.38/.357 prototype

[bruski]

Hey Sparky,

 I have not found any thing large enough for the housing yet other than some steel pipe. There is a company in New York that has some brass the size that I need but they have not answered any of my emails about small quantities shipped yet.

 

 I have studied and I have tackled the Bruce feeder but it is fighting back. I can\'t show any pictures yet because I tried casting brass in a sand mold with a pattern that I cobbled up and the end result looks nasty so I thought that I would use it as a practice piece. I have incorporated the star wheel in the design which worked out good so far. I can show a picture of the wheel and maybe the pattern for the unit but that is about it for now. Oh, and a picture of a single row stick that I machined the rim clearances loose to try out first.

bruski

[bruski]

Roller,

Do you have a picture or two of your Bruce feed that you could share with us? The patents are for some reason quite confusing to read and figure out.

Thanks a bunch,

bruski

[Sparky_NY]

Bruski,   Don\'t know if you already seen these but here are some decent pictures.

 

http://www.andersonguncraftgatlings.com/gatling-feed-devices.html\'>http://www.andersonguncraftgatlings.com/gatling-feed-devices.html

[bruski]

Thanks sparky, I did not see those pictures yet and they will help a lot.

bruski

[Roller]

Roller,

Do you have a picture or two of your Bruce feed that you could share with us? The patents are for some reason quite confusing to read and figure out.

Thanks a bunch,

bruski

Mine is not exactly like the original, no wheel, and doesn\'t clamp on the housing.  Made from leftover pieces of brass I had.  Got the idea from the youtube video.  Works well!  Having trouble posting a photo.

 

Frank

[bruski]

Howdy,

 Something else to watch out for while machining your magazine channels and your pan depth or diameter. Some of my 38 special ammo has a rim diameter that is larger than the .437 diameter. This is causing a feed problem on my single row stick magazine for the Bruce feed which is machined to exactly .437. Loose is better here and if that wasn\'t enough of a problem already, the PAN needs to be slightly deeper or larger also to prevent the rims from dragging on the pan bottom just as they are chambered. This makes them harder to extract momentarily and possibly a fail to extract in my case. When I machined my pan, I used a reamer to get a smooth .4375 hole. It would be better to purchase an over size reamer if you are doing it this way, or incorporate this in your cnc drawing to get about a .439 or .440 diameter. 

 

bruski

[Cutter]

Howdy,

 Something else to watch out for while machining your magazine channels and your pan depth or diameter. Some of my 38 special ammo has a rim diameter that is larger than the .437 diameter. This is causing a feed problem on my single row stick magazine for the Bruce feed which is machined to exactly .437. Loose is better here and if that wasn\'t enough of a problem already, the PAN needs to be slightly deeper or larger also to prevent the rims from dragging on the pan bottom just as they are chambered. This makes them harder to extract momentarily and possibly a fail to extract in my case. When I machined my pan, I used a reamer to get a smooth .4375 hole. It would be better to purchase an over size reamer if you are doing it this way, or incorporate this in your cnc drawing to get about a .439 or .440 diameter. 

 

bruski

 

 

That is also one of the problems with the RG-G design.

The barrel is counter bored .280 and the pan with a .140 radius.

 

My 357/38 model has a .230 pan radius.

A small step down when extracting works better

[bruski]

Cutter,

 Which would you recommend as a way to fix my pan. I plan to remove it and I was going to use a wooden dowel rod 3/8 diameter with a sheet of 220 sandpaper wrapped around it. Or use a 7/16 ball mill and take a few thousands off that way? I have a power table feed on my mill drill x axis that I can slow down to a crawl for a smooth finish.

bruski 

[Cutter]

Cutter,

 Which would you recommend as a way to fix my pan. I plan to remove it and I was going to use a wooden dowel rod 3/8 diameter with a sheet of 220 sandpaper wrapped around it. Or use a 7/16 ball mill and take a few thousands off that way? I have a power table feed on my mill drill x axis that I can slow down to a crawl for a smooth finish.

bruski 

 

A 29/64 /.453  ball mill should do the trick

McMaster-Carr 

[Sparky_NY]

What is the technique you guys are using for drilling the bolt carrier  (rear half).    I am getting ready and have the usual concerns of keeping the holes straight without the drill walking etc.   Also, what about the diameter, drill and ream?   I have a .735 drill but thats a awful lot to ream to get to .752.   I do have a 3/4 drill also.  The rear carrier holes will be 3\" deep,  3/4 (.752)diameter.   

 

Going to make one from aluminum first....  chicken shit to cut it in brass at first.

 

Love to hear your techniques.

[Cutter]

Drill and Bore, A standard for eons

[Roller]

Sparky,

 

If you want a straight hole bore it with a boring bar (single point).  If you want to drill and ream a .750 hole I would use a ..6875 drill, leaving .0315 per side for reaming. A reamer follows the hole, so if the drill walks so does the reamer.

 

Frank

[Sparky_NY]

Sparky,

 

If you want a straight hole bore it with a boring bar (single point).  If you want to drill and ream a .750 hole I would use a ..6875 drill, leaving .0315 per side for reaming. A reamer follows the hole, so if the drill walks so does the reamer.

 

Frank

Boring would be my first choice BUT I have this oddball boring head that never cooperates with the job at hand.    Its a real high quality US made one (CC.C CraleyMfg) but only has about 1/4 travel and bars mount either on center of one inch off center.    The bar mounting makes for a range of hole sizes you just cannot hit.    I am studying it now,  there is hope.

[bruski]

Sparky,

  Just to throw another bit of information your way. I center drilled with the largest center drill that I have, then drilled a pilot hole 7/16\" (new split point) followed by a new 3/4\" counter boring cutter with a 7/16\" pilot in my mill drill with a little drag on the quill. The cutter made smooth work like a knife through butter. Then checked it with a 3/4\" reamer but that wasn\'t even necessary.

 

bruski

[Sparky_NY]

Think I have that boring head under control.   So, the plan is to drill undersize and then bore to true up the holes and size them.    Bruski sure comes up with some unique ideas,  I am going with his ejection pin in the pan method.

 

Thanks guys !

[bruski]

The reason that I didn\'t go with the drill and bore method this time was do to chattering with a deep hole like these. For some odd reason, my boring head likes to chatter in brass. I tried every speed and feed that I could along with different sharpening angles and depth of cuts. Maybe it is because I don\'t use any cutting oil on brass, I don\'t know.

 

bruski

[Cutter]

For what it’s worth

 

With a boring head of 2.5 to 4.5 inches long plus

a long boring bar, the cutting tip gets farther away

from the spindle bearing causing chatter.

A preset boring bar straight out of your collet ( R-8 ? )

is my first choice for long bores on a knee mill ( Bridgeport ? )

[Cutter]

I’m finally getting off my arse and cutting something.

 

I’m boring chambers in barrel inserts for the model GG

[4171]

For what it’s worth


With a boring head of 2.5 to 4.5 inches long plus

a long boring bar, the cutting tip gets farther away

from the spindle bearing causing chatter.

A preset boring bar straight out of your collet ( R-8 ? )

is my first choice for long bores on a knee mill ( Bridgeport ? )

[4171]

Well I didn’t do that right!?! Jerry how would that work with the boring bar in the collet? They make an adjustable bar?

Mike