I have always enjoyed the Dissipator configuration (I have two); the combination of a carbine length barrel and a rifle length sight radius is to me the ideal set up.  I’m not sure if this belongs in the “Build it Yourself” or the “Refinishing” forums, since I’ve got a little of both in this post.




However, as my BRD advances to a more severe stage, I was wondering about modifying the standard Dissipator into something a little different.  I have been looking at several forums over the past couple of years, and have never seen a Dissipator with carbine length hand guards.  So, I de-pinned the front sight and gas block from one of my Dissipators, removed the triangle retainer plate from the front sight, and installed a round carbine retainer plate at the gas block.  The result looks like this:




That left me with the front sight out on the end of a bare barrel.  The sight still had the bayonet lug, front sling swivel tabs, and a roll pin that was installed to keep the triangle retainer plate in place.



While the rifle worked as advertised, it looked unfinished, and I decided to take an extra step and remove the unneeded parts and refinish the sight.
The first step was to de-pin and remove the front sight:



And remove it from the barrel.  This is a Bushmaster barrel, and you can see that there is no Parkerizing under the sight.  I can only speculate that Bushmaster must assemble their barrels “in the white”, sand blast them and then Parkerize.  I’ve seen this on other Bushmaster barrels that I have worked on.



Once the sight was off, I removed the sight blade and detent assy.



Since I was going to expose a fresh metal surface, the sight needed to be refinished.  I’ve used high temperature paint in the past, but this time I thought that I would try to Parkerize it myself.  The set up is pretty simple; get some Manganese Phosphate solution (Lauer Custom Weaponry), a stainless steel pan, a hot plate, a thermometer, and a couple of measuring cups.  A set of tongs are handy to have to recover anything from the hot solution, and since the solution contains Phosphoric Acid, safety glasses and acid resistant gloves are a must.  



Also, even though the solution is not highly acidic, I kept a container of Sodium Bicarbonate (baking soda / NaHCO3) handy to neutralize spills.  The solution is mixed at a ratio of 4 parts water to 1 part Manganese Phosphate solution, pour into the pan, and heat to 175 - 185 F.
The directions say to place a piece of steel wool into the hot solution for 15 minutes to activate it.  Be sure to degrease the steel wool prior to putting it in the pan.





While the steel wool was in the solution, it was time to remove the unwanted pieces from the front sight.  I used a Dremel tool with a #426 reinforced cutoff wheel.  These wheels have a fiber glass cloth imbedded in the abrasive, they last longer and do not shatter explosively like the sintered grit wheels are prone to do (don’t forget the safety glasses).  



Clamp the sight firmly in a vice and work slowly at a medium high speed and let the wheel cut at its own pace, a light touch will allow you more control, and prevent you from gouging something that you don’t want damaged.  Also, be advised, that the pieces that you cut off will be “branding iron” hot.  I removed the lug, swivel tabs and the tube in only a few minutes.



I then used a belt grinder with a medium grit belt to remove the remaining stubs and contour the surfaces.



I thoroughly degreased the sight and the wire that I used to suspend it in the bath.  I used soft annealed carbon steel wire, but I think that you could also use stainless steel.



I had the solution temperature at 175F, removed the steel wool, and placed the sight into the solution for 15 minutes.



After I cooled the solution, I noticed some grey sludge in the bottom of the pan, I found out later in a post in the Refinishing section that this precipitation is called “flocking”  and can be corrected by leaving the steel wool in until it dissolves.  I’ll try this when I get home.  (Thanks to Hebrew_Battle_Rifle for the info)

When I removed the sight, I rinsed it with water, and thoroughly soaked it with WD40 to remove all the remaining water.



At this point, the sight was refinished, and was reinstalled.  The punch is a specialty punch for taper pins; it’s made by Starrett, and has a concave face to prevent deforming the ends of the pins.  I got it from Brownells, and while it was a little pricy for a single punch, I’ve had good results with it.  The hammer is an 8oz ball pein.

Once the front sight is re-pinned, I replaced the sight blade and installed the flash hider.



So, fellow ARFcommers,  I present my “Mutant Dissipator”:  







Specs:
Bushmaster Dissipator barrel (chrome bore)
Bushmaster Upper receiver
YHM Phantom flash hider
RRA hand guards w GG&G M4 rail and Magpul AFG
GI carbine front swivel
BCM BCG and CH (mod4)
Trijicon front sight
Trijicon Reflex II (12.5 MOA triangle)
GG&G MAD BUIS
RRA lower receiver
RRA 2 stage FCG w Wolff hammer spring and RRA Star safety selector
Tangodown Battle grip
GG&G HK hook loop
Cavalry Arms A1 Stock w/ GI A1 buttplate
Standard rifle buffer w/ Wolff extra power spring

I will have to test this the next time I get home, which is about a month away.  If anyone is interested, I’ll write up a range report.  And if anyone else has done this modification, let me know how you like it.  Please forgive the huge post, there was just a lot of information.  Thanks, enjoy.

Huh...well, you do great work I'll give you that...but I have to ask...why???

For the same reason that my dog licks himself, because I can    And why not?  I've never seen this configuration before, and it was a fun exersize.

Fair enough. Like I said, you do good work and seeing the steps was very interesting. It just seems in the end nothing was gained except your rifle that was very nice looking now...isn't...



Regardless, thanks for posting, makes me want to get the chemicals to try some parkerizing myself...

Oh yeah, try it out.  I was surprised at how easy it is to do.  I still have a lot to learn about the "little things" that go into Parkerizing.  But I think thats half the fun.  Good luck.

Not sure that I would do it myself but it's pretty cool, it's different, I like that.

I thought it was because he didn't have thumbs.

It's kinda weird. I like it. Kinda like when you see a sci-fi movie from the 80's where they used AR's for the weapons, but removed the handguard and gas tube.

That is one ugly looking rifle.......

I LIKE IT..........

As long as you like it.

the rifle's different, but not in a bad way.
Nice write up on parkerizing. Now I know that it's pretty simple to do, thanks.
What kind of bike is that under the cover ?

Good job. I particularly liked the belt sander work, that looks real good.

H'mmm,  not sure what to make of that... [thinkin']

Good job on the work though, well done!

Looks like great work but definately not for me.

It would look better if it was a regular Dissipator barrel instead of an M4. It doesn't look bad but I do prefer the extra handguard territory on rifle length.

It's different, if a different person would have introduced this here there would be waiting lines, group masturbation and purse fights for position in line.

Good job.  Not my cup of tea, but that isn't necessarily bad.  I'd probably like it better with a standard contour barrel rather than the M4 style.

 Sorry, someone had to do it.

That's a weird looking rifle, all right.  I'll give points for originality.  I will say, I've seen stupider looking stuff put out by popular and well-known makers.  Looks like fine work on the sight modifications.

Nice work.

There is a lack of originality in most builds I've seen. That is original for sure. Nice work.

The more I look at it, the more I like it!
Nice job.

Needs some more enhancement of the "ugly" , add a Tapco SAW grip , Troy "battle axe" buttstock ,  Troy TRX 7  " Extreme , 20rd P-mag.

I actually appreciate the uniqueness of your creation.

It has an almost "AKish " quality about it with the front sight post way out front. I like it.

ah beat me to it^^^^^^ definitely has the ak-esque look

Thats kinda what I thought as well! Good work though on the home park job

As bad as I hate to say this, but......



you need some wood furniture to finish out the AK transformation.



In a weird kind of way, It grows on ya.

I like it. Gets the advantage of the longer sight radius of the 'dissipator' in a simple direct way. Wonder why this hasn't been done before by a major builder.  Am going to do this to a couple of my M4orgeries.







 

I'd like to see it with a set of Magpul MOE hand guards on it.

I think what throws off the look is the fixed stock. They always look like an emergency canoe paddle to me.

A CTR or even issue M4 adjustable might balance the overall aesthetics by lightening up massive look of the stock. I'm talking art, not necessarily function.

An MOE handguard with the sight petals to cover it would look unfunctional, unless they were trimmed off . . .  anyway, the rifle length sight position makes for interesting thinking.

Wow.  Yeah, I first thought AK as well LOL.

Impressive work.  Eminently practical.  I'd like to see a similar build with non 203 cut barrel and low pro gas block....

Was wondering why not leave the bayo lug and use some of the bayo lug mounting systems to put a light out there.

Mount all that with the chopped CavArms lower and the TRX handguard . .  add a 20 rd mP-mag . . .

Nice work......well, sorta.  

I like it.

I love the step by step "do-it-yourself" threads here. I could spend all day looking through them. So thanks!

As for the rifle, not my cup of tea but my opinion isn't really important. Enjoy your new setup.

Mid length.

This has been in my brain on the soak cycle and it keeps getting cleaner. I'm thinking Choate stock and a railed gas block,  non 203 cut, also.

I doubt we could measure a MOA improvement on the forward sight position, but what the heck. I've got Stickman's MOE handguard pic from SHOT as a wallpaper, I'll just have to stare at it and make the kids wonder if I'm beginning to lose it . . .

i have seen everything now.

nice gun! interesting set up.

I have always been a lurker here. Love the site and all the posts, but I never joined. I had to sign up just to tell you that you created one bad looking ride. She has a personality and some attitude. Love the long sight radius. Thanks for sharing!!