TargetTalk

Was wondering if anyone here has any expirience at rebuilding the hydraulic dampner unit in the anschutz 250? So far I have found out some info but am needing to know what rod seals were used what type and size, seems like a hydraulic seal manufacturer should have something that will work if I know what I am looking for, any help would be appreaciated thanks.

Yes I have done one. Unfortunately I can't remember the details. On my gun the breech seal was all gummy almost like bees wax and the hydraulic damper was leaking. I turned a new breech seal from nylon and that worked well. When I ordered the hydraulic seals I ordered two extra and have them here. I bought them from MSP Seals, Inc. in Indianapolis, IN. their phone number was (this was 2005) 317-541-9980. The description of the seal is 5x12x5.5 U-Cup, Symetrical Urethane. The thing I can't remember is if the seals just fit right in or I had to put it in my lathe and bore pockets for them to fit into. For oil I think I just used some 20 weight machine oil or similar. I shot the gun some with a new breech seal but the damper not rebuilt and the gun shot very badly. Once I rebuilt the dampener it was a really good shooter so the thing is pretty important. Beautifully made guns!

Thanks so much, and I measured a unit I have here and the seals sound absolutley correct, you are the first person to help me out so far on this, I appreaciate this very much.

I have a 250 that I bought new in 1968. I'm just now trying to get it shooting again. The breech seal is the same gummy beeswax, and I can probably make one out of nylon if I can get some and figure out how thick to make it. I don't know about the internal seals. How many are there and are there different sizes?

Thanks for any advice,

Alan

The only internal seals are in a hydraulic damper. It is a little cylindrical aluminum thing that has a rod sticking out each end. Inside it has a little piston with loose fit. Each end of this has a hydraulic seal. and these are what may need to be replaced if your damper is leaking. The breech seal as you said can be turned from nylon. I remember it being a little tricky to get the length of the breech seal just right. I think it took some trial and error.

pdeal,

thanks very much.

Alan

It may be too late to be of much help, but I have just over-hauled my 250. The damper seals are hydraulic ram seals 5 x 12 x 7 and readily available in Auckland NZ. The breech seal I machined out of a soft urethane and made a die with 65 degree angle and length to suit the breech. This I mounted in the lathe tailstock and the piston housing in the chuck. I heated die and run it upto the partly formed seal which melted a little and made a perfect seal at the correct length. The piston buffer was also disintegrated and this I made with a harder machinable nylon. The gun shhoots OK, but is very pellet sensitive and not all that powerful.

I just ordered a pair of 5 x 12 x 6 mm U-cup rod seals for my hydraulic damper unit. I got them from Brewer Machine in St Louis. The price was right at $6.00 each.

SteveM

What to look for: why do you want to replace the seals?
The 250 is a VERY weak design. Not meant for regular shooting really. Shooting without or with too little oil causes the action to split at the rear action pin. It can also cause stock cracks at the rear, behind the action.
If the action has a split, its a total loss..:(
I used automatic gearbox oil iirc.
Also check the hard damper plate inside the back of the action. This should buffer the oildamper on its backstroke. If its missing or too thin, the oil damper will damage the action for sure.(+ destroying the damper itself)
The 250 is anschutz''worst'design reliability-wise..It shoots very well though.
Make sure to glue those new seals into place. They'll start walking if you dont.

On the airgunbbs is lots of info about the 250 reseal. Garvin wrote his story there.

I also found that the 250 shot very badly (poor accuracy) without a functioning damper. I actually thought it was a very nicely made gun and mine shot well once I got it fixed up.

Yeah, if it leaks, you see a squirt of oil coming out of the barrel with every shot. Cant be good for consistancy. And of course, vibration and more recoil