45ACP/super Compensator .....

wquiles

Active Member
I am working on making my own 45 super setup, and I decided to go with a compensator. Since I still have some of the left-over steel I found earlier, I decided to make my own from scratch.

Clean the od, center drill:



For the boring, I got 3x diameters to hit:
  • exit hole (right now finished part sitting at .568")
  • threaded portion
  • over-the-barrel portion
I am using a solid-carbine boring bar with through coolant, which if you line up right, it works wonders:


You can see the squirt of fluid here:



Cut threads (.578-28):







And of course, the money shot, with my 45ACP Colt Combat Commander which has the fitted threaded barrel:
 

wquiles

Active Member
Cut/part the piece:





Easier to see here the 3x diameters:



Exit hole:



I need to do more "stuff" to it on the milling machine, but here is how it looks right now:



And of course a couple of photos of how this steel used to look like when I found it - diamond in the rough ....





Before I do the milling work I need to cut/make a small stubby barrel to hold the piece, so that is the next job (still on the lathe), so it will be a little while before I finish this piece.

Will
 
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Ian

Well-Known Member
Nice. I find a good suppressor makes a great handgun comp!

Is your other pistol an Ace Custom?
 

Gary

SE Kansas
Love your write-ups and the pics are great. I've got to get a 6 jaw like that when I manage to save up enough.
 

wquiles

Active Member
It is not done yet, so right now it only adds weight :)

But it will be a compensator/muzzle brake once I finish the milling operations ;)

Will
 

Pistolero

Well-Known Member
I have a pair of old Wilson LEComp 1911s. Looks like you are heading about there, maybe
a bit smaller diameter, so no flats.
They work well but build up a good bit of lead over time inside.

Mine look just like this one, one in .38 Super one in .45 ACP. Wilson moved the front sight out
onto the comp, a bit longer sight radius, and perhaps a slight accuracy improvement since
the sight is now on the barrel.

There is a big milled cavity beneath the top port, leaving about a 1/8" front plate.

8699

Bill
 
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wquiles

Active Member
Very nice Bill!

Yes, that is basically what I am after, although my current "paper" design calls for two chambers, which seems the most common configuration for hot 45 super and 460 Rowland conversions.

This one on my Commander is particularly "fatty" at the moment (OD-wise), so I might finish it to learn how to mill it, figure out wall thickness, chamber size/shape, and treat this one as a "prototype", before milling a second one.

From what I am thinking, from "visual" inspection of many pictures on the "net", the back/larger chamber is about 1.5 times longer, but the same width than the front one. In addition to the two large chambers, some comps have two small "side" ports as well, but so far I don't know why they would be needed - unless the comp is producing too much downforce, and the side ports help bleed extra flow to make it more "level" or stay on target better. I have never made one, I have no idea what I am doing, so I adjust the project as I go along :rofl:

Will
 

Pistolero

Well-Known Member
Don't waste gas pressure on side ports. The concept is actually pretty simple. The inside of the
comp has a uniform pressure pushing in all directions on the inside metal surfaces for a few milliseconds.
Pressure on the left and right sides cancel. And if you leave the top on, the force on the top and bottom
cancel. When the top is removed, the forces on the top (pushing up) vanish, and the forces on the bottom
remain, pushing down. The two chambers are IMO, superfluous. The forces on the front and back surfaces
cancel, so no net fore/aft force from having an extra 'baffle'. The front baffle is closely fitted to the bullet
to keep the pressure up in the comp chamber as long as possible.

Some comps, especially the big arrowhead, side vent style with high pressure cartridges like .50 BMG actually
redirect the gases, so have some momentum reversal forces but also just increase the forward side
area a lot to give the high velocity and high pressure gases something bigger to push on for a few
milliseconds. But, I have fired a .50 BMG with a big arrowhead comp and wiped a couple of filled
50 rd plastic boxes of 7mm and .30-06 ammo off the NEXT BENCH OVER (6-8 ft away) on the range. THAT was
a eye opener, and proves that with a huge gas volume and high rifle pressures, the momentum reversal
thing works. Think Pelton wheel if you know anything about water wheel power generation systems.

Low pressure pistol comps have far, far less gas volume and pressure to work with, IMO most of the
force is from the disparate areas for the gas pressure to work on.

If you want, I can post some more detailed photos of the LE Comps.

Bill
 
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Pistolero

Well-Known Member
Ok, will get a couple pix up tomorrow of the Wilson LE Comp on the .45ACP gun.

Here is how a Pelton wheel works, but this is only for very high velocity and pressure gases.
No applicable to a pistol comp. A bucket like this reverses the flow, extracting the momentum
of the moving fluid (gas or liquid). With the very low density of the gases, need very high
velocity to get much momentum to reverse with the bucket/comp.

8710

This is the kind of comp I am talking about for 50 BMG class guns.

8711

Bill
 
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Pistolero

Well-Known Member
OK, here are some pix of the Wilson LE Comp. This one is .45 ACP, but I have a .38 Super which is
essentially identical except for the size of the front hole.8720

8721

8722

It looks like they may have welded on the front washer, then milled the top opening, since the corners of the
hole at front are completely square to the washer. Can't have gotten those with a ball mill plunge cut....which I
think would work just fine. Note the lead buildup. The barrel is threaded into this, and there were originally
square corners in the rear side between the walls and the back face that the barrel is screwed into. The .38 Super
puts far more lead into the comp than the .45 does.

IIRC, very slight color changes in certain light on the .38 Super comp indicate weld bead which blued ever
so slightly differently on that one. Maybe in sunlight you might pick it up on this one, too, but not apparent
in artificial light....and my eyes are not what they used to be, either. I noticed the weld color diff many years
ago, have had these since the late 80s time frame, when they were the cutting edge of competition gun
technology. :) Still awfully nice guns, but not the latest and greatest any more. But, they both run 100%
and are exceptionally accurate, with low muzzle flip. And a plug for Metalloy finish. These guns show
zero wear in the lowers, and just seem to get slicker and slicker as they are shot more. I don't think you could
were one out. The .38 Super has north of 70K rounds of Major Caliber through it, 147-150 gr at 1225 fps,
chronoed. The .45 probably has something a bit less, but still way more than most guns will ever see, and
is in fine condition. Essentially all cast through both, bores look mint.

Bill
 
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wquiles

Active Member
Thanks much Bill. Great close-up pictures!

Gotta admit that I never thought about milling the whole piece, then welding a cover/plate, and then smoothing the resulting end. Pretty neat :)

Will
 

Pistolero

Well-Known Member
Seems to work, if you are a good welder. A crummy weld will definitely not survive too long.
It gets a pretty solid pulse on it each shot.

Hope it give you some useful ideas.

Bill
 
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wquiles

Active Member
Bill - this is the site I was mentioning that has the 460Rowland conversions and all of their comps are of the two chamber variety (except for a very compact one):
https://www.460rowland.com/








And here is the other one that is highly effective from Clark:



This is what has me thinking on the two ports for 45acp (45 caliber).

Will
 

wquiles

Active Member
I completed the prototype compensator today. Definitely a "little" more work than I expected - perhaps buying one might be the way to go if I need another one :p

To hold the compensator I created a stubby barrel to hold it on the 5C collet on the vise. I started from a piece of the left-over steel:








Test-fit on the prototype comp:
 

wquiles

Active Member
Ready:



"Barrel" in fixture:


Mark the end of the threads on the actual barrel:


Center:


Do a bunch of milling operations, mostly "blind", so I relied heavily on the DRO:
 

wquiles

Active Member



Mill the sides to match my slide's width:


Almost complete. Test fit:




No side ports per Bill's advice:


Good fit on the width: