Printable View
Anybody ever rebuilt an air rifle?
I have a RWS Model 45 and it's getting so weak that it won't down a starling and the neighbor's cats are just giving me the finger when I come out with it.
What's involved?
Where do I get the rebuild parts?
What about spring compression?
Am I better off paying for a rebuild?
/beagle
beagle
Happens I have that same model and rebuilt it. Thing is I got the parts from a friend at work whose brother worked for a big airgun place that does RWS work.
The hardest thing is removing the spring and putting it back. You can imagine the pressure it's under. Have the receiver mounted in a good holding device when working on that spring. There's not a whole heck of a lot of parts in the gun so it's pretty straight forward. Right now I need a need piston in mine.
Joe
What, with MONEY? This is something you can do yourself, if you can find a source of the parts. I think the address Hiller on the following ad, in the UK, is still a spares stockist, though I don't know about export.
http://www.airgun.org/books/info.html
Basically three main considerations can cause lack of power. The barrel seal washer can be worn or missing, and you should be able to do a good enough temporary job with silicon sealant to find out if this is the case. You may be able to make a permanent replacement with a general-purpose O-ring from a garage, or a piece cut from rubber tubing or leather.
The mainspring may have lost some power or even broken, and the way to check this is by comparing the cocking effort with someone else's RWS 45. If it is weakened, or especially if you hear any odd grating noises, you shouldn't try cocking it again, in case a broken end scratches the cylinder bore. A square wire spring may put marginally more power into the available space than a round one, although this is a complex interaction between numerous variables, and may not work out. If you have trouble getting a proper airgun spring, something in the range of springs sold by www.mcmaster.com for separating injection-moulding dies, with square wire, may be suitable. My small Martini got its mainspring this way, though it will be a while before I do business with this otherwise excellent supplier, since their shipping company for overseas orders has a $60 minimum. Within the US is probably quite different. You can reduce the outer diameter of one of these springs slightly by putting a wooden dowel through the centre, and letting it spin against a grinding wheel. Remember that a coilspring expands slightly, widthwise, as it is compressed.
The last possibility, and a difficult one to diagnose, is that the piston seal is worn or cracked. Again it may be possible to turn one or adapt something else. Free movement is more important than the most perfect hermetic seal. The temptation to ream out the airhole is best avoided, as it may actually reduce velocity. Rust or dirt blocking the hold is unlikely, provided that the cylinder has been properly lubricated with very small amounts of special air-rifle oil. Other oils can "diesel", which isn't dangerous or a source of extra power, but may make for some inconsistency and sooting.
At least you don't have to worry about getting a little extra energy in some way. In Britain licencing is required for more than 12 ft./lb. (or 6 in a pistol.) I can't see how public safety depends on this. (How do you make an air-rifle you can fire in someone's direction?) But the owner's safety certainly does.
Quote:
Originally Posted by beagle
Hey Ballistics, great to hear from you. Haven't seen your handle since the old shooters.com daze.
Using the wrong oil and causing dieseling can in fact crack your piston seal or worse. It can also flame cut the seal.
Joe
Quote:
Originally Posted by StarMetal
Yes, this is a SEE equivalent condition. ... felix
Beagle---The RWS are lifetime warranty. The warranty repair center is Airgun Express out of Montezuma Iowa. You can call them toll free and talk direct to their airsmith. My dealings have all been favorable--they seem to know their stuff. Their toll free number is 1-800-896-4867. Might be a case of why fix it yourself and spend money for parts when they will do it free?
Hey Ballistics in Scotland--good to see you.
Thank you, Fourarmed and Carpetman, for your kind remarks. I've been posting quite a bit on Gunboards under my maiden name of John Wallace.
Silly of me not to think of trying the distributor, which in this case sounds like by far the best bet. When all else fails, try something simple.
The most likely explanation for a damaged air rifle is that some intellectual has been firing it without a pellet. It depends heavily on there being a cushion of trapped air for the piston to impact on.
Most of us over-clean and over-oil our air guns. To not swab a bore is sinnister afterall???? From the RWS Manual---"Care is very simple. The working parts,like piston and mainspring,need no lubrication". It goes on to say that it is usually not necessary to clean the bore as pellets do not leave a deposit and actually clean the bore. There are a couple of conflicts. RWS does in fact sell both Spring Cylinder and Air Chamber oil. I guess you buy it but don't use it???? I have also read in RWS literature that pellets leave a residue which works as a lube----they are atleast consistent there as either case you DO NOT lube the bore. Every great once in a while I do run a dry patch through the bore. I use heavy .135 weed trimmer line and push it through. You can buy felt cleaning pellets. Problem is they are light and can have the same effect Ballistics in Scotland described as firing with no pellet. IF you use them--which I consider a waste of money--put a couple of them in with a pellet behind them. With air guns,there being no primer or powder,there is no combustion------unless you introduce it by oiling it and creating dieseling. With no combustion,things just stay clean and most cleaning efforts are counter productive. You do want to treat the outside surfaces as you would firearms.
Even at $2+/gallon diesel is cheaper than gunpowder, so if we could figure a way to run our guns on diesel?Quote:
Originally Posted by carpetman
I bought my son a Crosman rifle last year. Break barrel job that will pop a .177 pellet through 1/2" OSB at 25 yards. Cracks like a 22 but I haven't thought to crono it yet. Problem is yoou can't hit crap with it. I figure it's the gob of crap halfway down the barrel at the 7:00 position. Just got a 17 cal cleaning rod to try. Got a 15 lb trigger too. Made in Turkey. Maybe I should have bit the bullet and bought the Beeman GS1000 I really wanted.
A slight mist of oil in the bore immediately after firing is normal, and its depositin may reduce friction and avoid rusting. Assuming that that patch in the barrel isn't rust, the low operating temperature of air rifles means that it could be something which would scrub out quite easily if heated gently or soaked with a solvent.
I don't know the Crosman design at all, but the high pressure on the piston means that if an air rifle with a simple trigger has a heavy trigger pull, it may need it to be safe.
Thanks fellas. I'll check out the warranty station. If that don't work, I'll attempt to find some parts and do it myself.
I figured there was a spring in it the size of the one on a M2 .50. I once saw one of those pemetrate a ceiling tile so I didn't want to get carless here./beagle
When I first got my RWS Model 48 I chronoed it at almost 900 fps. I've killed such things as skunks and magpies with it. When it was new and I shot a bird, you would hear the pellet pop when it hit the birds body. Last time I chronoed it the thing was down to about 400 something. I think my piston seal is shot.
Joe