HUMA regulator for .22 Marauder a SUCCESS!

The Marauder that was a replacement from Crosman came with a horrible chrony. I had no idea it was a replacement, it came back with no note or explaination. ( I was told by Chip to "try a few different pellets"). Here's what came "specially tuned "(Chip's exact words) from Crosman for 30 shots:
spread 876 fps-784 fps
Avg speed 836 fps
spread total 92 fps
St. dev 31.33
After adjsuting the transfer port and Hammer tension I was only able to get 20 shots with a 50 fps spread. After the 5th shot things dropped quick. After installing the HUMA regulator from Air Superiority, here's what I was able to get immediately after installatiion:
Spread 899 fps- 873 fps
Avg. speed 888 fps
spread total 26 fps
St. dev. 7.34
I was successful in achieving my goal of at least 25 FPE and 30 shots. Nick states that it will take time for the regulator to break in so I believe I may be able to increase the shot count and shorten the spread even more. I may decide to widen the transfer port to help flatten the string. This a plinking rifle so I don't really need more power.

SPECIAL thanks to Nick at Air Superiority, AJshoots, and 30cal for all their help. 

[url="http://i.imgur.com/BQ4tiVO.jpg"][img]http://i.imgur.com/BQ4tiVO.jpg[/img][/url]
 
Doc, nice job. Did you install a lighter hammer? That's where a lot of your air conservancy will come from. Scott AKA Motorhead over on the GTA and Marauder forum makes some that are in the 25-26 gram range. I used one in my 22 Marauder when I regulated it and it worked great. Your gun is 22 correct? I was trying to find some of my old strings regulated and if I do I'll share them with you.
Jimmy
 
Thanks Jimmy,
I don't think I am done with this gun. I am on a mission with this thing! I was out shooting today and was able to get 3.5 magazines before the shot dropped. However, my POA was changing. I will recheck the chrony after I go through a tin or two. I was only able to get a few good groups with little wind so it looks like I will be swapping the barrel out. The new arrangement didn't like JSB's at all ( 14.35,15.89, and 18.1's). So I stuck with the Premiers. I think I will order a .22 Sampler pack from Straight Shooters when I order a new barrel. I will look into ordering a lighter Hammer. I might just change out the whole valve system. This ia my Son's rifle but I still want it to be on par with my other guns. I can shoot a better group with my Falcon pistol. To be continued……...

Doc
 
The light weight hammers work great. Of course you can go too light but the ones that Scott makes are plenty heavy to get you 30fpe. You have to remember that instead of the hammer needing to crack the valve open at say 200 bar like your unregulated gun used to do, now it's only needing enough energy to open it up to the regulated pressure that is in the plenum space which is probably going to be in the 130-140 bar range. With the factory hammer, more than likely it's over powering the valve and probably having hammer bounce. Once you get the weight down and the hammer energy balanced just right the guns shot noise drops a lot which is a good sound because now it's not wasting as much air. There are some other mods that can be done to the valve intake and exhaust along with the transfer port to really let the gun breath better which enhances the performance even more.
Jimmy