Dixie Slugs
12-25-2008, 09:38 AM
There is a growing interest on shotgun bores with rifled barrels. This interest is widespread and in states other than Shotgun-Only-States.
I would like to make some comments on rifled shotgun barrels ans slug/bullets designed for them.
First of all....Ross S. did some very fine work discussing the difference in guns set up for thin brass hulls and those set up for paper hulls. The difference was in the diameter between the two. The ones set up for thin brass hulls had a larger land/groove diameter.
The original Paradox gun (with the last few inches rifled) were designed for a squared bullet around 730 grs and with a velocity of 1000'/" (blackpowder). Later they increased the velocity to 1200'/" with Cordite. In 1893, H&H lists a couple of loads for fully rifled barrels....with included a 12 bore 600 gr load at a little over 1500'/"
When we move these velocity specs forward to modern rifled barrels some problems show up. Most modern rifle barrel are tighter that the original and run around .727" in the grooves and about .716" on th lands. Much too small for using the original specs. From actual testing, we have found the mold for modern barrels not to exceed .730" with the alloy you chose. Another problem is the twist in modern barrels (designed for longer sabot loads), mainy running as fast as one turn in 28". Since the original bullets were squared (diameter=length), the guns ahd a slower ball twist....this may cause over-spin in moderm guns. This seems to be no real problem with modern solids, but could be with hollowbase designs.
I will try to answer any questions I can on this subject.
Regards, James
I would like to make some comments on rifled shotgun barrels ans slug/bullets designed for them.
First of all....Ross S. did some very fine work discussing the difference in guns set up for thin brass hulls and those set up for paper hulls. The difference was in the diameter between the two. The ones set up for thin brass hulls had a larger land/groove diameter.
The original Paradox gun (with the last few inches rifled) were designed for a squared bullet around 730 grs and with a velocity of 1000'/" (blackpowder). Later they increased the velocity to 1200'/" with Cordite. In 1893, H&H lists a couple of loads for fully rifled barrels....with included a 12 bore 600 gr load at a little over 1500'/"
When we move these velocity specs forward to modern rifled barrels some problems show up. Most modern rifle barrel are tighter that the original and run around .727" in the grooves and about .716" on th lands. Much too small for using the original specs. From actual testing, we have found the mold for modern barrels not to exceed .730" with the alloy you chose. Another problem is the twist in modern barrels (designed for longer sabot loads), mainy running as fast as one turn in 28". Since the original bullets were squared (diameter=length), the guns ahd a slower ball twist....this may cause over-spin in moderm guns. This seems to be no real problem with modern solids, but could be with hollowbase designs.
I will try to answer any questions I can on this subject.
Regards, James