I wanted to go shoot about 100 test cartridges today but with weather creeping in, it just keeps getting worse. Supposed to get 12" to 24" of snow here in NC. I was going to wait until I shot these to share but figured I would go ahead and share what I have done already.
Not trying to reinvent an inferior bullet, I wanted to try and load an as close to an 1873 load as I could. The Winchester 1873 cartridge bullet appears to be a 200gr swaged bullet with two lube grooves and no crimp groove. According to the Winchester 1875 catalog this is what is inside. If this tests nicely, I will use some original late 1870's or early 1880's unheadstamped semi-baloonhead cases.
Attachment 231701
As late as 1875, we see this bullet on the second style box label. This particular label is the later label that does not wrap around the box end which would date it as to the last of that style right at 1875 when Winchester started sealing their boxes...note the external lube groove. If this is indeed the same swaged bullets offered in the catalog, this means the crimp is about midway of the foreword driving bad leaving the first lube grove exposed and not having a crimp groove.
Attachment 231703
The current 200gr Magma bullet closest resembles this bullet design from what I can fine. The Ideal/Lyman 42798 is too long.
Attachment 231704
I decided to seat the bullet and crimp just a tad past midway of the forward driving band. I used an RCBS Cowboy die two step roll crimp. I thought the lead would be too hard but it works well.
Before I go any further we should all know that I am just playing around and there is not enough bullet lube on these for many shots without fowling...like I said, probably an inferior design.
I used new, unsized Starline brass. In the bullet photo on the box and in the 1875 catalog, the cartridge show no sign of a bottleneck. New Starline brass shows no sign of a bottleneck and chambers just fine if not resized. I also used WLP primers.
The bullet is a Lasercast hard cast Magma design. I removed the lube, ran it through my lubesizer to .429 and added lube to the crimp groove for the exposed second lube groove.
Attachment 231705
I used 40gr of Swiss FFG and unsettled, the powder was even with the case mouth (#7 and #8). tap settled to .12" (#9). I used my modified bullet seating die to compress the powder .10" (#10). This gives me .22" to seat the bullet without any pressure on top of the bullet meplat...or just enough pressure to round the edges of the meplat.
Attachment 231706
Here are 5 loaded cartridges. The center cartridge has no lube in the exposed lube groove. The others have yet to have the excessive lube wiped off...using care as to not remove the external lube from the lube groove.
Attachment 231707
Showing the finished load but not cleaned.
Attachment 231708
Finished cartridge on it's side to resemble a late 1873 cartridge.
Attachment 231709
When I get a chance to run these through the chronograph and strain gauge, I will post the results.