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Challenger 2000 rifle rework.
Posted: Sun Jul 15, 2007 3:47 pm
by CharlesC
I have worked on a number of CH 2000 rifes that would not puncture CO2 capsules and were not accurate.
Here's what you do:
Pull the gas valve and put the spring that's behind the trigger inside. That trigger spring is way too strong as is the one inside the gas valve. That too strong gas valve spring is the reason these rifles don't puncture capsules. Replace the trigger spring with a very weak one from a hardware store. The weaker the better. If y'all want to know how to make the trigger much better let me know. Make sure the gas valve exhaust valve stinger is sharp. Sharpen if neccessary. Look at the sealing surface of the exhaust valve. About 50% of the ones I check are bad. Replace the tan CO2 gasket on the end of the gas valve. They are usually distorted from the gas tube cap being tightened too much. The rifle will now reliably puncture capsules.
Remove the paint that's no doubt in the end of the barrel. Use BIX paint remover or carburator cleaner. Rework the crown if dinged - most are.
The rifles I have reworked are 100% reliable and stack pellets.
Posted: Sun Jul 15, 2007 4:46 pm
by Pat McCoy
Good ideas, but remember these alterations make the rifle ineligible for use under the current 3P Air Rules.
Posted: Sun Jul 15, 2007 10:22 pm
by CharlesC
Pat McCoy wrote:Good ideas, but remember these alterations make the rifle ineligible for use under the current 3P Air Rules.
I didn't know that. I shoot only 10 meter and the rare field target event. Do you have to use completely stock guns? Define stock.
Posted: Sun Jul 15, 2007 11:11 pm
by CharlesC
I read some comments on 3P rules a few posts down about someone installing a non-OEM steel weight rail in place of the stock aluminum one. Would it be stretching the rules to use an OEM part but in a different place, i.e. a stock Crosman trigger spring substituted inside the Crosman gas valve for the one that's supposed to be in there? They look almost identical but have different spring rates. There is no performance gain, it only allows the gun to function as intended by the OM. What about minor reshaping of OEM parts such as a trigger sear? I read that a lot of 3P competitors "tweak" their triggers. The reason I ask is to have some idea of what is customarily allowed if approached by a 3P competitor for airgun repair.
I think I found the answer
Posted: Sun Jul 15, 2007 11:23 pm
by CharlesC
OK, I get it.
"4.2.5 Internal Modifications
The functioning of internal parts may be smoothened or improved, but only factory manufactured
parts designed for that specific model rifle and functioning as they were originally
intended to function may be used. It is permitted to polish, file or otherwise reduce the
dimensions of the hammer rim or sear or to install a setscrew in the trigger guard of Daisy
M853/753/953 air rifles as a means of reducing or controlling sear engagement."
Tom Johnson's Sporter Tips
Posted: Mon Jul 16, 2007 9:15 am
by jhmartin
As a follow on side note to this, I had emailed CMP to make sure that the modifications listed and described in the above booklet (from CMP) were indeed legal mods. 4.2.5 & 4.2.6 do not describe them, so I wanted to know if I needed to put unaltered springs back in our 888's & 887's for Nationals and the American Legion match.
Below is the reply from Gary Anderson on 6/21/2007:
It is permitted to modify the trigger springs on Daisy sporter air rifles by "cutting off a few turns" as is suggested in Tom Johnson's Sporter Tips as long as the trigger still lifts the 1.5 lb. trigger weight. This practice has been going on for many years and is regarded as a legal means of improving the functioning of internal parts. Given the current sensitivity to permitted and prohibited modifications, we may need to add a line in the rules specifically authorizing this.
Gary Anderson
I personally would be VERY, VERY cautious of any internal mods "that are not specifically authorized by these rules" (4.2.6). It is a very simple thing to email the CMP and ask for clarification. (Then keep the email & post the reply for the rest of us)
While I was pretty sure that anyone on the line(s) that had trigger mods, had the spring loops clipped, I wanted to make (da_n) sure I didn't mess my shooters up since it was not "specifically" called out in the rules.
For CharlesC: My reading of 4.2.5 would allow a crossman spring to be placed in a different location of another crossman spring, as it is functioning as a spring .... however someone else may say it is not functioning as trigger spring, but a gas valve spring .... dunno, if I had the C2000's I'd email CMP for clarification and explain just as you did here.
It's a shame that we have these questions in any case, especially when you look at the adjustments available to the CZ variants (XS-40's & T200's) right out of the box. (also the supposedly new AirForce rifle)
If you look at it in one way, you're paying the extra $150-$200 for trigger adjustability.
IM(H)O .... "1.5 lbs" should be sufficient
Also .... the replacement of the alum rail with a steel one is no longer allowed.
Also CharlesC .... where are you located in NM (down near Las Cruces?) Are you 4-H, club, or JROTC?
Re: Tom Johnson's Sporter Tips
Posted: Mon Jul 16, 2007 11:13 am
by CharlesC
[Also CharlesC .... where are you located in NM (down near Las Cruces?) Are you 4-H, club, or JROTC?[/quote]
Radium Springs is 15 miles north of Las Cruces by old Ft Selden.
I shoot 10 meter air pistol competition in the NM Senior Olympics. I'm currently the state champion in both benchrest airpistol and off hand air pistol. Next year I will shoot in the rifle events using a CH2000 rifle that I have reworked. I can barely see pistol sights anymore at the ripe old age of 67. A lot of our shooters in Dona Ana County used the Daisy 853/753 rifles but all are disappointed with them even after the Pilkguns trigger mod. Most complain the rifles are too light and the trigger still isn't very good. I haven't worked on them. I may add some weight to those rifles for next years games. I do all this for free as my contribution to the sport. I have also gone thru more Daisy 717 and 747 pistols than I would like to admit but that's another story. I use an old IZH-46 for bench rest and a custom pistol I made based on a Crosman 1377 for the standing event.
Posted: Mon Jul 16, 2007 11:22 am
by jhmartin
See you next year .... if not before.
I just turned 50, so I'll join you next year at least in the rifle event.
If you're ever bored, Dona Ana 4-H could use an Air Pistol or Air Rifle project leader/coach..... They fire smallbore rifle & pistol, but an air program(s) would really help those kiddos out.... I know there are good shooters in air programs in the LC high schools .... don't see them in the 4-H program though.
Posted: Tue Jul 17, 2007 6:29 pm
by CharlesC
I talked about the 4H program and airguns with the prime mover in airgun competition down here last nite. She said she had talked to them about airguns in the past but they weren't really interested. They're perfectly happy shooting their .22 rimfires.