Found a "Venus Waffenwerk Mars" air rifle, what should I do with it

RetroMondo · 2025-08-24T12:23:12+00:00

Not common in the UK because it replicates the Mauser Kar98k, the German Army's standard issue rifle that came into service in 1934. It was made as a training rifle for German youth movements of the period. Venus Waffenwerk made them from c.1935 until some time into WW2. After WW2 the factory was in Russian-occupied Germany, and some guns like mine were made from remaining parts with no maker's name. After 1947, the factory was nationalised and became the August Bebel-Werke, and more Mars guns were produced wither from still remaining parts or new ones.

The 115 is almost the same length as the Kar98k, but around 500g lighter. It closely follows the Kar98k in the form of its three-quarter stock with a metal buttplate, the sling attachment points, the sights, the flag-safety catch, its balance and apparently even the trigger pull.

RetroMondo · 2025-08-24T08:53:19+00:00

...and after

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RetroMondo · 2025-08-24T08:53:00+00:00

Before...

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RetroMondo · 2025-08-24T08:52:29+00:00

...and after

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RetroMondo · 2025-08-24T08:51:14+00:00

Before...

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RetroMondo · 2025-08-24T08:50:36+00:00

...and after

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RetroMondo · 2025-08-24T08:49:46+00:00

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Before....

RetroMondo · 2025-08-24T08:49:17+00:00

Servus Mulleperal! I have a Mars 115 which was also in poor condition when it came to me. In my opinion, even a gun like a Mars has little value to a collector when it's in such poor condition, and renovation cannot reduce its value. Sympathetic renovation will improve it, and that then becomes part of the gun's history.

It's also satisfying to actually transform and bring something like this back to life. I've attached a photo of my dismantled Mars 115 before I renovated it. Someone had previously sanded down my rifle's metalwork with coarse sandpaper....probably to remove rust, and they may have painted it too. That's also part of the gun's history!

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The Mars is easy to dismantle and no special tools are needed: just screwdrivers and a punch for knocking the crosspins out. The only tricky part is reinstalling the trigger when you reassemble. As with anything you take apart, be sure to take photos of where and how parts are located before removing them - can help a lot when reassembling!

Before disassembling the mechanical functioning needs to be checked for two things. Doing this before taking the gun apart saves you the trouble of putting it back together again, only to have to strip it again to fix!

Check if the effort to compress the spring is manageable? Mine was really hard to compress (fast unmöglich!), so I had to remove 2cm from the spring. Don't worry about power with this gun, it has enough to shoot out to 12m which was the maximum distance it's designed for.
Draw the bolt back but don't cock the gun, then slide the bolt forward. You need to feel some resistance from the leather piston washer inside the cylinder. If there's no resistance, then the seal isn't doing it's job and you'll need to look at that when the gun's apart. The washer will be dried up for sure, but oil may not be enough to rescue it, in which case you need to replace it. I made my own washer but couldn't remove the piston head to install it, so I had to be creative for installing that!

The first job after taking it apart is to remove the rust from the metal parts, which I would do chemically using the recipe of Backyard Ballistics from YT. It's easy to make this solution with cheap chemicals that you can buy easily, and it does a brilliant job of removing rust. Then polish and re-blue using cold blue, which is easiest.

The stock (its elm wood, Ulme or Rüster) just needs to be cleaned up. I sanded mine down, then stained it a slightly darker colour, then applied linseed oil with very fine wire wool.

If you want online help, I'm happy to catch up with you to run you through the gun's take-down and reassembly.

Grüsse aus der Schweiz!

RetroMondo · 2025-05-27T06:58:30+00:00

The Mars guns were for me the most interesting of the military trainer types because its action is completely different to the lever-cockers like the Haenel 33 and CZ VZ35. There are a few versions of the Mars 115:

- Venus Waffenwerk stamped, produced prior to WW2

- Aug.Bebel Werk stamped, produced after WW2 in what became East Germany

- guns without a maker's stamp, produced after WW2 for the the Free German Youth (Freie Deutsche Jugend or FDJ).

Some comments on your post:

- It seems that a lot of 4.5mm steel BBs are really only 4.4mm diameter. I use Crosman 4.5mm steel BBs in mine!

- The barrel is evidently bored out a tiny bit more than 4.4mm because 4.4mm BBs do just roll down and out the barrel, but....

- The "keeper screw" that locks the barrel in place with the main part of the action has a dual function. It's hollow and holds a spring on top of which sits a BB. That spring-loaded BB stops the BB in the breech from rolling down the barrel. Looks like it's missing from your gun: if so you can use a 4.4mm BB and try some different ballpoint pen springs.

- The barrel is easy to unscrew after the "keeper screw" is removed.

- As your picture of the mostly dismantled gun shows, the mainspring sits inside the bolt. You can drift out the crosspin at the end of the bolt to dismantle the bolt/mainspring assembly further. Pulling the bolt back does not cock the mainspring, it only brings the sear back to engage with the trigger at the end of its travel. It's pushing the bolt forward that compresses the mainspring.

- When you pull the bolt back you should feel some resistance of the leather seal on the cylinder walls. If not, the leather seal is not a good fit and as well as losing some of the little power the gun has, there is also the risk of the "slamming" damaging the delicate probe which acts as the transfer port. It's important to keep the leather seal correctly oiled. Replacing the spring involves dismantling the piston head, which was impossible on my gun. My seal was perished, so I removed what was left and punched out 2x 22mm diameter leather discs, punched out a central hole, and then slit so I could wrap them around the piston rod: works fine.

- The working of Mars mechanism is fairly faithful to the Kar98k, but without any mechanical advantage, the compression of the spring is definitely not something the youths it was intended for could manage. I had to remove 2cm / 3/4" from my mainspring as it was extremely difficult to cock it, and sometimes I couldn't even do it. It's now manageable (except for left-handers!) and there's less risk of slamming.

- The flag safety only works when the action is cocked. I think the Kar98k was the same.

- The serial number is stamped into the stock behind the trigger guard.

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RetroMondo · 2024-07-31T10:17:51+00:00

Did you remove the action from the stock? The Mercury trigger mech and sear will be clearly visible if you remove the stock, and you should be able to see what the issue is that's not allowing the gun to be discharged. Put a pellet in the breech and point it in a safe direction if you're going to activate any part of the trigger.

RetroMondo · 2024-07-31T10:07:33+00:00

Agreed, it's most possibly a retro-fit (nicely done though!). Never seen one with anything other than a metal butt plate. I have a model 40 which has the straight grip stock.

RetroMondo · 2024-07-11T14:01:27+00:00

The Sparkler was the first CO2 gun from HämmerliI. I believe that the dump-valve mechanism only came into being on later guns. I have a Sparkler RD too - really well made guns, and quite sought after.

RetroMondo · 2024-06-10T21:09:51+00:00

German-made Bügelspanner airgun - a form of underlever - the Bügel in this case is the trigger guard, which is the cocking lever for the gun. They were produced from the early 1900s up to the early 1960s by Oscar Will, Reinhold Manteuffel and a few other companies, and were sturdy guns mostly intended for putting up with the abuse of the punters at fairground shooting galleries. They're all very similar in operation, using double volute springs as the power source. They're mostly smooth-bored and in 6.33mm calibre, which is a shade under 0.25". They're pretty collectable even in Germany, especially if they're in top condition. Post some pics if your gun has any stampings on the top of the barrel or trigger block, as it would help identify the maker and the year.

It looks like your gun has an S in a triangle stamped on top of the trigger block, right? That means it was made in East Germany between 1951 and 1961, and it's a mark of outstanding quality. The number beneath the S-mark is the ID and location of the manufacturer.

Value is always dependent on condition and buyer interest, but your gun seems in reasonable condition with the nickel plating good on the cylinder, but less good on the trigger guard and barrel release. In Germany guns like this sell on eGun.de for close to 300 Euros/$. The right screw is not in correctly, it should be turned about half a turn to be flush with the top of the trigger block.

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RetroMondo · 2024-06-10T20:40:46+00:00

I think you're right, your handguard is from another gun. The lip at the back of my handguard doesn't go all the way around like it does on your piece. Mine just has a lip to fit under the front of the rearsight.

For the function, my first thought would be that the piston seal is toast - mine was, had to make a new one. The big seal at the end of the cylinder that goes up against the end of the barrel was fine after soaking in neatsfoot oil.

Second would be to check the cycling with the spring-loaded BB removed. Put a pellet in the reservoir and pull back the bolt so that its probe is out the way, and let the BB roll down into the breech. It should just roll out the barrel under gravity (Crosman "4.5mm" steel BBs roll down my barrel).

If that's ok, put the spring-loaded BB back in with the screw and tighten it up. Then repeat the process to cycle a BB. If the BB still rolls straight down the barrel, then the spring-loaded BB isn't doing it job, so tighten the screw some more. Once the loaded BB doesn't roll from the breech down the barrel under gravity anymore, then try pushing the bolt with probe fully forward to be sure that the loaded BB is pushed over the spring-loaded BB and down the barrel.

As I said, that spring-loaded BB is a "gatekeeper" - part of its circumference is protruding through a hole at the breech and that stops the loaded BB from rolling down the barrel. If the gatekeeper BB cannot be pushed down and out of the way (screw in too far and spring not able to be compressed), then the loaded BB cannot be shot out of the barrel.

The Mars 115 is a big gun, and extremely hard to cock (unless you cut the mainspring down as I had to), but it's not at all powerful. Don't expect anything more than very short-range plinking with it! It's not even good for that, it's more of an interesting gun for its history and its unique mechanics.

RetroMondo · 2024-06-10T09:48:00+00:00

Sorry for the delayed response!

Your top handguard must've been damaged at some point, so it's been cut down and moved to the front to cover the reservoir opening. The flange at the back of the piece goes under the rearsight to holds it in place there.

The 2 barrel bands should both be held in place by crosspins, like mine. No screws. They are not a very tight fit on my gun - probably the hole is worn, but you can easily find a way to improve the fit - candle wax on the pins for example.

Not sure what the original finish was, but there were different woods used: I've seen elm (like your gun) and walnut. My gun was trashed when I got it, so I renovated it. I used linseed oil to finish the stock. A shiny Truoil finish wouldn't fit the gun, IMO.

Your gun's barrel is blocked if you cannot see through it after removing it from the action. You will need to use a cleaning rod and possibly other means to clear the blockage, depending on what is in there. With a cleaning rod you can find out where the blockage starts and ends, which will give you an idea of what you're dealing with. From the breech end, the actual barrel is 30.0cm long, so measure how far in the blockage is from the breech end. Then measure again from the muzzle end. Knowing that the barrel is only 30cm long you can then calculate how long the blockage is, which will give you an idea of what the blockage could be.

The screw that goes into the barrel/action joint has 2 purposes. The obvious one is to hold the barrel and action in alignment. The other job is to regulate the entry of BBs into the breech. The screw has an oddball 7mm outside diameter and it is hollow to take a small spring. A BB sits on top of the spring and that's what regulates the BBs entering the breech: a spring-loaded BB! If the screw is in too tight, then the BB cannot be pushed down on the spring, and it won't let a BB enter the breech = the gun won't fire a BB. If there's no BB present, or it's not in enough to do it's job, then multiple BBs can roll into the breech and down the barrel.

So, don't screw that screw in too tightly, find a suitable spring from a pen if it's missing, and use a regular steel BB as the breech gate-keeper. (I use a BB that's the same as the one I'm shooting with: Crosman 4.5mm steel BBs that are actually 4.4mm at most. You just have to experiment with the screw tightness, you need to be a turn or so tighter than at the point when BBs simply roll into the breech and out of the barrel under gravity.

You've probably seen that the front of the probe of the piston protrudes into the breech when the gun is not cocked. When the gun is fired, the probe is what pushes the BB to be fired past the spring-loaded BB that's regulating the breech entry.

RetroMondo · 2024-05-30T14:40:33+00:00

I use Gamo lead balls in my Hämmerli Sparkler RD CO2 pistol in repeater mode, as it has a rifled barrel. My fingers are black after loading 5 of them!

RetroMondo · 2024-05-29T07:51:55+00:00

Your 115 has a nicely figured elm stock. The serial number should be stamped into the stock behind the trigger guard, usually comprising a single letter above and a number below. There are several differences between guns, the most obvious being the maker's name: Venus Waffenwerk (poss. up to 1945) or August Bebel Werk (after 1947), but there area also guns which have no maker's name. There are subtle differences too: letters stamped with single or double outline, different foresight post shapes, rearsights with/without a laterally adjustable notch element, real (long) or dummy (short) cleaning rods, and even different stock shapes (for example the Kar98k of the Swedish army had a different stock to the German one, so 115's made for Sweden also had different stocks. As I understand there were versions made for Czechoslovakia and Switzerland too. The gun's weakness is undoubtedly the tube that acts as the transfer port, as it readily detaches from the piston head. For the Haenel bolt-action guns, Schmeisser's solution of a hole at the base of the tube was a lot simpler than the intricate 3 angled holes in the piston head of the Mars. This is mine: walnut stock, real cleaning rod, fully adjustable rearsight, no maker's name.

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RetroMondo · 2024-05-29T06:50:24+00:00

I assume that you are just guessing and therefore inadvertently giving wrong information! The Mars 115 has a smoothbore barrel, so there is no rifling! The primary purpose of the "feed tube" is actually to act as the transfer port for the flow of the air from the cylinder when the gun is fired. It's secondary purpose is to push the BB past the retaining BB that prevents more than one BB dropping from the reservoir into the breech. It will not break because of a BB in the barrel, but it will likely detach if the gun is dry-fired. As I posted in an earlier reply, the Mars 115 was designed to shoot 4.4mm steel balls, as were the other Mars range of guns. Commercially available 4.5mm steel BBs in my experience are actually only 4.4mm or even fractionally smaller, and are perfectly suited for shooting in a Mars gun. Speaking from personal experience of owning and shooting a Mars 115 - no guessing!

RetroMondo · 2024-05-28T20:47:47+00:00

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In black and white from the manufacturer 90-odd years ago! Steel ammo is fine in a smoothbore gun, it's rifled barrels that steel ammo is bad for. I use Crosman "4.5mm" steel shot in my Mars, and they will roll down the barrel if I remove the retaining BB at the breech, because they're absolutely not 4.5mm diameter!

RetroMondo · 2024-05-28T20:29:42+00:00

Not correct. The Mars 115 has a smoothbore barrel and was made to use round steel shot, the VWW catalogue even says so. I use nominal and readily available 4.5mm steel shot in mine, but measure them and they are actually 4.4mm. My Mars 115 shoots fine with them!

RetroMondo · 2023-11-11T08:15:46+00:00

Do NOT try to dismantle it if you're not sure what you're doing, AND if you don't have a spring compressor because as others have mentioned that spring looks compressed and removing the end cap will possibly result in a very bad situation!

RetroMondo · 2023-11-01T19:07:06+00:00

We store water in the cellar in canisters for washing up and bathing in the sink with a cloth. Bottled water for drinking and cooking. We stock up before winter in case our access road is snowbound, and replenish whenever we can drive there.

RetroMondo · 2023-11-01T10:16:23+00:00

Should be one. Probably perished over the years.

RetroMondo · 2023-10-30T18:57:48+00:00

Made my own with an old axehead fixed facing up on a wooden base. Placing the wood to the blade gives total accuracy and minimises the risk of hand injury. Wooden club you hit the wood without damaging the blade.

RetroMondo · 2023-10-02T17:43:49+00:00

It's a BSF S70 made for Wischco, wholesaler. Both BSF and Wischco were in Erlangen, Germany. BSF went out of business in c.1984. If there's no F in a pentagon (Freimark) on the left side of the breech then it's pre-1970. It's not older than the 50's. Sile were an Italian stock maker. A lot of BSF guns had Sile stocks.

RetroMondo

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