Author Topic: 10mm Evo Project.  (Read 1131 times)

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Offline X16191

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Re: 10mm Evo Project.
« Reply #15 on: January 09, 2019, 11:42:06 AM »
Shoot I might have 4 or 5 when done lol.

9mm 10mm .40 45acp 22 tcm are the main only a I'm looking at.

Maybe a 357 sign as that would be fairly easy with the 10mm and .40 if all goes well

Offline 00goobs

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Re: 10mm Evo Project.
« Reply #16 on: January 09, 2019, 11:45:35 AM »
Are you planning to "mod" an existing barrel for 10mm?

Offline X16191

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Re: 10mm Evo Project.
« Reply #17 on: January 09, 2019, 11:48:36 AM »
No would require new barrel and trunnion also a slide( and spring) and magwell insert on say a "drop in kit"

Offline John A.

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Re: 10mm Evo Project.
« Reply #18 on: January 09, 2019, 12:01:37 PM »
Yeah, the barrel would need to start out with a 40/10 barrel blank and get a cz barrel fixture or trunion or whatever they call it and start over from scratch.  Ream and headspace once the bolt face is milled out and opened up to accommodate the case rim.




When people ignorant of guns make gun laws, you end up with ignorant gun laws.

Offline 00goobs

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Re: 10mm Evo Project.
« Reply #19 on: January 09, 2019, 01:02:14 PM »
Oh wow! This is a very involved project! I thought it was a modification of existing parts.

I would like to try a magwell adapter for existing high capacity magazines. What do you guys suggest?

Offline John A.

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Re: 10mm Evo Project.
« Reply #20 on: January 09, 2019, 01:17:15 PM »
The only magwell adapter that I am aware of is the Uzi mag adapter.

And I'm not sure if those are even still being made.

I love mine though.

That's still just for 9mm though.  I'm not aware of anyone making adapters for other calibers or other type of magazines, though we've discussed it on and off here on the forum for a few years now.







Sorry for the hijack-just trying to answer a question, now back to the regularly scheduled program.



« Last Edit: January 09, 2019, 01:24:14 PM by John A. »
When people ignorant of guns make gun laws, you end up with ignorant gun laws.

Offline Obiwan

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Re: 10mm Evo Project.
« Reply #21 on: January 09, 2019, 06:53:10 PM »
Goal as follows

Mil new pocket on Slide
mod or make a new extractor
Chamber 10mm barrels in 5 inch and 8 inch
Millout Magwell adaptors for Glock mags( or other option)
Order trunnion for 10mm Barrels.

Are you going to replace the recoil spring, and what is your plan on adding weight to the bolt?

Offline X16191

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Re: 10mm Evo Project.
« Reply #22 on: January 09, 2019, 10:40:57 PM »
No plan on adding weight to the bolt. To be honest its a good amount of weight one that many say is much bigger then needed for the 9mm to start with. A stiffer spring should do fine to help with recoil.

I am just sketching out the very most basic now of magwell to start on insert options. Dont  laugh  to much it will look so much better after some 3D rendering in solidworks. Just trying to lay it out on paper so can think aboult how I want to draw the part up. I am honestly tempted to draw the lower fully detailed just to get a better  plan but for now the magwell. We shall see.


Dam no photo hosting uses I'll open a photo bucket to start tracking the project for you folks.

Offline John A.

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Re: 10mm Evo Project.
« Reply #23 on: January 10, 2019, 08:02:19 AM »
Photobucket went retarded a while back and a lot of info was lost.  Most people deleted their accounts.

I have been using imgur since.
When people ignorant of guns make gun laws, you end up with ignorant gun laws.

Offline Obiwan

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Re: 10mm Evo Project.
« Reply #24 on: January 10, 2019, 01:33:33 PM »
No plan on adding weight to the bolt. To be honest its a good amount of weight one that many say is much bigger then needed for the 9mm to start with. A stiffer spring should do fine to help with recoil.

My understanding is that, while a stiffer spring would tame the additional recoil, it requires more weight in the bolt to ensure the proper minimum lock-time (to avoid the bolt opening prematurely before chamber pressures are down to safe levels). But I admit that I don't know how much more pressure 10mm cartridges have compared to 9mm, nor do I know what impact just 5000 more psi have on the dynamics. Just wanted to throw a word of caution out there. I guess you'll find out during testing if the bolt will need more weight.

Offline John A.

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Re: 10mm Evo Project.
« Reply #25 on: January 10, 2019, 01:51:54 PM »
Heavier springs will still help keep the bolt closed longer too.

If you think about it, the slide on a glock weighs what?  5 oz maybe?  6 oz?

The bolt on the evo is a lot heavier than it is.

I'm on the search for 18 and 20 pound springs at the moment that may would work for the 10mm project.  By guessing, the factory spring is probably 16 pounds.

I need to dig out some AK springs see if they fit in the scorpion bolt.  And some MP5 springs.  Then there are always 308 HK springs.  I just have to send a few emails to folks who might know what kind of # rating they are because I don't know.

I remember a topic here where we discussed heavier springs for the scorpion.  I'll need to look it up to save myself some time there.
When people ignorant of guns make gun laws, you end up with ignorant gun laws.

Offline Azrckcrawler

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Re: 10mm Evo Project.
« Reply #26 on: January 10, 2019, 02:33:38 PM »
A Glock isn't blowback. The barrel is locked up by the slide and the unlocking of the barrel is delayed via the link on the barrel (not the recoil spring). By the time the barrel unlocks the chamber pressure has dropped to a safe level.

Here is a great read on blowback operated firearms - http://www.orions-hammer.com/blowback/

There is also a spreadsheet on that site that allows you to plug in various variable to see what bolt mass is needed by caliber and projectile weight to keep the chamber closed long enough to avoid case head separation. The buffer spring has 0 effect in the first couple of milliseconds where the chamber needs to stay closed.

Heavier springs will still help keep the bolt closed longer too.

If you think about it, the slide on a glock weighs what?  5 oz maybe?  6 oz?

The bolt on the evo is a lot heavier than it is.

I'm on the search for 18 and 20 pound springs at the moment that may would work for the 10mm project.  By guessing, the factory spring is probably 16 pounds.

I need to dig out some AK springs see if they fit in the scorpion bolt.  And some MP5 springs.  Then there are always 308 HK springs.  I just have to send a few emails to folks who might know what kind of # rating they are because I don't know.

I remember a topic here where we discussed heavier springs for the scorpion.  I'll need to look it up to save myself some time there.

Offline X16191

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Re: 10mm Evo Project.
« Reply #27 on: January 10, 2019, 03:39:37 PM »
The evo slide is close if not more weight then a ar15 BCG.

This is also why I M working on 1 T a time at my expense.

And pulling the 1st few rounds with a string being safe is number 1. After I inspect not only the bras but barrel and slide extractor so on I will be able to find signs if it's going poorly after a few hundred rounds if it even gets that far. I will also do a "meltdown" test running 500 round down her fast as I can. Might even do it with the Binary  trigger

I'm sure I will find things both good and bad that need to be corrected.  But hey tons of folks want more then just 9mm options.

I am not here as a company. Nor do I have one. I am just a machinist that enjoys projects and fireams

Offline Azrckcrawler

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Re: 10mm Evo Project.
« Reply #28 on: January 10, 2019, 06:41:27 PM »
AR15 BCG is not heavy enough, you will need sbout 3.2lb of mass in the bolt to handle a 220gr 10mm load. 

The evo slide is close if not more weight then a ar15 BCG.

This is also why I M working on 1 T a time at my expense.

And pulling the 1st few rounds with a string being safe is number 1. After I inspect not only the bras but barrel and slide extractor so on I will be able to find signs if it's going poorly after a few hundred rounds if it even gets that far. I will also do a "meltdown" test running 500 round down her fast as I can. Might even do it with the Binary  trigger

I'm sure I will find things both good and bad that need to be corrected.  But hey tons of folks want more then just 9mm options.

I am not here as a company. Nor do I have one. I am just a machinist that enjoys projects and fireams

Offline Obiwan

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Re: 10mm Evo Project.
« Reply #29 on: January 10, 2019, 08:26:30 PM »
The evo slide is close if not more weight then a ar15 BCG.

You're comparing apples to oranges. :)  An AR is gas operated, either by impingement or piston. The Evo is simple blowback. In an AR, the powder ignites, pushing the bullet through the barrel, while the bolt remains locked. That gas is expanding. it will eventually reach the gas port, then part of the gas is redirected to direct force on the piston, which will start pushing the bolt carrier, or through the gas tube directly to the bolt carrier. Note that the bolt is still locked. Once the bolt carrier starts moving to the rear, the bolt unlocks, keeps traveling to the rear and extracts the cartridge. While all this is happening, the gas pressure in the chamber has already reduced to safe levels.

In a straight blowback gun, you don't have the bolt locked, no gas pressure expansion into the barrel and the gas piston or gas tube, no delay in the bolt carrier performing an unlock, etc. A lot of stuff happens in gas driven guns in a split second. In the straight blowback, the bolt mass is the only thing keeping the cartridge in the chamber. Once the powder ignites, it pushes the bullet through the barrel while at the same time pushing the bolt back.

If you don't get the timing right, bad things can happen. There's a reason folks are concerned about head spacing etc. Premature opening of the chamber will make for an exciting day.

I haven't look at the site Azrckcrawler mentioned, but it sounds like there's some good info (like the calculations) that you might want to review.

I'm not a gunsmith, but I would still highly recommend you do the math on the bolt weight before actually test firing.