Breechplug
Underclocked is the inventor of the term but not the problem. Many-Many people that shoot T7 get this bit of fouling just above the breech plug at or near the top of the powder. This ring of fouling will not allow a follow up loading to get to the correct height.
One of the biggest and most common complaints about shooting T7 is that it builds or cause a "crud ring" so named by Underclocked. In some guns the ring is so hard it is almost impossible to get rid of. It will not allow the proper loading of the next shot.
A lot of folks have to damp patch after each shot with T7 to clean the residue and allow the loading of the next shot.
I have always thought for years the ring was caused by the heat and pressure created T7 having a reaction (chemical) or not with something in the bore or the pores of the bore.
I am thinking the new conditioner might help reduce or eliminate the ring and the necessity of constant patching. Although running a patch for me is a good thing - it slows me down.
Here should also say that I have never been real suseptible to the 'crud ring' and I to was a user of BB in all of my barrels. I think if it is applied correctly it does reduce fouling, but I would also agree with other - it should not be trusted for long term storgage in a high humidity area. I stop using BB a couple of years ago when the blue T17 patches came out. They apply the natural lubein a much more even application in all circumstances.
It is a widely held belief that you can not 'season' a modern ML barrel - I also agree I hate that term because everyone instintivly thinks of the old cast iron pans.
All metals can be 'conditioned' and I believe the the new Montana X-treme bore conditioner might be doing that, but I still am testing and trying to detirmine that. Cayugad is also running a concurrent test. Dave has made several observations that do follow the points I have found. His last test with conicals is something I have not tested but I am really encouraged.
If you look at my last post... "another round @ the Dinger Farm' you will see the results of my last test round. I used a total of 5 patches for the whole shoot.
Really not much of a point here but I also did treat my trap gun last week and shot 100 rounds on Saturday and 150 rounds on Sunday. The choke held up great - not the normal amount of plastic fouling hung up in there.
This week I am switching to another ML a 50 Cal Renegade shooting PRB's to see if I can get simular results.