The Retirement Rifle has been a bit of a bear for me. For those not familiar with it, it's a Spaghetti Buffalo Gun from Pedersoli out of Italy.
That's an Italian copy of the infamous Remington rolling block rifle.
Rotten Rod The Gunsmith says they are fine enough
copies except for the heat treating: some of the internals are only case
hardened which can lead to shorter service lives for these guns.
What does that mean? I dunno...the originals are
now approaching 150 years and many are still shooting! If
mine lasts half that long... I'm okay with it.
She's chambered in 45-70, and she's an absolute pussycat with patty-cake target loads. The problem was that she won't group worth spit with my smokeless loads - which I prefer for winter shooting. I was getting consistent vertical stringing and erratic velocities - which, I'm told by the black powder geeks - is caused by relatively light powder charges in the big 45-70 case. There is so much room in the case, the powder rolls around anywhere it wants and you get inconsistent ignition.
That's the theory, anyways, and it seems to bear out with my rifle, my chronograph, and my targets. The fix, I'm told - is the CAREFUL use of case fillers. Being new to fillers, the concept scared the hell out of me. The rolling block is not a strong action and pressures have to be kept down on the tame side. But...jeez, the accuracy on this thing sucked with smokeless loads. I decided to consult with my experts - the stubfarts and liars over at Cast Boolits! Like anything involving middle aged or old men - if you broach a concept, legit or not, it will turn into a food fight with half the boys against, throwing pies and dung at the boys that are for it. I've seen internet experts say that using fillers will blow up your rifle; others say they've done it for decades with nary a problem. You have to choose your experts wisely - and I chose to heed the advice of Larry Gibson over at Cast Boolits:
That green fuzzy stuff is polyester batting that the womenfolk
use in their arts n' crafts for pillows, maybe their quilts and that sort of thing.
Us fellas can put this stuff to more serious use!
HAR HAR HAR!!!
The theory is that fillers take up some of the volume in the case, hold the powder closer to the primer and gives more consistent ignition. I figured I would give 'er a go and try it. I raided the old lady's sewing room, scored some of that green fuzzy stuff, and carefully loaded up a batch of 405 cast lead rounds and went to the range.
A group of three with one called flyer. HFS - the groups were
cut in half.
That one comes in at a few thou over 2". That isn't anything
to crow about for serious shooters,
good BPCR guys can do that and better with black powder.
But ... it tells me I am on the right track.
A few notes are worth mentioning. Previous to using fillers, I got 6" groups at 100m, and velocities were 1000~1100 FPS. That was a little slow; According to the book, the recommended charge weight for this load in these old school rifles is
405 gr. cast lead bullet
Charge weight 34 ~ 38.5 gr. IMR3031
OAL = 2.550
Velocities should run between 1161 ~ 1352 FPS
My rifle was running slow at 36 grains, possibly due to the colder weather in which I shoot. The same rifle, same load, shot WITH fillers:
405 gr. cast lead bullet
Charge weight 36 gr. IMR3031
OAL = 2.550
Velocities should run between 1400 ~ 1452 FPS
Increased velocities, increased accuracy! But... that is a tad hot. Although the brass didn't show any pressure signs, I am going to kick down the powder charge to get velocities and pressures more in line with the published data. My advice is that if you are going to do this, do it right: start off with the minimum charge weight and work your way up. HAVE A CHRONOGRAPH. You need to know what your rifle is doing when ya start goofing around like this. I was producing hot rounds with absolutely no discernable increase in recoil or noise. Guns won't necessarily warn you when you're about to blow them up. Oh - and wear shooting glasses when you are playing with new loads - just in case.