What is A Dissipator(technically) and while we're at it what is a gas block? What are the Dissipator's benefits and weakness' ?

Dissy is an carbine AR with an extra front sight/ gas block up front so it can use rifle handguards.

The gas block is the part that attaches to the barrel by the gas port and you plug the gas tube into.

Advantage of dissy = longer sight radius.

Negative = not as reliable as the real rifle length but then again its only 16"

Negative = much heavier than other 16" carbines and more cost.

it depends on the dissy setup.  the carbine length gas tube dissy is just as reliable as the rifle length.  the cut down 20" dissy setup requires some enlarging of the gas port.

as for the weight, with an m4 or LW profile, it ends up weighing just a tad more than a comparable carbine.

the dissy is the best of both worlds...the only cost addition I might see is a low profile gasblock for the carbine gas tube length dissy.

give it a try, you'll fall in love.

Click [url=http://www.bushmaster.com/shopping/weapons/pcwa2s16d.asp]here[/url] and [url=http://www.bushmaster.com/shopping/barrel-assemblies/pbbl-16da.asp]here[/url], let us know if you have any other questions

[url=http://www.bushmaster.com]bushmaster.com[/url]

The standard Dissipator[i](tm)[/i] is needlessly [b]heavy[/b], but like your porcine girl friend can be made into a beauty if she loses a lot of weight in the [i]right places[/i] [;)].

Note the HBAR (Horrible BARrel) barrel profile in the right hand link above.  If this profile is reduced to a reasonable diameter, say 0.630" [i]like the M16A2 barrel[/i], the [s]bitch[/s] barrel will shed most of a pound and be just heavier than the M4 profile barrel.  In this weight configuration the Dissipator is excellent.

Since we can all hit those 300 meter targets during qualification with the M4 Carbine sight radius, the longer radius on the Dissipator is a feature with little benefit.

It's almost impossible, though, to grab a hot barrel after a couple hundred rounds downrange, the main advantage for this carbine.

-- Chuck

Eh....I think this is needlessly trashing a great concept.  It's a 16" carbine with a full sight radius and full handguards.  What's not to like?

Weight?  Come on...if that weight bothers you you may wish to stick with your Ruger 10/22.

The Dissipator is a cool design and is design to 'dissipate' heat and provide some extra beef with regards to iron sight shooting.

I've got one, with a fluted barrel and an AK brake.  Thing kicks ass.  It's [b]VERY light[/b], NO recoil, dissipates heat, and with a competition front sight post, gives me all the iron site accuracy I'd want from a 16" carbine.

Chaulk me up as a fan of the Dissipator.  YMMV but in the end I'm right. [:D] lol

If you're not bothered by HBAR barrels you're not carrying one much.

I'll post a photo of my [i]lightweight[/i] Dissipator barrel when I can pry the camera from my wife who's in DC on Army business right now.  The weight difference will show up in the first half an hour shooting.

-- Chuck

You're not missing anything, the Dissipator[i](tm)[/i] (note the capital D) is a reliable firearm and is only produced by Bushmaster.

Bushmaster's website quotes (with some highlights).  Note the weights on the Heavy barrelled models compared to those of the M16A2 -- every one of 'em longer than 14.5" is heavier than the M16A2.

The standard Dissipator is a half pound heavier than the M16A2.

"BARREL WEIGHTS...
For informative purposes (and because we answer these questions all the time!) here are the comparative weights of our barrels.  

All weights are in pounds (for a milled front sight, subtract 0.2 lbs.)

10" - Heavy Bbl. - 2.0 / Fluted Bbl. - 1.9
11.5 " - Heavy Bbl. - 2.2 / Fluted Bbl. - 2.0
11.5x5.5" - Heavy Bbl. - 2.6 / Fluted Bbl. - 2.5
14.5" - Heavy Bbl. - 2.5 / Fluted Bbl. - 2.2
14AK" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.4
14VO" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.4
[b]16" - Heavy Bbl. - 2.7 / Fluted Bbl. - 2.3
16 Dissipator" - Heavy Bbl. - 3.0 / Fluted Bbl. - 2.6[/b]
20" - Heavy Bbl. - 3.5 / Fluted Bbl. - 3.0
24" - Heavy Bbl. - 3.9 / Fluted Bbl. - 3.1
26" - Heavy Bbl. - 4.0 / Fluted Bbl. - 3.2

And our Military style barrels...
XM177 Bbl. - 1.7 lbs.
[b]M4 Bbl. - 2.0[/b]
M4AK Bbl. - 2.2
M4VO Bbl. - 2.2
M4 Dissipator Bbl. - 2.3
[b]20A2 Bbl. - 2.5[/b]"
[emphasis added]

-- Chuck

I have always had heavy barrels, not a conscious choice, just never had an occasion to choose differently. Point being, I guess I have just grown accustom to the heavier barrels and I’ve been shooting with them quite a bit.

I’ve also been thinking of getting a Bushmaster Dissipator, getting the heavy barreled rifle and having it fluted. According to Chuck’s chart that would only be .1 lbs heavier than an M16A2 barrel. Thanks for the chart by the way. At this point for me it’s just a fun gun anyway.

J

I ain't pulling the barrel to weigh it, but my lightweight Dissipator (0.630" under the handguards) computes 8.5 oz less than the M16A2 barrel.  

Since these computations inlude the Vortex flash supressor on the Dissipator and the USGI compensator on the M16A2 the lightweight Dissipator is probably over 9oz lighter than the M16A2 barrel when both are stripped of muzzle devices.

M16A2 barrel weight is fine, but anything heavier I find hard to shoot, especially when engaging 30 or 40 targets spread across a wide area at varying ranges in a matter of a minute of two.

National Match pretty much demands a heavy barrel, but is an entirely different situation, one with little real world application.  Some, but not much.

-- Chuck

My 10 lb Dissi is pretty fast and handles great........for me. [:D]