So if their .001" over bore?

[charger 1]

Arent we going to atleast occasionally clean lead out. Cause we're cutting through and unless we're going painfully slow there will be fouling. NO?

[1874Sharps]

Charger-1,

There certainly is a logic in the question you pose. In shooting my Sharps 45-70 the fact is that I do sometimes find the scarcest traces of lead on the first patch or so. On my 30 caliber rifles I do not seem to find any leading, probably because the 0.309 gas check on the end scrapes out any lead that may deposit itself. If the patch is run a little past the nose ogive as 303Guy does, I do not figure the lead will have any chance to touch the bore.

[montana_charlie]

Arent we going to atleast occasionally clean lead out. Cause we're cutting through and unless we're going painfully slow there will be fouling. NO?
It actually depends on how thick the patch is...and how deep your rifling is.
As a coarse example, think about a two-layer patch that is .004" thick in a bore that has rifling .003" deep.

The inner layer of paper will be scored deeply (halfway through), but the land won't quite reach the lead.

I have the same situation right now. My inner layer of paper is not quite being cut all the way through, and the (naked) bullet is two thousandths over bore.

CM

[303Guy]

Does the paper - even when 'shreaded' - not remain between boolit and bore and act as a lubricant? (I have this two-groove Brit with rust damage - plenty pitting - which I fire-lapped. It does not pick up copper or lead. But then I do lube both. My theory is that the rust pits hold lube). I have tried seriously oversize patched boolits in both my 303 Brits and still the paper does not cut right through with very light loads. Heavier loads cut through the driving face of the two-groove. (But tracing paper - which sounds like it is 'Vellum' - does not cut through. At least, the groove on the boolit is not narrowed).

A recovered low charge patch from the two-groove.

http://i388.photobucket.com/albums/oo327/303Guy/MVC-056F.jpg

[pdawg_shooter]

Seems like when the paper is cut by the rifling it stays in place between the bullet and the bore until the bullet has left the barrel. I have never had any leading with paper patched bullets.

[windrider919]

I tried some extremely thin tracing paper once that only miked .001 and using two wraps it did not lead. I do not bother with reduced loads, just 50% to 95% velocity loads. I am not sure the rifling 'cuts' the paper with every type of rifling. With mine, examining the very small confetti I have occasionally found where the rifling went across a bit of paper. It was creased and shaped to the rifling but NOT cut. With my Shelen match, six land / six groove barrel the rifling is very narrow. The grooves are over twice the width of the lands and the lands are .003 high.

The only time I ever got leading shooting PP bullets was when I first started and used .450 diameter bullets wrapped to .458. It appeared that the patch was seperating from the bullet and the bullet was cocking slightly (uneven rifling showing on sides) and lead was contacting the bore. After I brought the bullet diameter up to .454 and patched to fit my chamber throat I got no leading and the best groups of any shooting in my entire life.

I have seen some people try "short jacket" type PP where most of the cylindrical surface of the bullet is patched but a narrow strip as the nose becomes barrel diameter is left uncovered. And they did get leading. When the paper goes up over the ogive of the nose enough that no lead can touch then there should be no leading. Assuming the patch stays intact and no blowby occurs to gas erode the bullet side , vaporize lead and deposit it on the barrel in front of the speeding bullet.

[303Guy]

... examining the very small confetti I have occasionally found where the rifling went across a bit of paper. It was creased and shaped to the rifling but NOT cut.This indicates (as an aside) that the angle of the paper patch cut is important from a patch 'separation' at the muzzle aspect.

I have found sign of the patch 'failing' in the bore with full loads and changed my patching technique to avoid such break-through of the patch. I can't say the break-through of the patch caused any leading - I didn't see any. This only happened with my two-groove.