Full Profile Comp

[wrmiller]

Hey Rick,

I'm not sure yet, what I'm going to do with the profile. I like the look of the 'slab side', but would have to leave a gap on the bottom for the backward movement of the slide/barrel combo prior to coming out of battery. I'll probably have to sketch it up a few different ways and see what looks good to me.

I like the idea of the full profile for this 10mm Auto as this will help tame down the rearward slide velocity a bit.

 

[Rick Leslie]

I'm sure it will look great with whatever you decide. Looking forward to your work.

 

[wrmiller]

Well, managed to get it drilled, bored, and threaded to .685x40. Bought a new boring head as I was having extreme difficulty in reading the one I bought from Shars. Didn't like the size/capability of the Shars 2" so I upped to a 3". It might be a bit large, but it works great...

The new 3/4x3-3/8 boring bar worked great. Uses a TCMT 21.51 insert.


Rick: Well, the piece of 4140 I bought kinda dictates the final shape. Never having done this, I asked my old mentor what size stock I should buy, and he said 1.5"x1" for a full profile. And it will work well. But had I wanted to pick up the profile of the extended dust cover, I would have had to start with 1.75"x1". Oh well, solves that problem.


I have the comp threaded on fully here and it is flush to the slide (no gap). I may have gotten the threads TOO good as I'm not sure there will be enough room for the Loctite, but time will tell. I cannot detect any play in the threads. It appears I will have about 5 to 8 thou between the breach face and the hood to work with to get the gap as minimal as I'm capable of. I've lost a bit of the fine motor skills over the last 20 years or so.


I thought I'd try one of those new fangled comp alignment reamers from PTG, but it measures at .416" which is WAY more clearance than I used to put in my competition garbage cans (round style). I was thinking more of like .408"? I've never had a bullet strike, but maybe I was overdoing it a bit. But I'll give it a go, and I guess I'll find out how efficient the comp is once I get to shoot it.

The last septum/front face of the comp is not to final dimension yet, and I will take it down to .2" once I get the comp-to-slide interface finalized so I can get the proper angle on it. Once fully fitted and profiled I don't think there are any external right angles anymore. Did I mention I've not tried one of these full profile comps before?

I've never run a profiling end mill either. Hopefully I won't break anything while I'm learning.

 

[sgisler]

Looking good! Been thinking lately I'd like to build a 2011, full dust cover and slab sided/comp'd. Maybe .460 Rowland, just 'cause.


Stan,
Sent from my iPhone using Tapatalk

 

[wrmiller]

And here it is fully fitted and in battery. I have no gap between the slide and comp where I can see daylight. Not bad for an Old Fart with some files and sandpaper.

Not happy with the typical rolled edges at the front of the slide. I am REALLY wishing I had a surface grinder about now...

But I will do the best I can. It will be a shooter after all, not a safe queen. I'm headed to the kitchen for drink and sustenance. I forgot to eat this morning in my rush to get to the garage.

 

[sgisler]

Great fit-up!


Stan,
Sent from my iPhone using Tapatalk

 

[Rick Leslie]

Very nice. I went back looking for a barrel bushing. Then I realized it was a bull barrel (.685"-40 TPI). Doh!!!

I like the look of the ports. Should be pretty effective with the pressure of the 10mm.

 

[wrmiller]

Very nice. I went back looking for a barrel bushing. Then I realized it was a bull barrel (.685"-40 TPI). Doh!!!

I like the look of the ports. Should be pretty effective with the pressure of the 10mm.

One of my first wide-body 1911s was built on a early aluminum para-ordnance .45 cal frame (steel didn't come out until almost a year later IIRC). The frame was rough, and the magazines pretty much junk, but I wanted to build a high-capacity gun for the USPSA sectionals in Mesa, AZ without resorting to 9mm major which the paid shooters were blowing up trying to get one to hold together. The .45 mags couldn't hold the 10mm auto, so after my mentor told me about a 'Centimeter' wildcat round, I decided to go with it and trimmed about 1000 pieces of 10mm brass to centimeter length. Used three chambers, .3" wide IIRC. Worked great, lots of shooters were checking out the gun and I even managed to get FTD on a couple of stages, beating Robby and Brian. Finished 3rd in Master Class. Not bad for a lefty shooting right handed (right eye is my master eye). Later when I was trying some really hot 'hunting' loads, a friend was shooting video and captured the muzzle of the gun actually dipping 'downwards' during recoil. But I also noticed that there was a significant amount of gasses following the bullet out the end of the comp. The 10mm Auto has a larger case, and more powder, so I figured that a extra port wouldn't hurt.

 

[Cavallino]

Looks good! Did you use the one degree angle cut on the front of the slide or is it 90 degrees flat?

 

[wrmiller]

Looks good! Did you use the one degree angle cut on the front of the slide or is it 90 degrees flat?

I went straight into the comp (90 degrees) with the barrel, so I had to angle the backside of the comp where it touches the slide. I did clean up the end of the slide slightly to remove some imperfections and tooling marks, but the angle is on the back of the comp. And as I like to fit my barrels a bit high for high(er) power loads I'm not sure 1 degree would be sufficient, so I ended up fitting the slide/comp interface by hand with files and sandpaper. Old School.