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Education / Training › RWS 850 AirMagnum: Part 2

RWS 850 AirMagnum: Part 2

by B.B. Pelletier

Yesterday, I took the 850 AirMagnum to the range and tested it at 50 yards. The temperature was 90 degrees – warm enough that a CO2 rifle should be performing well. There was no wind to disturb the pellet’s flight, so I was able to test the rifle in the best of all possible conditions. The Bushnell 6-18x Trophy scope was up to the task, and I was sighted-in in under 15 minutes.

JSB Exacts were first
I expected the JSB Exacts to out-perform all others, and I wasn’t disappointed. I shot the heavy version, which weighs between 10.0 and 10.2 grains. It averaged 656 f.p.s. for a muzzle energy of 9.65 foot-pounds (based on a weight of 10.1 grains). At 50 yards, it delivered 5-shot groups that ranged from 0.89″ to a high of 1.325″. The average was just under one inch. Because this pellet shot so well, I shot many more groups with it.

Beeman Kodiaks were next
The 10.6-grain Beeman Kodiak (10.4 to 10.7 grains) averaged 641 f.p.s. but had the largest velocity spread of all the pellets I tested (26 f.p.s.). The energy was the highest, at 9.67 foot-pounds. I thought it might challenge the JSB, but a best group of 1.328″ and an average of 1.399″ knocked it out of the running.

Premier lights were fast but not accurate
The 7.9-grain Crosman Premier (7.7 to 7.9 grains) was fastest, with an average of 708 f.p.s. and a muzzle energy of 8.8 foot-pounds. Downrange it was a disappointment, though, with a 5-shot group size that averaged 1.895″ Clearly, this is not a pellet for the 850 AirMagnum.

Premier heavies were better
Premier heavies weigh 10.5 grains (10.2 to 10.7 grains) and are sometimes the most accurate pellet of all in a gas or pneumatic rifle. They averaged 624 f.p.s. for a muzzle energy of 9.08 foot-pounds. The average group was 1.409″, placing them behind the Beeman Kodiak.

At 30 yards
I moved the target to 30 yards and the group size with JSBs shrank to 0.73″. This is a more realistic distance for the power and the accuracy the 850 AirMagnum offers.

This is a conventional bolt-action rifle. The sliding button below the bolt holds the magazine pin in place. Open the bolt and slide the pin to the rear to remove the 8-shot magazine.

The bolt is back, and the automatic safety button has popped out of the rear of the receiver.

Loading and feeding
The 8-shot magazine loads easily with every pellet. A large O-ring around the circumference of the magazine intrudes into each pellet chamber to hold the pellets securely in place. To remove the magazine, cock the bolt and leave it back, then slide the magazine retaining pin back as well. The magazine slips easily out of the receiver on the left side. When reinstalling it, I sometimes found the bolt a bit difficult to push forward. When reloading for the next shot, the bolt likes to be worked briskly. I had just one jam the whole time at the range, and that was the result of being tentative with the bolt.

This is a different kind of rifle for Umarex to make. It’s useful as a sporter and in .22 caliber as a hunting rifle, too. It offers PCP features, such as repeating action, for less than half the price.

184 thoughts on “RWS 850 AirMagnum: Part 2”

  1. Hey B.B.,

    I’m curious to know what you thought of the trigger pull, general ergonomics of the rifle, and the fit and finish? Since its Umarex/RWS, I’d expect high marks in all these areas, but am curious…


  2. ben,

    This was just my first look at the rifle, but you have a valid point. In fact, I should have commented on those things. The marks are all high as you would assume, but I will get specific in another report.

    I also have something that may change the way it shoots, so I guess we are in store for more on the 850.


  3. I like the groupings at 50 yards.

    Did it perform that way right out of the box?

    This is a bueatiful rifle. At least I think so. 8 shots, co2 powered, and accurate when it has the right pellets.

    Great post BB.

  4. Hi B.B.,

    I look forward to more reports on the 850!

    I’m strongly considering this gun as my next air rifle purchase. I’m completely sold on AirSource and CO2 guns in general with my excellent NightStalker experiences. They are fun, accurate, and inexpensive to feed.


  5. Hey B.B, i am comparing the umarex 850 with as392t (which looks like you own), can you give us specific pros and cons between these 2. I am sold on airsource co2 .22 cal as my next rifle.


  6. Okay, if you want to use the AirSource, either of these rifles will be good for you. They have equivalent power in .22 (the Benjamin is rated very conservatively and the 850 is about right with lightweight lead pellets.

    The 392 gives you a hardwood stock and American styling, but it is a single-shot and the scoping options are more difficult than for other adult air rifles. The 850 gives you 8 shots and a scope rail that is ready for a serious scope, but it has a synthetic stock. Both guns are sized for an adult.

    The 850 is more money, but you get more features, too. I think you would be happy with either rifle. You may want to read my next report on the 850 before deciding.


  7. bb, i’ve seen pictures of an adaptor for the crosman 1077 that changes from a 12g powerlet to any paintball tank with the correct threads. they say they get 4,000 shots from one of these tanks. even if they only get 500 shots from one of these tanks, i will be much mroe than satisfied! i’d love shooting bulk c02 from this gun. at 1.50 perfill, it is vastly cheaper than either 12g’s or airsources. the problem is, here in canada, the only thing sold here is maple syrup =/. in fact, the reason i wanted to get a 1077 was because its the only c02 rifle i can find in all of edmonton! i’m willing to pay the $60 FAC and paintball tank, but where can i buy an adaptor? preferably in-store, because the last thing i want to do is order online- too many bad experiences for me. wholesalesports, most likely the biggest store in edmonton for aigunning, dosnot stock this adaptor. if the adaptor isnt sold in stores, this will be bad for me. its the only rifle i’m comfortable hunting with. i know its a bit too weak to hunt with, but i assume from very close ranges and 5 hollowpoints to a vital spot it should be a humane kill. my window is very close to a number of trees, which is where i plan to make my kills.if by chance it isnt sold here, will a daisy 853 do the job? i love the accuracy.
    thanks for writing a great blog.

  8. B.B.
    completely off topic question. What is the difference between HW30 and Beeman R7 besides R7 having the reckord trigger. Is the barrel the same? Stock the same? Are both made in germany? There’s a difference of about $100 between the HW30 and R7, so I was curious why it’s a huge price difference. And howcome they raised the price on all Beeman products?

  9. 1077,

    Surely you’re aware that the AirSource adaptor will give you exactly what you seek without any fuss?

    I have a 1077 running on a 3.5 ounce paintball tank and it gets about 250 shots. There was a Constant Air version of the gun that adapted it to any size tank. You might find one for sale at the American Airguns classified ads website (see airguninfo.com).

    Also, any farm supply or industrial gas retail store will be able to put the pieces together for you.


  10. Bill,

    I tested the CF-X at 33 yards, so that compares to the 30-yard group reported here. The best group from the CF-X measured 0.886, compared to 0.73 at 30 yards for the 850. Both rifles are in the same ballpark.


  11. B.B.

    It seems like the 5605 Air Source to Air Source bottle stopper at http://www.cooper-t.com/bottlestoppers.html would make the AirSource bottle refillable. Not only that, but it seems like the AirSource bottle could then be filled with 900 PSI of air instead of CO2 and used with the 850 AirMagnum. Wouldn’t this give you better velocities (since air is thinner and more will pass through the valve while it is open) and make this gun useful in colder climates? What possible problems would there be with doing this?

  12. It’s not going to fit without an adaptor. The 850 AirMagnum expects to see an Airsource than that it has to pierce.

    Yes velocity would be higher. And you would get about one magazine before needing to refill. Air moves too fast for this small a container at this low a pressure.


  13. B.B.

    I called up Cooper-T about the 5606 Bottle Stopper and they informed me that it should fit the 850 AirMagnum. It is machined to fit around an AirSource bottle piercer. So you probably can use one of these to make the AirSource bottle refillable.

    Can you use an AirSource bottle filled with air to 900 PSI? Like you said, probably. But Tom Gaylord indicates you would only get one or two good shots (/article/What_About_CO2_December_2003/6).

    To really use air with the 850 AirMagnum, you need an AirSource adapter, a regulator (probably high flow), and an air tank. The tank stores the air up to 3000 PSI, the regulator reduces it to CO2 pressures and the adapter connects the whole mess to the gun. For the cost of this setup you might as well buy a PCP gun in the first place!

    An interesting idea though.

  14. So, would you please tell us when RWS 850 review 3 is going to be done, we all waiting for it…since you give us such a good and detailed info, it would help some of us to make a decision on this rifle. I`d like to purchase one but not before the third review.
    thank you.

  15. OK, for those who interested in .22 cal RWS850, i`ve done a little testing with RWS superpoint (14.5gr) and Beeman silver sting (15.7) pellets using a chronograph. Very accurate rifle up to 50 yards, if you hunt some small game like rabbits, squirrel or pigeon I advise you to stay within 30 yards. Here is what I got so far: It shoots 14.5 gr. pellet at velocity 620 fps average. Extreme spread is 15 fps with 10 shot string. Energy is 12.4 fpe.
    Next pellet is 15.7 gr. It performed a little better – 611 fps average with extreme spread is only 11 fps with 10 shot string. Energy is 13 fpe!
    Since you lose approximately 5 fpe of energy every 30 yards, that means that if you shoot with 13 fpe at the muzzle, you would have about 8 fpe at the end of 30 yard range, remember that rabbit only need 4 fpe to be dispatched cleanly if you place that pellet within the kill zone, pigeon and squirrel only need 3 fpe. So if you buy RWS850 rifle to hunt then .22 cal is the way to go, plenty of stopping power. 30 yards is nothing for this rifle. Even at 40 yards this rifle delivers a good kill-punch, of course with everything else done right.
    good luck!

  16. ok in my case it was around 80 degrees.
    the only thing that is not true about this rifle is number of shots it delivers. Advertised: 400. No way!
    I get about 120 – 150 full power shots, which is great, of course.
    Now, you can play around with lighter or hevier pellets, those two I found works best for me: RWS Superpoint and Beeman Silver Sting.
    Kodiak did not perform well at all, it`s too heavy for this type of a gun. It is the best pellet for my Condor but not for RWS850.
    Hope it helps.

  17. Also, I am sure JSB Diabolo will perform well too. You might say that pointed pellets are no good accuracy-wise (silver sting or superpoint), and you are right, for the long range shot – no. But for 30 yards with RWS850 it does not really matter what pellet you use, just don`t use any heavy ones.
    Medium weight good quality pellets are perfect.

  18. A few words about Umarex compensator. It is NOT a silencer, but it DOES muffle the muzzle report a little. Definitely worth 30 dollars. Made in Germany. You may say, well, if it does suppress the report, then it IS a silencer. I say, what kind of a silencer have 12 holes in it? So you decide what this thing really is.

  19. OK I`ve done one more test with RWS850 using RWS superpointextra pellet. All results are pretty much the same from the first test I told you about. 620fps @ 12.4fpe at the muzzle. Then I placed all numbers in the computer and using ChairGun2 software (airgun ballistics) I came up with this…First of all, this is my setup: 14.5gr pellet, scope magnification 7, scope height 1.5″ from the barrel, zero is set for 30 yards, 620fps. Now if your set up is different then expect different results. This is what I have so far: POI (point of impact) at 15 thru 25 yards is 0.75″ above zero, no need to worry about any elevation adjustments. Zero @ 30 yards. At 35 yards is 1″ below, again, really easy to make an adjustment. At 40 yards 2.5″below. At 45 yards 4.4″ below and at 50 yards 6.75″ below.
    Really good numbers for 12 foot-pound rifle. Next VELOCITY: Muzzle – 620, 20 yards-505, 30 yards-455, 40 yards-410, 50 yards-370. Now, the most important thing, ENERGY. Thats where this 12-pounder shines:
    12.4fpe at the muzzle, 8.2fpe at 20 yards, 6.6fpe at 30 yards, 5.4fpe at 40 yards and 4.4fpe at 50 yards. Remember I told you that rabbit only needs 4fpe (3fpe for a pigeon) to be dispatched cleanly?
    Look at the numbers. Impressive is it not? Next thing is Wound Channel Depth (average). 2.9″ at 20 yards, 2.6″ at 30, 2.3″ at 40 and 2.1″ at 50 yards. For example a common pigeon is a relatevely soft target so all those numbers would be a good reference point.
    There are a lot more usefull things in that program so I advise you to get one if you are serious about airgunning. It`s free.
    I am sure there are some folks who still trying to decide on this rifle, I truly hope I helped a little. Good luck.

  20. Forgot to tell you guys. This rifle is dead silent if you put some tape over the compensator, to cover those 12 holes. Electrical or non-mark camo tape.
    Staple gun is loud compare to this.

  21. The Cooper-T 5606 Bottle Stopper should not be used to refill an AirSource cylinder. The cylinder says, “Do not refill this cylinder – One time use only.” It probably would be difficult even to use one as a bottle stopper for the 850 because the connector is fairly deep inside the stock.

  22. B.B.

    I have good news and bad news.

    The bad news 🙁
    There is something wrong with my Mendoza RM-2000. I tried the DIY chronograph at http://www.seattleairsoft.com/modules/news/article.php?storyid=15&page=0 to measure its velocity. It came in at 500fps with .22 JSB Exact Jumbos (15.8gr) and around 640fps with .22 Mendoza solid skirt pellets (13.8gr). Not good!

    The good news 🙂
    I took a look at using air instead of CO2 with the RWS 850. There were two things that convinced me to go ahead and try it. First, air is less temperature sensitive. Second, the cost wasn’t as high as I figured it would be.

    Using the DIY chronograph, the RWS 850 performed as follows with air. JSB .22 Exact Jumbos gave velocities that varied from 591fps up to 602fps with an average of 594fps (12.38 average foot pounds). That puts the air setup about the same as CO2 on an 80 – 90 degree day. It was 73 degrees the day I tested.

    For the chronograph setup, the first paper was 5ft. from the gun and the second paper was 10ft. from the first paper. A good recording volume with my sound card seemed to be about 30% (NO microphone +20dB boost).

    For anyone interested, the recording volume was set to 50% initially. At that level, spikes from the gun report clearly recorded on both the first and second mikes. Using that information, the speed of sound that day calculated out to 1125fps.

    .22 multi-shot

  23. Thank you for the compliment B.B.! However, I still consider myself new. I don’t have breadth of knowledge or much experience yet. Thank you for sharing your knowledge and experience with us so that we can grow.

    By the way, I talked to Cabella’s and I am returning the Mendoza. (No, I’m sorry, I didn’t buy it at Pyramyd. Cabella’s had it at basically the same price but with a scope.)

    Thanks again,
    .22 multi-shot

  24. Small correction. Number of shots for .22 cal RWS850: approximately 160 full power shots. Imagine the whole day or two of hunting on just one charge. I notice a POI shift after 20 clips has been fired. I used a chrony throughout the whole experiment. Pellet is 14.5 gr RWS superpoint. An hour ago I blew a pigeon away at 40 yards! Outstanding perfomance. Not a single jam.

  25. I got an average velocity of 618 fps which is 12.3 foot-pound of energy. 84 degrees outside.
    I can’t get enough of this rifle!
    I shoot it more often than Condor, and I bought them almost at the same time.

  26. I guess so. When I was experimenting with 15.7 gr. silver sting I was getting an average of 12.7 fpe. Jsb exact (15.8 gr.) produces the same results. Anything heavier is no good. I don’t like changing the ammo, so I decided to stick with superpoint since I have a lot of it. It works well. I threaded one superpoint pellet into pigeon yesterday, right in between shoulder blades. It penetrated 2 in. deep at 40 yards. He made an attempt to take off, but fell dead couple of yards away. It was the first pigeon that I was able to retreave and chop up, all my previous kills were up on the roofs,- good for crows and hawks.

  27. FYI, I finally checked the output pressure of my air setup (see results posted above). The regulator output pressure is right at 800PSI. I’m working on another setup that will output 1000PSI. I will post results when I have them.

    .22 multi-shot

  28. Thank you for the tip B.B.! I’ve been hesitant to take apart the 850. I intend to gain experience in that area with a gun whose disassembly is well known (e.g. Crosman 2240) but will probably (eventually) take apart the 850.

    The new regulator I bought (Smart Parts Inline Max-Flo) is adjustable so I will have variable power too! It is a great regulator with tank (source) and output pressure gauges. It even bleeds off extra pressure if you adjust the output pressure down!

    .22 multi-shot

  29. B.B.

    Smart Parts doesn’t make the Inline Max-Flo regulator any more. I purchased it used on EBay. However, they still sell parts for it. Fortunately there is a Paintball store here that knows how to maintain that regulator (Smart Parts gave me the store name and location).

    My tank (13 cu. in. fluid capacity) came from PepperBall Technologies, Inc.. They were VERY helpful! One note – the PepperBall tank comes with a regulator that is permanent Loctited in.

    .22 multi-shot

  30. I’m interested in buying the RWS Model 850 Air Rifle Combo, I want a .22 cal, can someone clarify if the RWS 850 is a dual cal rifle (.177 and .22)simply by changing out the magazine?

  31. BMAC,

    The RWS 850 Air Magnum is not a dual caliber airgun. The barrel is not removable, so you must buy it in one specific caliber.

    Only AirForce Airguns offers a true dual caliber facility, as far as I know. Their barrels can be changed in a matter of minutes.


  32. B.B. Thanks. Can you tell me if the RWS 850 Air Magnum is available in the U.S. as a .22 caliber? I only see it advertised as a .177 caliber in the U.S., however, I see they offer an 8 shot .22 cal magazine for the RWS 850 Air Magnum as an accessory. If available, can you tell me who offers it in the U.S.? Thanks

  33. This rifle is a real pigeon slayer!
    The great thing is that it does not overpenetrate, which is great in the pest elimination business around buildings and stock animals. I love it.

  34. H & N Field Target & Trophy .177 pellets (8.66 grns)perform well in this rifle. Velocity 725 fps and ME 10.1 ft/lbs. Bisley Pest Control (8.8 grns) also give good performance 9.7ft/lbs & 707 fps, using 88g airsource in UK weather.

  35. FYI, I don’t know when I’ll be able to test the 1000PSI conversion. I am trying to find a tank inspection location closer to where I live. So far it looks like the closest is around 40 miles away. The tank doesn’t require a hydro (2″ diameter), but I want at least a visual inspection since it is used.

    I also plan to test with and without a muzzlebrake to see if it makes any difference at higher velocities.

    .22 multi-shot

  36. A maintenance question:
    How do you clean the inside of the barrel? The manual advises against the use of cleaning pellets. So is there some ways or tools to clean it without disassembling the barrel?
    The Boresnake I have would not fit in the breech end.
    Thank you,

  37. At a price range of under $500, for shooting sparrows and starlings from an orchard, what is your favorite gun for accuracy in the range of 30-40 yards. Can you give your favorite is CO2 and spring action and tell which type you prefer.



  38. Birdman.

    Correct me if I’m wrong, but it sounds like you are more than a casual shooter. This is your orchard and you use or sell the fruit?

    Your budget is great! Stay away from CO2; it’s temperature dependant.

    I think a .22 caliber RWS Diana 48 and a nice Leapers scope in a B-square 1-piece AA adjustable mount.


  39. B.B.

    I finally had the 13 cubic inch tank hydro’d and set everything up with the AirMagnum (1000PSI reg, tank mount and adapter setup). I haven’t done complete testing, but I thought you might like initial results.

    The regulator had an actual output of 1050PSI. With the small tank at that output pressure I shot 24 pellets (3 magazines) before the pressure dropped to 800PSI.

    I wasn’t able to chronograph because the light didn’t seem to be right for my friend’s chrono. It did give a speed of 619fps for one shot (Crosman Premiers), but otherwise it kept reading “Error”. I’m hoping the speed was incorrect – I figured I would probably get at least 650fps with the higher pressure. I supposed the valve might be designed to try to stabalize the output to compensate for CO2 pressure instability though. That would mean I’ll have to modify the valve (perhaps the spring?) to get higher velocities.

    I also tried the compensator with one magazine and noticed that it seemed louder with the compensator on (perhaps it reflects some of the sound back?).

    That is all for now. I’ll post again when I’ve done more testing.

    .22 multi-shot

  40. .22 multi-shot,

    I’m afraid you’ve gone too high on the reg output and are seeing the start of valve lock. If you set the pressure at 850 you’ll be exactly where the valve is designed to operate. The thinner gas will flow faster and boost the velocity by itself.

    I’m making a test rig for a Benjamin AS312T. I expect to go from 610 to 700 f.p.s. with .22 Premiers, just because of the thinner gas.

    I will report on this when I have it running.


  41. Wow, thanks! I should have thought of that!

    Originally I was going to test starting at 800 PSI and increase in increments up to 1000 PSI. However, I was excited after taking so long to get everything together. I also discovered that it is VERY hard to turn the adjustment knob to increase pressure while the air is on. It was hard enough with the air turned off! I guess I will go back, start at 1000 and work down from there in 50 PSI increments so I can find the sweet spot.

    Your project with the Benjamin AS312T sounds interesting! Are you going to post an article on it when you finish?

    .22 multi-shot

  42. Sorry B.B. I forgot you don’t get the context when you are answering questions. Here is my question with context.

    Out of curiousity, what are you using to connect to the AirSource fitting on your AS312T experiment? A Cooper-T or custom made adapter?

    .22 multi-shot

  43. Hi B.B.,

    Thanks, I wish I had known that Mac-1 had an Airsource to paintball adapter when I started this project!

    This is my first week home after being gone for five, so I haven’t had a chance to do pressure tests with my 850 air setup yet.

    I did take the stock off and found some interesting things inside. The whole valve just screws into the breech/trigger mechanism so it is very easy to remove! The valve end that screws into the main mechanism has two holes 12mm apart (center to center) for a special wrench (like the lock nut wrenches used to remove the lock nut on angle grinders). Screwing open that end should give access to the inside of the valve. I will take a look inside the valve after I buy/make a wrench to open it.

    It looks like all that would be necessary to convert an RWS 850 to a Walther 1250 Dominator is a different valve, the air tube and the new removal stock piece (unless, of course, they modified the mechanism, changed the material for higher pressure and/or used a different barrel). I wonder if they will sell a conversion kit?
    See the Walther 1250 Dominator web page

    .22 multi-shot

  44. It would be great if they did sell an 850 to 1250 conversion.

    I found the name for the type of wrench needed to open the 850 valve. It is a “face spanner” or “pin face spanner” wrench. The holes for the pins are 2.5mm in diameter and about 12mm apart center-to-center.

    .22 multi-shot

  45. FYI, I found an adjustable face spanner wrench at TrueValue (TrueValue called it an adjustable spanner wrench). I ground down the pins to the correct diameter, then ground off the metal between so the span would close down to 12mm. I then opened the valve.

    I won’t try to describe the valve, pictures would do much better. I was able to remove the puncture pin by tapping it out with a pin punch. There is also a filter screen held in place by the base of the puncture pin. Removing these should give much better air flow for the air conversion.

    I will probably taper the puncture pin seat for better flow and then reinstall the valve for testing.

    .22 multi-shot

  46. IMPORTANT – so the following won’t happen to anyone else. If the puncture pin and filter screen are removed from the 850 valve, don’t use a Cooper-T 5606 Air Source to Paintball adapter. I did, and something blew out of the adapter and into the valve. The valve stuck open and when I opened the valve, I found a small piece of spiraled, red aluminum inside. When I looked at the adapter, I noticed that something on the AirSource side of the adapter was missing (something that had been in the center of the hole before and I had wondered why it was there).

    One of the dangers of experimenting… 🙁

    .22 multi-shot

  47. Hi BB.
    I just bought 850 (.22) from Pyramid, & have some quetions for you.

    1. This is for Hunting & Pest Control, & Can I cut Top of Babbel, may be 5 to 8 inches for make as Carbine Style Rifle, so I can carry easy at Woods, bushes. If so What is the Maximum Cut inches??? Is it hurt Power or Accuracy???

    2. Is there any conversion kit, to make use of Air, instead of CO2??? If so how much cost will be, & know the web links???

    3. Also I would like put on Rifle belt on, Is it OK to put on CO2 cover of Front end ??? Is it strong enogh to carry all day???

    4. Last & most all, this 850 made by uramex of Germany, Is this company also makes Walther P22 (.22), PPK (.38), P99 (9mm)=Firearms??? I am thinking buying of those for personal carry, & Home Defense. Could you tell me about this Company, anythings inf. will be apprecliated. Also which hand gun will suit for parsonal carry, & self defense???
    Which handgun will you carry for self-defense purpose???

    I am very appreciated your commment here blog. I am not too much in Airguns world anymore-(have Beeman, Gamo, Crosman, Daisy etc.), used read everyday of your blog. and I am now more of Rimfire Rifle – Marlin, Rugar etc. using CB-Long Ammo ( 30 grain, 700 fps, 30 pfe very quiet, but sometimes too much power for small games, and Ammo is kind expensive- 100 rnd for $8., so this 850 is good alternative with cheap ammo, & good Accuracy)
    But time to time come back here to get touch with AirGun World.
    Thank you and
    Keep up Good Works.

    New 850 Owner!

  48. New 850 owner.

    Cutting the barrel of your rifle will usually ruin it. Cutting the barrel of a CO2 or pneumatic gun reduces velocity, as well as accuracy.

    Fifteen years ago when the fact that shorter barrels might produce higher velocity (they don’t) was published, there were a bunch of barrels ruined by cutting.

    There is no authorized conversion to air. I’m sure there are hobby conversions, but they will often harm your gun, too.

    The front cover is thin plastic and I thinks too fragile for all-day carry.

    Umarex owns Walther. Their reputation is well-known. I carry other defense guns, but the CP88 always appealed to me.


  49. FYI, there is a replacement valve for the RWS 850 AirMagnum with an advertised performance of 868fps. I assume that is for .177. RWS 850 replacement valve link.

    The site is in German but it can be translated with Google Language Tools. Go to http://www.google.com, click on the “Language Tools” link, go to the “Translate a web page” box, paste the link, select “German to English” in the dropdown menu and click “Translate”.

    .22 multi-shot

  50. Has anyone tried this valve replacement yet. I have a .22 cal 850 and I am not a gunsmith so I am hesitent to try it before an expert mod’r can tell me how.

  51. No, I haven’t tried the new valve. I did modify my valve and it was easy to remove and install.

    Of course, DON’T do this with an AirSource tank installed!

    1) Remove the cap that covers the AirSource tank.
    2) Unscrew the two screws that hold the stock on (at each end of the trigger guard). You will need the proper size hex key (wrench).
    3) Remove the stock.
    4) Use a wrench to unscrew the valve. There wasn’t any thread sealer on my valve.
    5) Screw the new valve in and tighten it with the same effort required to remove the old valve. I used a small amount of teflon pipe thread compound (the kind safe for plastic pipe) on the threads.
    6) Screw the stock back on.
    7) Put the stock cap back on.

    .22 multi-shot

  52. FYI, neither the regular or gel blue thread locker from Permatex made an airtight seal when I screwed the cap back on the valve.

    When I originally took the valve apart, it looked like white glue was used on the threads, so after some research on the internet, I decided to try Elmer’s Carpenter’s glue (interior). I used it instead of white glue because I found a mention that Carpenter’s glue stays more flexible than white glue when it dries.

    So far, the Carpenter’s glue has worked great!

    .22 multi-shot

  53. Sorry, I read my post and it wasn’t real clear. The place I used the Carpenter’s glue was on the threads of the “cap” (the valve seat) that screws into the valve body.

    .22 multi-shot

  54. David,

    Yes, at least removing the puncture pin did. I don’t know how much right now. When I am done with my mods I will post the results here. I will probably start a blog that goes into the details so I don’t clutter up BB’s blog. I will post the URL when I do.

    .22 multi-shot

  55. I finally have some results from modifying my .22 caliber RWS 850. Unfortunately, I lost about 1000 pounds of pressure when the off switch on the regulator decided to malfunction. This happened the second time I adjusted the pressure down. Because of this I was not able to shoot a nice series from 1000PSI down to 850PSI. The speed ranged from 685fps at 1000psi to 660fps at 850psi with JSB .22 Exact Jumbos.

    The setup was as follows. The valve was modified to remove the puncture pin and filter screen, the puncture pin seat was reamed away, and the entrance and exit ports of the valve were polished. The air tank was a 13 cubic inch (213cc) tank with a Smart Parts Max Flow adjustable regulator.

    I was amazed that even with the loss of 1000PSI, I got a total of 16 shots and still had some pressure left.

    .22 multi-shot

  56. B.B.,

    Are you still going to post your AS392T air experiment since the AS392T is discontinued? If not, might you do it with something like the QB79 instead (since it accepts a paintball tank directly)?

    .22 multi-shot

  57. My Rws 480 will be here next week.Can’t wait….so living in Wi. were the temp is 9.5 right now brings me back to Whitetail season,where some of my pals use those tear open hand warmers.I don’t,however I’m thinking , why not stick one or two of those in with the co-2. On a 35-40ish day,it would work. What do you think? Is there room? Fasdraw

  58. Fasdraw,

    I already answered this where you asked it before. The answer, again, is yes.

    If you go to the place where you posted the first comment, I give you the link to the owner’s manual on this website, where you can see the parts.


  59. Fasdraw,

    The 61 is a close-range gun, so a dot sight is appropriate. Of course you never mentioned what purpose you have for the gun, so that’s all I can say.

    Now, why do you want to remove the front sight? It probably won’t appear in any optical sight you use, so leave it where it is.


  60. Hey B.B.,I’ve been shooting a Tempest for 20yrs.now and was having trouble finding the sites. Don’t know what got into me , but after searching this site and reading your stuff; I’m getting an Rws 850 with a AR22 3×9. This gun in a 22.and will be for hunting.Also for the wife ,for targets: IZH-61 with a AR-22 4×32.Any advice on pellets and such.U-da-man……..Fasdraw

  61. Got my 850 22 yesterday Hits hard, shoots great. So far I’m puttin in a dime at 30 ft.with RWS Superdomes & points. It feeds nice also.What a great rifle! Compensator fit just fine.Shrink tubed it an left 2 bottom holes-1front & 1 back open. It’s now deadly quite. Have I said how much I like this gun yet? Fasdraw

  62. Hey B.B. , can you help ?I went to shoot my 850 yesterday and it was hitting 3″ left and high. I resighted it and all was fine ,until today. When I changed the co-2 . it started shooting low and right. I have sighted it once more,.and will see.I checked all the screws,ect….might be a bad scope I guess. But why, when I changed the co-2, would it change?

  63. New to CO2,

    Every time you change a CO2 cartridge, the first few shots are powered by liquid CO2. The are far more powerful and will shoot to a different place. You should probably blow off about 10 shots when changing AirSource cartridges. With 12-gram powerlets you only get 2 or 3 super-powerful shots.

    Does this describe the problem you are having, or is there something more?


  64. Hey,today the first two mags shot low left 1 1/2 “, then it came back zero slowly. Very strange. I just don’t know what is going on.How could it do that? It is 850-with 1.75x5x20 Tasco,.22 cal.W/compensator.I’m at 10 yrds, from inside to outside.

  65. Went thru an 88 gram yesterday. I now have a fresh one with 2 mags thru it. Will let it sit for awhile.Outside temp was 30 and inside was 65.The first time when I had to re-adjust the scope told me it was either the scope or the rifle.I also have a laser on it and had to bring it back to the crosshairs.It was like the scope changed itself overnight,high and left over 2in.Am wondering, could it be the compensator? I read someones blog about he thought it messed with acc.so he took it off.

  66. Your scope and laser test makes me think the problem could be temperature-related. The compensator had nothing to do with the laser losing alignment.

    When you shoot, wait 30 second between shots for the gun to warm back up. See if that has any affect on where it shoots.


  67. It’s 46 outside and I moved out to 30 yards. I’m inside a half dollar with 3 mags.I’ll let it sit over night and shoot it at 30 sec. intervals tommorrow.Hope it stays put. Thanks for the input.I don’t think it is the temp though.I had to move the laser cause I had to move the crosshairs.It’s like it all changed over night.

  68. Someone said you could unscrew the front sight and the barrel on a Izh-61. It would be great for cleaning ,but ,is it a good idea to unscrew the barrel? Or the front sight ? Are most barrels screwed on? Thanks

  69. I want to get a new washer for rws 850 valve (green one). I lost mine while i was putting taking out 88grm cylinder.
    do anyone have an idea where i can get it from? also should i get a new valve or just the ring?
    thanks in advance..

  70. The problem is that I want to give an AirMagnum 850 to a friend oversee who wants (needs) to hunt but neither she nor I have any experience with that kind of weapons.

    But I am not in haste. I can even wait half a year for your advice.

  71. 850,

    Well, I have tested the 850 AirMagnum already, but I see a lot of interest in the rifle from new shooters who want repeaters. So I can do another test of the rifle, using .177 Predator and Gamo Rocket pellets.

    The 850 isn’t a good long-range rifle, in my experience. It’s better-suited to 30 yards and less, so that’s where I will test it.

    Is that okay?


  72. Dear Sir,

    This would really be fantastic.

    But to have a full picture of the new situation, perhaps at the same time, you also could test a third hunting pellet: the Crosman Fireball Pellet .177

    Thank you in advance.

  73. Dear Sir,

    Because you know in advance that the Fireball pellets are bad stuff, then please drop them for the test and limit yourself to the Predator and Gamo Rocket pellets.

    Thank you very much in advance for the effort.

  74. BB,
    in the begining of the form you said that you can store the gun with the co2 in the gun.
    for how long?
    will the seals be more apt to break or wear?

    Thank you

  75. B.B.
    i have another question if you don’t have the model that came with a compencater but you want to buy one and put it on do you know how to install one?

    thanks again

  76. B.B

    what i meant to say is the bolt probe made of metal or plastic i am talking about the part that pushes the pellets into the chamber
    sorry about the confusion


  77. B.B.

    i wanted to know how durable it was it looked like a small part so i was hoping it was made out of a strong material i have orderd a RWS 850 should arrive on May 9th
    thank you for answering all of my questions you have been very helpful.

    thanks again

  78. B.B.
    i just got my RWS 850 from Pyramyd AIR yesterday and i love it. it is so accuret i was hitting a soda can 80% of the time standing at 30 yards with open sights no scope I was woundering is it bad to dry fire the RWS 850 with and without c02.


  79. B.B.
    i was wondering what you would sugjest for optics for the RWS 850 i want a scope that is non/iluminated and mil-dot retical i am in the price range of 50-80 dollers.

    Thank you for all you help in advanced

  80. BB,
    I have a Feinwerkbau 124 that I purchased from Beeman wayback 1979. I gun is very accurate and only fired it occasionally, maybe 700x. It is always in my closet protected and no blemish. Last month, I fired it once again, but the .177 pellet remain sitting in the loading chamber, untouched! I cocked the gun again and fired it once more, but the same thing happened. I picked out the pellet and looked inside the barrel and it’s clean. Everything works with the gun except it won’t push the pellet. Do you think the sears dried up?
    Do you know anybody who can fix it? I’ve heard Beeman company closed.

    I also have a Beeman PI and also has the same problem. I will appreciate your advice about what to do.

    Another question: Is it safe to mail the gun for repair? I am always afraid that I might not get it back. What is the safest way?

    Feinwerkbau Fan

  81. Fan,

    Your 124’s piston seal has deteriorated. It’s very common in a gun that old. The first seals FWB used didn’t hold up, and chamber oil dissolved them.

    Stop shooting the gun until it is resealed. You can use a cleaning rod or a straightened coathanger to push the pellet out of the barrel.

    The safest way is to fix the gun yourself, but a 124 isn’t as easy as many guns. If you don’t feel comfortable doing that, the only bother option is to send it to an airgunsmith.

    Here is a man I can recommend:

    Just make sure you package the gun well before sending it, and insure it for what it’s worth.

    The P1 doesn’t typically have the same problem, but yours sounds as though it does. The same man can fix it for you. You cannot mail a handgun of any kind, so you have to use UPS or Fedex.


  82. Do you think .22 850 airmagnum would be strong enough to shoot a squirrel at 50 yard. I am looking for an airgun that can do that. I am looking for an accurate, quiet (back yard) multi-shot repeater. Don’t care if it is co2 or pre-charged pneumatic, and my budget is between $500 to $800.


  83. I am new to this so excuse my trivial question. I have 850 AirMagum which is accurate at 25-30yard range.

    Now I am looking for one that has the same features and still accurate at 50 yard.

    Do you think the 1250 Dominator can achieve the 1 inch group at 50 yards since it will have more power? Have anybody here tested this gun?

    Thanks in advance.


  84. Hi walter,

    Welcome to the blog.

    When I tested the 850 AirMagnum, I started at 50 yards and the groups were over an inch in size. I don’t think the 1250 will be much better.

    You might look at the Benjamin Discovery, which will do a half-inch group at 50 yards under the right conditions. It’s a lot less money, too.

    It is a single-shot, but all the most accurate PCPs are single-shot.

    To get faster answers to any questions, you can ask them on the current day’s blog, which is here:




  85. Hey b.b.
    I read earlier in one of your blogs that the new air source co2 can be left in a gun. after installing a new one in the rws 850 (or any gun), will i have to finish it in one sitting? or after shooting 100 shots, can i leave the co2 inside the gun and shoot again the next day? or will it break the gun? ok..

  86. Hey BB, I know you said an airsource at 900 psi will get about a magazine, but Tom Gaylord says only 2 shots. Tom Gaylord is god so you must be a moron. He created airguns on that 7th day when god was slacking off.
    Wait, Text is incapable of conveying sarcasm, isn’t it?
    Sorry, I know you can’t stand random comments to old posts flooding your mailbox, But I was rolling on the floor when I realized your nom de plume was THIS effective. thanks for the terrific blog.
    – XxARSENxX

  87. can somebody tell me if i can shoot gamo raptors out of this gun in 22, if there accurate, and if they jam??? and in the winter, it is normally around 37, but sometimes it reaches negative 28, will it still be useable when between theses temps?? and in summer its realllly humid, about 90%, will this cause the gun to rust internally????

  88. Myles,

    Let me start by saying I've never owned an RWS 850 Magnum but I want to try and help you.

    First about gamo raptors. I've never shot a gun that grouped these pellets very well in either .177 or .22. There are a lot of good reviews on the Pyramyd AIR site about pellets that work best in this gun. Go the the top of this article where B.B.'s review begins and in the first sentence and click on the underscored words "850 AirMagnum". This will take you directly to this gun on the PA site. Scroll down to the bottom and read the REVIEWS on this gun. What I read in the reviews of this gun by others is reflective of what B.B. said in this article, "850 likes mid weight pellets. JSB's were most accurate". Don't let these reviews or even B.B.'s experience with one gun sway you from trying any pellet. Your gun may group pellets best with a different pellet.

    Low (cold) temperatures can affect CO2 performance. If it's cold try warming your CO2 cylinders before going out to shoot. Cold and humidity won't hurt your gun's internals but make sure to wipe down the outside of the gun after you shoot in any condition to protect against rust. Variation in temperature can cause condensation on the gun and can affect your poi (point of impact) if you shoot with a scope since the glass inside your scope (lenses) will expand and contract.

    You've asked some good questions but this is an old article (2005) and not many people check back here for new comments. I would encourage you to move your questions or retype them on the current/active comments section. Lot of great airgunners there asking & answering questions of one another. Maybe someone on the current blog has an 850 and help you more than I did. Here's a link that will take you there:


    Look forward to hearing from you on the current blog.


  89. To .22 multi-shot AND B.B.,

    In regards to the RM-2000 shooting low velocities compared to the advertised, I too noticed my RM-2000 was NOT anywhere near the 800 or 900fps it says.

    Mine was shooting RWS Hobbies arouns 550fps & their solid skirt HPs around 640fps too!

    So… I don't think it's just yours!

    I'm glad i read that, because I though it was just me.

    I'll break out my Alpha & try it again in the next week or two & confirm what it's REALLY doing in velocity, & we can compare notes.

    Also… 22-multi shot, B.B. has my email, so ask him for it if you want to talk & compare our findings.

    I have just about every decent pellet in .22 cal. so if there's other pellets you want me to try, I can.

    The thing that disturbs me, is that if you look at the reviews on PA's site… Other people are reporting much higher velocities than you & I are getting.

    I wonder if we have defective guns?

    Lets get together on this & see what we can figure out.

    The BBA

  90. BBA,

    I’m afraid I returned my RM-2000. I suspect mine had a dirty bore like BB’s, but I’ll never know now.

    Its too bad because I really liked the RM-2000. Perhaps if I had had more experience at that point …

    .22 multi-shot

  91. .22 multi-shot,

    Bummer, I know you're experienced & pretty knowledgeable, so I was hoping we could compare notes.

    Oh well… I'll chrony it again & see exactly what numbers I'm getting. If they're low, I'll clean the bore with JSB paste & try it again.

    I like mine too, so I'm not giving up on it yet. lol

    I'll let you know what I find out.


    I have a friend that's new to airguns, who bought my Super Streak .177 cal, & plans to microlon [sp?]the barrel.

    Do you think this will help fps
    &/or are there any down sides to this?

    Also, I just got a Powermaster Elite which is supposed to be the same gun, with the exception of some cosmetics. (For $100.00 shipped, I couldn't pass it up.) It does look like my old Super Streak, but I noticed the trigger is a lot better. It looks like the stock trigger, but it's smoother & breaks better.
    Do you think it just may be more broken in?



  92. BBA,

    Let me know if that cleaning helps the velocity! I wish I could have kept the Mendoza.

    I have experience with CO2, multi-pumps and PCP, but the RM-2000 is my only experience with springers. I have no idea about the microlon or trigger.

    .22 multi-shot

  93. ,22 multi shot,

    Not sure when it will be, but I WILL keep you posted.

    I'm pretty sure the trigger is just broken in, & according to my friend…. The Microlon will hopefully not only help to keep the barrel from getting leaded, but should help the velocity as well, by creating a slicker barrel with less resistance.

    BTW… Why did you get rid of your RM-2000?


  94. BBA,

    I returned it because I figured it was defective with the low speeds it was getting. I couldn’t afford to put out money for two guns at the same time and needed one that worked good for pest control (gophers) right away.

    .22 multi-shot

  95. .22 multi-shot,

    I hear ya.

    I really like my RM-2000 so I'll will see what I can do with it.

    I'll clean then test the velocity,
    then Microlon the barrel & test it again.

    I'm slammed with other things right now, so it will be at least a month or two, but I'll post back my findings.

    Take care & thanks for the input,


  96. I don't know if anybody can give me some advice here, but I have a Hammerli 850 .22 which performs with stellar accuracy sometimes putting pellets in the exact same spot at 20 yards, though recently I've noticed that the pellets are hitting my targets flat (tumbling). I don't really understand how I'm still getting pretty good groups if my pellets are consistently tumbling downrange and leaving keyholes on my paper, cardboard, and tin targets…. Is this tumbling something I can fix? I've only put around 450 pellets through the gun so far and by examining the inside of the barrel with a flashlight I found no indication of a dirty barrel. Should I maybe contact umarex about this?

  97. I don't know if anybody can give me some advice here, but I have a Hammerli 850 .22 which performs with stellar accuracy sometimes putting pellets in the exact same spot at 20 yards, though recently I've noticed that the pellets are hitting my targets flat (tumbling). I don't really understand how I'm still getting pretty good groups if my pellets are consistently tumbling downrange and leaving keyholes on my paper, cardboard, and tin targets…. Is this tumbling something I can fix? I've only put around 450 pellets through the gun so far and by examining the inside of the barrel with a flashlight I found no indication of a dirty barrel. Should I maybe contact umarex about this?

  98. Anonymous with tumbling pellets,

    Since your groups aren't opening up at 20 yards I don't think you have a problem with the gun but may have a problem with your targets.

    Here's a suggestion. Get some hard stock, NRA style targets (not paper, not cardboard) and shoot one pellet per bullseye. If you don't want to buy quality paper targets then put a piece of duct tape behind your targets on the paper you're currently using then shoot one pellet per bullseye.

    Since your groups aren't opening up I think you're getting paper tears that look like keyholing but this test will either confirm or kill my assumption.


  99. Thanks a lot Kevin. I thought that the targets might be an issue, but it just seemed like it was worth investigating. I'll test out some different targets in the next few days along with your duct tape suggestion and if its still an issue, I'll try moving out to 30 or 35 yards to see if the groups change dramatically.

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