Are you, Flbt talking abut .377" bullets? Those are rather specific for under 2,000fps. Pleanty of good .375" bullets for the .38 or .375 Whelen.
Here are some I made for varous rifles, from 458" to .358 using ctg. cases for jackets. The 1st two, are from my .458 2", driven at 2,070fps. Both were 480gr. to start and were shot into the end of a brand new fir railway tie at point blank range - at -40F. The first one had a wheel weight core and made 14 1/2". The much expanded one went only 11 1/2" & had a pure lead core. The longest one is a 350gr. from a shortened .223 case and weighed 330gr. The expanded bullet beside it wad extracted from a 14" diameter aspen tree, shot at -24 IIRC. It almost made the back side of the tree as in 13" of penetration.
Trees, especially living trees are quite hard at those temps.
Great looking bullets, and impressive weight retention and penetration given the solid wood testing media and hard frozen temperatures. I will take my 110 deg summers over your minus 40 deg winters anytime.
Did you bond the lead core to the jacket in your bullets?
I make my own bullets as well in most common calibers from .224 to .510. Below are some of the bullet types that I make in 38 and 375 diameters. The 38 caliber bullets I make are sized for the old 38-55 lever action round, at .379, but can easily be sized to .375 as needed. Some bullets I swage in .375 caliber. Of course I can make almost any practical weight bullet for the caliber. I can and do use cartridge cases (like you) for jackets (jacket thickness tapering from around .015 at jacket mouth to well over .05 at the case head), I can make jackets from copper tubing ( jacket thickness .035, straight wall from base to mouth). I can also use commercial guilding metal jackets, when available, from Sierra, Center X, J4, Hines, or Corbins ( commercial jackets usually taper slightly from around .015 at mouth to at/or over .025 at base). I also have cutters to put long or short tapers in the inside of jacket mouths, no matter the jacket type. I can also press the same cutters straight into the jacket mouths to score the inside of the jackets on regular intervals to insure reliable regular expansion in jacketed bullets.
Here are some pics of the bullets I make for my .375 Whelen and 375 H&H. Please forgive the discoloration on the jacket due to annealing of full jacket/case before swaging. These bullets haven't had a tumble "bath" to make them look shiny and new (of course they shoot just fine) Also please forgive poor photography.
1. These are what is called Long Round Nose (LRN) and Short Round Nose (SRN) point forms.
L to R
a. LRN flat tip 300gr copper tubing jacket (.035 jacket thickness, straight thickness mouth to base)
b. LRN soft point 240gr rifle brass jacket (.015 jacket thickness at mouth, increasing thickness toward base)
c. SRN open tip 230gr rifle brass jacket (.015 jacket thickness at mouth, increasing thickness toward base)
You can bond hard alloy lead, like wheel weight lead or hard alloys from McMaster Carr, inside the SRN for dependable deep penetration. You can also add a series of cannelures down the long bearing surface of this bullet to reduce pressure/increase velocity.
2, These bullets are SWC cutter designs with a sharp shoulder that are less prone to deflection in thick brush than typical spitzer point bullets, and the sharp shoulders "cookie-cut" clean, caliber sized, entry wound holes in the animals' skin to increase blood trails. (They also "cookie-cut" nice caliber sized holes in paper targets at the range for easy spotting.) These bullets are actually .379 diameter for use in old 38-55 lever actions. They can easily be made full jacketed and/or reduced to .375 diameter for use in any of the higher velocity 375's like the Whelen and the H&H. These are flat nose (FN) and round nose (RN) semi-wadcutter (SWC) point forms. All jackets rifle brass (223 brass)
L to R
a. Lead SWC FN 245gr for low velocity black powder loads. Gas checks can be added if desired.
b. Lead SWC RN 235gr for low velocity black powder loads. Gas checks can be added if desired.
c. DD 3/4 jacket SWC FN 250gr
d. DD 3/4 jacket SWC RN 235gr
The middle pair of bullets are dual diameter (DD), 3/4 jacketed bullets. These bullets are sometimes called "bore riders" because the forward part of the bull is reduced diameter (.366 diameter on these bullets) so that the forward part of the bullet rides on top of the lands of the rifling, rather than filling the grooves of the rifling. This reduces pressure (many mono-metal bullets are bore riders on the front to reduce pressure.) This dual diameter also greatly reduces leading in the barrels with 3/4 jacketed bullets. (The black arrows on the bullet show the transition point from reduced diameter to full diameter. Note reducing diameter on forward portion of bullet reduces the shoulder on the SWC, which reduces the ability to cut "clean" entry holes in game animals.)
e. 3/4 jacket SWC RN 235gr
f. 3/4 jacket SWC FN 245gr
Note these 3/4 jacket bullets can explosively expand even in soft skinned animals yet hold together in the jacketed area for deeper penetration. Any of the SWC Bullets can also be made hollow point to insure explosive expansion on soft skinned game, even at low velocities. You can also bond a hard lead alloy in the base, then swage a soft lead tip on. These are completely stable in flight, but on impact, the soft tip will radically expand and separate from the base, and the base will straight line penetrate deeper into the animal.
3. The next bullets are a 4S spitzer ogive truncated into a flat nose (FN).
L to R
FN open tip 240gr
FN soft point 260gr
When you reload, you can vary velocity and bullet weights and types and duplicate factory rounds, improve on factory rounds, or make rounds not offered by any factory manufacturer. When you swage bullets, you can vary weights, jackets, point forms, base shapes and cannelures to duplicate factory bullets, improve on factory bullets, or make bullets not offered by any factory manufacturer.