Not an issue.

Bullets that are tight in the bore; prevents the gas cutting around the bullet which normally causes leading.

Another way of sealing the base to prevent gas getting around the side of the base is to have very square base edges.

And we put a flared skirt on our bullet bases to tighten it up more.

Done by putting a concave divot in the end of the H&I push pin so the raised edges flare the bullet base by .002" when you size the bullet.

Perfectly sharp squared bullet base from sheering the base with the sharpened back edge of the sprue plate brought back after shearing the sprue.

Gases can start to penetrate around the side when you have rounded base edges.

Leading also occurs if the bullet diameter is less than the groove-to-groove diameter which allows gases to get around the side of the bullet.

The lands engraving the bullet does not cause the leading.

Your bullet may be a hair narrow since it does not appear it is tight between the lands.

I use bullets .001" or .002" wider than my groove-to-groove barrel diameter.

That's interesting to hear Dave.  The groove on this barrel is 0.3761" according to what Paul Shuttleworth stamped on it.  The bore hasn't been measured, but it's less than 0.368" because that's the nose diameter on the bullet and it engraves the nose.

Only the base band is larger than the grooves on this bullet.  Base = 0.377", then 0.375", 0.374", 0.373", 0.373", 0.371".   

The bullet that has worked best so far is the Hoch 376310 which has very similar diameter, but the grooved shank of the bullet is longer so the effective taper is less, but no nose engraving.

I guess I'll give it a try on Monday and see how the two bullets compare, but given what you've said, maybe a bigger bullet might be better.

Chris.

I believe Chris breech seated his bullet and did not insert it far enough into the lands to fully engrave the bullet base.

The tapered land cut is just from the taper of the end /nose of the land.

I believe fully inserting the bullet would cut the lands equally across the base.

With a tapered bullet it is more important the wider base be fully engraved to seal it so gases cannot penetrate around it.

While tapered bullets are easier to breech seat I prefer the straight walled bullets which seal a bit better.

I use a Weber seater for breech seating my .40-60 Maynard CPA.

Most of the time I use fixed cases for BPCR Silhouette.

I have done a lot of reading on breech seating and also how much engraving is enough or too much. First I have read multiple places where you should NOT fully engrave the base band when breech seating. I believe the theory is it will seal better to prevent any blowby. I also read that bullets with at least 60% of their length engaged with the rifling seem to shoot better. Someone stated they had recovered some bore rider bullets that were obviously pushed out of alignment since the bore riding nose showed land marks on one side and not the other. A lot to consider and test. Can not argue with the target.

Now this is too much engraving.  Just sayin'

Jack I think I might have to take up engraving and make a few of those.  Mine are going to have a deer scene on the shank .

Oh and Dave was right.  It turns out that there was no leading with the nose engraved like that.

Chris.