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Thread: Artemis/Snowpeak/Diana/SMK M-16A

  1. #1
    Boolit Buddy
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    Artemis/Snowpeak/Diana/SMK M-16A



    Backstory here is simple really. The local vendor that i do jobs for had a few of these laying around in 25cal.. and theyre to be phased out. So a deal was struck and i ended up with yet another 25cal PCP.
    That simple.

    For those not in the know the M-16A is a kind of budget to mid range PCP that sports a regulator as kind of a key feature. The Artemis line of chinese made PCP guns range from ultra budget (Stormrider) to the auto loaders like the M40, and the P15 to P35 as in between bullpups and what have you not. Ive been waiting for their new M-60 "FX Impact look alike" to surface.. to no avail yet.
    Anyways.
    M-16A



    IMO to call it a pretty gun would be stretching it. I believe the intent here was a basic regulated PCP rifle, one that sports a barrel length just as the Stormrider. Sports a shroud stock, and well get into that.. adjustable trigger and what have you. Regulator is to be adjusted from the outside btw while the stock "buddy bottle" has no provisions in form or shape of check valve or similar.

    Like the Kral and Reximex guns the Artemis offerings are often rather accurate in comparsion to much out there IMO. Thats to be said as i see it. So i expected this M-16 to shine in that dept..



    Shroud. Right. As the thing comes out of the box the shroud simply does not work. Point being that its a tube that rides atop the barrel and thats about it. Whats more the diffusor that rides at the muzzle of the barrel carries some sort of funky thread that im sure was a good idea to someone at Artemis/Snowpeak but.. whatever.
    As that threads larger than the industry standard 1/2"UNF though.. i just recut that and threaded it.
    Then. To make the shroud functioning i cut back slightly on the flange and then cut an o-ring groove into it. In this manner the shroud is sealed vs the diffusor, which hands that all gas thats expelled behind the bullet is free to move down the shroud and the shroud to pull its fair share of work muffling the piece.
    All good then?
    No. The other end of the shroud tube theres a series of holes for "venting" the shroud. Completely uncalled for as the air will just bounce back need be.. and them holes make the shroud omit.. noise.
    I just did a McGyver on that one and wrapped the tube with some elastic black electricians tape, adding one layer on the inside of the shroud tube as well to keep rattling to a minimum where it comes to a stop on the guns separate breech piece.
    So.
    At that point all content and ready to accept a moderator of choice. More on that further down...



    The M-16 is a regulated gun. That brings lower running pressures than if not, why i from the onset decided on opening the transfer passages up. In this case for starters to 6mm flat. At that rate the one of the two stock allen grub screws in M5 is out.. cause i drill that passage on one of the bench drills.. with the valve seat body set into the main block while at it, handing me absolute fit between the various opening when done.
    That also brought that i in turn had to drill what you see there in the picture to 6,5mm to accept an M8 tap.

    The poppet on most Artemis guns is rather small and light. Works off of a 3mm spindle. Opted to cut the center of said spindle, which works within the main valve exhaust port, back to 2,5mm on the lathe.

    Future mod, if needed, will be to open the valve seat through hole incl the space beneath it to 7mm flat. Need be.



    Hm. Yet another point where this gun sure isnt "done". Why is that? Anyways. It sports a barrel that threads into a breech piece. For whatever reason that part of the barrel that sticks into the breech bottomed out where its absolutely at its thinnest, within the breech, instead of at the flange so intended (in picture).
    Whats more..
    Theres two o-rings for the transfer passage between the block and barrel. All good. Theres an o-ring to seal vs the probe. Again all good. But theres nothing to keep it air tight between the barrel and the breech piece?
    So.. barrel on the lathe to cut an o-ring groove and then countersink the opening for the barrel on the breech piece.
    NOW it seals 100.
    To make that there happen i had to cut back 0,8mm on the piece that sticks into the breech, which in turn handed that i needed to cut back 0.6mm on the shroud tube - to make it all come together.

    So. There i was.
    Rifle now shoving "34 grain" (i use that phrase loosely) pill downrange at a reasonable 950-960fps (even saw 97o).
    But.
    That IS stonewall if were to use some sort of reason here. Mind you, at this stage i had ALSO weighed the stock hammer of a mere 19 grams down to approx 34 grams by "leading" it (melting lead into the cavity of it) and in turn replace the stock hammer spring with one for an FX Impact.

    So whats the issue then? Welp.. regulated guns in essence NEED whats known as plenum volume. Ie; an entity AFTER the regulator that only sees regulated pressure. This plenum is what the guns to draw from as the valve opens, and if not there.. the reg sure becomes a bottle neck to keep up with the pace were talking here.
    Issue is that the M-16 plenum is of a mere 11ccs... We normally say that 10ccs per 10fpe is a good rule of thumb..
    So what ive done is look into this, in more ways than one.
    Where well end up is anybodys guess as of current, but that it WILL happen and it WILL show the results to go with it.. you can take that to the bank.

    Anyways. Shooting.



    The M-16 sports what ive come to call a "semi weighed" trigger group. As theres plenty of direct contact in there, while other parts of it is spring loaded. Like the sear for instance (hidden by the frame work in the pic).
    No matter its kind of neat that it sports an entirely stand alone trigger group as i regard it.
    Anyways. Shooting.
    So the trigger can be adjusted for 1st to 2nd stage slack and then sear engagement too. This via two separate adjusting points holding M3 allen grub screws.
    I adjusted the trigger... and it wouldnt hold after a few shots. Adjusted again.. repeat n rinse.. sorta.

    Tracked that down to that the adjusting screw for sear engagement was way to loose in its threads...



    Indeed. Took the trigger assembly apart and handed that pesky little screw some blue Loctite and done deal. Since that was let to cure.. trigger is downright wonderful.



    In turn. Me i like VERY light 1st stages and as can be seen in the picture of the entire trigger group theres a small spring to act on the trigger for the first stage. Replaced that.. very happy.
    Sear adjustment in turn is such that theres no creep what so ever and id say that after cutting the angles of the sear as i see fit ive got a trigger pull somewhere around 1-1,5lbs approx. Real happy with that.
    Actual trigger blade holds the safety too btw. Completely useless..

    Then today.
    No pics, coming up.. But anyways, i sanded that god dreadful stock down. For some reason Artemis/Snowpeak friggin DIP their stocks in pore filler which hands a rather "plastic" feel to them, albeit wooden stocks. So fact is ALL my Artemis guns has undergone this. Have treated it with some dye and in turn linseed. Will revisit the dye come tomorrow.
    While at it.. that "forend" is simply to much. So i took the saw to it, getting rid of approx 1" of the absolute bottom of it.
    WAY WAY WAY better... now it looks like a "normal" rifle at least.. But ill get back to you on that.

  2. #2
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    W.R.Buchanan's Avatar
    Join Date
    Mar 2011
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    Ojai CA
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    Do keep us posted on your progress. You are the only Airgun Smith we've got here so your posts are informative. So I detect some of the "Queens English" coming thru your posts. Are you in the UK?

    Keep in mind we are all Colonials over here and by definition not nearly as sophisticated as you "Continentals."

    Randy
    "It's not how well you do what you know how to do,,,It's how well you do what you DON'T know how to do!"
    www.buchananprecisionmachine.com

  3. #3
    Boolit Buddy
    Join Date
    May 2018
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    239
    Thx.
    Nah. Im a half breed, thus i guess my both way to build a sentence as wording and what not gets clustered?
    U tell me.
    Live over here in Europe since ages though. When you hear me speak tho.. theres no mistake
    Ill in my case and then as an adult back for Az and Mr Cooper and what not for a while. So.. have moved around a bit, which sure marks my speech i bet.
    ..and for the sake of argument, yeah. A language or two doing so.

    Ill be happy to!
    What i "really" do is pull loads of work as far as old original BP firearms though, this whole PCP bit came out of us getting rat infested at the shop. (Dont ask..)
    As i keep three muts all in all poison was sure out, one thing led to another.. why i came to opt for PCPs. As the shop of mine is in a "semi" downtown area i cant use firearms sans permission while a moderated and shrouded air gun carries no such limits.
    Ergo..
    Then.
    Have a past with motorsports and that kind of brought that there.. "jack of many trades, master of none".. kind of.
    Been at it with the old original black powder guns for a number of years now and compete as much as time allows. On various boards and what not over here.

    Dunno if youre into it at all, but over the yrs ive come to end up with the occasional boom stick or two thats.. rather fabled.
    So.
    Albeit this the air gun forum here goes (as an exception)





    Here a basically mint Enfield P-53 "Export". IOW the exact same gun that got delivered for the CW. Yep. In essence new.





    An original London proofed 3d model Dragoon is full working order (and used such.. )



    Business end of a Cape RIFLE. A 500 Express made in ZA way back.



    Here my 8mm Kropatschek. This is a permit gun to me though (most of the others are not due their age)



    Merrill carbine..



    ...basically mint 1858 Army...

  4. #4
    Boolit Buddy
    Join Date
    May 2018
    Posts
    239


    ...a Swiss Milbank hybrid carrying one of the most beautiful tiger striped walnut stocks ive ever laid eyes on...
    Due a mishap (before me) i came to chamber the thing for 45-90 shells using 43" pills.



    A 45 cal Westley Richards rifle. A so called Monkey tail. Was this one EVER a trainwreck as i got it!



    1865 Rogers&Spencer



    Yet an 1858, one where the ship had sailed for real so i restored it and since use it for CAS.



    Starr cap n ball carbine in very good working order. As we CNC cut our own molds.. yeah. The one for this one is a bore-rider with its driveband at a full ,555" diameter.
    Although i own a Sharps -59/-63 rifle too.. ill be damned if i dont hold this Starr higher actually.





    Yes. An original Whitworth 451 Military match. We not only cut our own molds but play around with making swaging setups too on occasion.

    This just a few.. but as you can gather, yep. Find PCP tech very interesting and carrying a lot of potential.
    Uhu. Compete using "modern" guns too (time permitting. Ended up 2nd place this sunday at a rifle match actually)
    ...but more than anything its about the "oluns" to me.
    Mind you, the really old stuff.. not so much. I kind of got excited due what Whitworth and Purdey arrived on there back in the 1850s, where "modern" accuracy was born.

    Understanding PCP tech that said, not all that much of hazzle to me and as ive got the "guns" part already.. it was mainly about melting them two together, and here we are.

  5. #5
    Boolit Buddy
    Join Date
    May 2018
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    239


    Back on track. Took about an inch off of the bottom of the stock, making the thing way more prone to "normal" rifle looks IMO.
    Hue on the other hand, not so sure. That can always be changed though.

    Performance.
    Were aware the thing is regulated from the factory and that reg actually works semi decent TBH. Like all regs it takes bit of time for it to "settle" which i guess mainly is about the inherent belleville washers working up against each other.
    However.
    That reg has a mere 11ccs worth of plenum chamber downstream, and that simply wont suffice for where im headed so extra plenum volume is no doubt needed.

    Ive debated "inletting" an approx 70cc steel cylinder that heads into the stock placing of the pressure gauge (which reads regulated pressure), and.. might very well revoke to that all said...
    But.
    As the reg is on there i thought to myself that why not simply move the reg way more up front? 70ccs added, then a freshly made reg housing.. before the bottle.
    Yes. This would no doubt add length to that part of the rifle but all said and done the bottle and so forth are a rather far cry from the end of the muzzle as is.
    In short, i dunno what that "iteration" would come to look like, why im exploring it.
    Then again, it will keep the gun more "compact" if i just use the steel plenum ive already made and install that to the utmost rear underside of the stock bottle.
    But?
    Wont that look kind of cramped?

    Well. Give it a moment to sink in.. cause see, what this gun ALSO lacks is some manner in which to put a bi-pod and what not on there.
    So what im entertaining here is the idea of what i did to the bottle/cylinder on the Artemis CP-2 i made into a PCP gun. Weld the bracket needed to the plenum (in this case) and thereby.. im not so sure the final product would look all that funky when done?

    You guys tell me. That plenum is on a diameter of like 35mm or so (1,37")

    No matter which i NEED plenum volume to push on..

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Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check