Just wanted to share some data that I finished testing on this past weekend. I had recently chambered a .236 bore 7.83 twist 4 groove heavy varmint @28'' muller works barrel with a .272 neck .104 free bore ptg reamer installed in a defiance deviant single shot cone bolt face action. During a recent match this barrel had a 70-80 fps increase in velocity shooting Berger 105vld target @ 32.2 Varget with br4 primers over the course of the match. Shots were #50 to #130 on the barrel, needless to say the impacts on paper were not horrible but also not impressive. In my past barrel 7.5 twist 4 groove .236 bore heavy varmint @27'' Krieger this load shoots 2960 fps with single digit SD. In my quest to finish out load development I loaded 50 pieces of the Alpha OCD @ 31.7 Varget with br4 primers @ .012 in the lands. This load shot extremely well at a local 300-400 match. Velocities were as follows (all loads were .012 jam in the lands)
32.2 varget= 3038 fps with 9 sd for 25 rounds
31.7 varget= 2968 fps with 3.4 sd for 50 rounds
So I am not sure if it was the brass having a different volume or the barrel but thought I would share if anyone else was running into the same issues. Also wanted to share some insight into mullerworks barrels and their quality. This barrel is extremely smooth when viewing it through a digital bore scope. I have read that mullerworks spends lots of time in the lapping process and it shows when looking at the barrel in a borescope and also when cleaning the rifle barrel.
32.2 varget= 3038 fps with 9 sd for 25 rounds
31.7 varget= 2968 fps with 3.4 sd for 50 rounds
So I am not sure if it was the brass having a different volume or the barrel but thought I would share if anyone else was running into the same issues. Also wanted to share some insight into mullerworks barrels and their quality. This barrel is extremely smooth when viewing it through a digital bore scope. I have read that mullerworks spends lots of time in the lapping process and it shows when looking at the barrel in a borescope and also when cleaning the rifle barrel.