Help identify a MARES model and shaft size

[NICOLAS NYERGES]

I have an old working MARES speargun that I’m pretty sure it’s a Frontiersman / Sten. I need a spare shaft, but the problem is that I have some confusion about the exact Stean model. Actually Mares website has two types of Stean: STEN and STEN 11. The Sten have a 8mm shaft and the Sten 11, have a 7mm shaft. Please refer to the attached images, to help me identifying the model SIZE and the shaft diameter. My original shaft diameter is 7,5mm (can be the 7 or 8 model, don’t know). Also I don’t know where to measure the speargun size, to match the corresponding STEN model. Thanks in advance.
Nicolas

 

[popgun pete]

It is a Mares "Competition Line" Sten series gun. The 70 cm version is the "Medisten". The model here is the "Sten" as that gun is usually listed as a 90 cm, or slightly smaller, as at one time Mares quoted gun length from the muzzle to the rear edge of the grip handle rather than to the back of the inlet valve cap. This was the first of the "Sten 87" models and has the adjustable length (fore-aft) trigger which was deleted later on. The gun appeared in a few different colour schemes until it was superseded by the "Sten 2001" series. Some of the tooling for this gun is now used in the Mares "Jet". The gun fired an 8 mm diameter spear as standard from its 13 mm ID inner barrel. A slightly later version of this model (same colours) received a shaft retaining clip integrated on the lower surface of the front line wrap hook in 1989.

 

[popgun pete]

Mares routinely rename their guns for the US market, nearly everywhere else they are, in ascending length order, the "Miniministen", "Ministen", "Medisten", "Sten" and "Supersten". For the USA these same guns are the "Snub-Nose", "Shortie", "Frontiersman", "Californian" and "Long Tom", the changes are just the different tank stickers. Mares also used to sell a "Sharpshooter" in the USA which is just another version of the "Frontiersman", but it has a capillary type depth gauge added to the top of the rear handgrip and was finished in all-black, ditto for the similarly equipped "Long Tom".

 

[popgun pete]

As I own one of these guns here is the table from the instruction manual.

 

[NICOLAS NYERGES]

Peter, I am very grateful for your complete information. Thank you very much.

 

[NICOLAS NYERGES]

About the shaft. My shaft options are 43163994 Super 99cm steel or the 43163961 Super 99cm stainless steel shafts. Both are threated 8mm diameter shafts for the Sten. My question: I need to buy the tip for this shafts, so what is the side of the thread?

 

[popgun pete]

Screw threads are M7 on Mares 8 mm diameter shafts. Ditto for their 7 mm diameter shafts as well. All use the same standard Mares pencil point tip of average quality with two floppers. There are better ones, but you have to purchase them from aftermarket suppliers.

 

[nikif]

Could I use a 6.5mm tahitian Devoto shaft for this speargun?
A 65cm legth would be ok for a 70cm Medisten?

Any help appreciated!

 

[popgun pete]

You could, but you would need a washer or stop ring that had a hole in it of a suitable diameter for the 6.5 mm shaft, these guns using 8 mm shafts originally. The washer aligns the shaft in the muzzle when the gun is loaded by the washer sitting in a step in the front of the muzzle. I think a 65 cm shaft length is too short for the 70 cm model. For example JBL make an integral tip shaft for the Mares Cyrano 700 which is 32.5 inches long and that works out at 82.55 cm, so the shaft needs to be long enough to project from the front of the muzzle when the gun is loaded. They also make a screw tip shaft of 26.5 inches which is about 67.3 cm. I only cite these shafts as their length measurements are available in an on-line table.

The "Medisten" is shown in an early table as having an overall length of 70 cm without a shaft and 85 cm with a shaft. Now the guns have changed as the handle designs have changed, but that is still 15 cm poking out of the muzzle regardless of where the measurements are being taken from as gun length used to measure to the back of the butt and now to the rear of the receiver.

 

[nikif]

Popgun Pete your help is immense!
I keep reading your posts and learning a lot of things about pneumatics.

To clarify are there any available stop rings in the market or it has to be DIY?
A quick rule of thumb would be that the shaft is 10- 15cm bigger than the gun?

After performing some maintenance and opening my old Medisten, I couldn't find any "one way valve" near the gear mechanism- as there is one in Mares Cyrano. Have I lost it or there isn't such thing in the Medisten?

Thank you!

 

[popgun pete]

The non-return valve is made up of parts 68 and 69 which are shown here on the parts diagram. The gun should have one, although it will not if the gun is the single power version where the power regulator block is not fitted and the selector gate is blanked off.

The spear length poking out of the muzzle varies with the gun length, but I cannot say whether there is a particular rule at work as the numbers go up and down for the length increments on the shafts.
gun length w/o shaft: "Sten" 900 mm, "Medisten" 700 mm, "Ministen" 575 mm, "Miniministen" 415 mm
gun length with shaft: "Sten" 1088 mm, "Medisten" 850 mm, "Ministen" 771 mm, "Miniministen" 600 mm

I think you will need to make a stop ring as Mares never used 6.5 mm shafts in their 13 mm barrel guns. The "Mirage" had an optional 7 mm shaft, the "Mirage" being a 13 mm barrel gun, with a special stop ring that fitted the muzzle recess, so you will need something similar.

 

[nikif]

Many Thanks Popgun Pete!

 

[docmin]

Hi guys I have a Mares Cyrano and not sure of the model.
It is Black with Blue handle
Total length from end to end is 1120mm
I read that a Cyrano 970 is around 1200mm in length
Sop my gun would be a Cyrano 900, would this be correct?

The reason is I am trying to source spears and my spear is 7mm threaded 1 length is end to end without tip is 1100mm thanks guys

 

[popgun pete]

The original Cyrano models were 550, 700, 850, 970 and 1100. That was printed on the tank sticker. Your gun is most likely the 1100, that measure being the length from the muzzle to the rear inlet valve cap and not including the rear handle butt. The numbers are sometimes rounded, for example the 550 is actually a 540!

 

[marco15499]

Pete is a bible!

 

[docmin]

The original Cyrano models were 550, 700, 850, 970 and 1100. That was printed on the tank sticker. Your gun is most likely the 1100, that measure being the length from the muzzle to the rear inlet valve cap and not including the rear handle butt. The numbers are sometimes rounded, for example the 550 is actually a 540!
View attachment 56817

Thanks mate you are correct appreciate your assistance, managed to get a new spear so happy now. Merry xmas champ