Binding hammer in the Maximus

[KnifeMaker]

Having an issue with hammer bind in a Maximus .22. Changed the hammer  to a Challenger hammer, to get past the valley issue.

In the original hammer, i added the nylon buttons. Thinking of doing the same here. (I can polish the rear edges and front edges of the hammer and the issue goes away for apx. 50 or so shots.)
I checked the tube, and there is definitely galling going on. There is also abrasions at the leading edge of the bottom of the hammer, and top leading edge, which I polish out. It quickly re-appears though.

Seems a lot of the issue is the way crosman designed the hammer to have a pin in the rear for the cocking bolt to hit and push to the rear. Adding an BNM Breach has made the issue worse. As there are times I simply cannot add enough elbow grease to fully pull the bolt to the rear. Bolt is ultra smooth without the cocking pin in place.

The SSG in the gun helps a LOT, as when cooking is very difficult, I can actually use the SSG as a cocking handle. Pulling it to the rear, cocking is Smooth. 

Thinking of milling the hammer for the nylon pins for the bolt to ride on, or asking one of our tuners here if they make a synthetic hammer for these guns! 

Any input is very welcomed!!!

KnifeMaker

[dmeguy]

I had to do quite a bit of polishing and lubing of the bolt and breech on my BNM. I also found that if I only screw the allen screw into the bolt just far enough for the head to clear the tube, so that it engages the hammer pin as low as possible, helped quite a bit.

[FuzzyGrub]

I also found that if I only screw the allen screw into the bolt just far enough for the head to clear the tube, so that it engages the hammer pin as low as possible, helped quite a bit.

I ran into that same binding trying to make a breech riser for prods (to use a mrod shroud) and using the longer challenger hammer pin.  Heavier springs made it all the worse.  The bolt lug would engage the pin part way up, and cause the hammer to tilt/gall.  I wasn't able to make the bolt lug longer without machining some of the breech and riser.  Went back to the prod shroud, vs the Mrod one, because of this issue.

[Doug Wall]

Several of us have changed the stock hammer spring to a lighter one, to get a better shot curve, more shots, and a lighter cocking effort. Try it.
Hill Airguns 0.042" wire, 1.5" x 0.3". Also, if you have a heavy SSG, you have to remember that it also acts as a heavier hammer (slows down hammer velocity) until it stops, and the hammer travels on it's own

[Tater]

I think I'm having similar problems with my wife's and my Maximus'. Not capable of much repair or mods here, but following closely.

[FuzzyGrub]

If your SSG is the type where the rod is attached to the hammer and passes through the end cap, and uses a stop, I would think that would prevent the hammer from tilting/galling.  I use a guide on my Mrods that does seem to prevent it there.  If so, how much gap between rod and where it passes through end cap? 

PS: David (Rocker1) does make MDS hammers for prod/1720T platform.   I think I recall you have the Mrod trigger assy, so they should work on your maximus configuration.

[Dairyboy]

The MDS hammers are great! Had one on my Prod from David which he actually owns now from a trade between us. I'm a huge believer in the MDS hammers!

[KnifeMaker]

I would like to try one of Rocker1's hammers. I just pm'd him about them.

I ran the bolt on the probe out almost to the pressure tube. It now cocks just fine. It was indeed hitting the hammer pin too far up, making for a lot of unwanted leverage and tilting the hammer.

Now the Bad Part! All the hard cocking apparently cracked the rather thick bolt handle and caused an unseen crack inside. It came off in my hand this morning while testing. GRRRRRR~!!!

Thanks for the reply Guy's. Really helped.

KnifeMaker

[dmeguy]

Now the Bad Part! All the hard cocking apparently cracked the rather thick bolt handle and caused an unseen crack inside. It came off in my hand this morning while testing. GRRRRRR~!!!

That's exactly what happened to me. I set the BNM handle aside, I plan to rethread it and use it in it's now shorter form. In the meantime, I threw a Disco bolt handle on it and kept shooting!


I'm glad you got the binding taken care of. I also sent Rocker1 a PM about his MDS hammers, it should work great in my frankengun.

[KnifeMaker]

Should have one one of Rocker1's hammers here in a few days. Both called BNM and e-mailed them. No response so far. Will Let you know what they say.

Knife