View Full Version : R1 twanging

09-24-2013, 09:07 PM
My Beeman R-1 was making a really bad twanging sound when fired. Soooo..... I thought that I would tear into it and check for problems.
Well, the mainspring is bent, that will account for the sound and it is really dry. I suppose that 30 years of little humidity will do that.
I ordered a new mainspring from Pyramid Air as well as a new breech seal and piston seal. I hate to pay freight, so to make free freight, I have a new Crosman Viper coming along for the ride. It should be here next week and I'll try to give you a review on it.

09-25-2013, 11:22 AM
Google, Air Rifle Headquarters, and check out their lube combination. Apparently the original owner has left because there use to be quite a bit of information on how to use the lubes and I don't see it now. However the information is readily available. Using the proper lube and the proper amount will go a long way to eliminate the twang.

09-25-2013, 02:08 PM
Silver Bullet: would you tell us how you tore the gun down?

What did you do to contain the spring?

Was there any problems with stuff flying about?

I need to take my HW35 apart to clean the auto safety. The HW 35 was the father of the R1 so they should be nearly identical.

After 40 years mine could probably use a new spring as well.

Is there an internet source for instructions on how to do this?

I know that using a Molybdenum Disulfide grease (black stuff) and coating the entire spring is one way to quiet them down. I did mine along time ago (thru the slot) and it is as quite as they can possibly be.


09-25-2013, 10:43 PM
Randy: Actually, the R1 is one of the easier ones to take down. Remove 2 pins that hold the trigger group. You do not need a compressor, the rear cap unscrews off with just a little tension. does the HW35 have a rear cap on it? The R1 only has two cross pins in the reciever to hold the Rekord trigger group. I believe that there may be more cross pins if the rear is not threaded and just a push on. Try looking on You Tube for instructions for the 35, there are a lot of helpful vids there.

Taking mine apart, I found a lot of dings, scratches, burrs , etc. on the spring guide, piston, etc. They are getting smoothed out tonite. I am going to put thrust washers on each end of the coil spring seats and polish the spring ends.

There are quite a few maintence vids on You Tube and several cover the springers quite well.

09-26-2013, 07:22 PM
I found them on youtube and also found out the R1 is just an HW35 with a longer stroke. Mine is supposed to have about 2" of preload on the spring. However after talking to the smith at Pyramid Air yesterday I elected to not go that deep into the gun.

I removed it from the stock knocked out the two pins, pryed the trigger assy out and washed in Diesel fuel to remove the 40 year old grease. My safety was sticking which was the whole reason to go into it in the first place, and It had to pry it out as well, cleaned everything and put it back together and it runs perfect. One of the good things about German made stuff is generally it doesn't wear out it just needs to be cleaned and put back together, Lots of stuff on my 1983 MBZ 300SD is like that. Clean, reassemble, drive for another 20 years.

One thing I did find out is that my gun has a leather piston seal. The Pyramid Air smith said that they rarely go bad as long as they are kept moist with oil. My gun still shoots really hard and I'm sure it is at least 650 to 675 fps and all any of the HW35's will do is 700fps, so I elected not to go any deeper into it. I don't have a spring compressor and with two guns I probably won't build one. My gun was made in 1975. and it was another 10,000 or so guns before they converted to the plastic seals.

The limiting factor on the HW35 was the 35MM piston stroke. The R1 is the same basic gun with a longer stroke and no barrel latch. I also found out they are still making HW35's but don't import them anymore.

All in all I got what I needed to service my gun. A few years ago this information was not available widely as the people who knew how to do it wouldn't share the knowledge. There really isn't that much to it but knowing this is more important than finding out all the little idiosyncrasies by making a mess out of your personal gun.

thanks Al Gore!

Also the guy at Pyramid Air was very helpful and he would have told me step by step how to completely disassemble my gun if I hadn't already saw the whole process on Youtube.


09-26-2013, 09:30 PM
In taking the R1 down, I found that there are NO plastic parts! Except for the piston seal, that is. The workmanship in these is not complicated and they are, as you said, built to be rebuilt and not replaced. Craftsmanship is sure appreciated. No wonder these rifles are not 99.00!!

Silver Eagle
09-26-2013, 09:56 PM
I have heard and seen many people scoff at paying that much for a "pellet gun." I have asked how them how much they would pay for a finer powder rifle? Quality airguns are built to the same (or better) tolerances and workmanship of a fine powder gun. Many of these arms with only routine maintenance have been handed down for generations and still command an excellent price in the used market. The saying "you get what you pay for" definitely qualifies on these fine arms.
Since 22 ammo has become scarce and the prices have skyrocketed the domestic airgun market has taken a very positive turn. People are realizing that they can be an excellent value for the money. Whether you are plinking, target shooting, or hunting they are an excellent alternative to powder guns.

09-26-2013, 10:11 PM
Consider getting a Vortec tune kit for that R1. It has a sleeve that covers the mainspring, and will eliminate the twang. Plus chances are it will improve the power a little also. The R1 is a fine airgun. People can justify paying $600 for a deer rifle that they will shoot once a year, but cannot see spending the same amount on a quality air rifle, that they can shoot thousands of rounds a year, indoors and other places that they can never shoot a regular firearm.

09-27-2013, 06:20 PM
I was on MidwayUSA last night, and they are out of a lot of the air guns and especially pellets! I found that to be surprising. I have put away my .22's for now and am shooting the R1 more. I can sit on the patio, shoot into a quiet pell trap. No driving to the range, no range fees, no expensive ammo, very little gun cleaning, and just as much fun. My R1 will do about 850 fps in .177 and my .22LR will do about 1200. Not a lot of difference on paper, or little green army men hiding in the garden!

09-28-2013, 07:08 PM
Just recieved my parts...I was wrong on the mainspring thing...I think that I will need a spring compresor, the new one is 2.5 inches longer than the old. I guess that 26 years is plenty on a spring. You lwill need a comressor to work on this model.

Silver Eagle
09-28-2013, 08:24 PM
With that much preload to take care of you will definitely need a compressor. Expect the velocity to go up a good bit after it breaks in.
Give it a good cleaning and relube while you have it open. Grease with a high Moly content is a good choice.

Silverboolit: Check out Pyramydair and Airgunsofarizona for a good airgun and pellet selection. Many more sites out there are specializing in airguns nowadays.

One advantage to shooting airguns into a trap is you can recycle the lead to make boolits! Some brands are nearly pure lead.