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October 17, 2017
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Depends on what vintage. Very early DW’s had a removable gas ring, and the shim goes under it; problematic sometimes getting it out. Later models can be shimmed at the crane flange. Nothing like the S&W; more like older Colt’s.
November 1, 2022
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I’ve been getting low velocities from my DW15-2 4in as well. I tightened down the cylinder gap but it’s still struggling to get over 1200ft/sec with any load without showing signs of serious pressure (stuck casings and flattened primers). These were the three best loads (all with the 4in barrel):
10.5gr of True Blue with 125gr ~ 1240ft/sec, with flat primers and stuck cases.
13gr of AA#9 with 158gr ~ 1130ft/sec, safe but primers starting to flatten (will load hotter next time).
125gr ~ 1364ft/sec, with completely flattened primers and stuck casings. (I don’t know how much charge these had, I loaded them a lot time ago and they were unlabeled).
Even my 38+p loads (7gr of True Blue, 0.7gr over max) only yielded around 950ft/sec with the 125gr bullet. Pathetic!
I’ve seen other 4in 357s get significantly higher velocities. Paul Harrell tested Hornady American Gunner 125gr XTPs through his 686 and got over 1400ft/sec, but my Dan Wesson got only around 1250 with the same factory ammunition.
Is the barrel just old? Could a worn cylinder cause these issues? I checked for cylinder end-shake and found it to be perfectly steady.
I’m considering buying a new 4in barrel from CzUSA, hoping the newer and more modern rifling might help. Any other ideas?
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February 22, 2009
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I doubt the problem is a worn barrel- could be, but barrels tend to speed up as they're used a cared for properly. Less friction= more speed (to a point). I'm going to guess that maybe the cylinder chamber diameter is smaller (tighter) than the bore of the barrel. Revolvers should be largest in the chamber and smallest at the muzzle- the bullet should be squeezed on its trip to freedom. Think of a funnel with the large end being the cylinder. If the bore is larger than the cylinder's chamber diameter, gas escapes around the bullet as it travels the length of the barrel, and you'll never get the velocities of a properly sized set up. Ideally, the chamber diameter should be .001-.002 inches larger than the bore diameter.
Technically, the glass is always full; half liquid, half air....
May 6, 2024
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rwsem said
I doubt the problem is a worn barrel- could be, but barrels tend to speed up as they're used a cared for properly. Less friction= more speed (to a point). I'm going to guess that maybe the cylinder chamber diameter is smaller (tighter) than the bore of the barrel. Revolvers should be largest in the chamber and smallest at the muzzle- the bullet should be squeezed on its trip to freedom. Think of a funnel with the large end being the cylinder. If the bore is larger than the cylinder's chamber diameter, gas escapes around the bullet as it travels the length of the barrel, and you'll never get the velocities of a properly sized set up. Ideally, the chamber diameter should be .001-.002 inches larger than the bore diameter.
Yes.. Also..Since I shoot 99% Cast Boolits..the velocities are considerably Higher. You do Not get to Pick a Velocity...just go to a reasonable Loading, and Be Happy with whatever results obtained..Nothing you Shoot will know the Difference...much less Complain..
Be happy...or Screw on a Different Barrel
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