Alros Trailsman - a 'plumber's' modification....

**chieffool** · 27-05-2015, 10:33 AM

The Alros |Trailsman has recently appeared in a couple of posts. I thought it might prove useful to any other owners to briefly catalogue a 'plumber's tale' of ownership (though i am also a fitter, joiner, electrician, tiler, etc).... I digress:

The Alros Trailsman is a true take down air rifle. PCP/full power. There was also a CO2 version, and there are a slim tube (looks nicer to my mind) and voluminous 'bottle' version - as well both single shot and multi-shot via a fixed rotating 8 shot magazine.

i have a slim tube/multi-shot in .22. Love the look and concept of it, and the balance is very nice, fun to shoot - can't help but grin as accurate.... comes ion a tool roll, assembles in minutes (Day of the Jackal...)
...though trigger feels like a clutch peddle in comparison to most of my other rifles.
However, like all things, you get used to it.

The slim tube (i have 2 x tubes now because of an adaption U.K.Neill sorted out on a CO2 'spare' i had) gives me 16 shots at between 11.6, down to 11.2, then a further 8 shots from 11.2 down to 10.5 ft lbs. That's 3 x reloads of the 8 shot rotating fixed mag.
And a tube only takes about 45 pumps to get up to 200 psi, though i have found 195 psi (ie just a tad under on the gauge) gives me the best and most consistant shot count. I have a pump because this is my only PCP.

The shot level is now very consistant now: it wasn't when i got it.
The gun operates by firing a 'slam weight' which has been cocked back a sort travel (the pull of the bolt) into the stock.
The trigger engages, and when released ORIGINALLY the weight was propelled forward from a short spring held by a fitted baseplate set behind the slam-weight. The spring is small/stiff - and hence very 'nitpicky' about adjustment. And adjustment is achieved by taking the brass stock piece out, and altering a threaded colour (range of about 4 complete turns) which effectively reduces fractionally the penetration of the slam-weight against the air reservoir pin. Fiddly and largely unforgiving stuff.

When i got the rifle, it was only producing about 6.5 ft lbs.
I took it apart and could see how adjustment of the spring was supposed to work, i tried the equivalent of 'washers' to increase preload, but tolerances were so tight i couldn't get the bolt to engage smoothly.

Amongst other things - i am a plumber. And IF a short stiff spring won't do - then how about a longer/easier one?
I sourced some suitable candidates from the bay, tested it with a setup that uses the end of the aluminium shoulder piece which is inserted into the stock as my rear spring plate - and hallelujah - the figures reported above. Cocking motion is sweet and easy - and adjustement (that 4 turns range i mentioned earlier) now gives me a starting ft lb of 'above 12ft limit, down to about 8 ft lbs. I've set the start poiunt at 11.6 - and haven;t found a pellet yet that chronos above the magic 12 on this setting.

So - for the 'non-plumbers' (although it looks odd dis-assembled) my solution from stuff in the van is remarkably simple.
Hence the PICs posted for info. You'll see i've used a JG speedfit 22mm insert with a 15mm insert jammed in as the 'top hat'. It all recesses with minor carving into the back of the spring neatly, with a 15mm insert on the 'back plate' end.
The back plate is just a suitable hard tap washer, which sits against a piece of JG speedfit 15mm pipe - which after trial and error gave me the correct level of pre-load to make bolt comfortable and range of adjustment 'sweet'.

It works so well - i've done nothing else since. The stock is set at the distance i want, and this all rests against the stock end - but i could just as easily refit the previous back plate somewhere in the 'preload' area to keep adjustment of the stock independent of the spring sysrtem.

PICS are hopefully self-explanatory in logical order comparing old and new configuration. So enjoy.

**chieffool** · 27-05-2015, 10:42 AM

**Mark D** · 27-05-2015, 10:59 AM

Great write up - lovely little rifle and a tinkerers delight.

BTW - you aren't a plumber ! - no ptfe tape to be seen

**chieffool** · 27-05-2015, 11:01 AM

....oh come on - derrr! How can i be a real plumber - its all PUSHFIT!

**mike hunt** · 27-05-2015, 11:54 AM

Cheers Chief,

very informative, will have a play

**kash2001** · 28-05-2015, 11:05 PM

Hi can you kindly let us know what spring too search for on the bay to replace the olden. Atb...

**fatttmannn** · 29-05-2015, 06:17 AM

My apologies, only just noticed this, a great thread thanks for shareing with us all.

**chieffool** · 29-05-2015, 07:46 AM

Originally Posted by kash2001

Hi can you kindly let us know what spring too search for on the bay to replace the olden. Atb...

will dig out the info and send over with vernier reading as well on dimensions. My current mod uses plumbing parts, so i chose a spring that fitted those, but also tried larger/wider that would fit inside the stock. The amount of preload (produced by the short piece of plastic pipe, though could just as easily be a bit of stick!) is demonstrated in a pic which shows you how much of the weight protruded from the stock end before the brass retainer piece was fitted - but because you are dealing with a 'squiggier' longer spring, nothing is really critical and easy to adjust with trial and error.

**dontpester** · 16-12-2016, 07:49 PM

Great write up I have an alros like yours part of the end of the valve is missing the rod

**greasemonkey** · 17-12-2016, 08:16 AM

hi,great write up ,thanks for sharing.i have the same model but single shot in .177.the only significant modification i have made to mine is to fit a concealed trigger sear engagement screw,makes for a much improved and lighter trigger pull. i havent used my gun in a while and was thinking of selling it but may now use it as my interest has been re-invigorated by this thread,cheers greasemonkey..

**Benelli B76** · 17-12-2016, 08:24 AM

Thanks for the info, just turning up a new exhaust valve for one of these. They are just plain nylon and tend to crack and leak with all the impacts on firing. When you strip them looks like someone made them up as a home project, but good performers and very accurate.

Baz

**chieffool** · 18-12-2016, 08:57 AM

Originally Posted by Benelli B76

Thanks for the info, just turning up a new exhaust valve for one of these. They are just plain nylon and tend to crack and leak with all the impacts on firing...

Baz

Post a PIC please. Do you mean the exhaust valve on the air cylinder? Cheers, Richard

**Benelli B76** · 21-12-2016, 06:49 AM

Originally Posted by chieffool

Post a PIC please. Do you mean the exhaust valve on the air cylinder? Cheers, Richard

Richard, yes the valve hit by the hammer on firing. This rifle is not mine and is back with its owner so I have no pic, but I am going to make another valve the week after Christmas so will take some then.

Regards, Baz

**chieffool** · 21-12-2016, 03:00 PM

Originally Posted by Benelli B76

Richard, yes the valve hit by the hammer on firing. This rifle is not mine and is back with its owner so I have no pic, but I am going to make another valve the week after Christmas so will take some then.

Regards, Baz

Thanks baz - .Would greatly appreciate it if you can squeeze some pics onto the thread as suggested when you do the next exhaust valve 'repair' as would be good to have all the references in one place....
.... But mainly because I would like to see and know how to deal with any similar future problem on my gun.

Seasons greeting s to all who chance this way in the meantime!!!!

Richard

**shovelchop81** · 11-04-2017, 06:40 AM

Hi! I've been thinking about getting one of these but can't see the pics for the mods, can you please upload them again if you have them? I think the Photobucket account must be out of date, cheers!

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