Numbers don’t lie so if you want to see those numbers, scroll down and check ’em out.
Definitely seeing a velocity boost evolving during the treatment phase. Looks like SD’s are growing but we won’t know the long term trends on this for another week as there are more shots to fire. Treatment phase is 5 sets of 5 shot groups. Between each group we apply a very light coat of MSS Accuracy Oil down the bore on a patch wrapped around a brush. That pulls the carbon out pretty well and puts another layer of their crazy effective lubricating oil down the bore.
This test data shows 50 rounds of history gathered during bench-rested zero-checking, load development and grouping data collected over the last year with me not cleaning the bore at all on my heavily customized, Columbia River Arms barreled Mossberg MVP .223 followed by another 25 rounds of very recent history from last weekend’s testing with MSS’s cleaning system being used.
Avoiding much discussion of velocities we can look at group sizes. This rifle with this load has been a pretty consistent 1-1.5MOA rifle. It doesn’t like this load, never has, and that has annoyed me because it should be a killer load. During the testing and doing the Accuracy Oil re-application treatments I saw very consistently that the first shot was wild, then the 2nd-5th shots gradually closed in on each other finally ending with shots 4-5 stacking on top of each other. Overall group sizes started at 1.2MOA and by the end of the initial Accuracy Oil treatment plan had reduced to a very nice group under .7MOA with the last 3 shots touching and the first 2 just slightly off that cluster (could have been shooter error but I doubt it). This behavior was consistent from the first string to the 5th string. I have not cleaned the barrel after shooting. I did run a patch down the bore with Accuracy Oil on it though. Before shooting next time we’ll run a few dry patches down the pipe to make sure it’s completely dry and then we’ll see what happens.
Each string below represents a 5-shot set with statistics reported for the string. This load has slowly evolved over the last couple years with a little OAL and a little powder being added between string 1 and string 9. I stopped messing with the load spec after string 9 because I just wasn’t shooting the gun. Now I’m sticking with that practice while we finish up our testing. 75 rounds in to the testing we’re seeing definitely trend line activity but we’ll save the analysis and conclusion drawing until we have more data.
So what do you think? Will this trend continue? Will it even out? Will it reverse? We shall see.
Note: This is not one of my match loads. This is a load I never shoot in competition because it’s not been consistent enough. I’ve wanted to do a little more work on it because it’s a really mild load with long legs. I chose this load because it’s not a one-holer out of the gate so we have some room to see if MSS’s claims are worth taking seriously. So far, they’re at least intriguing.