Help stripping a BSA Meteor Air Rifle?

[Joshua1993]

I'm trying to refurbish my air rifle which hasn't been used for a few years however I'm having a little trouble. Its a Mark 5 BSA Meteor.

 

After I take out the spring and guide, the piston doesn't want to come out. It turns in the tube freely and comes up about 7mm then becomes stuck. I cannot see anything stopping it coming out but it doesn't want to :(

 

Am I missing something?

 

Any advice would be good. Thanks in advance

Edited May 14, 2013 by Joshua1993

[Scottoj18]

The trigger.. Gets in the way

[Joshua1993]

Thanks for your advice.

 

I've just got it out!

 

A little brute force managed to budge it - and I did notice that the trigger got in the way near the end.

 

 

 

The trigger.. Gets in the way

Edited May 14, 2013 by Joshua1993

[bruno22rf]

If you google Chambers gun spares you should find a diagram of the gun.

[Capital Bee]

What was the buffer washer like behind the piston? They have a habit of breaking down and then causing piston jam in the cylinder.

[Joshua1993]

If you google Chambers gun spares you should find a diagram of the gun.

 

Thanks.

 

What was the buffer washer like behind the piston? They have a habit of breaking down and then causing piston jam in the cylinder.

 

Well it definitely needs changing however luckily it all came out in one piece.

 

I will upload some pictures soon because I'm looking for some advice on how I can make the gun more powerful.

 

So far this is my list:

 

New breech seal (I was informed to get a breech seal for the HW35 as it fits better?) - http://www.ebay.co.uk/itm/250559813913?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

New o-ring

New buffer washer

Stretching the spring - possibly a new one

Possibly adding some extra washers - I've heard this sometimes helps increase the power.

 

Also, when I'm looking to buy an o-ring, I can buy 1 for £2.90 or I can get 10 for less £2 if I know the size - does anyone know the size?

 

Here are the links: http://www.ebay.co.uk/itm/Genuine-BSA-Mercury-Piston-O-Ring-Washer-/370529672787?pt=UK_SportingGoods_Hunting_ShootingSports_ET&hash=item56454a1e53

 

http://www.ebay.co.uk/itm/221059162294?var=520096687189&ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

 

Again, if you can offer me any advice I would be most grateful.

 

Thanks

Edited May 14, 2013 by Joshua1993

[Capital Bee]

Buy a new spring, restretching the old one won't give you anything after it's started to collapse. Look at Chambers or john knibbs site and you'll see tuning components for the meteor, a 'top hat' and spring guide to to fit either end of the spring. This will smooth out the cocking cycle and give extra compression of the spring (and therefore greater power on spring release). Polish the ends of the spring anf give the piston and cylinder a polish with wet and dry or 3M abraisive pads. Also, when you rebuild, ensure you grease the spring and spring ends with moly grease. Don't put any moly in the cylinder and add a smear of synthetic motor oil around the new O ring before you refit it to the cylinder.

[Joshua1993]

Thanks for the advice Capital Bee.

[bruno22rf]

If you really want 10 O rings then you could join the BSA owners forum and ask or just take the old one,along with the piston,to your nearest engineering workshop and ask them to measure the groove dia in the piston and the thickness of the O ring.I would suggest that,if you are looking for maximum power,you think about buying a gun designed to work at the top end of the legal limit rather than "super tuning" a Meteor.

[Joshua1993]

If you really want 10 O rings then you could join the BSA owners forum and ask or just take the old one,along with the piston,to your nearest engineering workshop and ask them to measure the groove dia in the piston and the thickness of the O ring.I would suggest that,if you are looking for maximum power,you think about buying a gun designed to work at the top end of the legal limit rather than "super tuning" a Meteor.

 

Thanks for the advice regarding the spring and o-ring. I'm getting a new spring now and I've ordered some o-rings as I found a recommended size on another forum.

 

With regards to tuning the air rifle, I think I may not have explained things well or you have mis-understood me. I'm not looking for a maximum power rifle, the reason I want to increase the power is because currently the rifle was probably less than half the legal limit - all the seals had has gone and the spring was very worn.

 

I got the gun for free because my dad pulled it out of a skip about 15-20 years ago and he gave it to me when I was old enough. I'm not looking to spend hundreds on a nice rifle so I was hoping to spend between £20-£30 to refurbish the gun - make it look nice and increase the power slightly.

Edited May 16, 2013 by Joshua1993

[Capital Bee]

Ignore the new delrin spring guide and top hat for now then. Poilsh and deburr the piston (including the cocking slot). Polish the new spring ends to very smooth finish with wet and dry. Polish the cylinder with wet and dry on a dowel, held in a battery drill. Keep it dry. New breech seal to go with the piston seal and grease spring and spring ends prior to re-assembly. On a 'dry run' reassembly ensure the piston and new seal fits suitably in the cylinder - too tight will lose power as much as too loose. The piston should fall in the cylinder under its' own weight and you should then be able to stop it by covering the transfer port with your finger. So you might need to 'polish' the piston seal 'O' ring with some wet and dry to get the best fit.

Hope it goes alright for you.

Edited May 16, 2013 by Capital Bee

[Joshua1993]

Thanks again Capital Bee.