Load one: 95.0 RL-25 with the 180 ACCUBOND
Velocity 1: 3485, Note that the bolt was stuck and had to be tapped open. There was a major extractor mark and cratered primer. Velocity 2: 3437, note that extraction was easier but sticky. Extractor mark as well. Velocity 3: 3395, note that the extraction was easier yet but still a bit sticky.
Accuracy = 3” @ 300 Yards.
Load three: 96.5 H-1000 with the 180 ACCUBOND
Velocity 1: 3373, Velocity 2: 3344, Velocity 3: 3380
Accuracy = 2.082” @ 300 Yards.
It is noted that this load was hot due to slightly sticky extraction and ejector marks.
Load four: 90.0 H-1000 with the 180 E-Tip
Velocity 1: 3238, Velocity 2: 3227, Velocity 3: 3218
Accuracy = 3” @ 300 Yards.
Something is not right
This certainly isn’t the end of my development, but there are enough load notes above to gauge the overall performance of this rifle. It is at about this stage that I feel like something dramatic is wrong. It seems as if my pressures are going up with the same loads from day to day. I start dropping powder charges lower and lower and they still seem hotter and hotter. Also it starts to copper foul really bad. After a total of between 200 and 250 rounds fired, the barrel settles down and pressures and velocity appear to become consistent.
Now I start the load development over. To make a very long story short, this rifle will no longer shoot the 200 ACCUBOND with any degree of accuracy and no matter what powder or the charge weight, extraction is tough and the brass is beat up. I have fired it with H50 BMG with as little as 3000 FPS and the extraction and brass are not good. I have also tried using RL-25 and H1000 with even more horrid results. The 180 ACCUBOND doesn’t act as bad but acts very similar to the 200. Now after its settle down mode, the loads it likes the best is the 220 SMK over 90.0 H50 BMG at 2850 FPS, the 208 AMAX with 93.0 H50 BMG at 2925 FPS, the 190 Hornaday BTSP atop with 88.5 grains of RL25 and the 178 AMAX with 90.0 H-1000. All will hold .5 MOA or better with the 220, 208, 178, especially the 208 doing so the best. The 190 averages 0.5 to 0.6 MOA and sometimes does better and sometimes hits the 1 MOA mark.
My Worst Fears Are Realized
I took my barrel to a local smith the other day along with the old Lilja barrel I still have that has over 1000 rounds through her. I compared the throat of each side by side as well as several inches up the barrel. To my surprise, the ABS looks almost identical to the Lilja with not even half as many rounds through it. At this point, it become clear as to why it copper fouls so bad now and won’t shoot the same as it did in the beginning with the same loads. I only had between 60-65 shots through it when I noticed the major changes. The throat was somewhat cooked already at that point.