Author Topic: .38/.357 prototype (Read 65987 times)

Sparky_NY · « **Reply #60 on:** June 18, 2018, 10:22:14 PM »

So what about a thicker barrel plate with a feed ramp milled in? To help with loading cartridges..

That is a interesting idea ! All this talk about bolts is partly to allow room for a decent extractor and the inside components (firing pin, spring and such)

bruski · « **Reply #61 on:** June 18, 2018, 10:34:40 PM »

Cutter,

That will work OK, but difficult for some of us to machine unless you can show us how maybe!!!!!!!!

bruski

Sparky_NY · « **Reply #62 on:** June 18, 2018, 10:39:18 PM »

The wiggle room might be a problem for sure. Remember the problems that I had with the .500 bolts and recoil bounce. What about a 7/16\" x 5/8\" rectangular bolt? The carrier and pan slots could be milled no problem.

bruski

I see a lot of the original gats had a raised boss under the top cover to restrain the shells. I am guessing it was for recoil bounce like you experienced. I did this on my redesigned DE gun and it worked out very well.

Here is a pic of a original showing that boss.[attachment=10550:top cover.jpg]

RumRunr · « **Reply #63 on:** June 18, 2018, 10:49:17 PM »

Well with out cnc you can do some math and use Cutters bolt jig and rotate bolt in it manually and make a radius. Just have to make stops for left and right sides of bolt

RumRunr · « **Reply #64 on:** June 18, 2018, 10:50:49 PM »

Think pendulum rotating on pivot point

Sparky_NY · « **Reply #65 on:** June 18, 2018, 10:52:51 PM »

Well with out cnc you can do some math and use Cutters bolt jig and rotate bolt in it manually and make a radius. Just have to make stops for left and right sides of bolt

Cutter and I have cnc capabilities, not sure about Bruski. That opens a lot more possibilities.

RumRunr · « **Reply #66 on:** June 18, 2018, 11:23:36 PM »

That is how I made radius on rods for model engine.

Cutter · « **Reply #67 on:** June 19, 2018, 10:29:27 AM »

Cutter,

That will work OK, but difficult for some of us to machine unless you can show us how maybe!!!!!!!!

bruski

The radius on the front of the bolt needs some clearance, itâ€™s

not a match fit. A faceted shape would work just as well

bruski · « **Reply #68 on:** June 19, 2018, 11:49:05 AM »

I have CNC capabilities but I am still looking for the correct post processor for the controller on the Bridgeport mill.

bruski

Cutter · « **Reply #69 on:** June 19, 2018, 11:56:58 AM »

I have CNC capabilities but I am still looking for the correct post processor for the controller on the Bridgeport mill.

bruski

I\'ll email some processors for Bridgeports

Cutter · « **Reply #70 on:** June 19, 2018, 03:33:48 PM »

The wiggle room might be a problem for sure. Remember the problems that I had with the .500 bolts and recoil bounce. What about a 7/16\" x 5/8\" rectangular bolt? The carrier and pan slots could be milled no problem.

bruski

I believe we can use a similar Cam design that I

used for the Rat Gat. Having the problem cartridge half way

in the chamber at time of recoil eliminated any displacement

RumRunr · « **Reply #71 on:** June 19, 2018, 05:48:27 PM »

Cutter That\'s a good idea, I agree.

Are you thinking 3/4 or 7/8 bolts?

Cutter · « **Reply #72 on:** June 19, 2018, 06:56:56 PM »

Cutter That\'s a good idea, I agree.

Are you thinking 3/4 or 7/8 bolts?

Nothing final yet, but probably .750

Cutter · « **Reply #73 on:** June 19, 2018, 08:00:01 PM »

Notice in the video the first cartridge is well into

the chamber before the second bolt reaches TDC.

Firing at that position at BDC.

https://www.youtube.com/watch?v=oD5kiAeClgE

Sparky_NY · « **Reply #74 on:** June 19, 2018, 09:29:40 PM »

Notice in the video the first cartridge is well into

the chamber before the second bolt reaches TDC.

Firing at that position at BDC.

That video is worth a couple thousand words. Does that fast closing change the \"feel\" of the gun when cranking, compared to the stock cam profile? The flat area of that cam, at the top, must be really a short section.

Cutter · « **Reply #75 on:** June 19, 2018, 10:21:11 PM »

That video is worth a couple thousand words. Does that fast closing change the \"feel\" of the gun when cranking, compared to the stock cam profile? The flat area of that cam, at the top, must be really a short section.

I only made a steeper angle at the beginning , flats are the same.

Cranking is no problem, When not cocked I can rotate it with the rear knob

( two fingers )

RumRunr · « **Reply #76 on:** June 19, 2018, 11:03:37 PM »

Well it sounds like we have a winner

RumRunr · « **Reply #77 on:** June 19, 2018, 11:04:24 PM »

Do you think the flats will need to be longer to keep bolt closed longer?

Cutter · « **Reply #78 on:** June 20, 2018, 10:14:22 AM »

Do you think the flats will need to be longer to keep bolt closed longer?

I donâ€™t understand your question.

The flats and bolt closure are different functions

bruski · « **Reply #79 on:** June 20, 2018, 11:09:48 AM »

Thanks cutter for the post processors, I will try them hopefully today as I was out of town yesterday.

bruski

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Author Topic: .38/.357 prototype (Read 65987 times)