After cleaning barrel - huge pressure spike.

Filled bore with Bore-Tech Eliminator, let it sit for 2x days. Cleaned out/dried out bore with some patches. Packed a nylon brush full of Iosso, stroked bore 50-70x and short stroked throat area a lot more. Cleaned bore again to get out Iosso. Stroked bore 8x with a bronze brush soaked in Bore-Tech followed by 4x dry patches, followed by 8 strokes w/ soaked bronze brush every 4x patches. Top is first patches, bottom is end patches.

Keep cleaning?



Be aware, bronze brushes will give a false positive with BoreTech Eliminator. You have to use stainless or nylon copper free brushes.
 
Bulldog,

Has the problem just been with the DTACS and if so are they coated? I tried adding a wax coating over my tungsten coated .308's once. It didn't take very many shots to know something wasn't right. I didn't have any blown primers but the barrel was so gummed up I could hardly get a jag and patch through it. I darn near had to pull out of shoot. I managed to quickly get it clean and had a different box of ammo with out the wax coating.
 
Uncoated DTACs in Alpha Munitions brass. Showed big pressure 39.5 grains and 2920 fps. Shot 110 SMKs today and didn't have pressure til 41.9 grains. Couldn't even finish the ladder with the DTACs. SMKs got to 3050 before pressure. All with H4350. Sprayed foaming bore cleaner in after I got done shooting and pushed 4 patches through on a jag.

Hornady brass allowed me to get 3050ish with DTACs when carbon ring wasn't there. Strange stuff.
 
Have you put a micrometer or digital caliper on the DTACs and SMKs to see if there is a measurable difference? Do the first cleaning patches have difficulty being pushed down the barrel? The other thing I might try is tumble clean some of the DTACs then lay them out on paper towel to spray with non-chlorinated brake cleaner. Roll them between paper towels, replace the towels with clean dry ones then rub/roll again, load them and try. The boron-nitride is not supposed to have a visible appearance when done correctly. If wax was used as in my failed experiment, it wouldn't necessarily be visible but the tumbling and wiping with brake cleaner should strip it off. Also, If you can shoot a full session with SMKs and no problems it has to be the DTACs. However, the DTACS might have a longer bearing surface that will force you to not be able to push them as fast the SMK's. I'm starting to run out of ideas.
 
Have you put a micrometer or digital caliper on the DTACs and SMKs to see if there is a measurable difference? Do the first cleaning patches have difficulty being pushed down the barrel? The other thing I might try is tumble clean some of the DTACs then lay them out on paper towel to spray with non-chlorinated brake cleaner. Roll them between paper towels, replace the towels with clean dry ones then rub/roll again, load them and try. The boron-nitride is not supposed to have a visible appearance when done correctly. If wax was used as in my failed experiment, it wouldn't necessarily be visible but the tumbling and wiping with brake cleaner should strip it off. Also, If you can shoot a full session with SMKs and no problems it has to be the DTACs. However, the DTACS might have a longer bearing surface that will force you to not be able to push them as fast the SMK's. I'm starting to run out of ideas.


These are supposed to be uncoated DTACs.