since the only "real" Dissipator actually MUST be made by bushmaster, and all others are dissipator-type rifles, then let's agree that lower case d dissipator is a short barrel, full length hand guard with front sight works.. under 18" barrel,

Barrel - McGowen 16.5, stainless, modified hbar, wylde, 1:9, rifle position tube had to open the port to .094 as it was at about 85% function due to being under gassed - I'll try again another day on .109 and see -- it may need to go even more, but let's take it in steps.

YHM popup front sight gas block - this may change due to weight


kaw valleylinear" compensator --


DPMS carbon fiber forearm. They changed these to be a weave texture rather than smooth - NICE

hogue ergo grip

m(f)93 stock

rock river NM trigger

DPMS LPK - less trigger and grip


I used a nikon 2x7x32 and a tasco reddot - black hills 69gr blue box ammo

at 100, the groups were between .75 and .8 GROSS, 3 shot -- two groups after sighted in, took off scope and tried the tasco, then put it back on, and it head within .25, and next 2 groups stayed same size, no scope drift after first shot. Its NOT a target scope, as its a buckmaster 32mm 7x -- I think the rifle would shoot better with a big 24x scope, but, well, it's minute of piggie eye at 100 ...

at 50 - tasco reddot (5 MOA is USELESS at 100 for target work, 3" groups) - just at 1" at 50, 3 shot groups .. took it off, moved about .5" first shot, then a couple more groups .. about an inch with a 5 MOA red dot .. even when moving, the groups overlapped - so minute of rabbit head or piggie was easy.

I did have to ream out the gas port - it wouldn't feed properly with black hills 69gr most of the time, as described above - I'll take it out another day and see.

"why short heavy barrel AND rifle gas length?"
1: I LIKE the recoil impulse of the rifle system over mid or carbine - I didn't say recoil, just the impulse -

2:" I knew I would be putting on a 1.5 greater length linear comp. The Linear comp throws a lot of the noise and gas FORWARD - mush more pleasant to shoot

3: short heavy barrels are USUALLY more accurate than longer barrel of the same weight - and sometimes of the same contour

4: I like that it is 3.5" shorter than a standard 20" rifle gas, with the m/f93 stock, it is a VERY firm lock on the stock, so no rattle/unstable platform

Anyway, just my latest build, and I am happy with it.

turns out that matchkings in 223 are GREAT hunting bullets -- for rabbits!!

in short, it short stroked at "regulation" .. 0.07x with good ammo, including not fully ejecting.

it worked at 0.094 with good ammo/winchester 5.56 and other usa made.. wouldn't cycle steel cases at all, not even a single round and lock open on the mag.. nope

at 0.109/0.110 it cycles everything just fine -- from the cheapest bronze bear ammo on out, including tula .. everything cycles great...

ding ding ding
we have a winner - if you go with a short barrel and rifle system, you might consider .090 as a starting point -- but 0.110 works with everything, and I BELIEVE that you really can't be over gassed with the pressure being so low that far out..

next one will be a soda straw barrel and likely magpul furniture ... just a light weight, 16ish EXCELLENT thin barrel, but likely a low profile gas block and magpul popup sights...

What bolt carrier and buffer are you running

BCG - ares arms
http://www.predatorarmament.co...ier-group-mk1-mod-0/

buffer and spring - tapco carbine buffer and stock spring -- well, it SAID brownells, but its a tapco.

zero tricks there

With a M16 BCG and a 3oz buffer this leaves little option to improve cycle but to open up the gas

When you get it to cycle 100% with all ammo it will be a sweet system and easy on brass

You may need to cut weight on the bolt carrier before going munch bigger on your port

Ted -
thanks -- this is NOT being sarcastic -- its working perfectly now, and I though I said so.. but obviously I didn't say it clearly --

can you help me with a little feedback as to how I could have said its working now 'better" than I did?

at roughly .110 (which is what MANY other people "discovered") it works perfectly, with standard parts...

Ted,
I appreciate the help, and i didn't get my point over very well.. thank you for wanting to help, and I am serious in this.. thank you...

i am NOT being a jerk here.. that's not the ar way, right?

I was just sharing the journey, and i obviously could have said that better ... and I don't mind learning

Sorry to said anything....the M16 bolt is heavy but what do I know?

good luck in your further endeavors

the platform has many ways to make it run

quote:

Originally posted by jeffeosso:
Ted -
thanks -- this is NOT being sarcastic -- its working perfectly now, and I though I said so.. but obviously I didn't say it clearly --

can you help me with a little feedback as to how I could have said its working now 'better" than I did?

at roughly .110 (which is what MANY other people "discovered") it works perfectly, with standard parts...

Thank Ted,
If changing the port size hadn't fixed it, I would be looking at buffer weight and spring rates next, then looking at the BCG

I reckon changing out the BCG would also have come into play, thank goodness it didnt --

Had it all come to pot, I'd have tigged up the rifle position port, put one in midlength, and kept going, but that would have defeated me ---

if that hadn't worked.. well, there's always fishing, four-wheeling, and flying!

My last 3 have been on 14.5" tubes

Fixed A2 sight tower with rear bus topped with
Aimpoint T1's so 100 yard accuracy wasn't on my mind nearly as much as over gassing

short barrels are Inherently more accurate than longer barrels of the same(ish) contour --

this 16.5" is very sub MOA, without a high power scope or super trigger.. and with a 6 pos stock

i like GOOD short barrels ... and i realize that a light and short barrel isn't going to be a p-dog rifle past 3 shots and a cool down

Not too long ago a had similar thoughts as to a short barrel and a rifle length gas system. So I built a 16" rifle length gas, Black Hole 8 twist .264 LBC. Which turned out well and accurate enough, I wanted a carbine I could use for hunting here in Washington State where minimum bullet diameter for big game is 6mm.

i liked that one so much that i built another, not FULLY light weight, but trying to be much lighter
.625 barrel this time, even lighter CF forearm, alum gas block, alum linear brake, and lighter buttstock than the x93 .. the 93 weighs over a pound!!

i don't expect 5 shot MOA, but I do except 3 shot MOA .. this will be a "patrol" carbine.. aka truck and stand popgun

and this one is stupid accurate ...