Gunsmithing PTG barrel fluting cutter

[chipsfan]

Hi,

I ordered a 3/16" PTG barrel fluting cutter. What RPM, depth of cut and feed rate (per inch) are you guys using to flute stainless barrels? I'll be running it on a Bridgeport with a power feed.

https://shop.pacifictoolandgauge.com/index.php?main_page=product_info&products_id=107

Thank you

 

[Tac284]

Cutter diameter?

 

[mcfred]

~300RPM and ~0.003" per tooth with a solid setup. PTG may have some advice as well.


edit: oh yea, and ~0.030 depth per pass and I'd skip around, like torquing a bolt pattern... Just my $0.02

 

[fastshooter03]

Prob depend on how solid your barrel setup is for feed rate and depth of cut.
Not sure how you can set a specific feed rate for a bridgeport type power feed though.
Might want to ask PTG what they like for surface speed.
That type of setup I usually go by how it sounds and feels and what the machine can handle for feed and doc.

 

[chipsfan]

That you. I plan on having a 10" rotary table with an 8" chuck at one end with a tailstock at the other. Probably counterboring the muzzle end to match the tail stock. I'll also have two angle plates behind the barrel to provide added rigidity.

 

[Straight Shooter]

Yup, that about how I was fixin to do it. I bought all the stuff. Then I thought about what happens if it starts chattering, raises a burr, runs off track with barrel flex, warps barrel, etc. This just cost you a barrel and delayed the build by 13 weeks to a year. 10' of money shot machining. Any little imperfection and I own it. I decided to just let the barrel makers have their $100. One day I'll stick my 10-22 barrel in there and risk that one but I just really would rather not be risking a customers barrel.

Now if a guy had really stout CNC mill in perfect shape I believe a guy could get the rigidity and consistency needed to do it right. You could also do the interrupted and twisted fancy stuff.

Let us know how it turns out. Pictures please.

 

[chipsfan]

Yup, that about how I was fixin to do it. I bought all the stuff. Then I thought about what happens if it starts chattering, raises a burr, runs off track with barrel flex, warps barrel, etc. This just cost you a barrel and delayed the build by 13 weeks to a year. 10' of money shot machining. Any little imperfection and I own it. I decided to just let the barrel makers have their $100. One day I'll stick my 10-22 barrel in there and risk that one but I just really would rather not be risking a customers barrel.

Now if a guy had really stout CNC mill in perfect shape I believe a guy could get the rigidity and consistency needed to do it right. You could also do the interrupted and twisted fancy stuff.

Let us know how it turns out. Pictures please.

LMAO- I was thinking the same thing. I already own all my barrels so I could always learn how to re-taper one or turn it down to an ar barrel... I already had a bad ass uber over priced rotary table. I just needed the chuck, tailstock and cutter.

It really is amazing how inexpensive $100 for fluting looks when you calculate how long it could take to get it right- or what could go wrong.

 

[chipsfan]

FYI: here is a cool thread with some pics of set ups

Recommended Super Spacer for Barrel Fluting?

 

[Boltfluter]

Hi,

I ordered a 3/16" PTG barrel fluting cutter. What RPM, depth of cut and feed rate (per inch) are you guys using to flute stainless barrels? I'll be running it on a Bridgeport with a power feed.

https://shop.pacifictoolandgauge.com/index.php?main_page=product_info&products_id=107

Thank you

I just picked up a couple of .25 PTG cutters. Ended up at 490 RPM and 6 IPM. Hope that helps. Start slower and work your way up if you can. I started at 300 RPM and went from there.

Paul

 

[chipsfan]

I just picked up a couple of .25 PTG cutters. Ended up at 490 RPM and 6 IPM. Hope that helps. Start slower and work your way up if you can. I started at 300 RPM and went from there.

Paul

Thank you

 

[glbreil]

I use an AB tool cutter which is similar to PTG. Mine is 2" diameter and 12 teeth, I run it at 300 RPM and 3" per minute and cut .065" deep in one pass. You need something to support the middle of the barrel.

Gary

 

[chipsfan]

Hi,

I got the cutter and did a number of test cuts. The PTG cutter is around 2" in diameter. I didn't count the teeth.

I ran it 300-800 rpm and .020"-.090" deep from 2-6" per minute feed rates on a shot out stainless barrel without coolant.

I was going for a .090" flute depth (arbitrary). I seemed to like making one pass .070" at 550 RPM and 4-5" per minute with a final pass at .020" at 6" per minute or making one pass .090" deep at 2.25" per minute. Both looked the same. no coolant, cutter and barrel were cool to the touch.

I did make a cut without a middle support to see what happened, and it did vibrate a lot. I then bolted an angle plate 10" wide behind the center of the barrel and it didn't vibrate at all. The flute I was making was 13" long. I had a 3 jaw chuck on a 10" YUSA rotary table with an adjustable tailstock with dead center shoved in the crown. I zeroed the DRO at the end of the cut so starting and stopping the flute was a piece of cake.

No pictures yet.

Do you guys cut you flutes one after the other- or rotate around like tightening nuts on a tire?

 

[bhoges]

Lets see some pictures!

 

[chipsfan]

No pics yet. I did a bartlein HV just now. .090" deep about 14.000" long. I went 4.25" per minute at 550 RPM. I had slight chatter in two spots that will blast out with abrasive media prior to cerakote.

 

[glbreil]

I just cut one flute after the other no tire lug stuff and have never had a problem.

Gary

 

[chipsfan]

I just cut one flute after the other no tire lug stuff and have never had a problem.

Gary

Thanks. The problem with flitting 180 on each cut is the tension provided by the angle plate changes. This is where I got minor chatter. I'll be cutting one after the other from now on. Once I make it around once, I'll readjust my plate and have at it.