Author Topic: .38/.357 prototype (Read 72417 times)

Sparky_NY · « **Reply #120 on:** July 12, 2018, 06:02:12 AM »

Thanks so much for the info Bruski ! The spring I was looking at compares favorably to yours so I think it will be plenty close enough to start.

Don\'t know if you started the longer bolts yet but there is a fellow on ebay with 9 inch lengths of 4140 prehard, 28-32 Rc hardness, 3/4 diameter for $3.00 each. I ordered several for this and future projects. Ebay item # 202001399872 He has longer pieces also.

Thanks again

George

Sparky_NY · « **Reply #121 on:** July 12, 2018, 10:32:47 PM »

Hey everybody,

Here is a picture of two new style 357 bolts in the making. They are 4 inches long with a .750 diameter rear end and a .437 diameter front end and that is about 2 inches long on the flats. I plan to use firing pins from a 1917 Enfield rifle that will be reworked a little. Not sure on the extractors yet.

bruski

Wondering how you are drilling 3/16 for the firing pin, the ejector slot on the bottom and a pocket on the top for a extractor without any of the cuts breaking thru into the others. There isn\'t a lot of meat in the front of the bolt and 10lbs of shit in a 5lb bag.

I have been struggling with the same issue, 3/4 bolt dia, ejector slot on bottom, extractor pocket on top and its unbelievably tight fitting it all in there.

bruski · « **Reply #122 on:** July 13, 2018, 01:19:17 AM »

Not sure how it all fit but I think cutter has a different idea for the ejector and doing away with the slotted bolt bottom. He will post some pictures after a few tests with the extractor are made.

In the mean time, my brass has arrived and the chips are flying over here about 2 pounds of chips any way. I am making the carrier, pan and barrel plate as separate parts as the pan is countersunk into the carrier .125 of an inch. This eliminates any wondering with long drill bits. I used my rotary table to index the parts separately being careful not to move it any, as a matter of fact, it is still bolted down to the mill table now.

The pictures show the carrier and pan together with one of the short bolts in it. Still have to mill the slots for the cam follower pins as they will be about a third of the way up from the rear end of the bolts. Won\'t know until assembly with a cartridge chambered on BDC in firing position.

Got to get the shop vac out and clean up a little around my shop now.

bruski

Sparky_NY · « **Reply #123 on:** July 13, 2018, 09:26:17 AM »

Looks fantastic Bruski ! I find it interesting that you don\'t do the customary flats on the pan section of the bolt carrier.

bruski · « **Reply #124 on:** July 13, 2018, 12:29:41 PM »

Sparky,

There are flats milled into the pan and are about .125 wide on each side. The pictures don\'t show it very well with my lighting not the best.

bruski

Cutter · « **Reply #125 on:** July 13, 2018, 01:30:41 PM »

This picture shows the tapered notch as a possible

alternative to the pin and slot method for kicking out

the casing.

Sparky_NY · « **Reply #126 on:** July 13, 2018, 01:46:20 PM »

This picture shows the tapered notch as a possible

alternative to the pin and slot method for kicking out

the casing.

Curious, have you used that method on any of the guns you built in the past?

Cutter · « **Reply #127 on:** July 13, 2018, 02:05:27 PM »

Curious, have you used that method on any of the guns you built in the past?

No I havenâ€™t.

The idea comes from the Colt reproduction

bruski · « **Reply #128 on:** July 14, 2018, 10:21:29 AM »

The more that I study the ejection method, the more I like cutters way of ejecting the cartridges out. The pin route is much more work and takes up valuable space on the bolts plus removing the pressed in pins is difficult. With cutters way, if the cartridge doesn\'t drop away when the rim drops into the groove under extractor spring pressure, it will certainly be kicked out when the rim contacts the back of the groove. The groove in the pan doesn\'t have to be very wide say about .093 should do it and about .060 deep or less.

bruski

Sparky_NY · « **Reply #129 on:** July 14, 2018, 11:04:57 AM »

The method of ejection is interesting. Cutter, what repro gun is that in the pic you posted? Hard to see in the picture but it looks like the pan has the customary groove cut around it also, for a ejector finger, just like the RGG design. This brings a question up, maybe that relief isn\'t for ejection but rather for feeding... so that the rim drops down enough so the extractor hook goes over the cartridge rim, I wonder.... More commonly know as controlled feed vs push feed in the rifle world.

Could be wrong, but I believe this ejection method relies on the extractor spring pressure and travel to push the rim down into that relief cut/edge. Not that its a problem, just have to make sure the extractor has sufficient travel.

Lastly, if the replica gun pictured is a true replica, then one of the original guns must have had this feature also, I wonder which model?

Cutter · « **Reply #130 on:** July 14, 2018, 11:36:49 AM »

This is the video of the 1877 Bulldog reproduction

I stop it at times and move frame to frame

Here\'s two frames I copied

https://www.youtube.com/watch?v=ildteJbZ9Jw\' title=\"https://www.youtube.com/watch?v=ildteJbZ9Jw\">https://www.youtube.com/watch?v=ildteJbZ9Jw

Sparky_NY · « **Reply #131 on:** July 14, 2018, 11:48:48 AM »

Ah ha ! Those pics show a lot more ! I retract the previous guesses.

Sparky_NY · « **Reply #132 on:** July 14, 2018, 11:55:10 AM »

Just watched that youtube video you linked. THAT gun clearly has a ejector finger and its groove in the pan. Look at 4:30 in the video, with the cover open its clearly visible. The still pics you posted do not look that way.

Cutter · « **Reply #133 on:** July 14, 2018, 12:11:04 PM »

Just watched that youtube video you linked. THAT gun clearly has a ejector finger and its groove in the pan. Look at 4:30 in the video, with the cover open its clearly visible. The still pics you posted do not look that way.

Yes it does, a groove at the front of the pan

and a scoop on the magazine adapter

Looks like it lifts the front of the casing

just about the same time the rim hits the rear edge

In my opinion just hitting the edge will knock it out

bruski · « **Reply #134 on:** July 14, 2018, 01:10:57 PM »

Interesting, what to do now? Why do you think the extractor is soooo long on those bolts? I guess that it is a spring steel extractor that flexes for it\'s entire length with no coiled compression spring under them. What do you guys think?

bruski

Cutter · « **Reply #135 on:** July 14, 2018, 01:24:40 PM »

Iâ€™m not sure Bruski, but I think spring

based partly on this picture

bruski · « **Reply #136 on:** July 14, 2018, 01:33:10 PM »

I like the idea of having a positive feeding bolt rather than a pusher, this would eliminate feeding problems while another barrel is recoiling. So maybe the groove should be cut a little wider with a taper of course to ramp up the rim under the extractor while feeding. I know from my experiences while testing the prototype very well that recoil is a big problem all of the sudden compared to the rim fires. Like opening up a new can of worms so to speak. It is hard to tell in the video how much shaking and shocking the gun is going through because it is so heavy to see the actual movement.

bruski

bruski · « **Reply #137 on:** July 14, 2018, 01:36:28 PM »

Cutter,

Why would there be a limit pin on the bottom side of the firing pin I wonder?

bruski

Cutter · « **Reply #138 on:** July 14, 2018, 01:47:21 PM »

A problem with the taper to clear the rim while feeding

it will also lose the rim when extracting

I read somewhere the one in the video was around 300 lbs.

More weight is needed to suck up the recoil.

Cutter · « **Reply #139 on:** July 14, 2018, 01:54:13 PM »

Cutter,

Why would there be a limit pin on the bottom side of the firing pin I wonder?

bruski

What I was pointing at with ?? is on a surface parallel to the extractor

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Author Topic: .38/.357 prototype (Read 72417 times)