Tuning What I did to my Marauder/Armada today

[Thatdarncat]

I had a sticky bolt problem on my .25 Armada, the magazine was sluggish to rotate to the next pellet so I advanced the spring tension one hole, then after a few magazines it stuck a pellet, where I couldnt close the bolt nor remove the magazine.

So after fighting and trying to coax and wiggle the magazine out, I gave up and used a .22 caliber aluminum cleaning rod to bump it back enough to free up the magazine to release,

Since im not a big fan of putting my hand over any loaded weapon other than a fork, I decided to bump it outside against a large pine tree...it only took a gentle nudge.

So, I advanced that magazine spring to another pin hole and it seems to function flawlessly now.

Now to the bolt problem I had too, I was having to hold the bolt back in its furthest most rearward position to insert or release a magazine...which required me to reach under the rifle with my left hand to tug on the magazine while I held the bolt back with my right hand....awkward!

Well I decided to tackle that problem too, so I tear down the armada, and loosened up the 3 button head cap screws that holds the trigger group in place and while holding the trigger group tightly in its most rearward position I tightened up the screws....drats... the bolt probe tip was still too long and still interfered with the magazine insertion!!!...So I grab some gage blocks and found out the bolt tip protruded .023 thousandths into the magazine well. So I take the bolt out and after measuring the bolt overall length which came out to 4.217, I took .027 off the face of it ( giving myself an extra .004 in case that trigger group should work its way forward again) then I put the slight bevel back on the bolt probe tip.

Oh by the way, I didnt need any special equipment to do this, other than the gage block but a pair of calipers could have gotten the same results! I took the bolt tip to a belt sander and got it to within .005 of my finish number and then, put it in a vee block and slightly tightened it down and ever so gradually bumped the bottom of the bolt forward till the tip just kissed a big honing stone layed flat against the vee blocks face, them I would stoned the probe tip until it stopped and bumped it again ( rinse and repeat) until everything was nice and square and to my finished number. To get the bevel I jut angled my stone, every so sliglty let the hold down screw on the vee black touch the bolt and I began rotating the bolt like I was winding up a propeller on a toy rubber band airplane. I just held the stone in place at the angle and it did the rest.

For all you metal heads: It appears the bolts are fairly hardened, it can be filed but it files with reluctantcy...I would estimate the hardness to be around 55-57 RC

Now the Armada appears to humming along nicely...no more fighting the awkward bolt pulls while removing magazines, etc...it seems to be operating smoother with the extra spring advancement in the magazine spring too...The difference is night and day in how it loads and the bolt functions....Now Im cursed...Im burning through some pellets now!

 

[biohazardman]

So is it still putting the pellets in the right place, just past the transfer, port or did you choose to loose a bit of power?

 

[Thatdarncat]

I can see the pellet past the transfer port

 

[triggertreat]

There was a rash of that same issue maybe a year or two ago being posted on the forums. My two are more like four years old. I don't have that issue. Not sure what was the remedy or cause, but you may want to search those past threads on the forums, if interested. It's good that your pellets still clear the TP. Nice job!.

 

[Thatdarncat]

HI I did notice that as I rotated the bolt in the vee block that the probe tip did have a good bit of run-out ....it seemed the larger diameter of the bolt was true while the probe area ( the whole reduced diameter portion) had the run out-out. It "looked" ( without using an indicator) that it was around .020. That coupled with the bolt heat treatment and the smaller diameter that it warped from the machining stresses or was already in the bar stock.

I think there is something funky with those factory bolts and that could came from a myriad of manufacturing machining processes. If not in the bolt, the fixturing that machined the .25's got something in behind a stop or was cranked on which shifted some hole locations....lol someone's work at Crosman's slipped under the radar once upon a time, hey poo-poo happens, its still a fabulous air rifle...even as heavy as it is. )

 

[pnwairgunner]

The fix to both of your problems , magazine not rotating and difficulty inserting could both be fixed by working on the magazine, not changing the rifle. 
The marauder magazine will stick if the tiny Allen screw is too tight. Just a tiny bit of loosening will free it up usually. 
A very simple solution to the two handed magazine insert/remove is cutting a shallow groove into the clear face plate of the mag using a small flat file or a dremel. 

 

[FuzzyGrub]

A new mag should not need the spring rotated. Too much spring pressure can start causing pellet scrapes, especially in softer pellets, like JSB.

If the barrel is too far into the breech, the mag will fit tight and have rotation issues. You can loosen the two set-screws and move it out a few thousands.

The probe issue came when the Gen 2 25 mrod was released. Gen 1 had a flow thru bolt. Initially they machined the bolt lug and hammer lug to make up the difference. They changed the design after the initial production. I believe the 25 Armadas, have always had this issue. As long as the pellet skirt is out of the transfer port, you should be good, now.