Smoothing a rough throat?

[nekshot]

I have a 303 brit that is extremely accurate for about 6 rounds then every thing heads south. The leading builds up at beginning of rifling. I spent this week soaking and brushing out the bore and I am sure I am down to metal. The bore glistens like a mirror but the throat looks like nasty pitted. If Rover drug his butt over this surface I think he would bark "Ruff Ruff". I am thinking of taking a boolit that is a tight fit and roll it in fine valve grounding compound. Any one have advise of what worked for you?

[Greg S]

Maybe Tubb Final Finish System roll your own style. I've also heard of 22 lr smiths using diamond lapping compound to polish throats after chambering to clean up any imperfections but not familiar with the proceedure.

Another option would be to set it back a thread or two and rechamber.

[gnoahhh]

Is it just the throat that's rough or is it a short section of the rifling too? What's the diameter of the throat, and is there room to run a slightly larger throating reamer in there?

[No Blue]

http://forums.gunboards.com/showthre...d-quot-Warning

Here's some more reading....

[MostlyLeverGuns]

Search on fire-polishing - LBT, NECO, Midway, maybe others have fire polishing 'kits' with instructions. Lots of info out there, fire polishing will smooth a rough throat. Lots of opinions whether good or bad. Can help with rough bores and throats.

[nekshot]

I rolled some boolits in fine compound, took a 30-06 casing and ran it up as far as it would go in the 303 sizer(this leaves brass show so I can be sure of measurement, tapped primer hole for extension) and I gave it some love rpm's and recleaned and that is when I saw(with magnification) the groove diameter is frosted out aways. I think I will go resurrect the paper patch job and see how that goes. We definetly are down to metal so I will slick it up with barrel kote and see what the future holds. Thanks for all input, you guys are great!