Some additional insight from the smokeless realm. . .
20+ years ago, one of the writers in Precision Shooting Magazine was discussing the theoretical advantages of sharp-shouldered, Ackley-style cartridges over their more tapered counterparts. One of these was that the sharper shoulder angle tended to "bunch up" the combusting & compressing powder at the front of the shoulder, where the tapered case would tend to act as a funnel, allowing the still-to-burn powder granules more easy passage into the bore. The first gain was more consistent ignition of the powder in that tighter space, but a second (more relevant to this thread) was that it limited the amount of "sandblasting" those powder granules were doing to the throat of your barrel.
In the context of black powder and lead projectiles, the pressures are a lot less, but you still have those crunchy granules at the front of the stack getting slammed forward at something like 10,000-15,000 CUP - if the smokeless "trapdoor equivalent" loads are any guide.
Armoring the stern of your projectile against that just makes good sense, especially after all the collected wisdom around promoting the necessity of a sharp-edged, uniform base.
WWJMBD?
In the Land of Oz, we cast with wheel weight and 2% Tin, Man.
I'm a flatlander (600feet elevation) never seen it here - parts of Aus where it snows proper is all national park - no gun totin allowed there - I got caught up in a for real blizzard in the Nebraska sandhills in 2005 - was kinda interesting.
Do ya dig the boolits out when ya shoot - if yes how far do they penetrate? or have to wait till it thaws down and find em?
Your sandblasting phrase is interesting
I am no expert - have retrieved several part rusted blackpowder barrels but only ever dealt with one wore out barrel. A blued barrel 22/250 (on a winchester model 70) its had about 4500 rounds near as I can figure - proly a third of those were factory ammo and the reloads mostly winchester 760 powder (early on I used Nobels rifle ? but its crap in a rotary measure)
ok - that barrel lost its edge - got to the point where best I could get was about a 2" group at 100 - yeah still shootable and useful, but it was gone for longer range work.
one day fooling around with an old ML barrel someone gave me as trashed - I use steel wool and brasso and plenty elbow grease - an old brass brush to hold the steel wool and tight as can be got in the barrel - soon as it gets easy to push wrap a little more steel wool - half an hour of that then I finish it with jewellers rouge on a soft patch - anyway why not try the same on that winchester 70 ? I got that thing back to as good as before (3 in my thumbnail at 100 yards) when I cleaned it for storage I put a light down it - surface was bright and shiny but in the bottom of the grooves was what looked like little hairline cracks in the surface - wiggly not straight - sandblasting ???? looked more like heat erosion to me. I dont expect my restoration job to last long but easy enough to do it again - the front end of the barrel is still good. Maybe if I can keep it smooth inside it will see me out? Dont shoot it much but still handy on occasion.
Realise this is out of place here but .................................
Joe,
The penetration runs from 6 feet to 12 feet depending if the snow fell on a cold windy day. The cold dry snow the bullet gets pretty deep and also depends on the calibre. The wet heavy the penetration is about 1/2 or better.
If I'm in a hurry to see what the alloy looked like I get out the Mine Lab metal detector.
[/ATTACH]This is some of the other word white stuffIt makes it tough walking to the shed to get the tractor out with a 6' snow blower
But we don't get the snow that we used to anymore.
I am aware that the over powder wad is reputed to increase accuracy. A few yrs back, I used to converse with Dave Scovill when he was editor of Handloader/Rifle magazine and mentioned my success with a smokeless powder load in a 45/70 using an over powder wad made from milk carton. He said that it was a BIG no-no and even had Mike Venturino email me to tell me that I was in danger of ringing my chamber. Needless to say, I stopped loading the wad over the charge, but I have to ask why it is such a sin to do that.
IT AINT what ya shoot--its how ya shoot it. NONE of us are as smart as ALL of us! The more I travel, the more I like right where I am.
You're creating a cylindrical space with the powder at a right angle to the bullet base. Now if that wad were a bit ahead if the powder and would it allow to slump a bit, no problem. But by putting the wad ON the powder, you've created the ideal scenario for chamber ringing, which is an overpressure scenario creating shockwaves between wad and powder column.
Worst case, it will burst the barrel. Best case, you risk ringing your chamber.
Put that wad joff the powder with some space between, and no issue.
You'll have to to reread I believe, especially the reference to Vieille and the ability to generate rings without a wad when the barrel is held vertically. Nothing piston and compression, otherwise most breechseating would be an issue.
The Modern Schuetzen Rifle - Charlie Dell and Wayne Schwartz
Also https://castboolits.gunloads.com/sho...hamber-ringing
Cognitive Dissident
After referring to the 2020 thread above, it pics another question. Would card wads stacked on top of the charge all the way to the base of the boolit remove the effect of shoving the expanding gasses against base? Fillers must work and have for me in the past, but a soft puffy filler sounds like a chamber ringer waiting to happen, especially if not done correctly.
IT AINT what ya shoot--its how ya shoot it. NONE of us are as smart as ALL of us! The more I travel, the more I like right where I am.
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |