.357 Gen 1 Mrod based pistol

[mackeral5]

A really nice build; you have one heck of a gun there. 
Jesse

Thank you Jesse.  It has been fun playing with the modularity of the Gen 1 Mrod platform.

I put together another configuration today.  Swapped barrel over to an 18" GM .25 barrel with the choke removed and bolt to a .22 Gen 1 bolt that is sleeved up to .25.  Thanks to sealing the valve to breech and the Gen 1 bolt design this is easily accomplished without removing the breech.  Literally a 5 minute process to go from .357 to .25.  Overall length is 39" with a Tatsu and the stock fully extended.



I didn't touch the SSG and ran a couple shots of JSB MkII's across the chronograph---they were running a little hot at 1060fps!!!!! 50gr slugs went in the 850's.  Dialed it down to a MkII tune that starts at 875 and peeks at 910 then back down to the 870's.  It seems to do around 25 or so shots  tuned like this.

After quite a bit of frustration around accuracy of the .25 barrel I realized I was trying to run too hot for the GM's relatively fast twist.  MkII's running in the 950-990fps range were producing 4-6" groups at 80 yards.  I dialed velocity back down to a 870-900-870fps string and found decent accuracy. 

here is a 25 shot string from 2700psi down to 1700psi.  5 shots on each bull, with the center bull being my last target.  Distance is 80 yards, MKII's tuned at 870-900-870fps. Conditions weren't the best with a swirling wind and drizzling rain, but I think this is representative of its performance. 

This little modular monster goes from a 120fpe .357 to a 58fpe .25 with a 5 minute bolt/barrel change and a slight SSG adjustment. 

[YEMX]

VERY nice!!  If only caliber swaps were this easy w/a BD!!   

Although, w/a FLEX-type bolt probe, I guess it could be!

[mackeral5]

A long awaited package from RI arrived today.   The package contained some very cool parts, perfectly machined and packaged.  Amongst the assortment of coolness was this little 7" Gen 1 Brod tube.  I had other things I needed to do but I couldn't resist putting the short Brod tube in. 



The short tube allows for a 350cc bottle with the 16" barrel.  I don't recall how long a 500cc is, but it may fit as well??

Setup like this with the Ronin and extension, 120fpe is truly backyard friendly.  Shot count is somewhere in the mid to high 30's.  Haven't shot it enough yet. 

I believe I have enough parts to reassemble the 8.5" barreled pistol, I just need to pick up another Prod trigger assembly.  If anyone has a spare to sell shoot me a PM. 

[FuzzyGrub]

Even cooler than before!        

[mackeral5]

I swapped tanks between this and a Gauntlet .25.  This gun being unregulated couldn't take advantage of a 4500psi tank so it made sense to move the old 480cc Talon Tunes tank over to this gun and the 350cc 4500psi tank to the regulated Gauntlet. 



It is amazing how much louder the gun is without the DonnyFL extension on the Ronin...

[mackeral5]

Something still wasn't quite right with how the gun felt.  So, let's try this for a bit..

[YEMX]

That ultra short tube looks fantastic!

[mackeral5]

Another configuration....  This time with an Mrod tube extension screwed in place of the bottle block and using the 12 inch barrel.



This little tube is probably around ~80cc?  It yields 10 shots of 91gr NOE pellets 625-670-625fps. 

Ultimately I think I prefer the 12" barrel configurations.  I have a 23ci bottle on order for when I want to put the tank on it.  The pic with a skinny tank and 12" barrel is a 17ci tank..

The short 7" tube with no gauge block design allows for fairly straight forward conversion of the valve between Simplified Balanced valve and Powerhouse configurations by unscrewing the balance piston carrier and changing out poppets.  In Powerhouse format and with the 16" barrel it will push a 174gr BBT 750fps, 134gr BBT 805fps, and 91gr pellets 890fps. 

[YEMX]

VERY cool!!

[mackeral5]

VERY cool!!

Thanks!  This has grown to be my favorite Lego kit. 

The modified Koi worked surprisingly well, but was still a fairly sharp "POW".  So I modified another shroud I had but it is too fat for the longer tanks.  Right now it is setup with a 13ci tank. 





Collapsed it is 25.5" long, extended with the can it is 36" long

[FuzzyGrub]

Mini-Mike Mock-up:

Mike, Tom, and I collaborated on getting an AR stock adapter made for G2 Mrod tube, but using the Prod trigger assy w/Lloyd's sear.   We collaborated on the dimensions, and Al did the hard work of making it into reality.  Beautiful work at that.  It does require drilling a couple of holes in the tube and threading one. 

Originally, I was last on the list to receive one.  Tom went another path after not being able to find a sear.  Mike is still having fun with the G1 and other projects, but will probably get back to it, in the future. 

So, being the first, had to at least get the mock-up done to verify, which I did.  The AR adapter was perfect, and the only issue was my ability to get perfect hole placement.  More accurately, my inability.   

Now, its a Mini-Mike because it is only 22 cal, vs Mike's favorite, 357.   

[YEMX]

Mini-Mike Mock-up:

Mike, Tom, and I collaborated on getting an AR stock adapter made for G2 Mrod tube, but using the Prod trigger assy w/Lloyd's sear.   We collaborated on the dimensions, and Al did the hard work of making it into reality.  Beautiful work at that.  It does require drilling a couple of holes in the tube and threading one. 

Originally, I was last on the list to receive one.  Tom went another path after not being able to find a sear.  Mike is still having fun with the G1 and other projects, but will probably get back to it, in the future. 

So, being the first, had to at least get the mock-up done to verify, which I did.  The AR adapter was perfect, and the only issue was my ability to get perfect hole placement.  More accurately, my inability.   

Now, its a Mini-Mike because it is only 22 cal, vs Mike's favorite, 357. 

I'm ecstatic that the AR adapter's holes and such are spot on!  That adapter looks fantastic!! 

[mackeral5]

Mini-Mike Mock-up:

Mike, Tom, and I collaborated on getting an AR stock adapter made for G2 Mrod tube, but using the Prod trigger assy w/Lloyd's sear.   We collaborated on the dimensions, and Al did the hard work of making it into reality.  Beautiful work at that.  It does require drilling a couple of holes in the tube and threading one. 

Originally, I was last on the list to receive one.  Tom went another path after not being able to find a sear.  Mike is still having fun with the G1 and other projects, but will probably get back to it, in the future. 

So, being the first, had to at least get the mock-up done to verify, which I did.  The AR adapter was perfect, and the only issue was my ability to get perfect hole placement.  More accurately, my inability.   

Now, its a Mini-Mike because it is only 22 cal, vs Mike's favorite, 357. 

I'm ecstatic that the AR adapter's holes and such are spot on!  That adapter looks fantastic!!

Looking good. 

The adapter worked out perfectly.  I only hope others will buy a few more from Al. 

[mackeral5]

Dustiing off this old thread as I dusted off this kit of legos today. 

Current configuration is regulated at 2000psi with 17ci tank.  Does 24 shots of 80gr NOE pellets at 775fps on a 3kpsi fill.  It really smacks my reactive targets.



Hopefully in upcoming months some long awaited parts modifications will be complete and I can assemble the remaining configurations.

[YEMX]

VERY cool!!  I've also been thinking about re-visiting my version of this build!  Though, in .30... 

[mackeral5]

VERY cool!!  I've also been thinking about re-visiting my version of this build!  Though, in .30...

Hey Tom-

Long time no talk....  I was wondering if you ever picked your .30 up again.  Last I recall you picked up an Impact and a Flex. 

This evening I shot some 1 hole groups at 50 yards and tried my luck at 100.....lobbing 81gr JSBs at 750fps. 

I didn't have enough adjustment in my scope to get on target.  So I started guesstimating holdover.  Ultimately with all the up dialed in and using where the crosshair goes from fine to coarse I was able to get somewhat on target.

The bottom left group represents the first attempt at guessing holdover.  then the middle group was the second attempt.  Then the top group was 5 shots holding the coarse part of the crosshairs on the center bull of the top target.