Model 69 and leading issues?

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fortyshooter

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Was just reading a review in Handloader magazine on a new Model 69 4.2 inch barrel and while testing a variety of mild loads 750-950 FPS using cast bullets they noticed a good bit of leading in the barrel.
Next they used same loads in an older 629 Mountain Gun and any leading was minimal. Explanation was it could be due to the EDM process used for cutting the rifling in the new guns.

I know from my years as a toolmaker that the EDM burning leaves a rough or textured finish.
 
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Thank goodness I don't use lead bullets too often.
 
I was thinking of getting one to go along with my 629-2E and Ruger .44 Mag SBH. But do I really need it?? I wonder if the PC bullets would prevent any leading from the rifling or would it just scrape it from the surface.
Any owners of the Model 69 that shoot lead bullets have any input on this?
 
I have a Model 69 and have been shooting cast bullets in it since I got it two years ago as well as jacketed. I have have some leading problems with some bullets mostly bevel base MBC bullets. My home cast 250 grain RCBS KTSWC does not lead to any noticeable degree. I think it like any other gun depends on several factors and not so much the rifling method. Also the Model 69 leads less than my 29-3 with the same bullets and loads.
 
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I've had 3 guns with ECM barrels and none had or have a leading problem. Penn Bullets cast is what I use, wadcutters in target alloy and everything else in premium alloy. All my 44 Smiths have .430 throats and I use .430 bullets.
 
Leading issues has nothing to do with the cut of the rifling . I have several smiths with edm rifling so I can speak with experience . If you really want to learn how to shoot cast bullets successfully in revolvers , semi auto's or rifles . Then go to " LBT Molds " website and purchase Veral Smiths spiral bound short booklet entitled , " Jacketed Performance with Cast Bullets " . It costs about $15 and will answer all you questions and tell you how to solve them .
 
I have a model 69 with 2.75" barrel. I have shot only Dardas cast bullets, 240gr. LSWC
I have been experimenting with (so far) 3 different powders from mid range 44 special loads to mid range 44 magnum loads. Most of the time leading has not been a problem. The only leading was with low power special loads in magnum cases. (640 average fps)
Any loads that clock out around 800 fps or higher has not leaded the barrel. I have only had this gun for a month and am still hunting for the perfect (for me) home loads. It has been a slow process due to very low temps. I tested 2 this morning at only 11 degrees.
 
Its funny you mention this because I had a similar experience with my model 69 4.2". It leaded the barrel with the exact same load that does not lead my 629-4 8 3/8" barrel. Now my 629 does have tight throats and the bullets used were .430" but that's besides the point. I know my 69, while not maybe not identical, does not have loose throats. I did not have lead in the cylinder or on the cylinder face but rather just in the barrel.

The load was 19 gr Accurate #9 behind a 240gr hardcast bullet. I am going to start powder coating my bullets here soon. Since then I've just been shooting jacketed.

Now my 29-3 does have much looser throats, around .432. I size bullets accordingly just for that gun
 
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fortyshooter said:
.... Explanation was it could be due to the EDM process used for cutting the rifling in the new guns.

I know from my years as a toolmaker that the EDM burning leaves a rough or textured finish.
Click to expand...

Which would be true if the process was EDM. (ElectroDischarge Machining) What S&W is (or was, according to certain reports) using is ECM. (ElectroChemical Machining) ECM tends to smooth surfaces, rather than roughen them.

I've been shooting quite a few newer .44 S&W revolvers in long range competition, and have found no leading dramas related to the rifling. But, as noted above, running hard cast bullets slowly can be a problem, as can the powder selected. And most commercial lubes are too hard for best results.

Solutions found effective include:

1) Tumble lube your hard cast bullets even if they already have lube.

2) Run hard bullets "fast".

3) Use slower burning powders if you get forcing cone leading.

4) Flat based bullets may help prevent gas cutting. (Try and find some fired bullets that you've shot and check for erosion along the lower flanks.)

I actually mostly shoot soft swaged bullets at ~1000 fps with zero leading!

ETA:That includes (no competition use, yet) an early Model 69 4.124" which has typical ECM non-sharp edged rifling features.
 
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No problems with my 2.75" Model 69. I usually run my cast loads in that 750-950 range... no problems, no drama.

I will second cowboy4evr's recommendation to pick up a copy of Veral Smith's Jacketed Performance With Cast Bullets. Lots of truth and wisdom in that little tome.

Another excellent resource is Beartooth Bullets Technical Guide, by J. Marshall Stanton.
 
The general rule of thumb for leading in the first inch of bbl is improper fit or hardness. Too hard can fail to obdurate in the forcing cone allowing gas cutting. In the latter part of the bbl leading is best considered a failure of lube. Manufactures sell hard cast bullets with hard lubes as they give one the best chance of arriving through shipping with the lube intact and thee bullets not dented. In most cases softer lube and softer bullets are better for the accuracy of the gun and cartridge.
I have no problems cleaning my guns but prefer to cast and load so I don't need to remove leading.
If I had a new 69 the first thing I would do would be to run 2-300 jacketed rounds through it to smooth things out.
 
Pay attention to what cowboy4evr said. I have no leading issues in my model 69 but I reamed the cylinders to .430. They were at .428. That will lead Everytime! I'm getting ready to cut the forcing cone to 11 degrees which should help more.
 
mtgianni said:
....
If I had a new 69 the first thing I would do would be to run 2-300 jacketed rounds through it to smooth things out.
Click to expand...

Just be sure to remove any copper fouling before transitioning to lead. Whilst gilding metal covered bullets will remove gross leading deposits, the copper wash left in the bore is very prone to grab lead as it squishes past, thus starting a vicious cycle. Most of my lead shootin' revolvers get NO jacketed rounds, just for that reason.
 
Every gun has a personality of it's own , no 2 are alike . Just because you had no issues with lead in the barrel with one gun doesn't mean it will be that way in a different gun . When you have one that has lead in the barrel , it's telling you there is an " issue " or " issues " . Cylinder throats too small , choke where the barrel threads onto the frame is real common . Maybe using too small of a diameter bulllet for that particular gun etc . Or just shooting lighter loads and are using way toooo hard of cast bullet . The casters mostly sell bhn 18 , which is just too hard for most loads . My fiance shoots a lot of 38spl and uses swaged bullets from speer . Her loads that I put together are +P and the barrel and cylinder are very clean after a 100 rounds . I will have to say that I checked the internal dimensions of her guns and corrected problem areas .
Don't take someone elses word on what size to use as their gun is different internally , even if the same model # . If I remove a few flakes after a range session , I don't consider that a leaded barrel . When I have a whole lot of flakes or 1" strings , then I have a problem . Regards, Paul
 
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Looking at the OP, the test reported was between a brand new gun and a well used gun. So far as leading is concerned, this is kind of like the old apples & oranges comparison.

Regardless of the method of rifling (unless the barrel's been lapped), new barrels have little machining irregularities that get smoothed out by use. Using the 1911 as an example, it's been my experience that Colt factory barrels need a dead minimum of 200 rounds of hardball before they'll shoot lead without leaving deposits. I had a famous name match barrel that needed around 600.
 
Another firm believer in "breakin in" a pistol barrel with jacketed bullets. To further the cause if needed, polishing the bore and forcing cone with JB paste and lead away kit can help.

Just tried some of those new powder coated bullets in 625, and sent about 300 200 lrnfp's downrange. Clean up was really quick and easy.
 
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