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September 8, 2024
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Hello to all,
I have been a gun owner for many years and saw a DW .357 model 40 supermag/max 8'' and without hesitation fell in love with it!
I am a bit of a tinkerer (lol) and have a few questions about setting the barrel distance from the cylinder, which I believe go beyond the
normal questions asked. ( OR I AM BEING TOO ANAL ABOUT THIS, LOL). The normal procedure does not seem to work quite well in my situation,
which brings me to the conclusion of a possible problem. I've called CZ and tried to get hold of the DW person for a month now, but to no avail.
I have no gun smith's in my area so I am hoping someone in the forum could help me out.
Thank you, J
DWF Supporters
July 12, 2020
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Welcome to the forum from PA!!!!! DW gives a .006 gauge with the guns, others here feel you can go less for more performance from your ammo. One thing for sure is set your gap (whatever you deem) at the tightest chamber on the cylinder. Other more knowledgeable members will chime in for sure.
September 8, 2024
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Thank you so much for the welcoming 605DART.
The .357 supermag calls for a .002 gap, but there in lays the problem. I have 2 barrels and they gap the same,
I'm thinking that the cylinder may be off a tad. I hope I'm wrong .lol
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Dans Club
March 25, 2013
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I am confused by your post. The model 40 and 740 come with an extra barrel tube. It was DW's solution to forcing cone erosion from shooting bullets lighter than 158 grains. 170 grains and up is even better. The gap for a Supermag is .002. That is measured with a shim slid between the forcing cone and cylinder without pushing the cylinder backwards against the dedent ball. When you tighten the barrel nut keep a finger on the forcing cone to prevent the barrel from turning, which would result in a smaller gap. Do not over tighten the barrel nut. Snug is good. I find a set of automotive shims more effective than the DW sliver. Especially when setting the gap on small frame Dans. Whether it is .002 or .006, the gap should be measured by the proudest, chamber. Measure each chamber and set the gap on the one with the smallest gap. Small frame guns cylinder faces often are not perfectly perpendicular. Large frame guns are usually more perpendicular. Also, small frame cylinders will expand after a number of rounds so a larger gap is required. Large frame guns will not do that. I prefer a smaller gap on the small frame guns. .004 is what I use. Once you get familiar with your gun you can dispense with the shim and hold the gun up to a light and cycle the cylinder and check the gap on each chamber by sight. Much faster.
I hope I addressed your concern. I really didn't understand what you were saying about the two barrels gaping the same. You only use one at a time and the gap is what you set.
Dans Club
February 24, 2013
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I don’t understand “I have 2 barrels and they gap the same,” either. When you install one of the barrels, you set the gap to .002” using the proudest chamber on the cylinder. To me, if they both gap the same, that’s a good thing!
Welcome to the 
from central IL!!!
September 8, 2024
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Thank you Ole Dog!
Sorry I have not responded sooner, I had to go up north for some family issues. I totally understand what your saying and appreciate the advice.
I my have not explained it properly. I hope this will correct it and not make more confusing. I wanted to say that when I used the shim, and putting the shim in
the left side of the gun at .002 it would only go half way toward the other side and get hung up a bit. So, I thought that the barrel might have been bent. That is
why I said I wanted to try the other barrel to see if it was the barrel that had the problem. needless to say it specs the same So my theory was wrong and the
barrels are fine. After some research it seems that the crane ( has more wear then it should) and or crane lock are the problem
I spoke with a gun smith and what I described to him, he thinks it may be the crane? before I do anything else I will set the barrel as per your advice and go from
there. Thank you once again, I greatly appreciate it.
Dans Club
February 24, 2013
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Someone in the past may have “Bogarted” the cylinder (closed the cylinder when it is loaded with ammo by flicking their wrist clockwise thereby slamming it into place/closed) which can bend the crane. Like Humphrey Bogart always did in his movies.
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Dans Club
February 22, 2009
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djs1234567 said
the left side of the gun at .002 it would only go half way toward the other side and get hung up a bit. So, I thought that the barrel might have been bent. That is
It could be the face of the cylinder. Many DWs are not faced true, so the gap is inconsistent across the face of any particular chamber. Hard to say without the revolver in hand.
Technically, the glass is always full; half liquid, half air....
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Dans Club
March 25, 2013
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Open the gap to .003 and check every chamber. Don't push the shim in, just slide it. Ron is correct about varience.
September 8, 2024
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Thanks to all you guys for the responses. To KurtB: ( LOL ) I had thought about that also, some yahoo could have done that. By the way your set is BEAUTIFUL!!!
To SOWELA: I have a lathe, so when I remove the cylinder and the crane to check them I'll see if the cylinder concentricity is off, and check that the cylinder
length and width are all the same at 6 different points. and yes I will use brass or cooper as soft jaws on the chuck. Thanks.
To OLEDOG: will do.
But that raises another question? If I set it to .003 at the tightest chamber, what is acceptable for the largest gap at the loosest chamber?
Is there an expectable amount of play from smallest to largest gap?
Thank in advanced again guys, Jay
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Dans Club
February 22, 2009
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djs1234567 said
To SOWELA: I have a lathe, so when I remove the cylinder and the crane to check them I'll see if the cylinder concentricity is off, and check that the cylinder length and width are all the same at 6 different points. and yes I will use brass or cooper as soft jaws on the chuck. Thanks.
No need to do that- shoot it and enjoy it with the gap set on the chamber that appears to be most proud. Unless, of course, you just want to.
Technically, the glass is always full; half liquid, half air....
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Dans Club
March 25, 2013
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Yes to what Ron said. Please don't use a lathe on the cylinder. BTW, the gun chambers 38 Special, 357 Mag, DW 360,357 Maximum and 357 Supermag.
September 8, 2024
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Thanks guys. I was so determined to check this I worked late into the night. dissembled the whole gun found the problem among other problems.
most importantly the cylinder was only off by .0005 in length. crane seemed fine and I believe the crane lock was not in correct position which would not allow
the cylinder to set in properly. put it back togather, set the gap, as per your suggestion ( .003 )
gauged it .0025 at smallest, .004 at largest. Will go to the range this week depending on the possible coming Hurricane.
thanks again for all of your help!
February 16, 2016
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Dans Club
March 25, 2013
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Very happy for you. You can't have too many Model 40s/740s. Truly an iconic revolver that will never be made again. I just recieved another one for my pile. It appears ANIB.
September 8, 2024
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Thank you stinger and ole dog!!! do you know of anyone or anywhere other than E-bay where I might be able to purchase different length barrels?
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Dans Club
March 25, 2013
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Keep an eye out on Gunbroker too. Expect to pay a lot.
September 8, 2024
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thanks OLE DOG Stay Safe and tell Milton to shove off!!!
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Dans Club
March 25, 2013
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Milton seems to be moving south. We about 120 miles from the center of the cone. Might have 70 mph gusts. Unfortunately, lots of folks lives are going to be impacted. Snake-eye and Dakota Jack are much closer. My heart goes out to those poor folk in NC.
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