AR-15 Buyer's Remorse (re: Irons and Carbine Gas System)
- Thread starter ZombiesAhead
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Zach S
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Nothing wrong with CAR irons. My 9mm AR, the one I shoot the most, has an A1 carry handle with an A2 aperture (my prefered rear sight). The better you shoot with irons, the better you'll shoot with an optic.
I prefer the dissipator set up though. If your bbl is .750 at the rifle FSB location, you can simply hack the front sight tower off (leave enough to act as a gas block though), touch up the bare metal with paint, K phos, or cold blue, and add another FSB in the rifle location. I've measured several M4 bbls that were .745-.750" where the FSB would land for a rifle sight radius. Seems like most were BMs, I wont swear to that though.
My 9mm is .718, so I'm going to have to get an A1 FSB and drill or ream it out. I'd have it done already but I keep forgetting to order the sight:banghead: Thankfully Kurt at KKF was willing to make a rimfire dissipator for me.
I prefer the dissipator set up though. If your bbl is .750 at the rifle FSB location, you can simply hack the front sight tower off (leave enough to act as a gas block though), touch up the bare metal with paint, K phos, or cold blue, and add another FSB in the rifle location. I've measured several M4 bbls that were .745-.750" where the FSB would land for a rifle sight radius. Seems like most were BMs, I wont swear to that though.
My 9mm is .718, so I'm going to have to get an A1 FSB and drill or ream it out. I'd have it done already but I keep forgetting to order the sight:banghead: Thankfully Kurt at KKF was willing to make a rimfire dissipator for me.
I myself have crummy eyes and can shoot a 20" decently but have trouble with getting a focus on carbine length Irons. For me it makes a huge difference but for someone with decent eyes-not so much.
Reconfiguring an upper really saves you no money unless you desire some combo of features not generally available. Just buy a new upper and then sell off the carbine if you need the cash or the space in your safe.
The one AR I spend the most time with is a flatop with a govt profile (light) 20". This gun is light and handy with great ballance and is an easy shooter.
Reconfiguring an upper really saves you no money unless you desire some combo of features not generally available. Just buy a new upper and then sell off the carbine if you need the cash or the space in your safe.
The one AR I spend the most time with is a flatop with a govt profile (light) 20". This gun is light and handy with great ballance and is an easy shooter.
arthurcw
Member
You'll be fine. Even those who have optics still learn to use the irons for when Murphy takes a dump on the power supply/reticle/buttons of the glass.
I think the only AR's I've seen NOT intended for irons are the long distance one's that have honking huge scopes.
Now as to getting new uppers: You can do that if you want. You can also change out the barrels and convert to a different sight radius. But I think that's over kill.
Get good with the Carbine and its irons then when you've milked it for all it's worth; get optics OR get a 20 inch to try and punch tighter.
My crappy eyes demand optics, not the model of rifle. Heck, I’d put a scope on a K31. How sad is that?
Bartholomew Roberts
Member
I think the best recommendation is to just keep shooting the rifle you have and when it is time to replace the barrel, you can upgrade if you like.
The sight radius will make it a little harder; but the 16" carbines are still plenty effective with irons. At 300yds, 8" plates are no problem from prone with irons. Some people find the regular AR sight post a little thick with the shorter sight radius but for a few dollars you can switch it out with a thinner post.
If you are really dead set on having a longer sight radius, the cheapest way to do this is cut down the FSB to a low profile (AR15.com has a tutorial on how to do this) and install a 9"-13.2" free float tube with a rail-mounted front sight. This will let you have a front sight radius anywhere from midlength to rifle length. If you later decide you want to change the gas system too; you can use these same parts on a new barrel or upper.
A couple of important points though:
Somebody already pointed out that the practical difference between the sight radius is around 10-15%.
The difference in lock time between a rifle and a carbine is 175 microseconds (that is 1/one millionth of a second).
So while there are tiny advantages - they are just that - tiny. Training is by far a much more important factor than minor differences in sight radius or gas system.
The sight radius will make it a little harder; but the 16" carbines are still plenty effective with irons. At 300yds, 8" plates are no problem from prone with irons. Some people find the regular AR sight post a little thick with the shorter sight radius but for a few dollars you can switch it out with a thinner post.
If you are really dead set on having a longer sight radius, the cheapest way to do this is cut down the FSB to a low profile (AR15.com has a tutorial on how to do this) and install a 9"-13.2" free float tube with a rail-mounted front sight. This will let you have a front sight radius anywhere from midlength to rifle length. If you later decide you want to change the gas system too; you can use these same parts on a new barrel or upper.
A couple of important points though:
Somebody already pointed out that the practical difference between the sight radius is around 10-15%.
The difference in lock time between a rifle and a carbine is 175 microseconds (that is 1/one millionth of a second).
So while there are tiny advantages - they are just that - tiny. Training is by far a much more important factor than minor differences in sight radius or gas system.
Z-Michigan
Member
So, the thread started by "ZombiesAhead" is turned into a zombie thread... how fitting.
Shawn Dodson
Member
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I prefer iron sights to optics.
I have no problem making head shots at 200 yards on IPSC cardboard targets (6x6" square target area) with my 16" M4s.
However I got rid of my detachable carry handles (I disliked those big attachment knobs (snag prone)) and installed ARMS #38 SWAN Sleeves with the low-profile, flip-up rear sight, which is my primary rear sight.
I have no problem making head shots at 200 yards on IPSC cardboard targets (6x6" square target area) with my 16" M4s.
However I got rid of my detachable carry handles (I disliked those big attachment knobs (snag prone)) and installed ARMS #38 SWAN Sleeves with the low-profile, flip-up rear sight, which is my primary rear sight.
Art Eatman
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Die, Zombie, die!
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