X22LR Max-11A1/15 Prototypes

LawBob

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No. the case will not slide up under a top mounted fixed firing pin..
Yeah the case prob wants to start seating in the bolt face fully and slide into position where as with a side or lower pin location it doesn’t know where to seat just yet until it’s shoved into the chamber and boom
 

strobro32

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I'm looking into a closed bolt conversion now.
 
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strobro32

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I did add a lot of weight for yesterdays test but the mainspring could not move it with enough force to reliably fire the cartridges with a fully loaded mag. I stared removoing material until it worked. The weight is maximized for the spring but it can not reliably fire 25 rounds in a full mag. 23 rounds works. That's why I think it needs a stronger mainspring.
 
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strobro32

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The new 6 lb main spring works great and I added a Borebuddy buffer.
 
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Offmarksman

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Would you be interested in trying a dedicated .22lr cmmg 16” barrel? I would loan you mine if you were interested in using one for testing?
 

strobro32

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Thank you but probably not. The CMMG 22LR 16" M16 full auto videos released on YT look fun. I'm sure the 16" barrel would work since the 4.5" barrel works great. The 4.5" Micro Max is just too gigglerific.
 
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strobro32

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I removed some weight and it ran faster.

CCI MM 40 gr 2180 RPM
CCI SV 40 gr 2140 RPM
Federal Bulk 40 gr 2245 RPM
 

Garrett

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I kind of like the silly-fast ROF.

Around 20 years ago I took a home-built MAC10 .22 conversion out to help the local farmers with their jackrabbit issues. That thing ran around 1500 RPM with regular .22 ammo, and around 2000 RPM with CCI Stingers.

It was sort of like using a cross between buckshot and a lead-spewing fire hose. It was quite effective at exterminating those rodents.
 

LawBob

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Speed
1280 fps is 15,360 inches per second or 15.3” per thousandth of second.

Rate
2240 rpm is 37 rpsec / 1000 so no
 

LawBob

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Speed
1280 fps is 15,360 inches per second or 15.3” per thousandth of second.

Rate
2240 rpm is 37 rpsec / 1000 so no

So the bullet takes about 1/1000s to travel 16”
And it’s firing the next one in about 36/1000ths

Please check my math.
 

LawBob

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Wonder if águia SSS would keep the same RPM.

1050 fps is 12.6”/1000th so that doesn’t help much

We need to get that rate of fire up by a factor or 35
 

strobro32

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I reduced the weight of the bolt more last weekend... cause why not? I will test this weekend.
 

A&S Conversions

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I reduced the weight of the bolt more last weekend... cause why not? I will test this weekend.
Because it is a blowback system? Like all blowback systems, the mass of the bolt is what keeps the shell supported. If the bolt is too light powder charge pushes the shell out of the chamber during the high pressure stage. Without the support of the chamber, the shell can rupture. Depending on the orientation of the rupture, brass shrapnel can come out of the ejection port. I have seen this happen with 9mm. Just a thought.

Scott
 

collector98

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Would it be possible to get a pic of the boltface? I just bought a stripped cmmg bolt to try and weld a fixed firing pin, but I don't know how wide or tall to make the firing pin.
 

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