I have been a member for a couple of years but don't post often. Just a quick resume so you know a little about my experience. I started reloading when I was about 13 after I found an almost new Rock Chucker kit at a yard sale and taught myself how to reload after reading the RCBS manual front to back numerous times (yes, even the b.c. Tables in the back
. Coincidentally, on a side note, I found out many years later that this was in the same little ranching community Fred Barnes started making bullets in his basement back in the 30s. That was over 25 years ago and in the meantime have reloaded 25-30 different cartridges ranging from .17 Rem up to .450 Ackley and for numerous different guns. I'm not an expert, but very proficient and somewhat competent. I have shot a lot and am a competent recreational shooter and hunting shot.
Now for my conundrum. I recently bought a 28 Nosler from a company with a good reputation for accurate rifles. The test target sent with the rifle shows a tiny little group (180 VLD Hunting, WLRM primer, Nosler brass, 81 gr Retumbo, 3.540 oal) and I got right in to breaking in the rifle and developing loads. Factory loads were hoohum and I thought I would be able to get something good for shots out to 800 +\- fairly easily. My goal was a 175 ELDX at 3100 fps which was pretty easy using Retumbo and then because of poor accuracy and powder fouling switched to H1000. The ELDXs would not shoot so I tried some 168 VLD Huntings and 175 ABLR (current bullet of choice) with better results. I have now tried numerous loads (~150 shots so far) with Retumbo and H1000 and have yet to get a consistent accurate load. I have tried a couple different charge weights at most lengths from SAAMI spec up to touching the lands. My main primer is some of my hoard of Federal 215 match but have tried cci 250 and some WLRs (did not have WLRM at the time) with similar results. I have some WLRMs to try now but waiting for the rain to stop. I finally thought I had a decent load (78.3 gr H1000 at 3.500" oal, 3075 avg, 14 es) that was pretty decent, ~2.25" at 340 yards, but the last time I took them out groups were 6" (main group ~2.5" with some big flyers).
I am beside myself, I have never had a gun shoot so erratic. I have had some 100 yard groups I could better with my muzzleloader and this gun is nothing short of erratic. The scope base was bedded, locktighted, and torqued. The rings lapped and locktighted. Tried two different scopes. Checked bedding. Brass is all within .005", flash holes trued, and primer pockets as well. Brass weighed within a grain. Powder within .1 gr.
I'm using Redding dies and since it is a hunting rifle I am FL sizing. I don't have a means to check runout accurately but maybe i got a bad die?
Some observations, powder fouling seems excessive, I have put in a lot of time brushing the bore (after different foaming cleaners and copper solvent) and am getting no fouling with a nylon brush and nitro solvent but a lot of black fouling using a bronze brush. I have never gotten a moderately clean patch following the bronze brush. I am beginning to think the new (Tipton) bronze brushes I am using are causing the black patches but have never had it to this degree in the past. Do I potentially have some hardened carbon fouling that is just a nightmare to get out? I cleaned it fairly well but probably not good enough during break in.
Have others had problems like this? Anybody have any ideas to check? Things to try?
I plan to recreate the test round once I get the bullets but have not had the chance yet. I am also going to test fresh powder and primers in my other loads. The 215 match primers have always been good but these are 3 years old, so? Never had problems with much older primers but I am trying everything.
If you read this far, thanks for reading my ridiculously long venting post.