View Full Version : Colt M4 Carbine Dissipator Build
I always wanted to do a good dissipator build but never wanted to use some goofy Del-ton/BM/ OPOS barrel. So recently I decided I would use some components that I had gathered up and do it. I wanted to use a midlength, but I got a good deal on a carbine barrel so I decided to go for it. Here are the specs.
1. Colt M4 upper and lower receiver. Both were sent out and Cerakoted in burnt bronze.
2. 16" carbine gas system 1/7 5.56 barrel with Vltor low profile gas block and pinned FSB.
3. Centurion Arms 12" C4 rail system.
The Finishing Details:
4. B5 Systems Bravo stock in Multicam.
5. BCM MOD 3 Gunfighter pistol grip.
6. Colt BCG.
7. BCM MOD 4 Gunfighter (temporary until I get an ambi handle).
8. ALG Defense QMS trigger.
9. Vltor A5 lower receiver extension with green Sprinco spring and H2 buffer.
10. Battle Arms Development 45 selector lever.
11. Magpul trigger guard.
12. Mossie Tactics UQDL sling attachments with swivels.
13. KAC 2-600M rear BUIS.
14. Blue Force Gear padded Vickers sling in Multicam.
15. BCM Stubby VFG.
16. BCM MOD 0 Comp
21788
Looks great. Just so I'm clear (obviously new) dissipator = rifle length front sight with shorter actual gas system?
Looks great. Just so I'm clear (obviously new) dissipator = rifle length front sight with shorter actual gas system?
Yes.
Looks good! Did you do the FSB yourself?
In love with that dissy... Please make dissipator uppers BCM!
Also isn't a carbine gas system "correct" for a dissy build?
SeriousStudent
12-02-13, 16:20
Yes.
Looks good! Did you do the FSB yourself?
Agreed, can you tell us a bit more about how you mounted the FSB, when you have an opportunity?
I did it at a shop using an FSB alignment jig. We set it at just a tad over the standard location for a rifle because I wanted to be sure that any 12" rail wouldn't hit the FSB.
Yes.
Looks good! Did you do the FSB yourself?
Basically we used an FSB alignment jig. I took measurements from a true FNMI rifle upper and tweaked it slightly. Then installed the FSB the standard way.
Agreed, can you tell us a bit more about how you mounted the FSB, when you have an opportunity?
SeriousStudent
12-02-13, 16:52
Very cool. Thanks for the info, that makes a lot of sense.
Eurodriver
12-02-13, 18:16
I am a fan, but that's practically impossible for someone without access to serious tools to build...which sucks.
"Iraqgunz"
Your Build = TOP NOTCH! Very Nice, that COMBO looks PERFECT
- Are you going to run a Optic on it?
Please make dissipator uppers Again BCM
^ Fixed it for you ;)
I am a fan, but that's practically impossible for someone without access to serious tools to build...which sucks.
"Eurodriver" Check the link below
https://www.m4carbine.net/showthread.php?142254-The-quot-Kino-Config-quot-XL-Who-s-Interested
^ Keeping it M4C ;)
Do you mean an optic? It already has a sight. BCM never did a Dissy for full release. I think Paul made a limited number for testing and product demo.
"Iraqgunz"
Your Build = TOP NOTCH! Very Nice, that COMBO looks PERFECT
- Are you going to run a sight on it?
^ Fixed it for you ;)
"Eurodriver" Check the link below
https://www.m4carbine.net/showthread.php?142254-The-quot-Kino-Config-quot-XL-Who-s-Interested
^ Keeping it M4C ;)
Do you mean an optic? It already has a sight. BCM never did a Dissy for full release. I think Paul made a limited number for testing and product demo.
^ Opps, yeah I meant Optic besides Irons.
- I just recall seeing pics from "Stickman". I had thought a limited went on sale, I guessed wrong. Thanks for the info. on that.
What was your reasoning for the color combo? Looks great, but wondering why you went mismatching
What was your reasoning for the color combo? Looks great, but wondering why you went mismatching
Not many people on this board care if their rifle matches their shoes.
Very nice, I wouldn't mind having something like this done.
Quite simply because I am not a Fashionista. What I care about is that my weapons work and are reliable. Whether my grip matches my shoes and purse or rail is of no concern. Also, Centurion Arms only makes a 12" rail in black.
What was your reasoning for the color combo? Looks great, but wondering why you went mismatching
Simple enough. I just didn't know if there was any practical reasoning behind it other than it's what you wanted. Either way it's cool. Don't think I've ever seen that receiver color before. i just assumed since you had the receivers cerakoted a specific (non black) color, there may have been a reason you chose the color scheme you did. it kind of reminds me of a reverse mk18
Iraqgunz - I was wondering what were your thoughts on the Centurion Arms 12" rail. I have one on a 14.5 BCM middy and it can be kind of a hand grinder without gloves. What are your thoughts?
Very nice build there IG. Whats up with the sling qd not in the socket? Is it there just in case you want to attach it a different way?
jaragon - I had a C4 12" on a Rainier Arms upper and I thought it was a very smooth/comfortable rail.
col.1981 - thanks for the input. guess I'm still getting use to quad rails from standard heat shields.
I put one of the new Mossie Tactics UQDL mounts on there and wanted to try it out as opposed to attaching it to the stock. With the loop design the sling actually becomes ambidextrous and I can sling it left or right as opposed to having the detach it from the stock and move it to the right side.
Very nice build there IG. Whats up with the sling qd not in the socket? Is it there just in case you want to attach it a different way?
jaragon - I had a C4 12" on a Rainier Arms upper and I thought it was a very smooth/comfortable rail.
Can you expand on why you chose the Vltor A5 receiver extension without using their buffer and spring kit? What do you gain using it vs. a standard RE?
Serpico1985
12-09-13, 10:09
The vltor A5 h2 buffer is the standard buffer sent with the kit. I think he just left off the A5 before the h2.
I think you are the only person who drew this conclusion. When I said A5 tube with H2 it's implied that we are talking about the Vltor H2 since the tube isn't supposed to be used with a standard carbine buffer.
Can you expand on why you chose the Vltor A5 receiver extension without using their buffer and spring kit? What do you gain using it vs. a standard RE?
I think you are the only person who drew this conclusion. When I said A5 tube with H2 it's implied that we are talking about the Vltor H2 since the tube isn't supposed to be used with a standard carbine buffer.
Thanks for the clarification, I understood the A5 tube was to used only with Vltor's buffer and spring. I was not aware it was H2 weight thus my confusion.
superstratjunky
12-11-13, 18:28
Cool rifle.
I love to see when someone else builds one of these. Nicely done. Is that a clamp on FSB?
No. It's pinned into place.
I love to see when someone else builds one of these. Nicely done. Is that a clamp on FSB?
What was your reasoning for the color combo? Looks great, but wondering why you went mismatching
With easy availability of spray paint in a plethora of fashionable colors, the owner can change the color to suit their needs. Nice rifle BTW.
No. It's pinned into place.
Opps, I see that now in your OP. Did you pin it or have someone do it? Sorry for the questions, its just that when I built my Dissy, pinning the SFB was the one thing that I paid someone to do. BTW, I am a machinist. LOL
Hey "machman72", look at the 1st pg. post #6 & #7 should answer your question(s)
Hey "machman72", look at the 1st pg. post #6 & #7 should answer your question(s)
How embarrassing. Thank you.
bnanaphone
12-13-13, 10:22
I assume you have never handled a Larue or LMT monolighic rail for comparison? I have found the CA rails to be the smoothest I have handled, without gloves. The sharp edges found on the two rails I mentioned are nonexistent on the CA rails I have handled (I have a 10" and a buddy has the 12" CA rails).
Iraqgunz - I was wondering what were your thoughts on the Centurion Arms 12" rail. I have one on a 14.5 BCM middy and it can be kind of a hand grinder without gloves. What are your thoughts?
I assume you have never handled a Larue or LMT monolighic rail for comparison? I have found the CA rails to be the smoothest I have handled, without gloves. The sharp edges found on the two rails I mentioned are nonexistent on the CA rails I have handled (I have a 10" and a buddy has the 12" CA rails).
No I haven't handled the Larue or LMT mono for comparison. Maybe it's just my rail or maybe it's just my lack of experience with quad rails. Most of my guns have traditional M4 hand guards. My BCM 14.5 middy is the first upper I've had with a full quad. I have rail covers for it I was just wondering what other people have experienced. Thanks for the input.
scoutchris
12-13-13, 15:32
I always wanted to do a good dissipator build but never wanted to use some goofy Del-ton/BM/ OPOS barrel. So recently I decided I would use some components that I had gathered up and do it. I wanted to use a midlength, but I got a good deal on a carbine barrel so I decided to go for it. Here are the specs.
That's just weird, I would have had you pegged for a Del-Ton guy.
K.L. Davis
12-13-13, 21:02
Ooops... wrong thread.
Lost River
01-06-14, 20:39
IraqGunz,,
I know you really are a fashionista at heart. I am sure you spent hours stressing about the fact that every part on your build were not going to be just the right shade... (drips with sarcasm). :)
That being said, I like the burnt bronze color. Normally I could care less about colors. That being said, the same old, same old FDE and other desert colors get old. I hated being issued all sorts of crap (clothes/kit) in tan, working in an environment that was just varying shades of tan mud/sand, etc, living in tan buildings, looking at a dust filled skyline that was just another shade of dirty middle east tan, etc, etc. One of the reasons I always wore a lot of green when downrange.. That and the damn tan 5.11s made a guy look like a gun toting janitor!
I like the very practical nature of that rifle. It would be a great GP iron sighted hunting gun for my neck of the woods.
Quite simply because I am not a Fashionista. What I care about is that my weapons work and are reliable. Whether my grip matches my shoes and purse or rail is of no concern. Also, Centurion Arms only makes a 12" rail in black.
.......
cool !
That's nice! I've wanted to do a carry handle dissipator forever! I finished it last month and I'm loving it. It's nothing special, but it handles well and I can shoot tennis balls at 100 meters. I'm happy.. Cheers..
I know I'm bumping an ancient thread but since this seems like the right way to do it I have a question.
So I assume the gas block is .750 but the barrel at that point is something like .730. Is that correct? We're there any issues pinning to the barrel with it being undersized? If really like to do this with as many colt specific parts as possible.
Also, do you have to use a rail or would the distance you chose also be able to use a set of round handguards?
Lastly, where could you get an upper built like this?
Also, do you have to use a rail or would the distance you chose also be able to use a set of round handguards?
Lastly, where could you get an upper built like this?
Original Dissy's were rifle-length gas and 16" barrels. Round handguards were the norm.
As for where to get one built, I'm sure ADCO could help (I'm sure there's others).
Adco said the only way it would work with a barrel that was .730 would be to turn it down to .625 and use that size front post. Not very cost effective but I bet it would work great.
This particular barrel was just under .750 in that position and pinning it wasn't an issue. We later did another run of SIONICS barrels with the .750 continuous profile for people that wanted to build a Dissy.
You have to pin the FSB in the rifle position to do so you need the correct jig.
Not sure where you could get this done. Your biggest issue is getting a proper profile barrel to correctly pin the FSB. After that it is pretty gravy. I built another such upper with one of our barrels, and then used a KAC RAS.
I know I'm bumping an ancient thread but since this seems like the right way to do it I have a question.
So I assume the gas block is .750 but the barrel at that point is something like .730. Is that correct? We're there any issues pinning to the barrel with it being undersized? If really like to do this with as many colt specific parts as possible.
Also, do you have to use a rail or would the distance you chose also be able to use a set of round handguards?
Lastly, where could you get an upper built like this?
advntrjnky
05-22-16, 07:52
You could also ream the I.D. of a .625 FSB to match the barrel O.D. That way you could match it to what ever the actual is .740", .730", .735", etc. You can get cheap adjustable hand reamers from various sources. I bought a set to do just that, but ended up tapping the hole under the sling swivel for a set screw. I then cut a strip of .010" shim stock to fit about 2/3 around the diameter of the barrel. That filled out the .730" barrel diameter to match the .750FSB, and also allowed the set screw to tighten/ center the FSB against the barrel. I used a torqued/ aligned A2 HG to set the distance, and tightened the set screw. Center the rear sight, shoot to confirm mechanical zero, adjust as needed, and then drill the front band of the FSB to pin permanent. You can leave the set screw or pull it and install a second pin in the FSB.
advntrjnky
advntrjnky
Adco said the only way it would work with a barrel that was .730 would be to turn it down to .625 and use that size front post. Not very cost effective but I bet it would work great.
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