MRodAir Air Max Varmint in .177

[avator]

That's it.... That's why I didn't post a name... I'm getting old and I'm grateful that memory is the only thing going to h3ll so far. Anyhow.. I did put the free floating barrel band on my AMV for the reasons stated. I don't think I'll put one on the Plinkster because it probably will not be going to the woods.

[Ribbonstone]

Haven't done a dimentional study, but have had them both a apart at the same time.

Co2 valve:

DSCN1745[1] by Robert Dean, on Flickr

Co2 uses a fixed pin and a seal.
DSCN1746 by Robert Dean, on Flickr


PCP valve:





Can tell they were made pretty much the same, the valve stem/retrun spring will swap.  The valve stem seal is a seprate part that can be removed from the valve stem.  The two halves of each will interchange.  The PCP valve doesn't have the 12gr. piercing nipple/seal.  The screw holes/transfer port all line up the same.


Gauge uses a gauge block, o-ringed on both sides of the hole in the air tube to allow the gauge stem to pass though.  Air passage in gage block is rather small and off center (the gauge extends pretty deeply into the block, up agains a delrin seal, so the air passage is off center).

PROBLEM:
The only way to get past a problem is to admit one exists and find a way to fix it.  These rifles do have a problem or two; o-ring material is one of them.

******YEah....going to "harp" on that one more time.  It's not so good and easy fix on their end.  Gotta buy o-rings any way, and the right material doesn't have to cost one bit more.  BUT it seems endemic to SPA...they used the same material o-rings on the M-10, Plinkseter,CP1, and MkI/MkII PCP as well.*****

The o-ring work and seal, but they really are the wrong material (brown color is a clue).  They swell and pretty much stay swollen even after days of sitting open and unpressurized.
 The factory one on the far right was never in the rifle...the ones on left were used under pressure.



So taking the valve and gauge block our of the PCP can be a real chore.

The gauge block and valve are removed back to front (there is a "dent" in the tube to keep  you from trying front to back).


Maybe other ways, but I just gave the tube a good dose of white litium spray grease (knowing I'd have to clean all that greasy "stuff" off after it was apart), a 5/8" wooden dowl, and a rubber hammer.  Drill the center of the 5/8" with a 1/4" hole (acturally, only have to be  1/4" deep as the valve stem doesn't poke out the valve very far) so that the valve stem will fit into the hole in the dowel.

Likely will size an dice the swollen  o-rings on the gauge block and valve.  Not a real issue, as once you get those parts out, you'll replace the swelling o-rings with ones that won't swell.

I really hate giving sizes...and if someonw knows for sure, please correct me.  In my case, I used Nitrile SAE A 113 in place of the metric ones orginally used. Aren't a perfect match, but it's been holding air and not leaking for months.

[A.K.A. Tommy Boy]

That's it.... That's why I didn't post a name... I'm getting old and I'm grateful that memory is the only thing going to h3ll so far. Anyhow.. I did put the free floating barrel band on my AMV for the reasons stated. I don't think I'll put one on the Plinkster because it probably will not be going to the woods.

Bill your not alone in this....Everybody feels the memory pinch. 

[WesBob]

Thanks for sharing Ribbonstone! Great pictures! You didn't happen to compare end caps did you? I was wondering if the threads are the same. I can see varmint has more threads and oring but wondering whether the threads match the plinkster tube?

[avator]

Haven't done a dimentional study, but have had them both a apart at the same time.

Co2 valve:

DSCN1745[1] by Robert Dean, on Flickr

Co2 uses a fixed pin and a seal.
DSCN1746 by Robert Dean, on Flickr


PCP valve:





Can tell they were made pretty much the same, the valve stem/retrun spring will swap.  The valve stem seal is a seprate part that can be removed from the valve stem.  The two halves of each will interchange.  The PCP valve doesn't have the 12gr. piercing nipple/seal.  The screw holes/transfer port all line up the same.


Gauge uses a gauge block, o-ringed on both sides of the hole in the air tube to allow the gauge stem to pass though.  Air passage in gage block is rather small and off center (the gauge extends pretty deeply into the block, up agains a delrin seal, so the air passage is off center).

PROBLEM:
The only way to get past a problem is to admit one exists and find a way to fix it.  These rifles do have a problem or two; o-ring material is one of them.

******YEah....going to "harp" on that one more time.  It's not so good and easy fix on their end.  Gotta buy o-rings any way, and the right material doesn't have to cost one bit more.  BUT it seems endemic to SPA...they used the same material o-rings on the M-10, Plinkseter,CP1, and MkI/MkII PCP as well.*****

The o-ring work and seal, but they really are the wrong material (brown color is a clue).  They swell and pretty much stay swollen even after days of sitting open and unpressurized.
 The factory one on the far right was never in the rifle...the ones on left were used under pressure.



So taking the valve and gauge block our of the PCP can be a real chore.

The gauge block and valve are removed back to front (there is a "dent" in the tube to keep  you from trying front to back).


Maybe other ways, but I just gave the tube a good dose of white litium spray grease (knowing I'd have to clean all that greasy "stuff" off after it was apart), a 5/8" wooden dowl, and a rubber hammer.  Drill the center of the 5/8" with a 1/4" hole (acturally, only have to be  1/4" deep as the valve stem doesn't poke out the valve very far) so that the valve stem will fit into the hole in the dowel.

Likely will size an dice the swollen  o-rings on the gauge block and valve.  Not a real issue, as once you get those parts out, you'll replace the swelling o-rings with ones that won't swell.

I really hate giving sizes...and if someonw knows for sure, please correct me.  In my case, I used Nitrile SAE A 113 in place of the metric ones orginally used. Aren't a perfect match, but it's been holding air and not leaking for months.

Ribbs;
Thank you so much !!! This post will definitely get bookmarked in my AMV folder.

[fishinglakes]

HI Craig, where did you get the M10?

Our first M-10s came from Mrodair. The others came from people selling them on the classifieds, and not knowing what they had. With the large transfer port, they will shotgun the lighter weight pellets that most probably shot through them. With heavy slugs, 30 to 35 grain, they are quite impressive! I'm shooting a .33 grain swagged slug in nice tight groups around 950fps. OOTC

[Ribbonstone]

M10. The transfer port is a separate brass fitting to the rear of the barrel (also carried the internal bolt probe o-ring). The standard port is like 5mm.  Mine came with a spare (smaller 4mm) transfer port.  Even 4mm that was too large unless you were slinging +30gr. pellets.



Used the orginal 5mm mm transfer, rotated the port 90degrees, drilled it for a 2.5mm port, drilled a "dimple" for the set screw on top, and plugged the orginal 5mmm port.


Later one, reditlled that new port from 2.5mm to 3mm.


So basically, without any other changes, got readings for 4 port sizes (5mm/4mm/3mm/2.5m).

5mm would manage about 47-53 foot pounds (but the heavier the pellet, the higher the energy, can with really heavy slugs increasing the foot pounds).

4mm would manage 44-51 foot pounds

3mm would manage 35-44 foot pounds

2.5mm would manage 24-27 foot pounds..which is a pretty good area for  cheap 14.3gr. to live (would be going about 880-905fps).

So I just decided to adjust it with the 4mm port in place.  Tried it with cast slugs (sized appropriately) and got good results...but not enough better than 25.4gr. JSB's to make casting/sizing slugs worth it for me). Did manage to get a really heavy slug to make it to +60 foot pounds.


Now I do NOT HAVE a lot of use for a +50 foot pound .22, just aren't that many opportunities to shoot big critters far away in my area.  But I do have occasional uses for those traits, so I've found a place for it...even though it gets used a whole lot less often than lower powered PCP's.

[avator]

Yesterday I picked up my Varmint after not shooting it for a couple days and "click" no air pressure. I knew I left it low but I've never shot it til empty. I filled it and checked this morning. Maybe lost 1k of pressure in 24 hours. So off to the bench it went. I've never had the gun torn down so I wasn't too disappointed. Gives me a chance to see what makes it "bang".
 I completely expected to see a bunch of swelled and distorted O-rings like I've seen posted by some members. I guess the swelled and distorted O-rings are only typical with the c02 guns. Mine looked pristine other than the one on the front end of the valve. It just looked fatter. There was not a fatter one in the spares that came with the gun so I think maybe a wrong o-ring was used from the factory. Or it could be swelled. If so, that's a perfect swell. None of them were chipped or nicked.
I cleaned every thing up and put a dab of moly here and oil there. I replaced the "swelled" o-ring with one from the spares and put the gun back together. I chose not to do any mods at this time. I don't really have any complaints on the gun.
I connected to the tank and pushed "play". Cranked it up to 3k and listened for leaks..... nothing. I'll check it in a bit to see if it's gonna hold. I suspect either that fatty o-ring or the gauge needed tightened.
BTW... the gauge don't need to be "torqued". It has a seal. It does need to be removed before the stock can come off. I think this is a .177 thing. I was able to do that with needle nose pliers.

[Wayne52]

Bill I almost wonder if the .177's were older stock because there is one guy on the forum who ordered his in .177 and got the same guage and stock from Mrodair that are on my .22

I picked me up a UTG 3-12X40mm EZ Tap at the airgun show today, got it mounted on my Varmint,  dialed in great@20yds for $40, it even came with a good battery and 11mm rings.  Now I'm ready for long range with it.  I also picked me up a vintage box of 500 Sheridan pellets in the yellow plastic contain just like the ones I bought for my Bluestreak in 77.

[avator]

I have no idea Wayne. I don't have a .22 to compare to. It is the same shade of wood as the .177 Plinkster we have.

[Wayne52]

When I ordered mine I also ordered the .177 for my brother too, his stock IMO looks nicer than mine, it's got a darker stain on it.

[keithd]

I was told by Mike that the 177 had gauges that need thin wall socket and the 22 does not. Maybe they are all the same now. My Varminter leaks as but I could not even sneak needle nose in mine.

[avator]

From the .22 Varmints I saw pics of, the gauges say "Artemis" on them. My .177 does not. Also, that is strange Wayne.. I thought the .22 had the darker wood?. Hmmmm.... wonder which one is that "Fine German Beech"?

[Wayne52]

Yep mine says Artemis on it.

[avator]

I guess that means that it's just a "luck of the draw" thing. Maybe a transition into a new lot of parts. I know we try to FIFO (first in first out) at our plant but it don't always happen unless the is an EO change.

[gendoc]

mine dont say anything but an MPa scale. it also appears that the gauge does not need to be removed to remove the stock......interesting 
i will know more when the time comes.

[avator]

Well.. I still got the slow leak and I don't have the right O-rings of the type Ribbs suggested:
Quote:
I really hate giving sizes...and if someonw knows for sure, please correct me.  In my case, I used Nitrile SAE A 113 in place of the metric ones orginally used. Aren't a perfect match, but it's been holding air and not leaking for months.
So I placed an order for a 100 pack at $10 shipped.

[Rat Sniper (AKA: PaulT58)]

I took the stock off my AMV today just for giggles.  It has the Artemis gauge, and it doesn't have to be removed to remove the stock.  Also, I thought I read the triggers were adjustable on these.  Anyone figure out how to adjust them?

Any other easy Mods for these? 

[tomiboy]

I just ordered a Varmint in 22 yesterday. Hope I don't get a leaker!

[avator]

the O-rings will need changed... sooner or later.