Awhile back Saeed did an experiment to see the effects of muzzle damage on accuracy. He dinged up the muzzle of a rifle pretty good and I believe it actually had better accuracy afterwards. E-mail Saeed.

I'm a family doctor too, getting older all the time. The quote's taken from Proverbs 17:22.

I recently acquired a 6.5X55 rifle with some surface rust in the bore at the muzzle. The barrel looks new except right at the muzzle and the rust cleaned out leaving only minor pitting. What do you suppose the effect on accuracy will be? Anyone ever had this problem?

Only way to tell if accuracy is affected is to take it out and shoot it. Have had rifles w/pitted barrels that shoot quite well, others that don't. I have an M1 Garand which has light pitting the entire length of the barrel and it shoots great.

One thing for sure, even if it does shoot good, you will have to be especially careful in cleaning it from now on as residues will collect in the rough surface and cause further corrosion if not thoroughly cleaned after each range session.

Another option might be to shorten the barrel slightly to remove the rough spot.

Regards,
hm

Light pitting alone shouldn't ruin your accuracy. Muzzle wear that makes the bore loose at the muzzle is a problem, and that's often seen with clean, nice looking barrels that have been cleaned with rods from the muzzle end. Any other condition where the bore's much looser near the muzzle than near the throat will cause problems. Sometimes the bore's tapered, and instead of it tapering down from the throat to the muzzle it goes the other way. Sometimes there's a tight spot in the bore near a sight dovetail (Not a Mauser problem.) Sometimes there's buildup of fouling in the throat, effectively narrowing the bore there. In any case, after the bullet's been swaged down in the tight spot, if it's rattling around in the muzzle end of the bore it's got lots more opportunities to exit the muzzle on a tangent and yawing erratically.



Slugging the bore's always a good idea. Not only to match bullet diameter to the grooves of the bore, but to feel where the loose spots in the bore are, that the slug just slides through with little resistance. If it's in the last couple of inches at the muzzle, you're screwed. Takes counterboring or cutting some of the barrel off and recrowning to fix that. BTW, you have to push the slug from the breech to the muzzle to identify that condition. If you started in the muzzle and that was the loose spot, of course the slug just starting into it would be a tight fit.



A very quick and dirty test is to poke the bullet of a loaded round into the muzzle and see how far it goes in. With a tight bore having little land wear at the muzzle, there'll be maybe 3/8" or so of the ogive exposed between the muzzle and the case mouth, with most spitzers. If the ends of the lands are even, the bullet should feel tight and solid in the muzzle. If it's wobbly, something's not right. Usually it's cleaning rod damage to the lands.

As long as the crown was not damaged it is likely that there'll be no effect whatsoever! I once had a relatively pitted Norwegian Krag, and it would even shoot cast bullets into less than 1.5" @ 100 yards, and did better with jacketed slugs.....