesn't change how well it works for you. Don't worry about resale either. If things get crazy again and someone offers you crazy money for your AR, the shaved FSB ain't gonna matter
Check to see at what height your Eotech is mounted. If it's at true co-witness height- that is, when you look through your iron sights, you are looking through the middle of the optic, you might find you will like a change to a one third lower co-witness. With a one third lower co-witness, the optic sits higher and when looking through the iron sights, they line up through the lower third of the Eotech. I like the lower one third set up better because the front sight doesn't intrude in the field of view as much.
But I must admit, after shooting my AR pistol with an RDS and no front sight, I don't like going back to having a front sight. If you still don't like having the front sight in your FOV, shave the FSB and don't worry about what anyone thinks about how it looks. I think carbine length handguards look goofy on a 16 inch carbine, fsb or no fsb. What I think of how your carbine looks doesn't change how well it works for you. Don't worry about resale either. If things get crazy again and someone offers you crazy money for your AR, the shaved FSB ain't gonna matter
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