In a never ending quest to increase my knowledge and experience of turning expensive pieces of metal into valueless piles of chips, I decided that I needed to make a FN style flash hider for my PS90 that would fit the 1/2x28 adapter on the muzzle.

I had one to use as a reference, and rather than cut the back off and thread it 1/2x28 I decided that I would use this as an excuse to make one from scratch and possibly learn something on the way.

I recently picked up a LeBlonde 15x54, and have been tooling it up and getting it ready to do what I need.  (Still need to open the rear cover, and make a spider for the back side of the spindle so I can hopefully do some through the head barrel work.)


Old FH as reference next to the chunk of 6061 scrap I used for this:


First step was to check it up and roughly dial it in (can you have a surface finish that is equal to a "pile of gravel"?)

One I had that I flipped it leaving enough to indicate on and dialed it back in, cleaning up the rest of it.


I failed to photo a few steps here, but I turned the OD down as needed, drilled the center 7/16ths, cut a 5 degree angle from the mouth into the bore, and then grooved and parted the hider off.

I then flipped the hider in the 4jaw, redialed it, used a boring bar to bring the bore to .453, and then since I do not have a threading tool small enough for interior 1/2" I used a tap to thread it from the tailstock.

Then it was over to the bridgeport  and the Spin Indexer, where I held it while cutting 90 degree included angle cuts every 8 degrees.


Then after marking TDC of the hider while mounted on the receiver, I tilted the head 10 degrees to slant the front of the hider.


Then I marked the vent holes for 45 degrees off vertical for both sides,  and tilted the head to 45 degrees for the drilling.


Full disclosure, this is the 2nd one, as "mistakes were made" on the first one, specifically with the spindexer not holding the work securely, and having it wander some while cutting. :(  But, this went in about 1/3 of the time as the first, so progress was made. :)

Before deburring:




and after cleaning it up:

Nice work...bet mucho satisfying

Was really disappointed when I screwed the pooch on the first one, which made this one that much more satisfying to complete it somewhat quickly and without issues. :)

Now, I can make a living on these, assuming a steady supply of people that will buy these for $1k a piece. :)  (Not holding my breath here. )

Nice work.

Show off!

I wish!  I feel like the slow kid in class around everyone who works on this stuff every day.  If I do something right it merely means its cause I screwed it up at least once or twice in the past. :)

(Does make it feel good when something comes out right though.)

Just gotta figure out how to convince the wife I really NEED a Haas CNC mini mill.  And a place to put it.  I'm sure she'll go for it, just gotta sell about 55 of those $1k flash hiders first!

I'll take one and can pay you...... (peeks in to wallet)..... $2.  Deal?  

Seriously, that's excellent work and looks great!

Nice work!

How long is the spindle on your gear head version? My 15x54 Servo Shift spindle is 27” long which sucks for through the headstock barrel work. What little long work I’ve done has been off a steady rest way down the bed.

I have the regal, not the servo shift, but that sounds pretty close to what it is. (I'll have to go out and check it tomorrow to know for sure.)

In the past I've made an extension to thread the chamber end of shorter barrels into that is held by the spider while working on the muzzle near the chuck, but that won't help me much for a fresh barrel that needs to be fit. (of which I have 3 sitting in the workshop waiting for me to stop being a pansy and actually attempt to chamber them.)

I'm probably going to need to build a steady rest as one did not come with my lathe when I got it.  More opportunities for me to turn large chunks of steel into piles of chips, and mostly disappointing results. :)
(Figure I need a roller rest that can hold a spider, but have not figured out the best one to make just yet.)

I like it. Are you planning on anodizing it?

I don't think I can anodize it since its steel (I could be wrong), but I was planning on using the Caswell's Black Oxide finish that I've used before, which came out pretty decently.

Ran it through the black oxide tonight, this should work. :)

Impressive work! I like it.

I like it

IMHO, just get away from using a chuck all-together. Use a face/spindle mount fixture specifically made for holding barrels. Large diameter pipe/tube with 8 threaded holes and 8 brass tipped bolts will make fine barrel holding fixture that can be easily adjusted for runout and concentricity. Just google "lathe barrel fixture" in images and you'll see tons of them.

My Leblonde came with 2 steady-rests and I've never even used them... One is the large-bore heavy-duty steady that is impossible to find...

I actually have one that you hold in the 4 jaw, but its smaller and for actions.  Had not considered one on a faceplate.  (Need to get a faceplate still. :( )

Thanks!

Or just make one from scratch that mounts right on your spindle... I have an L00 on my Leblond, assuming you also have an L-series spindle nose it should be fairly easy to get the taper setup right, maybe with a little trial and error. Once you get the taper you'll have to figure a way to broach/machine the key slot in it but there are ways of doing that... Then its just machining the large retaining nut threads on the outside. If you need drawings for the L-series tapers let me know.

Mine is a L1 mount (don't ask about the wrong backplate for an L0 I bought before I figured that out.), but I am wondering how I can ensure the barrel portion in the spindle/headstock doesn't start oscillating / flopping around and causing harmonics that might screw up my work.  Maybe some delrin sleeve I can put around the unsupported barrel in the spindle.

Would be a great excuse to buy a shaper, except I know the wife would straight up shoot me if I by another machine right now. :)

You would have to be spinning pretty fast to get it to pull off-center and start flopping around. For any barrel that is stiff enough to be shot/handled on a gun (IE, not a barrel liner etc), as long as it is rigidly held and you aren't being stupid it's no problem. Many rifle builders & smiths run similar setups with no bushings/sleeves to prevent it from pulling off-center. But if it makes you more comfortable then make a bushing; aluminum, delrin, wood, the material wouldn't really matter much.