Model 69 Two Piece Barrel

[Mike_Fontenot]

If you can get a thin strip of ordinary computer paper to move freely in the gap, you will not have any problems with too narrow a gap. The paper is in the .003 to .004 inch range.

Thanks for that tip. I tried it with my M69, and a single thickness slipped in with no resistance (but also no light showing), but two thicknesses wouldn't. Surprisingly, all of my other revolvers were slightly narrower: my 1st 360sc (scandium/titanium .357 snubby) gave a slight resistance to one thickness. My 2nd 360sc wouldn't accept it at all. My 3" .357 60-15Pro offered a very slight resistance, and my Charter Arms .38Sp snubby wouldn't accept it at all.

 

[Mike_Fontenot]

Mike, you can pick up feeler gages for between 10 and 15 dollars at almost any auto parts store. Just make sure you ask for a set intended to use with setting the valve clearance on a solid lifter engine.

Thanks for that tip.

 

[yfdcap]

While I do see B/C gap to be a sign of quality control, I admit it really has little effect on how the gun shoots. My OCD just seems to kick in. I have had a chance to shoot my 69 and I really like how it shoots and feels in the hand. Stock grips work great for me.

 

[mag318]

I was turned off to the Model 69 because I just didn't like the way the 2 piece barrel looks. But I have a Governor and 3 Ruger LCRs all with 2 piece barrels and they have never given me a problem. So I now think the barrels are fine but I still don't like their appearance.

 

[Mike_Fontenot]

While I do see B/C gap to be a sign of quality control, I admit it really has little effect on how the gun shoots.
[...]
Stock grips work great for me.

It would seem reasonable that the gap might well affect the muzzle velocity achieved, all else being equal. But too small could hurt reliability.

I too like the stock grips. I bought the M69 with the hope of being able to conceal-carry it under my shirt, in a vertical shoulder holster and homemade harness like I use for my full-size all-steel 10mm 1911. The M69 weighs an ounce less than my 1911 (37 vs 38 oz), but the M69 is about an inch longer and about an inch taller. It appears to be possible ... I've been carrying it full time for several days now ... concealment isn't as good as with my 1911, but it is adequate, I think (and I'm actually pretty picky about concealment). The grip produces more of a bulge in my shirt than the 1911 does, from the longer grip, but it's not so large that I can't disguise it with the even larger bulge I get from all the stuff I carry in my left shirt pocket (fat cell phone, four pens/pencil, and two small notebooks). Most people probably wouldn't be willing to routinely have a full shirt pocket like that, but my pocket already looked like that long before I started carrying under-the-shirt ... typical nerdy engineer! N-frame-sized grips would be too large for under-the-shirt concealment, I think.

 

[yfdcap]

It would seem reasonable that the gap might well affect the muzzle velocity achieved, all else being equal. But too small could hurt reliability.

I actually had two 6.5 inch model 29's. One with .004 B/C gap and the other at .010( the .010 was a -3 I have since sold). I actually tested some hand loaded ammo with my chronograph. I carefully weighed each powder charge and each bullet using new brass to try and eliminate variables. The difference between the .004 and .010 was not really more than normal velocity swings from round to round through the same gun. I no longer have the notes but if I remember correctly it was about 25 or so fps for a 12 shot average from one gun to the other.

 

[cal50]

So that brings up a different question about the two piece barrels. Is there any special knowledge/materials/tools required to work on a gun with a two piece barrel?

S&W has the tools and they are not making it easy for the gunsmith or home gun-plumber to wrench on them.

I modded my 500 mag that had an excessive ( IMHO ) barrel / cylinder gap by cutting the shroud and barrel in half and re-machining it.

http://smith-wessonforum.com/s-w-re...311636-peek-inside-s-w-500-barrel-shroud.html



On my gun the barrel it torqued using a wrench off the rifling / bore to tighten it down against the shroud as other S&W production guns. <y performance center 500 has an extended brake that is a barrel / shroud nut and can be turned off easily using a bar passed thru the slots.


Jump to 1:53 and you can watch the barrel being screwed down into the frame then locked using a spanner wrench on the brake.

I personally like the tensioned / 2 piece barrel system but hate the S&W approach. Its simple for them to manufacture but the Dan Wesson system is far better, user and tolerance adjustable.


https://www.youtube.com/watch?v=13QFwS422HE




Feeler gauges are cheap and a good item to have ~

 

[yfdcap]

That is a very interesting video. If I check my revolvers like Smith does by rotating cylinders while checking gap, my gaps are quite abit tighter. My 69 is closer to a .007 versus a .009+. That is being able to rotate through all cylinders with feeler gauge in. Hmmm. Nice job on the 500 by the way.

 

[cal50]

That is a very interesting video. If I check my revolvers like Smith does by rotating cylinders while checking gap, my gaps are quite abit tighter. My 69 is closer to a .007 versus a .009+. That is being able to rotate through all cylinders with feeler gauge in. Hmmm. Nice job on the 500 by the way.

The 500 I cut down shot OK but it bothered me because it had a .010~.011 cylinder gap which I felt was excessive. Besides I had a pair of 500's and it was the excuse to myself to chop it, lol.

My PC 500 is set tighter and the .004" in the video matches my factory revolver I have but if I want to "tweak" it I can.........

 

[Mark F]

sure be glad when I can ransom mine out of layaway! Can't wait, but good things come to those that do wait, right? BTW, how many of you who do have a 69 have changed the grips and if so, what did you put on it?

The very first thing I did to my M69 was to install "X" Frame grips on it. While the original grips appear to be good, they are hard rubber on the backstrap. The "X" Frame grips are soft. So far, I've shot about 300 rounds of max load Magnums and the recoil is very controllable and comfortable. I have also added a Red-Dot for quick point capability. I love this revolver so much, I'm seriously thinking about letting my 629-6 go.

 

[Voyager28]

OK, you guys win. I snagged a 69 on GB described as LNIB.

Should be here in a few days. I'll post pics when it gets here.

Next, X Frame grips for it.

Bob

 

[Mike_Fontenot]

It would seem reasonable that the gap might well affect the muzzle velocity achieved, all else being equal. But too small could hurt reliability.

I actually had two 6.5 inch model 29's. One with .004 B/C gap and the other at .010( the .010 was a -3 I have since sold). I actually tested some hand loaded ammo with my chronograph. I carefully weighed each powder charge and each bullet using new brass to try and eliminate variables. The difference between the .004 and .010 was not really more than normal velocity swings from round to round through the same gun. I no longer have the notes but if I remember correctly it was about 25 or so fps for a 12 shot average from one gun to the other.

It IS amazing that that much gap variation would have such a small effect. Thanks for that info.

 

[yfdcap]

It IS amazing that that much gap variation would have such a small effect. Thanks for that info.

I was very suprised myself. Check out this test. BBTI - Ballistics by the Inch :: Cylinder Gap

 

[skypilot1941]

I have really enjoyed this thread. Glad to hear people are enjoy shooting the 69 so much. Mark F, glad you like yours so well. I don't know about selling the 629 though. Of course, that's up to you, but unless something really serious comes up, I'm keeping my 8 3/8 629-2E. I shoot 50 rounds yesterday. It's amazing how quickly 50 rounds go. Sure was fun though. All but two of those rounds were handloads of 7.3 grains of Trailboss under a 240 gr SWC. Really looking forward to shooting those in my 69 when it gets home. Also shot a couple of rounds of white box Winchesters. I don't imagine I'll make a steady diet of those through the 69. They are stout!

 

[Mike_Fontenot]

[...]
Also shot a couple of rounds of white box Winchesters. I don't imagine I'll make a steady diet of those through the 69. They are stout!

I don't know if the Winchesters you shot were the same as the Winchester 44mag 240gr JSP's on Midway's site, but Midway's page shows a muzzle energy of 741 ft-lbs, which is near the bottom of .44mag energies I've seen for the commercial .44mag rounds I've looked at on Midway. I've seen at least two commercial .44mag loadings with energies of about 1200 ft-lbs. There seems to be a huge gap between the upper .44Sp loadings and the lower .44mag loadings ... nothing like the difference I see in loadings between upper .40S&P loadings and lower 10mm loadings.

 

[TX2010]

I modded my 500 mag that had an excessive ( IMHO ) barrel / cylinder gap by cutting the shroud and barrel in half and re-machining it.

Thanks for posting that - a very cool project and really nice workmanship.

It's simple for them to manufacture but the Dan Wesson system is far better, user and tolerance adjustable.

I like the Dan Wesson approach as well, but I understand the barrel nuts can occasionally shoot loose and require re-torquing. That could be a warranty nightmare for S&W if the owners didn't know it was required. I have had for years a lightweight J-frame (342PD) with the two piece barrel and it has been perfect - no issues at all. S&W put that barrel on straight, so I know it can be done.

Speaking of Dan Wesson, I have one of the new pre-production model 715 revolvers on order. Should be here Monday.

 

[jaymoore]

...Speaking of Dan Wesson, I have one of the new pre-production model 715 revolvers on order. Should be here Monday.

Very nice! They also seem to have some product support for older models. An IHMSA friend got a new barrel recently for an 8 or 10" revolver(don't remember the details as I was in the middle of match prep at the time...), as the old one just would not group. Seems to have helped the situation.

 

[Kilibreaux]

Eons ago Dan Wesson proved the efficacy of the "three piece" barrel system - a shroud, barrel, and barrel nut. Competition shooters (myself included) utilized the ability to set the BC gap close to maximize power during silhoutte competitions.
Smith does it differently, but the engineering behind it it the same. A barrel that is not tensioned into the frame doesn't need to be a thick and robust, and accuracy is enhanced because the shroud acts to "pull the barrel forward" away from the frame which sets it in TENSION. A traitionally screwed in barrel is NOT under front-to-back tension and is not and never can be as accurate as a barrel that is.
The only thing "wrong" with what S&W is doing is they have chosen to make the barrel/shroud a factory serviceable issue versus user based...I suspect they'd still make plenty of cash with a user-screwable barrel because people like to have an entire gun with a given barrel.

 

[cal50]

S&W has a patent on the system they use to attach and secure the "barrel tubes" to the revolvers. The beauty of their system benefits them the most from a manufacturing point of view. Faster & easier ( for them) to assemble and set the BC gap than the traditional method they were using.

The Dan Wesson system benefited DW AND the owner / user for versatility, accuracy and ease of configuration. I once owned the DW pistol pack, the .357 frame with the 2", 4",6" 8" vented heavy barrels in the carry case. It was easily one of the most accurate revolves I have ever owned.

DW hit the nail on the head many years ago.

 

[zzclancy]

Thanks for the info. After reading the comments I'm picking up a 69 with the 2.75" barrel tomorrow on hold for me. I have a Lew Horton 629 with the 3" barrel. So I know it will be another flame thrower and recoil is brutal. I was concerned about the 2 piece barrel.

I have a M&P 340 with the 2 piece barrel and have had no problems. However I have shot only a few 357 magnums rounds, mostly 38 special + P without any problems.

Plan on taking the 69 to the range Monday. Only other concern is if the barrel isn't canted. If it is I probably won't buy it.