Advice on hammer travel Disco with Challenger/Prod hammer with modified striker

[TF89]

After reading some great posts I have some questions regarding hammer travel settings and fill pressure.
Scott (Motorhead) thread https://www.gatewaytoairguns.org/GTA/index.php?topic=117585.20 really got me thinking.

This I thought was a great post, https://www.gatewaytoairguns.org/GTA/index.php?topic=107946.0 explaining the concept.

In that post Bob (resterne) stated: "I maximize the hammer travel so that I can use the least possible preload to make the gun easier to cock.... I don't worry about the lock time, perhaps I should, but I figure I'm not a good enough shot to see any difference.... More preload will generally result in more hammer bounce, and of course the best setup is to use an SSG to eliminate that completely.... The Disco already has only 0.58" of hammer travel, and if you fit a PRod (Challenger) hammer, even with the adjuster screwed in all the way  you will be reducing that to about 0.50".... I do use PRod hammers in my guns, but I replace the striker with a 1/4-28 setscrew with the cup point ground off square and set below flush by up to 1/8" to increase the hammer travel, but then I am usually chasing an increase in power, not a decrease.... "

That leads me to my question regarding increasing hammer travel in the .22 Disco which I have modded for more power.  As a reference the disco in question has a BNM breech,  20" barrel, retractable probe, lots of porting done, marauder valve stem/poppet, SSG with .04 x .30 x 1.875" hammer spring and challenger hammer with striker ground off to allow adjustment.  My current fill pressure is 2300 to 1600 with an avg of 937 covering 18 shots using 18.1 JSB.  I have been using a Discovery hammer (buttoned and polished) and I just installed the Prod hammer and have not actually shot it yet.

I'm having issues with hammer binding due to the cocking pin.  This new hammer as well as the original Disco hammer have been buttoned which has certainly helped, yet the hammer will suddenly bind up.  To that end I've ordered a hammer cocking pin from Alchemy on ebay that will hopefully help with the pin tilting.  The cocking effort currently is not that bad, stiff for sure but smooth, that is until the binding happens.  I have the cocking lug adjusted so that it fits close to the base of the cocking pin. 

Back to my questions of which I have two.  Where Bob says (back in 2016) would adjust up to 1/8" for the striker to be recessed in the face of the hammer.
My gun is back together and I don't really want to take it all apart if I can help it to find out the answer to question (1).

1) With the valve stem fully pushed into the valve, does it still stick out of the back of the valve and if so, what is that dimension?

2) Does anyone know at what fill pressures this is being done? I'm looking to avoid over driving the hammer.

I know that I'm in for fiddling regarding the SSG and spring compression etc, just looking to wrap my head around the hammer travel.  I want to keep the power up and hopefully lose some of the spring load. 

Thank you,

Dave

[FuzzyGrub]

All crosman valves I've used were capable of the valve stem going flush to the back of the valve.   I think that would be the case with your disco valve, even though you changed to the Mrod poppet.  If they didn't the poppet stem would get beat over or damage the valve when degassing via shooting it down. 

[TF89]

I found a spare Discovery valve and found that the valve stem doesn't go flush to the valve back.  It sticks out .077 when fully depressed into the valve. 

I received the hammer pin from Alchemy Airwerks https://www.ebay.com/itm/New-Custom-Stainless-Steel-Hammer-Pin-for-Crosman-CO2-AIrguns-2240-2250-2300-etc/302061826370?epid=686787827&hash=item465449b142:g:6C4AAOSwEK9UI50d

Because I'm using the prod/challenger hammer I had to drill the cocking pin hole deeper because his hammer pin is longer on both the bottom and top of the pin.  If I was using the stock hammer it would have just fit without any adjustments.   It was surprisingly easy to drill out the hole, with a drill press anyway.  I also had to shorten the pin on top by 1/16th"  because it was too long for the BNM breech and interfered.

I highly recommend this hammer pin because there is absolutely no movement (wobble or tilting) once the pin is installed.

As far as adjusting hammer travel, hopefully I will be able to get some chrony time soon to find the optimal set up. 

[FuzzyGrub]

FWIW: The challenger hammer pin is tall (on top) like the SS pin you bought.  The prod one is short.  I've used the challenger pin for breech risers on Prod.   A slightly filed down challenger pin will fit prod, and helps slightly with the hammer tilting with heavier than stock springs.  It was more of an issue on the breech risers, where I couldn't lower the bolt lug closer to the air tube. 

Thx for the info on the disco valve poppet extending.  The Prod/1720T/1701 valve, Fortitude valve, and Mrod valve will go flush.   I did have a disco valve, back a while ago, and thought that went flush, too.  Sorry for wrong info. 

[TF89]

That is good to know.  I don't know why Crosman doesn't add another 1/16th or 1/8" to the bottom of the hammer pins?  That extra bit of length would go a long way toward reducing hammer bind.  Thinking the Maximus and new Fortitude with the heavy cocking would use a better pin.

Maybe they do and I just don't know about it.

[FuzzyGrub]

That is good to know.  I don't know why Crosman doesn't add another 1/16th or 1/8" to the bottom of the hammer pins?  That extra bit of length would go a long way toward reducing hammer bind.  Thinking the Maximus and new Fortitude with the heavy cocking would use a better pin.

Maybe they do and I just don't know about it.

FWIW: The Fortitude Gen 1 pin is longer  

[TF89]

Is that longer on the top or the bottom?

[FuzzyGrub]

Is that longer on the top or the bottom?

Top.  I suspect it is the same part as the Challenger pin, but didn't have one available to measure and confirm.