[Unclenick]

The lube on cast bullets winds up on everything in the gun and tends to offer it some protection. Most years some friends and I get together and over several days we will run about 750 rounds a day, each, through our 1911's, not cleaning until the end of the week unless one starts to fail or gets stiff. Under that circumstance I've shot over 3,000 rounds of 200 grain cast H&G 68 type bullets through my 1911 without cleaning or suffering function failures. It gets pretty caked up, but seems to keep the cake pushed out of the way of anything critical.

The bore in my 1911 I is worn so smooth that it never builds up enough lead to interfere with accuracy, even after 3,000 rounds. I've seen some revolvers with constrictions in the barrels where they screw into the frame, and these can pick up quite a bit of lead. If the bore is rough, it happens even more easily. Accuracy is generally poor in these guns and gets worse when the build up is in place. At that point, cleaning is necessary. You can prevent the problem by firelapping constrictions out and the bore surface smooth.

As was mentioned earlier, copper is really worse. It can accumulate in rough bores to the point of deteriorating accuracy in just a couple dozen rounds. Occasionally you see a rifle with so much copper built up from inadequate cleaning that it starts seeing pressure signs with factory ammo. That used to be common with the old cupro-nickel jackets, and isn't so common these days, but it can eventually happen without proper periodic cleaning. Again, firelapping goes a long way toward prevention by smoothing the bore. Since no protective lube is on jacketed bullets to coat the bore, you don't want to leave a bore unoiled after firing bullets with jackets. I'm in the habit of cleaning after every use of jacketed bullets to prevent build-up from starting.