Y’all I’m tempted
- Thread starter BlueBuck
- Start date
If your rifle works as is, keep it that way. If you want it to cycle faster, yes, get the dissipator.
The bayo lug will be useless... 
Why would that affect the bayonet lug?
You'd have to shorten the handle of the bayonet. This is from a gootoob vid of some guy that did it...
UPDATE: rando internet pic of an M7 bayonet below. The text in the pic above obscures the "regular" size...
Last edited:
- Joined
- Dec 31, 2024
- Messages
- 182
- Reaction score
- 187
- Points
- 43
Doesn't make sense. How does replacing the handguard with a dissipator move the gas block/ front sight posts closer to the end of the barrel?
No affect on the lug. The bayonet handle is shorter. Two different things but I see what you were trying to say.
The gas block stays, it is the end of the barrel that moves towards it...
From PSA (on sale): (note flash hider is pinned and barrel is shorter)
ARTICLE on Dissipators...
Pics courtesy of PewPew...
Last edited:
- Joined
- Dec 31, 2024
- Messages
- 182
- Reaction score
- 187
- Points
- 43
Ok, I guess I missed the gas block between the front sight posts and upper receivers in the first pic. Makes sense now. All this time I thought "Dissipator" was a type of heat shield designed to "dissipate" heat from the barrel faster. Silly me.The gas block stays, it is the end of the barrel that moves towards it...
From PSA (on sale): (note flash hider is pinned and barrel is shorter)
View attachment 31910 View attachment 31911
ARTICLE on Dissipators...
Pics courtesy of PewPew...
View attachment 31912 View attachment 31913
So, if you want the Dissipator look, or you want Carbine length barrel with rifle sight radius, the PSA is the better solution. As mentioned in the post by Bobster, first gen Dissipators with the gas port in the rifle position, but with a 16" barrel have cycling issues. Basically, there isn't enough dwell time before the pressure in the gas system drops off for reliable function. Moving the gas port rearward and concealing the gas block under the handguard is a viable solution.
I'm assuming you like the look. The same sight radius can be achieved with a rail out to the flash hider. This gives the same sight radius with the advantage of a floated barrel, and a rail to mount accessories if that is a consideration.
Another alternative to keep the look and have a floated barrel is a Service Rifle float tube that High Power shooters use. Completely concealed under the handguards, you get all the advantages of a floated barrel and keep the Dissipator look. It will add about $120 to the build budget though.
I'm assuming you like the look. The same sight radius can be achieved with a rail out to the flash hider. This gives the same sight radius with the advantage of a floated barrel, and a rail to mount accessories if that is a consideration.
Another alternative to keep the look and have a floated barrel is a Service Rifle float tube that High Power shooters use. Completely concealed under the handguards, you get all the advantages of a floated barrel and keep the Dissipator look. It will add about $120 to the build budget though.
My first retro build was a 20" A2. I built a dissapator later but used a A2 upper/A2 marked lower as I couldn't find a A1 with m4 feed ramps [that was what my dissapator barrel kit came with] now I have seen them available, might pick one up eventually and switch the barrel assemble over, but then I need an A1 lower ...sigh
Attachments
Last edited:
- Joined
- Jun 19, 2022
- Messages
- 1,147
- Reaction score
- 1,693
- Points
- 128
Ditto... That's why I prefer a pin and welded 14.5" carbine upper or a full length 20" rifle upper with the standard A front sight. No need to modify an M7 to match a shortened muzzle dimensions, it just goes on as-is. It is just my opinion, but the dissipator always struck me as a solution in search of a problem. Beyond the look of the dissipator, the benefits just don't seem worth the efforts to make one.
Last edited:
I think the MAIN reason was for use with a suppressor in Viet Nam. The shortened barrel made up for some of the extra length of the can while the can added lost backpressure due to the shorter barrel.
- Joined
- Jun 19, 2022
- Messages
- 1,147
- Reaction score
- 1,693
- Points
- 128
I agree. It also never gained wide-spread use for a good reason... there are better ways to achieve the same benefit. I would say the best way to run a can is to use the carbine length and deal with the buffer end for reliability. The rifle length was for un-suppressed use where bullet velocity is the goal, not reduced sound signature. The rifle length with the can is just plain awkward to use. The dissipator with a can is just as unwieldy, were as the carbine with a can is just about as handy as the rifle length without a can. So from my point of view, why bother with doing it. Making one for the looks is kinda cool. Just not vary practical.