Bad advice. See comment on Post 39. Maybe using a bronze brush caused the problem.
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Has anyone seen this problem - 351PD
- Thread starter Talldog
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Bad advice. See comment on Post 39. Maybe using a bronze brush caused the problem.
cmj8591
Member
There is no warning in the manual about using a bronze brush to clean aluminum cylinders. In fact, the manual recommends a brass bore brush of appropriate size for cleaning bore and chambers. If a bronze bore brush damaged the gun, it was because it was misused. Very misused.
SweetMK
Member
Well, on a 22LR (NOT a 22MAG) I can repeatedly cause this sticking problem to occur.
(Actually, I am surprised MANY people have not mentioned this!!)
On a 22LR revolver, simply fire a couple cylinders full of 22 SHORTS,,
After firing the shorts, fire the normal 22LR ammo,,
the brass WILL stick.
This is almost 100% repeatable, and only 2 rounds per chamber needs to be fired to initiate the problem.
To expand this concept, I wonder about firing hyper velocity 22LR ammo,, then there is the 60 grain cartridges that use 22 LONG brass,,,
So, I would imagine that ANY change in brass length could cause the issue.
I have purposely done this with my Colt Trooper MKIII, and some S&W pistol, probably a Model 17-4.
In each case, the shells stick, then cleaning the cylinder until the visible ring is gone makes the problem go away.
It has been over a half century ago, but I would bet it was first seen on the bolt action rifle my dad gave me in 1960,,,
I shot EVERY ammo that I could find,, including some corrosive primed stuff we found in an old guys home.
He gave us the ammo, then some how we figured out it was strange,
It may have been black powder and "smokey",,,
I expect S&W uses a hard anodizing as a surface finish for their aluminum cylinders. Anodizing creates a controlled oxide layer in the aluminum. Aluminum oxide is very hard and will resist copper, bronze, brass, and nylon brushes. Reaming the chambers may remove the anodized surface, creating a soft surface that would be more easily scratched by soft metal brushes.
FWIW-this morning I just took my 351PD down to my range behind the barn. 100 rds Fiochi and 100 rds CCI maximal. Zero issues with extraction, although the cases were not all falling free upon extraction toward the end. Build up and crud were obviously causing the cases not to fall free, but extraction itself remained easy. A quick brush against the cases with a hand and they immediately fell to the ground. I’d fired one hundred Winchester through this same piece on Thursday, and had NOT cleaned it, so we are talking 300 through the beast without ANY hard extraction. Headed to the vault now for a thorough cleaning and lube. Mine has been a GREAT little revolver.
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cmj8591
Member
The anodizing is for corrosion resistance and appearance. The aluminum cylinder gets it's structural hardness from the heat treating process, not the anodizing. Running a finishing reamer into the chambers won't accelerate wear. It will however, make it so that the gun will more easily accept cartridges that are on the high side of the SAMMI specs. Everyone makes their own choices and people who don't feel comfortable should absolutely stay away from DIY. But aluminum chambers can, and regularly are, successfully reamed.
Sorry, but anodizing is a surface hardening treatment somewhat like color case hardening on hammers and triggers
What is a Barrier Layer in Anodizing?
The electrochemical reaction causes pores to form on the surface of the aluminum as excess positive ions escape. These pores form a geometrically regular pattern and begin to erode down into the substrate. The aluminum at the surface combines with the negatively charged O2 ions to create aluminum oxide. This is called a barrier layer, a defense against further chemical reactions at those spots.
As current continues to be applied, the relatively weak and reactive areas of the pores will continue to penetrate deeper into the substrate, forming a series of column-like hollow structures.
A regular pattern of surface porosity is created when electric current is applied.
The longer the current is applied the greater the penetration of these columns. For typical non-hard coatings, the depth can be up to 10 microns. Once this level is reached, and if no color is needed, the process is stopped and the surface can be sealed simply by rinsing in water. That will leave you with a hard, natural aluminum oxide coating, able to withstand chemical attack and very scratch resistant. Aluminum oxide is rated 9 out of 10 on the Mohs hardness scale, meaning second only to diamond.
What is Hard Anodizing?
Hard anodizing, sometimes called Type III, offers greater corrosion protection and resistance to wear in extreme environments or with moving mechanical parts subject to a lot of friction. This is produced by continuing the electrical current until the depth of the pores exceeds 10 microns, all the way to 25 microns or even more. This takes more time and is more expensive but produces a superior result.
What is a Barrier Layer in Anodizing?
The electrochemical reaction causes pores to form on the surface of the aluminum as excess positive ions escape. These pores form a geometrically regular pattern and begin to erode down into the substrate. The aluminum at the surface combines with the negatively charged O2 ions to create aluminum oxide. This is called a barrier layer, a defense against further chemical reactions at those spots.
As current continues to be applied, the relatively weak and reactive areas of the pores will continue to penetrate deeper into the substrate, forming a series of column-like hollow structures.
A regular pattern of surface porosity is created when electric current is applied.
The longer the current is applied the greater the penetration of these columns. For typical non-hard coatings, the depth can be up to 10 microns. Once this level is reached, and if no color is needed, the process is stopped and the surface can be sealed simply by rinsing in water. That will leave you with a hard, natural aluminum oxide coating, able to withstand chemical attack and very scratch resistant. Aluminum oxide is rated 9 out of 10 on the Mohs hardness scale, meaning second only to diamond.
What is Hard Anodizing?
Hard anodizing, sometimes called Type III, offers greater corrosion protection and resistance to wear in extreme environments or with moving mechanical parts subject to a lot of friction. This is produced by continuing the electrical current until the depth of the pores exceeds 10 microns, all the way to 25 microns or even more. This takes more time and is more expensive but produces a superior result.
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cmj8591
Member
So the cylinder receives it's strength from the anodizing? Which brings me back to my two original questions. Will the finish reamer remove enough of the anodizing to make a difference? Will removing the anodizing from the chambers compromise the strength of the cylinder?
It seems to me that the surface "hardening" provided by anodizing would only be a real benefit on parts that are subject to wear from friction. Like the slide and slide rails on a semi-auto.
I'm not seeing where anodizing would provide any significant benefit on the inside of the cylinder chambers. That is not a surface that is subjected to frictional wear.
As Steelslaver points out in his post, a bare aluminum surface exposed to atmospheric oxygen very quickly forms a layer of aluminum oxide that provides all the corrosion barrier that is needed.
A great example would be all the bare aluminum parts on a typical motorcycle. Things like cooling fins and brake/clutch levers are made of bare aluminum with no coatings to prevent corrosion. They quickly develop a hard surface layer of aluminum oxide that prevents any further corrosion - unless it is stripped away by a corrosive agent like salt water.
Seems to me that the same would be true for the bare aluminum surface of reamed cylinders in a revolver. But I could be wrong - it wouldn't be the first time.
No it does not receive it strength from anodizing. But it does receive its scratch and erosion resistance from it, Removing it will not make the cylinder weaker, but it will erode much faster from the hot gasses.
The layer developed by natural exposure is way thinner than than developed by purposeful electrical anodizing.
Even a purposely anodized layer is not very thick and if a reamer removed enough to effect ejection it would most likely ruin it.
Ever use TiN coated drills and end mills? Very similar to anodized aluminum. The Titanium nitride is a thin hard coating that when properly applied and used on the materials it was designed for will add cutting speed and longer life to the cutter
The drill itself is not one bit harder, but its surface is.
Color case hardening is similar. Steel is packed in a carbon material and heated to the point some of the carbon migrates and bonds with the steel on the surface of the part and when quenched the surface of the part is very hard, but the center sections are not. 2 benefits, surface is hard and wear resistant while center remains softer and more impact resistant. IF you stone of very much from a hammer or triggers sear surfaces you get back to soft material and the edge does not hold up.
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cmj8591
Member
That's my point. The anodizing on these cylinders is mostly for looks, as you really can't blue aluminum. The chambers get anodized during the process but anodizing the chambers is not the main goal. The anodizing that gets in the chambers actually wears away relatively quickly even if they have not been reamed. I don't agree that the hot gasses will wear the cylinder more quickly if the anodizing is not there. If it was made of pure aluminum, then yes, they would ware away but the aluminum is alloyed to resist ware. We've been reaming these aluminum cylinders to make them more reliably eject spent cases since they came out with them. I'm going to bet that you have even done it. I haven't seen one that was done properly have any detrimental effect on the life of the gun. But I will be the first one to admit that I've seen a lot of things, but I haven't seen everything. I still think that when he sends his gun back, Smith is going to say that the chambers are within spec and send the gun back to him. The problem will come back the first time he uses some ammo that is outside the SAMMI specs and we're going to be reading about how crappy Smith's customer service is. The fix for the problem he is having is reaming the chambers and that happens outside of the factory.
Well, no.
After the last batch of comments, I cleaned the gun again as thoroughly as I could and made sure the charge holes were completely clean and dry. And I've never used a bronze cleaning brush (don't know where that came from), just brass. When I took it back to the range, the cases stuck again on the first cylinder. And when I say stuck, I mean I had to use a hammer and wooden dowel to get a couple of them out, and it wasn't easy. After that, it went back to S&W.
I got the gun back from the factory on Monday, 10/16. The paperwork said they "replaced cylinder and repaired the yoke." It went back to the range last Thursday.
The good news is that cases are no longer getting stuck. The bad news is that after the first couple of cylinders, it started getting harder and harder to close the cylinder after loading and pull the trigger. By the 7th cylinder, I couldn't pull the trigger far enough to drop the hammer. That's where I stopped. Function seemed to return to normal after the gun cooled down, but I didn't shoot it again.
I've already said it a few times, but I guess I have to say it again. This gun as been fed NOTHING but Hornady Critical Defense and CCI Maxi Mags. Neither is poor quality ammo. And I've never even heard of non-SAAMI spec .22 magnum ammo.
And as far as expecting a brand-new 800-dollar gun to function properly without having to take a reamer to the charge holes, well I guess I'm just funny that way. My wife's 351PD, purchased at the same time now has almost 700 rounds through it and hasn't had even a hint of a problem.
Anyway, it's gone back to S&W again, and they just got it today.
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Well that's no good! 
Sounds like maybe the barrel-cylinder gap was too tight with the new cylinder installed & it started rubbing as it got hotter?
No excuse why it should have left the repair shop that way of course.
I hope it gets fixed & returned to you soon.
.
Sounds like maybe the barrel-cylinder gap was too tight with the new cylinder installed & it started rubbing as it got hotter?
No excuse why it should have left the repair shop that way of course.
I hope it gets fixed & returned to you soon.
.
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