Author Topic: .38/.357 prototype  (Read 75052 times)

Offline Sparky_NY

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.38/.357 prototype
« Reply #200 on: July 22, 2018, 07:28:55 PM »

Got the pair made.     12/24 tooth, 16pitch.    Center distance is 1.591 which will look much better with this size gun for the crank placement.   My housing is 4\" ID, 4-3/8 OD.


 



Offline 4171

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« Reply #201 on: July 22, 2018, 09:24:35 PM »
You should sell them!

Mike

Offline bruski

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« Reply #202 on: July 22, 2018, 11:55:13 PM »

Sparky,


 Those gears look great. If you don\'t mind me asking, what are you using for your housing material and where to purchase some? 


Thanks,


bruski



Offline Sparky_NY

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« Reply #203 on: July 23, 2018, 06:06:58 AM »


Sparky,


 Those gears look great. If you don\'t mind me asking, what are you using for your housing material and where to purchase some? 


Thanks,


bruski




I got very lucky and found a guy that had the piece of brass tubing, 15 inches long.   It was a hydraulic cylinder judging from the sticker and has a bit of scoring inside but the outside is great.   For the bolt carrier, I found a guy on ebay that has a lot of brass drops, got a 4\" dia x 3\" long piece for $60 with free ship.    I think I have enough brassfrom years back collecting for the remaining parts.


 


The price of brass is crazy.    I was considering Cerakote finish as a alternative but still may use it for the barrels and frame for rust prevention and looks.


« Last Edit: July 23, 2018, 06:08:57 AM by Sparky_NY »

Offline bruski

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« Reply #204 on: July 23, 2018, 12:46:32 PM »

Sparky,


 I have been looking for a piece of brass tubing or pipe that I can use for the receiver housing for a while now. It needs to machine to 4-1/2 inch ID and be about 6 or 7 inches long OD anything from 4-3/4 up would work out nice. Can\'t seem to find online anything larger than 4 inches OD but I know it could be out there some where. Now I know why cutter is sticking to the smaller bolt circle. bruski



Offline Sparky_NY

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« Reply #205 on: July 23, 2018, 02:12:01 PM »


Sparky,


 I have been looking for a piece of brass tubing or pipe that I can use for the receiver housing for a while now. It needs to machine to 4-1/2 inch ID and be about 6 or 7 inches long OD anything from 4-3/4 up would work out nice. Can\'t seem to find online anything larger than 4 inches OD but I know it could be out there some where. Now I know why cutter is sticking to the smaller bolt circle. bruski




Considering the wild price of brass,  what about steel or aluminum and have it brass plated?      Nobody would know and I promise not to tell.  


Offline bruski

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« Reply #206 on: July 23, 2018, 02:43:51 PM »

I was thinking about casting a piece of brass tubing from some scrap pieces that I have on hand if I can\'t find anything. I have a piece of steel thick walled tubing that could be machined for it, but I dread machining it to size. With chattering being the main problem.


bruski



Offline Cutter

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« Reply #207 on: July 24, 2018, 04:38:28 PM »
The bolt ends are counter bored and the back threaded.

Drilled and reamed for the follower ( dowel pin )

Milled a V-groove in an Aluminum block and

will locate on the follower to cut the flats.


Offline Sparky_NY

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« Reply #208 on: July 24, 2018, 04:45:18 PM »


 


The bolt ends are counter bored and the back threaded.

Drilled and reamed for the follower ( dowel pin )

Milled a V-groove in an Aluminum block and

will locate on the follower to cut the flats.

 




Thanks for working out that fixture for me.   LOL        I am drilling the last of the bolts now, then thread the end for the bushing.    I will be contouring the end soon.


Offline Sparky_NY

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« Reply #209 on: July 24, 2018, 04:52:35 PM »

Cutter,  are you going to turn the reduced diameter boss on the breech end of the bolt before doing the flats/contour?



Offline Cutter

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« Reply #210 on: July 24, 2018, 05:40:12 PM »


Cutter,  are you going to turn the reduced diameter boss on the breech end of the bolt before doing the flats/contour?




 


 


These bolts won\'t have that boss.

I might counter bore the barrel plate about .09

to slip over the pan, not sure yet

I started with bolt material 5.850 long.

The bolts finished at 5.825 , the carrier is 2.925

I’ll need a different cam and recoil block, also a new cocking point

Adjusting to old parts and material
« Last Edit: July 24, 2018, 06:15:20 PM by Cutter »

Offline Sparky_NY

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« Reply #211 on: July 24, 2018, 06:21:17 PM »

Speaking of old parts.....   My D&E bolt \"butt plugs\"     I opened them up  to 3/16.   Made the spanner wrench to install.   Thread is 3/8-24



Offline Cutter

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« Reply #212 on: July 24, 2018, 07:43:14 PM »
Got the first one cut today, the other six tomorrow.

This one was tight at first, had to recut just the flats ( .002 )


Offline Cutter

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« Reply #213 on: July 25, 2018, 02:14:28 PM »
That operation is finished, all bots in,

 had one off 20 millionths, but close enough   


Offline Dave

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« Reply #214 on: July 25, 2018, 07:32:33 PM »

20 millionths! Thats just butchering metal! Lmao



Offline Sparky_NY

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« Reply #215 on: July 25, 2018, 08:03:52 PM »

Cutter,  what kind of dimensional clearance to you run bolts to carrier,   pan to bolt and bolt flats to pan flats?       


 


Lastly,  profiling the bolts,  did you use the 1/4 endmill with .015 radius you mentioned and the stepovers you previously mentioned?     That step is coming up soon for me.


« Last Edit: July 25, 2018, 08:05:51 PM by Sparky_NY »

Offline bruski

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« Reply #216 on: July 25, 2018, 08:41:08 PM »

Cutter,


 What kind of dial calipers are you measuring with? Your bolts are looking good though how ever you measure them.


 


 I got the firing pin holes all drilled and working on a couple of different firing pins to try out.


bruski



Offline RumRunr

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« Reply #217 on: July 25, 2018, 08:43:31 PM »
Way to go guys! Looking great! I\'ve still not made a chip yet ugh.. but soon enough. I have to finish up my other projects first otherwise I don\'t have room on work bench

Offline Cutter

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« Reply #218 on: July 25, 2018, 09:09:12 PM »


Cutter,  what kind of dimensional clearance to you run bolts to carrier,   pan to bolt and bolt flats to pan flats?       


 


Lastly,  profiling the bolts,  did you use the 1/4 endmill with .015 radius you mentioned and the stepovers you previously mentioned?     That step is coming up soon for me.




 


 


I try for at least .002/.003 clearance on all

A little loose is better than tight. One of the old

Six Shooters had .004 bolt to carrier didn’t made

any difference that I could tell.

 

I did not have a good 1/4 with .015 radius ,

so I stoned a small radius on a 1/4 3 flute carbide.

I still stepped over .01

Offline Cutter

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« Reply #219 on: July 26, 2018, 10:40:32 AM »


Cutter,


 What kind of dial calipers are you measuring with? Your bolts are looking good though how ever you measure them.


 


 I got the firing pin holes all drilled and working on a couple of different firing pins to try out.


bruski




 


Bruski,

Most of the time I use Mitutoyo 8” dial

 

I have some 1/4 “ O1 drill rod for firing pins

It\'s been leaning in the corner for years

« Last Edit: July 26, 2018, 10:42:24 AM by Cutter »