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Alstone · Moderator & Site Supporter

HaHa, Navel/Naval. I don't know what I was thinking about. Laughing

As for the thread sizes I'm not sure, but they come with a nice pair of Boffor's. Mr. Green

Alstone · Moderator & Site Supporter

The only thing I haven’t looked at on this gun is the valve, so I took it out this morning and stripped it down, It has been working all right but you need to have had a look inside to check that everything is in the right place, apart from the valve face being a bit rough, so it was cleaned up and polished, while it was apart I decided to do a couple of mods to it but nothing that could not be reversed. I took a couple of threads off the valve cap to increase the volume in the body, also ground out the port from the valve seat to the exit hole to increase the flow.

After re-assembling everything I charged it up and setup the crony for a shot string, the crony is coupled to a laptop to record the string etc. The power setting was set in the middle which is about two coils cut off the standard spring.

The output had increased by about 10 fps but the shot string was even flatter then before, so I am well pleased with the results also the shot count had not gone down like I thought it would.

All I want now is some decent weather.

Al

Brutuz · Senior Member

Looks like an excellent string to me Cool

rsterne · Moderator

My guess is that increasing the volume did nothing as since you are in "self-regulating" mode you are only using a small part of the volume in the valve anyway.... You likely picked up some efficiency in the flow between the valve seat and the transfer port to gain the 10 fps there.... you're using the small amount of CO2 the valve is releasing more efficiently....

IMO opinion, you were lucky altering the port.... I've never been successful doing that in .177.... Now .22 cal?... that's another story entirely.... Mr. Green

What are you getting, about 60 good shots at 52*F?....

Bob

Alstone · Moderator & Site Supporter

Hi Bob I did take into account what you said about altering the valve before I started, but you know what enquiring minds are like “What happens if I do this?” Ha-Ha so you have to have a go. If it had gone wrong I could have sleeved the valve body and the port down or put a reducing washer in the port as you suggested.

I was wondering why the increase was only 10fps and you have explained that, so I’ll leave things as they are now as I’m happy with the output.

On the last string I got 66 good shots over 500fps and from there only about 10 until empty, so that is good especially with the temperature at 52*F, I will be interested to see how the fps and shot count increases with higher temperatures. I think I am in the same boat as you trying to get a steady temperature in your garage for testing, I test in a glass conservatory which is susceptible to temperature change very quickly.

Cheers

Al

rsterne · Moderator

Alstone · Moderator & Site Supporter

I got one grip made today, I like the colour but not sure what the wood is, the problem now is do I checker it and possibly mess it up or leave it alone ?

BTW Slavia your tip of scanning a grip and using it to get the correct shape was a good one. Thumb Up!

Al

Alstone · Moderator & Site Supporter

I finally got the grips finishes I was going to have a go at checkering but thought better of it for now, the wood is I believe a light mahogany anyway it looks nice, I made them a bit fatter than the originals which gives me a better grip. Also I just used teak oil to get a nice sheen on them.

I was going to re-spray the frame as it needed cleaning up to get rid of the casting marks, once this was done and polished I decided to see what aluminium gun black would do to it, so I painted a bit at a time and wiped of the surplus straight away and hey presto perfect blue black which won’t chip, it did look nice just polished metal but it didn’t go with brass.

Al

Slavia · Moderator

Nice work, Al.

I agree that blue/black next to the brass is more attractive. The screw cup is a nice accent, too.

Brutuz · Senior Member

Looks great Al Cool

Alstone · Moderator & Site Supporter

Finished !! One custom 2240, I took it down to the range today because it’s a bit warmer in there and I haven’t shot it in a higher temperature than 60*F, the range is 72*F so the Fps went up a bit to around 550fps with 7.2 grain Hobbys, I didn’t crony all shots just about every ten, also the good shot count was well into the 70s. Cool

On the 20m range I was getting 25mm groups shooting from a bench, and 60mm standing which I was pleased with, this btw using iron sights I don't find much diffrence between them and a Red Dot, the accurcy is I'm sure better than my figures I just need a decent rest which I didn't have with me.

I must admit I am quite impressed with the basic Crosman pistol, and they are a lot of fun to upgrade in fact probably one of the easiest. I would like to thank the guys on this forum for there help and suggestions which kept me going in the right direction. Thumb Up!

So all in all a successful project which was going to last me through the winter, and it lasted less than a month, I guess I’ll have to look around for something else to bash around. Mr. Green

Al

Brutuz · Senior Member

Excellent result Cool

Will you be using it in the bi-weekly comps?

Alstone · Moderator & Site Supporter

I will Brutuz it shoots very well now and that barrel you supplied is A1. I’ll give it a go tomorrow at the present target.

Cheers

Al

Alstone · Moderator & Site Supporter

Changed things a bit today I fitted an extra barrel band as I was not happy with the way the breech was fastened down, and could allow the barrel to move, but now it is solid and the extra band takes the load off the small screw holding the breech down, the other change is to .177 Bisley Pratice pellets which the 2240 seem to like.

The target posted below is 10 shots with one flyer from a bench, the group is 16mm at 20m / ¾” at 21.5 yds, using iron sights. So I am very pleased with the results.

Al

broommaster2000 · Moderator

Sexy.