Didn't need it but I did it anyway

zoned · April 10, 2011, 11:54:04 PM

Quote from: eric on April 10, 2011, 10:43:49 PM
don't think they came from crosman he states expensive grips($75) and they do look like keith's

Agreed.

ChokingVictim · April 11, 2011, 02:44:34 PM

Quote from: eric on April 10, 2011, 10:43:49 PM
don't think they came from crosman he states expensive grips($75) and they do look like keith's

+1

mr007s · April 18, 2011, 01:19:27 AM

We had some great weather today so I set the chrony up outside and ran some Hobby pellets down the barrel.Changes made were the addition of a HDD,12 inch Mellon barrel, reducing spacer fitted inside the stock valve, and smoothing of the trigger assembly. still haven't got the shot count where I would like it and the velocity is still higher than I need. I am thinking of preloading the valve spring with some stack washers and/or fitting a lighter hammer spring. The first 30 shots are very good with really low SD. If I can duplicate that and get the shot count up I will be pleased.

quickster47 † · April 18, 2011, 02:33:54 AM

The data is looking good.

Another thing you might try is a lightened hammer.

Carl

mr007s · April 18, 2011, 03:23:46 AM

Quote from: quickster47 on April 18, 2011, 02:33:54 AM
The data is looking good.

Another thing you might try is a lightened hammer.

Carl

Any recommendations? I know I can search Ace or other stores but am wondering if a certain model Crosman would have a lighter spring. I don't want to go so light the powerlet won't pierce.

quickster47 † · April 18, 2011, 03:35:51 AM

Not sure about the spring but if you like I could post a couple of pictures of how I have lightened my hammers. Usually get a reduction of about 8 to 10 grams.

One other thing you can try is making a new transfer port piece out of aluminum and decreasing the size of the passage. The Marauder pistol and the 1701P both have a 0.080" transfer port ID.

Carl

mr007s · April 18, 2011, 10:58:56 PM

Thank you Carl, if you could post the length and diameter of the turned down section I will cut one tomorrow to try.

quickster47 † · April 18, 2011, 11:40:30 PM

Here are a few numbers for you to ponder.

OEM 2240 striker = 59.6 g - average of 5 hammers.
OEM 2300KT striker = 57.5 g - average of 3 hammers. (this has the notch)

Weight reduction = 9.3 g

Diameter of cut = .540"
Length of cut = .450"

Carl

mr007s · April 18, 2011, 11:44:07 PM

Thanks Carl, that helps a bunch. Will report my findings in a day or two.

arkmaker † · April 19, 2011, 01:06:12 AM

Those are nice numbers up to 39. I will be reading this post with much interest as this is where I wanted to go originally. The power demon took over and I ended up going the other way, but......keep going!
Rich

mr007s · April 20, 2011, 12:40:29 AM

Got some things changed today. Thanks quickster for reminding me about reducing the hammer weight. So, arkmaker, quickster, and others that may be following this thread, here are the changes and the results.

I would have better data if i could have done each change separate and recorded the results but I get tired of all the taking apart and putting back together. There were three adjustments that produced results that are where I want to be with Nugget.

1- machined hammer to reduce weight by 135 grains. The post Carl made showed his was reduced 143 grains so I got it pretty close. Did a bit more polishing and applied a light coat of moly paste during assembly.

2-Turned out an aluminum transfer port with a .082 orifice size. Polished drill marks from hole.

3- Placed a .035" shim in the valve, the end where the piercing pin is. By compressing the valve with the spring installed it had .050" space. I decided to fill part of it and hope to increase the spring rate as a bonus.

I had time to set up the chrony but not the printer and fire off 30 rounds. The first two shots to pierce the powerlett sounded very weak. I thought oh no, I went too far. But, to my happy surprise the first shot was 416. The remaining shots never went below 412 or above 420. I am very optimistic that the shot count will be up where I want it. The grass needs cut and more rain is in the forecast so it may be a few days before I get a count with some averages and SD's.

The trigger feels even lighter now or maybe that is just my mind playing tricks. One thing for sure, she is very quiet for a 22.

Thanks, for the help Carl and others, It is appreciated.

arkmaker † · April 20, 2011, 12:46:05 AM

That had to have helped the shot count too, right??
Rich

quickster47 † · April 20, 2011, 02:14:57 AM

Sounds like we have come up with a winner. We need to do a little document on the things done and how to do them for others looking to get increased shot count for target shooting.

Did you end up keeping the OEM hammer spring or did you find a substitute?

Good job!

Carl

mr007s · April 20, 2011, 02:31:55 AM

Quote from: quickster47 on April 20, 2011, 02:14:57 AM
Sounds like we have come up with a winner. We need to do a little document on the things done and how to do them for others looking to get increased shot count for target shooting.

Did you end up keeping the OEM hammer spring or did you find a substitute?

Good job!

Carl

I have not changed any springs and they look like factory springs. Have no reason to believe the previous owner had changed them either.

mr007s · April 25, 2011, 02:28:20 AM

Nice out today and I had time to chrony "NUGGET". Temps in the mid 80's. Looks like around 70 good shots. The chrony had 10 or so errors during the run so the number count would be a little higher than my graph shows.
I am well satisfied with this set up and plan to leave everything like it is and just shoot the heck out of her.