.38/.357 prototype

[Cutter]

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

This is what I do.

Take a 5/8 boring bar with a slot in the end for a tool bit , held in with  set screws.Put an angle plate or something perpendicular to the table and pick it up with your edge finder.Dial over the radius of your bore and put in your boring bar ,set your tool. I would first set the tool using a shim to rough,reset for finish.

Or, if you have a granite type plate you can use V-blocks and indicator.

I prefer the first method.

[maccrazy2]

Looks like this. The cheap boaring bars are junk though.

[Cutter]

Looks like this. The cheap boaring bars are junk though.

 

 

 

No Sir,

No Boring Head

Boring bar only

[bruski]

OK, I think I got this down. Provided you use a .625 diameter boring bar and want a .750 diameter hole to be bored. Half of the boring bar diameter is .3125 to get the center of the bar subtract this from half of your hole size needed (.750 divided by 2 equals .375 minus the .3125) which equals .0625 that you will need protruding from your boring bar right?

 

bruski

[maccrazy2]

I thought Mike was asking about a boaring head.

[maccrazy2]

Thanks for the photo and the info. I wouldn’t of thought to do it that way.

[Cutter]

OK, I think I got this down. Provided you use a .625 diameter boring bar and want a .750 diameter hole to be bored. Half of the boring bar diameter is .3125 to get the center of the bar subtract this from half of your hole size needed (.750 divided by 2 equals .375 minus the .3125) which equals .0625 that you will need protruding from your boring bar right?

 

bruski

 YES !  MR. B

[4171]

I was asking Cutter about using a boring bar in the collet without a boring head. I was wondering if he had some new fancy way to bore the holes.

Mike

[bruski]

Well, I re-cut the pan grooves to allow for the difference in rim widths on the cartridges. I also widened the rim channel in the single row test magazine. Everything is sliding and chambering good now so it is ready for another test. 

 

bruski

[Cutter]

Some progress on the model.

Good rotation, extracting, and ejecting.

The kick out pins are 3/32 roll pins sticking up .040

[bruski]

Hey cutter,

 Your model is looking great and rotates smoothly. I like the way that it rotates so smoothly and loose like.

 

I made a round trip to Phoenix yesterday and woke up this morning sneezing with a runny nose. I will have to concentrate on some chicken soup today and get this under control before I do any more testing it looks like. I should have washed my hands before dinner last night on the road dang it.

 

bruski

[Cutter]

Hey cutter,

 Your model is looking great and rotates smoothly. I like the way that it rotates so smoothly and loose like.

 

I made a round trip to Phoenix yesterday and woke up this morning sneezing with a runny nose. I will have to concentrate on some chicken soup today and get this under control before I do any more testing it looks like. I should have washed my hands before dinner last night on the road dang it.

 

bruski

[bruski]

Funny cutter,

 This is a weird one. When I am standing with my head in the vertical position all symptoms go away. When I lay down, the stuffed up and runny nose comes back along with the sneezing. I guess I am going to have to sleep standing up tonight leaning against the wall or something.

 

bruski 

[bruski]

Just noticed a cardboard tube package leaning against my shop . It must have arrived yesterday while I was gone. It is a piece of brass rectangle 1/2 X 1-1/2 wide and 2 feet long for the Bruce feed double row stick magazine. I might as well cut some chips while I am still vertical today. I tried to get 1/2 X 1-1/4 but my supplier didn\'t carry that width.

 

bruski

[bruski]

Howdy,

 Here are a couple of pictures of the Bruce twin slot magazine that I have been working on today. It holds a total of 46 rounds, I was shooting for 50 rounds but my aim was off a little today do to the head cold :-| .

 

bruski

[Sparky_NY]

Looks great Bruski !        I knew I put my best man on that job LOL

 

You said you bought a 2ft piece of brass for it,   how long is the mag in the picture?

[bruski]

The total length is 11 inches with 10 of it with the grooves in it. My drawing shows the rim thickness grooves at .065 but they are actually .100 in the finished magazine picture. The left over material will be used for the backing plate behind the magazine. I don\'t plan on adding the extra length above the magazine to align the box of cartridges up with the grooves. 50 rounds is quite a bit more than the actual Bruce feed magazine, so that is enough for me. If you are building an exact scale model, the swinging stick will be about 6 inches long and the box alignment portion another 5 inches or so above it.

 

bruski

[4171]

Kinda of a modified Bruce feed? I assume it will swing back and forth to line up with a single feed grove?

Mike

[4171]

I mean groove. Can’t find the edit button.

[bruski]

4171,

 That is right. I cut the slots on the sides for the triangular wedged shape pieces that should hold it over to one side, then swing over after that column empties. I can\'t be sure if this is what is going to happen until it is a little more completed.

 Sorry for the late response, I was out of town for most of the day.

 

bruski