Shortening the Barrel of a Marlin 62

[Prince of Wales]

I have a Marlin 62 that was converted to 357 from 256. When I took the gun in I requested that the new barrel be 18 1/2" -20". When I picked it up the smith informed me that "it came out 22". I have tried to get used to it but because the forearm has been shortened even 22 inches seems to be too long. I want a carbine because this is to be the grandkids first centerfire rifle.
 My question is two part. First can I shorten the barrel myself using ordinary tools and crown it to produce accetpable accuracy? and secondly  will a 19" barrel extract total velocity(in a practicle sense) from the 357 Mag?
 Thanks and good luck. POW

[gunnut69]

To answer your question some.. 18-20 inches will be fine.. after all we're talking about a pistol cartridge here..  Brownells sells tooling(2 different types) that will square the muzzle and form the crown.  I have used them for years with complete satisfaction..