My experience has been that both FPE and shot count tend to increase as the weight goes up.... If you are fighting a tight bullet fit in the bore, however, the extra drag of a longer bullet that is too tight might change that.... I still find it just wayyyyyyyy too weird that you got an LW barrel that is NOT .308" bore....
Bob
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count!
I asked Mike about that and think I may have found the answer. LW does 2 different depths to rifling abotu .0025 deep and .004 deep. Mike said they recomended the shallower rifling for pellets so that is what he ordred. I expect that the bore is a tight just under .300 maybe a bit smaller with a .005 increase in major diameter. The 2 different ties Mike slugged the barrel there was a .005 difference.. the actual measurement is unknown. Also less rifling passes with the button would result in less wear on the minor diameter. I expect for the pellets to fit and show the rifling it does must be on the tigher size. Also the fact that the .303 un resized mr hollow points fit very very tight.... makes me think we are on the smaller size and this is why te pellets work. If I was going to only shoot pellets I woudl be tempted to get a slight chock on the barrel to ensure a more optimal fit fo the pellets as they come out the barrel. Then order another barrel for .308 ammo... Thinking that might be the best option overall really. Then swap barrel for what I want to shoot, change hammer spring and change stroke.Originally Posted by rsterne
When Veral gets the slugs, I will ask him to let me know the size for minor and major so I know.
Bruce
Bruce first off let me say that your build is absolutely brilliant! Nice job.
I maybe able to help you out with some of those barrel issues.
Firstly, you said a .303 Mr Hollowpoint was really tight. Was it a .303 British casting? If so thats actually a bigger bullet than a .308.
Looking at your push through it really looks like the leade has some issues. My guess is that there is some displaced metal right at the entrance to the bore which is skewing the results. The indication for that is the grooves that are showing in the rifling imprint. Those should be flat and very shiny on a button barrel.
There is only one fix but it is relatively easy to do. Your going to have to lap out the constriction with a cast lead lap and some compound. I'm going to guess that you should be able to get that bore to .300/.306
Sean
Yeah, decent efficiency there for sure.... Accurate numbers are only for the geeks like me that need to know.... *LOL*.... If they all go into the same POI that's all that matters.... The efficiency and shot string length in my gun seemed to peak in the low 900's for some reason.... in several states of tune.... When I finally settle on a configuration I'll do some fine tuning instead of full turns on the RVA and see what I can get....
Bob
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal: Too many to count!
So 11 shots within less than 2% should be great for longer distance shooting ay 100 yards. I will be backing things off slightly I hope to keep the peak under 950... When time and air allows will be seeing exactly what I get for a shot spring. Surprising how much quieter things are at this power level.
Bruce
Pushed some projectiles through the bore.
Not alot of bite on the pellet head.
Bruce
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