What is your 586/686 barrel diameter?

[ghh3rd]

I do plan to slug my S&W 686 once I get it, but know it will be difficult to get a accurate reading of the barrel because of the odd number of rifling.

I was curious about what other 586/686 owners have found their barrel diameter to be. Perhaps I'll be lucky and be able to use the .358 Lee sizing die that I already have.

By the way, I've heard good things about Hi-Tec so ordered some yesterday, and picked up a convection oven today.

Randy

[slide]

Can't help you with the diameter. I have used Hi-Tek for several years and really like it. Get some kind of a digital multi meter to check your temp on your oven. Don't go by the dial. The temp is probably the number one reason guys fail. Follow the directions and you will do well.

[Whitespider]

I've given up... I don't even attempt to measure 5 groove (or odd numbered) rifling anymore, no method I've tried has been accurate.
I do slug the barrel though... here's what I do...
First I slug the cylinder mouths and record the number(s), then I slug the barrel and and make sure it will fall through the cylinder mouths, and finally size my boolits to cylinder mouth diameter (or just a touch over).
Now, because I have more than one .xx caliber revolver, and I've recorded their cylinder mouth diameters, I can try the barrel slug in all of them to sort'a narrow-down the dimension. However, repeated handling and cylinder tests will eventually kind'a knock-down the "high" spots on a soft slug, so I'll slug the barrel 2, or even 3 times so I have a (relatively) fresh slug for different cylinders.
*

[Mitch]

I have both and thesy measure .357 and the cylinders are .3585.The 686 is a no dash and the 586 is a dash 3.I would measure anyway.If all else fails size to the cylinder Dia and go shoot it.

[mdi]

Don't own an S&W .357 Mag, but a lifelong machinist/mechanic here and I can get pretty close with measuring 5 groove slugs with my methods. One I use is to gently, slowly close the mics on the slug as I'm turning it. When there is a little drag, I stop and read the thimble. I do this several times and I usually get within .001". Another method is to get some thin shim stock, .005" or smaller. Wrap the shim stock around the slug, measure (gently) and subtract twice the shim thickness. Works for me...

More often than not, I just use the bbl measurements to make sure the cylinder throats are larger than the groove diameter. I size all my revolver lead bullets to the same size as the cylinder throats ("drop through", "easy push through", etc. are not measurements so I measure the throats, either with pin/plug gauges or slugging). Sizing smaller than the throats can result in barrel leading, and larger than throats doesn't matter as the throats will swage the bullet as it leaves the cylinder...

[JonB_in_Glencoe]

SNIP...

Another method is to get some thin shim stock, .005" or smaller. Wrap the shim stock around the slug, measure (gently) and subtract twice the shim thickness. Works for me.
This is how I do it, I use popcan metal...most cans are .0045 but check whatever you are using.

[tazman]

The barrel diameter is of less importance than having the cylinder throats all the same size and larger than the barrel diameter.
Size to the cylinder throat diameter or just slightly larger. Then test fire a bunch of those boolits and see how your leading situation is working out.
Most S&W barrels will work with .358 without issue since they will usually measure .357 or less. I have one that measures .355 and the .358 boolits shoot just fine in it.

[ghh3rd]

Good to learn that sizing to the cylinder throats is a good starting point. I do already have a lee push through die that's .358 so I am all set for my first experiment. That is, if I can boil, scour, scrub out all traces of lube (alox and Felix) from it before sizing, as I will also be trying Hi-Tec coating for the first time.

Thanks everyone

[tazman]

Those lube traces really don't need to be removed. They will scrub out with the first 2 or 3 boolits you run through the die anyway. At worst, it will be slightly easier to push the boolits through the die for a little bit.
Hi-Tec coating is an excellent product and works well in my handguns. The traces in the push through die will have no effect on the Hi-Tec.

[ghh3rd]

Good to know... thanks