comparison of 13xx aftermarket valves, pistons, springs, ports, etc.

[DHunter]

Can anyone here direct me to, or write up, a comparison of the available aftermarket 13xx valves, pistons, springs, ports, and anything else that may increase the power of my 1322 rifle?  What I have from David Grimes at Alchemy Airwerks (who is wonderful to work with!) has:

• 18" barrel, re-crowned by him
• steel breech
• RP valve
• longer bolt probe
• larger transfer port
• stronger hammer spring

and it has approximately double the power of my mostly stock 1322 pistol (comparing at 12 pumps)¹; but I know other 1322 owners have gotten a lot more power.  I would like to get the 18-grain JSB's up to at least 650 FPS if practical, ie, 17+ FPE.  I'm not necessarily trying to get it as high as possible, nor to 850 FPS, and I don't want to pump 40 times .  I have a .25-cal Marauder which will easily put a pellet through a 2x4, and my next airgun might be a .257 Texan with about 180 FPE.  I don't have any interest in going further, like into the .50-cal ones suitable for really large game.  17 FPE would give a nice distribution of power level ratios from one gun to the next, across the four of them.

Doug

¹ That's comparing by using Davio's blogged method of comparing power by how many layers of cardboard the pellet gets through.  A friend has offered me his chrony, but we have not yet been able to arrange a time to get together yet to make the transfer.  What's in it for him, you ask?  I was going to do some testing on my Marauder that he hasn't been able to do on his; so he would benefit.  Just the sound of the delay between the hammer strike and the pellet hitting the target tells me the 1322 rifle isn't shooting the pellet anywhere near as fast as the Marauder is.

[DHunter]

bump (since I just got a chrony and I'll be doing some testing soon)