While setting up my new 28 Nosler, Browning X-Bolt rifle, it started shooting like a house of fire right out of the chute and then accuracy started to get increasingly degraded. Here is the process I used and how I found adding an extra step to my cleaning process restored my accuracy.
After getting my new rifle I thoroughly cleaned the bore with a Bore Tech Eliminator and Kroil as I have with all my firearms in the past.
For my first outing to the range, I had 10 rounds loaded up with H-1000 powder. The first shot was to verify the point of impact from bore sighting using the simple look down the bore technique. Then I had three different powder charges for three shots apiece. All three of these three-shot groups shot sub MOA with one grouping at 3/8" at 100 yards. Awesome! That was quick, however, I needed to shoot more to verify it would be consistently accurate.
Trip two to the range I shot two more three-shot groups at 100 yards with the tightest load from the first trip to the range. The first group was just over an inch and the second was back under an inch at 7/8" and I shot a third three-shot group at 300 yards that were five inches with a flier to the right. Not so good. Hmm...
My third trip I shot three, three-shot groups again at 100 yards and all three groups were in the 1 1/2" to 2" range. Ahh!!! Opening up even more. This was when it clicked that I had to be having fouling problems.
I tried my usual cleaning process of Kroil and Bore Tech Eliminator. And headed back to the range again this time to shoot a ladder test at 300 yards with different powder charges incrementally in 0.2 grains. On this trip, I found a couple powder charge nodes with the best node being right where I had been loading my favorite load from the very first day. However, the ladder wasn't as tight as I would have liked it to be and the theme of fliers going to the right was continuing. Ahh!!!
Ok, I was convinced that there was an issue with the barrel fouling and discussed the issue with my engineer friend. He recommended JB Bore paste. As I learned, sometimes a new rifle bore needs a little polishing with a mild abrasive to smooth out any imperfections that persist from the factory. I have heard of this working awesome on barrels in the past but have been very nervous about taking any kind of abrasive to my rifle bores. My X-Bolt has a chrome line bore and I wondered how the JB Bore paste would work. My friend confirmed that it would work great with the chrome-lined bore.
So here are the three things I run through my bore on cloth patches. The first item is Kroil that is an oil I like that will penetrate, help lift carbon and other debris in the bore. Second, Bore Tech Eliminator is an awesome chemical process that breaks down the copper. You can leave it in the barrel and it won't harm your barrel like an ammonia-based Barnes CR2 cleaner would. The third is JB Bore Paste, which is my new addition to my cleaning process. JB Bore paste that is a mechanical process that scrubs and polishes the bore.
So before my next trip to the range, I used a combination of Kroil, Bore Tech Eliminator and JB Bore paste. I would run patches of Bore Tech Eliminator from the chamber and out the muzzle followed by dry patches. After this, I would run a patch of JB Bore paste except with the JB Paste I would stroke the patch back and forth in the barrel for around 10 times. I would then follow with a couple of dry patches and then repeat the process with using the combination of the chemical and then mechanical cleaning agents.
After I had repeated the process 10 times my chemical patches were only a very, very faint blue color. Blue is the color your patch will be when it reacts with copper. A couple of dry patches and a Kroil patch to finish it off and I was ready to head back to the range.
On this trip to the range, I wanted to test a couple things at 300 yards. First I wanted to try a group with the original H-1000 load and then I wanted to try Retumbo powder ladder. So I first shot a fouling shot at a clay pigeon I had sat out at 300 yards and I drilled it. Cool! Immediately after that I shot three shots with the H-1000 load. Bingo. These three shots made a 2 1/8" group that measured only 1" vertically. And the one "flier" for the group was to the left instead of the right which at 300 yards the varying wind speed can easily effect. Even at that, this is the equivalent of a group under 3/4" at 100 yards. This is right at the size of groups I was getting with the load at 100 yards previous to the JB Bore paste cleaning.
Right after firing this group I started on my Retumbo ladder test. Holy crap the first two shots of the ladder were near touching at 300 yards and the velocity and point of impact is the same for the H-1000 load I had just shot. That's awesome! In this ladder test, there were two three-shot sub MOA nodes. The overall group from the ladder was three inches narrower that the previous (non-JB Bore Paste cleaned) ladder with the same light wind conditions.
Next trip I'm going to shoot some Retumbo loads in the tight 1 and 2 shots powder charges from my ladder test. And I think I will clean the barrel again but only run a couple JB Bore paste patches this time.
I'm hooked, JB Bore Paste is now going to be a part of my cleaning process. I can think of a couple of other rifles I would like to use it in that have had group sizes getting a little larger than I would like. Hmm...
My first outing with my 28 Nosler, @browningfirearms X-Bolt. Three different loads with the @hornady_mfg 175 Gr ELD-X all shot under an inch at 100 yards. I think I'm going to really like this rifle. #browningclover #3shotgroup #browning #targetshooting #sundaygunday #eldx #vortexnation #vortexoptics #whatgetsyououtdoors #getoutdoors #outdoorlife #28nosler