Buckshot
10-01-2011, 03:12 AM
..............Finally took a photo I'd been meaning to take for some time. As you know, in the Rem Rolling block the chamber isn't what we're used to seeing. The area beyond the chamber (commonly called the throat) is reamed with no 'step' (ID reduction) at the casemouth. Instead, beyond the shoulder the chamber in essence is the same OD until it reaches a very short abrupt leade. What this means is when you chamber a round there is a bit of clearance around the caseneck so it may expand upon firing to release the boolit.
However, it also means the boolit has that clearance PLUS the addition of the nominal caseneck thickness added to deal with in it's run to the leade.
http://www.fototime.com/4B9EBE131ADC269/standard.jpg
In this previously shown photo, a 45 cal boolit was dropped in the 43 Spanish chamber and then driven forward to give an impression of the leade at the end of the throat ( that long unrifled portion at the end of the casemouth). As may be seen by the pink lines, the leade is abrupt.
http://www.fototime.com/CFE4FB6484BDAE6/standard.jpg
In this photo the RCBS boolit was left 'As cast' @ .441", upended into the caseneck loosely, then chambered and the breechblock closed. The boolit was then pushed back into the caseneck by the leade. The so called 'throat' is right at .500" long.
http://www.fototime.com/912EA02D06C7231/standard.jpg
This is the new photo. The boolit is from a mould produced by Dan @ Mountain moulds when he still produced full custom designs. It's nominal weight is 420grs, and the idea was to try and span the distance from the caseneck through that large empty space to the leade. The photo didn't turn out as well as I'd hoped, but the nose just above the top lube groove IS engraved for a distance of about 0.100" by the 5 lands. Neither the Lyman nor the RCBS boolit designs shown in the middle photo will do so, simply because of their reduced nose OD's.
Granted, I've gotten some very fine shooting from those 2 boolits. While I've had this heavier Loverin type design for probably 5-6 years I've never shot it using smokless powder. In fact the ONLY time I've shot it was my one rather lack luster attempt at loading the cartridge with BP:roll: As a matter of fact the lube shown on those boolits in the photo is that BP lube, as these were leftover boolits from that abbreviated 20 round experiment. In case you were wondering 5 rounds pretty much used up a paper plate target at 50 yards. IIRC I used 85.0grs of 2Fg Elephant, a lubed felt wad and a card wad. Recoil was interesting and the smoke and BOOM! was fun, while the accuracy as mentioned, left a bit to be desired[smilie=1:
...............Buckshot
However, it also means the boolit has that clearance PLUS the addition of the nominal caseneck thickness added to deal with in it's run to the leade.
http://www.fototime.com/4B9EBE131ADC269/standard.jpg
In this previously shown photo, a 45 cal boolit was dropped in the 43 Spanish chamber and then driven forward to give an impression of the leade at the end of the throat ( that long unrifled portion at the end of the casemouth). As may be seen by the pink lines, the leade is abrupt.
http://www.fototime.com/CFE4FB6484BDAE6/standard.jpg
In this photo the RCBS boolit was left 'As cast' @ .441", upended into the caseneck loosely, then chambered and the breechblock closed. The boolit was then pushed back into the caseneck by the leade. The so called 'throat' is right at .500" long.
http://www.fototime.com/912EA02D06C7231/standard.jpg
This is the new photo. The boolit is from a mould produced by Dan @ Mountain moulds when he still produced full custom designs. It's nominal weight is 420grs, and the idea was to try and span the distance from the caseneck through that large empty space to the leade. The photo didn't turn out as well as I'd hoped, but the nose just above the top lube groove IS engraved for a distance of about 0.100" by the 5 lands. Neither the Lyman nor the RCBS boolit designs shown in the middle photo will do so, simply because of their reduced nose OD's.
Granted, I've gotten some very fine shooting from those 2 boolits. While I've had this heavier Loverin type design for probably 5-6 years I've never shot it using smokless powder. In fact the ONLY time I've shot it was my one rather lack luster attempt at loading the cartridge with BP:roll: As a matter of fact the lube shown on those boolits in the photo is that BP lube, as these were leftover boolits from that abbreviated 20 round experiment. In case you were wondering 5 rounds pretty much used up a paper plate target at 50 yards. IIRC I used 85.0grs of 2Fg Elephant, a lubed felt wad and a card wad. Recoil was interesting and the smoke and BOOM! was fun, while the accuracy as mentioned, left a bit to be desired[smilie=1:
...............Buckshot