Swimming Against the Current

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ironlion269

ironlion269

Member
Mar 10, 2017
773
78
North Central Indiana, United States
Like all y'all, I've noticed the trend here on AGN to go bigger, go further, hit harder, and so on and so on. Higher cost rigs, including air sources, scopes, slugs, and of course guns.

I am going the way of the contrarian, deciding to bring down the power of my Maximus in order to suit my preferences in shooting: less power, more shots, high accuracy. I enjoy the 25-50 meter stuff; a Crosman Challenger 2009 set up for 25 meters is my cup of tea. I plan to work my Maximus down to about 14 fpe, starting with taking 1.5 coils off the hammer spring and polishing the new end. From there I'll look into either filling the TP with JB Weld and then drilling a new, smaller port or just going for a Challenger TP as a straight replacement. Time will tell.

Of course, no project of mine would be complete without a bonehead move that delays the whole thing. In this case, after stripping the Maximus down to parts and clipping the spring, I hulked out and stripped the head of the teeny, tiny breech screw that sits beneath the pellet probe... only afterwards realizing I'd forgotten to put the TP back in place on top of the air tube before putting the breech back on. Holy Andrew Dice Clay, but that little screw has me flummoxed! So it's off to Harbor Freight tomorrow ("Hobby Lobby for men") to search for a teeny, tiny tap to get that screw out. Then I have to either find a substitute screw at the local RC shop or go begging to Crosman for a replacement. Maybe I should just get the Challenger TP at the same time and plan to drill it out a bit. Anyways, just more the of same from the ironlion household. As has been said, "The best laid plans of mice and men gang oft aglay." Especially when a bonehead is the one laying the plans.
 
Those tiny screws with the .050 allen heads suck they are the first mod I make to all of my Crosmans. You can replace the 4/48 with a 5/48 without even drilling if you carefully turn the screw in a bit then back out a bit kind of like tapping it. The 5/48 is found in the specialty firearms screw drawers section of your local hardware store or on ebay. I drill the tube out and tap it for a 6/40 these days though although I have gone to an 8/40 for the 9mm. Then I spin the screw in a drill and hold a file to the head to make it the right size for the breech I am using.

Also if you strip the holes out in the stock screws you can just drill the head off the screw, with a bit the size of the screw shaft, remove your breech and use pliers to pull out whats left of the screw. I have done this twice and the screw actually came out with my fingers never even needed the pliers. 

OH, and by the way those guns probly would not be fighting you so much if you were giving them mo power rather than taking it away. ;^)
 
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I have gone the way of the weakling myself. 12 fpe home brew pcp. Lots of shots. I was whacking an empty Gatorade bottle just last night at 75ish yards. Closest one is the lower powered rig and the other is at 15 fpe.

Here are a couple of the boys doing the same thing. They sort of took over... well, I invited them to so they did.

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Update on my quixotic quest for the "perfect airgun":

It began simple enough: take out the hammer spring on my Maximus Hunter (.22, giving about 23.5 fpe at the muzzle) and trim off a coil or two to reduce the power and increase the shot count. This is me we're talking about, so... hilarity ensues. It begins with me failing to recall that without loosening the grub screw in the barrel band, the barrel would remain tight against the air tube and the transfer port would pose a problem when I tried to slide the breech block forward. I managed to lose the TP for 2 hours on the garage floor; when found it was clear that one of the TP o-rings was damaged and the other lost (and never found). Strike One.

After getting everything else apart without crisis I clipped 1.5 coils off the hammer spring, polished the clipped end, put the spring in a vise to scrunch it a bit (less force when the sear releases the hammer), and finally lubed all of the metal-to-metal contact points in the breech and hammer assembly with Moly. It turns out that "scrunching" the spring was Strike Two. But I'd find that out later.

I began the rebuild and had the whole gun back together sans the stock when I tried a couple of test fires without air in the tube. Checked the trigger pull (modded it earlier this year) to make sure everything was in order. Panicked when the sear wouldn't catch... until I reasoned out that the spring to operate the sear is also the spring under tension with the cross-bolt safety. Put tension on that spring and viola! the sear catches and all's well. Uh, well, almost - that's when I realized that I'd forgotten to put the TP back in place on top of the air tube. Strike Three! 

It gets worse. Took the breech apart all over again to install the TP and managed to mess up the hammer/probe arrangement when I put the gun back together... again. Only this time I also stripped out the hex opening on the top of that damnable little screw that sits in the breech under the pellet probe. You know, that tiny screw that can't be seen until you disassemble the back end of the breech and take the probe out. I'd hulked out and tightened that little sucker down 'til the Allen key spun right around in that hole. Smooth move, Exlax. It was as if I'd been beaned by the pitcher while going back to the dugout after striking out. 

I went to Harbor Freight, bought a screw extractor kit, used the smallest extractor in the set, and by God's grace alone (I promise you, there were tears and prayers by this time over this silly gun) managed to extract that tiny screw. And destroy it in the process. Just one more critical piece to replace. Oh, and I managed to lose the TP again in the process. It's still lost. In my own garage. A fire-engine red piece the size of a corn kernel is hiding somewhere in my garage laughing at me even as I type this.

Tally so far: lost the TP for my air rifle, lost a critically needed and extremely hard-to-replace screw for my breech block, lost one TP o-ring and damaged the other beyond use, and clipped AND smushed my hammer spring. Instead of a rifle I had a diverse set of parts, O-rings, and tools scattered across my workbench. Murphy 4, Ironlion 0.

I admitted defeat and turned to Crosman's wonderful Customer Service department to order parts. I first obtained an online Maximus parts diagram to figure out what I needed: TP, o-rings for same, hammer spring (actually didn't know I'd need to replace my kluge but had my suspicions at this point). I didn't order the breech screw because, in the only bright spot among my self-inflicted woes, I managed to craft one out of a 3x8mm screw from my local RC shop. I had to dremel the shaft shorter and then dremel down the diameter of the screw head to get it to fit down into the small recess in the breech block. It's better steel than the original and sits down in there solid. W for the Win!

Turns out you can still get the TP and hammer spring for the Maximus Euro version from Crosman, so I got both a standard and a Euro set of each. After reassembling (without issue!) the gun I began testing it. First was the Euro TP with the original/kluge spring. I'd never shot a sub-200 fps gun before. It sounded like the gun was spitting out phlegm instead of pellets. Quick breech disassembly and in goes the standard TP with the kluge hammer spring still in place. Marginally better fps (~400 fps?) but the POI was all over the place. Hard Air Magazine has an article about tuning unregulated PCPs... points out that ultra-low tuning indeed yields more shots, but there will be no consistency due to severe sensitivity to variations in the hammer strike. I shoulda filmed my results and submitted it as an addendum to that article.

Last night I finally found my nirvana when I opened up the breech block one more time, this time installing the Euro TP and hammer set I'd bought. Daylight was fading so I only put a few shots down range but the results look extremely promising. What a way to go about learning more about my air guns. At least I now know how to use a screw extractor.
 
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She's back together and is shooting great... except for the pronounced DROOP that wasn't there before my boneheaded adventures! Been online looking at droop-compensating alternatives and find that lots of suppliers just don't have the rings/mounts I need. Everything is "Pre-order". Eh, I'll try double-shimming with extreme care on the way I tighten down the tops of the mounts. I'm not calling it a money pit just yet...
 
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Did some Chrony work tonight, including the de-tuned Maximus. Only got through two pellet sets but am really pleased with the result of installing the Maximus Euro transfer port and hammer spring from Crosman. I had 40 shots from a 2000 psi fil down to 1050 psi (basically the 'Green Zone' on the gun's on-board gauge) and recorded the resulting Chrony readings. 

H&N Sniper Magnum 17.9 gr

  • 25 shots from 1900 psi down to 1300 psi produced: High 556.6 fps, Low 527.0 fps, Ave 543.6 fps, ES 29.6 fsp.
  • 20 shots from 1900 psi down to 1450 psi produced: High 556.6 fps, Low 532.5 fps, Ave 546.8 fps, ES 24.1 fsp. 
  • Mostly the FPE came in just under 12 ft-lbs although the 550+ fps shots did cross the 12 ft-lb threshold. Still and all, it's right there in the Euro neighborhood.

Crosman Domed 14.3 gr in the tins

  • 25 shots from 1900 psi down to 1350 psi produced: High 605.5 fps, Low 572.9 fps, Ave 595.0 fps, ES 32.6 fsp.
  • 20 shots from 1900 psi down to 1500 psi produced: High 605.5 fps, Low 582.6 fps, Ave 598.4 fps, ES 22.9 fsp. 
  • Here the FPE came in just under 12 ft-lbs consistently. Very pleased with these results; my range findings for this gun affirm that CPDs in 14.3 grain are good for this gun.
 
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