anyone tried the lothar walther barrel on a crosman co2 pistol?

[Andrewjames]

quite alot of money but want a step up from the standard crosman barrel..

was hoping someone out there could give some advice on the potential differences with a LW barrel as seen on GMAC http://www.gmaccustomparts.com/epage...cts/5-1700-017


thanks
andy

[eyebull]

I would be inclined to address all the other areas of inconsistency in the action and try recrowning the existing barrel before splashing out on a LW barrel (probably £100+ after postage and RFD fees).
Not much point in having a match barrel if the velocity is all over the place?

[Andrewjames]

thanks for great response,

i have made some adjustments to the workings like trigger, re crowned barrel and some upgrades like steel breech etc, but haven't yet made any adjustments regarding the consistency..

infact, are there any recommendations you can make about improving the variation? i expect the next upgrade i will make will be a power adjuster screw for the hammer spring..


cheers
Andy

[TonyL]

Totally undecided on this, personally.

On the one hand I think, "Why not? For those that can, great, let's see how much we can go with these things and how much improvement can be gained." And there's always the case for "why not" indeed.

But then on the other hand I'd cringe at the sheer amount of money I'd have tied up in one when there are other pistols that perform better out of box, some expensive, some not so expensive, and I'd feel I'm ignoring one of main attractions of the pistol as a good performer at a budget price point.

And there's always the performance variation with temperature changes to be taken into account.

One thing I think I would want to explore is reducing gas wastage by reducing hammer tension, reducing power slightly and increasing shot count further. Even easier with a longer barrel which would also increase the sight base.

[short-carabine]

I would be inclined to address all the other areas of inconsistency in the action and try recrowning the existing barrel before splashing out on a LW barrel (probably £100+ after postage and RFD fees).
Not much point in having a match barrel if the velocity is all over the place?

Agree with you on addressing any other "areas of inconsistency", but I'm not sure whether Crosmans are particularly prone to having velocity all over the place. Chronoed my (admittedly customized 2250B, which still runs on a single 12g CO2) on the weekend. Over 10 shots;
High: 540 fps
Low: 531 fps
Av: 536 fps

Not too shabby.

[eyebull]

thanks for great response,

i have made some adjustments to the workings like trigger, re crowned barrel and some upgrades like steel breech etc, but haven't yet made any adjustments regarding the consistency..

infact, are there any recommendations you can make about improving the variation? i expect the next upgrade i will make will be a power adjuster screw for the hammer spring..


cheers
Andy

While balancing the hammer and valve springs does get some results, it only gets you so far.
The absolute best thing you could do IMO, is make a Stopped Spring Guide. If you are a bit handy and have some basic tools they are not hard to make.

I made one for my .177 2240 target pistol a couple of years ago, and it gets me 120 shots at 3.5 ft/lb, with a good band of consistency.

See this thread: http://www.airgunbbs.com/showthread....40#post7231940

If you have any questions just ask away.

[eyebull]

Totally undecided on this, personally.

On the one hand I think, "Why not? For those that can, great, let's see how much we can go with these things and how much improvement can be gained." And there's always the case for "why not" indeed.

But then on the other hand I'd cringe at the sheer amount of money I'd have tied up in one when there are other pistols that perform better out of box, some expensive, some not so expensive, and I'd feel I'm ignoring one of main attractions of the pistol as a good performer at a budget price point.

Ah Tony, if logic came into it at all then you would be completely correct

Half the fun is in the building of the thing - does it make financial sense? God no. Is it immensely satisfying to make and shoot your very own unique pistol? Absolutely

[eyebull]

Agree with you on addressing any other "areas of inconsistency", but I'm not sure whether Crosmans are particularly prone to having velocity all over the place. Chronoed my (admittedly customized 2250B, which still runs on a single 12g CO2) on the weekend. Over 10 shots;
High: 540 fps
Low: 531 fps
Av: 536 fps

Not too shabby.

For a 10 shot string that is indeed not too shabby, but have you tried measuring the velocity over the entire fill...?

[Shed tuner]

I rebarrelled a few, but you don't need to spend £100 on a brand new walther barrel - totally OTT for the gun. I just use an old springer barrel - e.g. an HW or BSA .22 barrel - and machine it to fit, simples. You can find them cheap on the bay.

[Andrewjames]

I rebarrelled a few, but you don't need to spend £100 on a brand new walther barrel - totally OTT for the gun. I just use an old springer barrel - e.g. an HW or BSA .22 barrel - and machine it to fit, simples. You can find them cheap on the bay.

Great advice and thanks for your post, i have the standard barrel here that i can practice on, also a sc3 seig mini lathe with all sorts of tooling.. i asked about the new barrel as i cant seem to fix the barrel i have and thought it might be a good opportunity to upgrade at the same time..


i have already re-crowned the muzzle with an 11 degree taper and it seems like a job well done, the issue really is the breech end..


Initially when slid my barrel into my gmac steel breech, their appeared to be a 1mm gap between the barrel breech end and the back face of the breech itself (which annoyed me when loading pellets) so i thought i could stick it in the lathe and machine 1mm off the barrel breech end. However, it appears that there must be a chamfer or taper left inside the steel breech which ultimately hasn't helped me get rid of the gap, instead i have widened the gap by taking another 1 mm off the barrel's breech end..

as a secondary result the air flow hole on the barrel is now 1mm too far back to match the transfer port hole.. the job has become a bit more difficult for me as it is my first barrel machining experience.


so as i understand it, i need to part off the breech end and re do it BUT the .177 hole is so small i cannot get any tooling in there, i also need to make the chamber hole match the taper on the gmac bolt probe and get it seated at the right depth to accommodate the probe oring etc..


do you have any advice on chambering .177, the tools i might need and process etc?

the other option is to buy a LW barrel


thanks
A

[Andrewjames]

While balancing the hammer and valve springs does get some results, it only gets you so far.
The absolute best thing you could do IMO, is make a Stopped Spring Guide. If you are a bit handy and have some basic tools they are not hard to make.

I made one for my .177 2240 target pistol a couple of years ago, and it gets me 120 shots at 3.5 ft/lb, with a good band of consistency.

See this thread: http://www.airgunbbs.com/showthread....40#post7231940

If you have any questions just ask away.

I will be making this my next project! i expect i will have questions, stay tuned for the weekend

Andy

[short-carabine]

For a 10 shot string that is indeed not too shabby, but have you tried measuring the velocity over the entire fill...?

Yep. It stays in that range to shot 23. Only peters off after that. Granted it has had a valve job, so while I don't get many shots, the consistency is good.

[eyebull]

I will be making this my next project! i expect i will have questions, stay tuned for the weekend

Andy

Forgive the crude drawing, but this is basically what I built:

[Andrewjames]

Forgive the crude drawing, but this is basically what I built:

Looks great, i will have a go.. question, how would you adjust the power on that system? should the power be adjustable? i guess you can with a co2 power plant?

best
A

[eyebull]

Looks great, i will have a go.. question, how would you adjust the power on that system? should the power be adjustable? i guess you can with a co2 power plant?

best
A

The trouble with external power adjustment on a 2240 is that if you've done a few other mods it's not difficult to crank the power right up past the limit. For the pistols at least it's best to set the power internally (leaving a decent margin for the coming summer heat) and be done with it.
While the 2250 rifle is a PITA to get to full power, the 2240 pistol has the opposite problem.

With this system you set the power by adjusting the length of the allen bolt (I had a few on hand so was able to play around chopping them up), by using different springs, and by adjusting their preload with the two nuts. Once you have it where you want it you can loctite the nuts and then turning the allen bolt from the outside will not effect the power. The amount of preload on the spring, and the clear distance between the spring and hammer, is what changes both the power and the amount of hammer bounce.
You'll know when you are getting there because the report on firing will sound quick and sharp, rather than 'farty'. If you have a moderator on it will be just as noticeable if not more so.
This does meaning a few repeated teardowns/builds, but taking the time to get it right is rewarding.