polish the throat

Polishing throat!

Wayne,
I think you'll notice a profound difference in the first shots amount of coppering on that barrel! In fact I think you'll find that a breakin regimen isn't even needed!
 
Wayne Shaw said:
My curiosity got the best of me. I chambered a barrel last weekend, looked at the throat and it looked like any fresh cut chamber/throat. So I took a short cleaning rod, bronze brush one size down, and wrapped a patch real tight around the brush. I took some Flitz and smeared it on the patch while rotating it in the direction a wrapped it, letting it soak into the patch. Put the barrel in a vise and short stroked the throat for maybe 20 cycles, didn't count them. Cleaned it out and looked again, a very noticeable difference in the way the throat finish looked. I can't imagine Flitz causing much harm or wear in such a short amount of use, but it sure did take the radial tooling marks off the throat.
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Is your ....@shawrifles.com not working anymore?
 
What you want to see though the bore scope is a land that is the same width all the way from the bore back into the leade.

If there are bad burrs rolled off the sides of the land the profile of the land to leade transition will look like an oar handle where it transitions to the blade. Not that dramatic of a widening of course but you will still see that the land appearing to widen out where the reamer cut the rifling.
 
I'm sure this certainly does no harm, I can definitely see where it would be almost a necessity for cast lead or rimfire. I do some work for some cast bullet guys, and I always told them to fire about 5 rounds of jacketed bullets, clean, then have at it with the lead.

I had no issues with the barrel I just did.
 
reamer finish

I only do rimfire barrels but I imagine center fire reamers are pretty much the same as to finish quality. A very sharp reamer will leave a very fine finish that will polish to a bright shine with just a tight patch or felt polishing pellet and Flintz, 40 to 50 short strokes is usually all it takes. I'd be very careful with spinning an arbor or felt bob in the barrel, a heavy hand will tend to round off the entry side edge although for the little bit of polishing required it probably isn't a problem. Who knows, that could be the next big thing in rimfire accuracy, rounding the sharp corners of the entry to ease the transition to the bore. Also a small note, some rifling styles are tapered so that the base of the land is larger than the face so it will have that canoe paddle look to it even after polishing.

Dennis
 
I have been polishing the throats on all my chambering jobs. For me, it eliminates barrel break-in. No big project, Just some 500 grit on a patch, just in the throat for maybe 5 or ten short strokes. Then push wet patches thru from the muzzle to clean the stuff out.
Rich De
 
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