Question

[1984]

does anyone know what metal the spring gun piston tube is made from, it seems quite hard material ,where can it be sourced.

[edbear2]

Hi ......it depends on what you mean.......I am presuming you mean the cylinder ie. compression chamber.......you may struggle unless its an older bsa or webley to get an exact match of the bore/O.D........Material wise you are looking at an alloy steel, either T45, 15cdv6, or 4130 cond N......if you go to a specialist supplier (I use superalloys ltd.) online, they will advise you, and have sizes posted in their stock section.....obviously you are looking at a cold drawn seamless tube in all the above, probably of a higher spec. than originally used......Heat treatment wise, I am not sure what the makers do, of the three above 15cdv6 is probably the least hassle to do, I think its 600 degrees celcius only.......T45 would be pretty good as it comes, 4130 also, as it is a pain to heat treat and you pay by the furnace load ie. £150 a go minimum price even for one piece!........be prepared to have to buy a minimum of 6 meters at £12 - 18 per meter..Maybe cheaper to just buy a new gun..P.S......Do NOT braze 4130! if you have to attach stock lugs etc.......tig is preferable on all the above, Also if you are welding, or getting it welded.....make 100% sure the guy uses the correct, matched filler rod!

[1984]

hi, im looking at the piston tube itself not the air chamber, what would this be.

[edbear2]

Hi again......later ones are rolled.......if you want to turn one from billet, I would go for either 080M40 (EN8 old spec.)......or 606M36 (EN16)........EN8 is a fairly easy to machine steel, well up to the job.....16 is a manganese/moly tougher steel if you want to make a bomb proof one!........If you google the numbers, you should get suggested uses, tensile strengths etc. Both are widely used and any small engineering firm or handy person on a lath could run up a piston of the quality used in say a air arms TX with ease.........one day I will get round to trying it myself, with O rings, or a weihrauch type seal for one of my old bangers!

Google steel stockholders in your area......this type of bar can often be bought in sawn lengths to suit your needs.

[1984]

thanks edbear2 ill get hold of some en16 and turn some up on the lathe.