squarepants33889
Member
After a day at the range, I feel the need once again, to consult the gurus here on this forum.
I wanted to shoot my muzzleloader after cleaning the breech plug and changing the vent liner.I cleaned and scrubbed the barrel while it was opened up.
Wanting to shoot out the fresh oil, I weighed out 18 charges of IMR SR 4759 to make sure my Savage muzzleloader was ready for the early whitetail season.
They all weighed 45 grains +\- .1 gr. on my RCBS chargemaster.
Because I had some extra time, I yarded out my RCBS Ammomaster chronograph.
In 15 shots, my shots on target were typically just over 2250 fps.
I was actually adjusting the scope to the left while shooting, so I'm not certain of what my average group size would be, but no shots were distinctly "out of whack". I would estimate that I was shooting about 2 1/2 inch groups.
The part that doesn't make sense, is that I had 3 chronograph results that showed about 1790fps.
There weren't any significant flyers on target.
It's possible that my chrony mis-measured some of the shots, but they were all so close to 1790 that it seems fishy.
All 20 shots it measured on my .270 win were bang on where I expected them.
I thought about posting this in the Blackpowder forum, where some of the frontstuffer experts might have some insight, but I wasn't sure if the smokeless powder part of the equation would confuse the matter.
Possible charge compression inconsistency, or nuances in the Savage's breech plug "flame chamber"?
Would a 400 fps deviation only result in an inch or so P.O.I. change? I would have thought 400fps at 100 yards would result in an obvious shift in vertical impact.
There were 5 charges that were left over from last year, stored in old cleaning brush tubes.I actually did weigh them this morning just to make sure they were 45 grains.
Could storage in a tube effect the powder this much? And if so, why not the other two?
What are your thoughts, guys?
I wanted to shoot my muzzleloader after cleaning the breech plug and changing the vent liner.I cleaned and scrubbed the barrel while it was opened up.
Wanting to shoot out the fresh oil, I weighed out 18 charges of IMR SR 4759 to make sure my Savage muzzleloader was ready for the early whitetail season.
They all weighed 45 grains +\- .1 gr. on my RCBS chargemaster.
Because I had some extra time, I yarded out my RCBS Ammomaster chronograph.
In 15 shots, my shots on target were typically just over 2250 fps.
I was actually adjusting the scope to the left while shooting, so I'm not certain of what my average group size would be, but no shots were distinctly "out of whack". I would estimate that I was shooting about 2 1/2 inch groups.
The part that doesn't make sense, is that I had 3 chronograph results that showed about 1790fps.
There weren't any significant flyers on target.
It's possible that my chrony mis-measured some of the shots, but they were all so close to 1790 that it seems fishy.
All 20 shots it measured on my .270 win were bang on where I expected them.
I thought about posting this in the Blackpowder forum, where some of the frontstuffer experts might have some insight, but I wasn't sure if the smokeless powder part of the equation would confuse the matter.
Possible charge compression inconsistency, or nuances in the Savage's breech plug "flame chamber"?
Would a 400 fps deviation only result in an inch or so P.O.I. change? I would have thought 400fps at 100 yards would result in an obvious shift in vertical impact.
There were 5 charges that were left over from last year, stored in old cleaning brush tubes.I actually did weigh them this morning just to make sure they were 45 grains.
Could storage in a tube effect the powder this much? And if so, why not the other two?
What are your thoughts, guys?
