Bigslug
06-23-2018, 01:20 AM
We just finished up the group buy with MP Molds for this lovely reproduction of the British .455 MKIV:
222558
Fresh from Slovenia with HB and solid base pins, a pair of Cramer rods for each pin, and a steel nose punch. I understand Miha usually makes extras. We were doing both .455 and .457 diameters.
And the end product. . .
222559
To those who aren't familiar with the .455 Webley family of cartridges:
MKI was a 265 grain HBRN atop a longer case than shown using black powder
MKII was this shorter case with the same basic bullet slightly re-shaped to improve stability. This fellow here:
222560
MKIII - aka "The Manstopper" was a 218 grain hollow base, hollow point that was only in military service a little over a year around the turn of the 20th Century due to that pesky Hague Convention nonsense that popped up at around the same time. Sadly, one needs swaging equipment to make those. :(
MKIV is the bullet above under discussion. 220 grains of the regulation 12-1. I cast these of 20-1 and got 228-229 grains. The MKV was the same bullet made of a low-antimony mix. (99-1 says Wiki). These were around from 1900-1914 when supposedly Political Correctness kicked in again and they decided to go back to the MKII.
The MKII stuck around until the FMJ MKVI arrived just before WWII.
Most of what I've gleaned from the libraries of members here is that all the smokeless variants tended to 600 (ish) feet per second.
If you followed our lengthy thread on the later British use of 200 grain bullets in the .38 S&W, there was a lot of discussion on the theory and performance characteristics of both these and the .455. There was much speculation on whether or not they tumbled & I sacrificed a score of stalwart milk jugs to conclude that the probably didn't unless some glancing strike made them.
So. . .another dive into the pond of pre-WWI terminal ballistics. My last batch of MKII bullets were propelled by 3.4gr of Red Dot at the top end of the British military spec of 580 +/- 30fps, so I backed the charge down to 3.2 for these. Have yet to chrono - will report when I do. Targets were a row of gallon pool chlorine jugs - same size and shape but a bit thicker plastic than those for milk at about ten feet. Keeping a trick from my testing of the MKII bullet, I put sheet of typing paper between each of the jugs to provide any evidence of tumbling (they didn't). Here is what I fished out of Jug #4:
222555
Bullet went through in a nice straight line to the back wall of Jug #4, perforated it, dented the front wall of #5 and bounced back into #4. If thinner milk jugs were used, I'm certain this bullet would have been into #5. The nose was slightly compressed and flared out, but really no change to it's profile. Despite the low velocity, there was enough displacement force to split the first jug along one corner.
222556
This is the entry side of the last jug penetrated #4 - nice, round, nose-first entry.
Terminal performance musings: The FBI Jell-O protocols state that 12-18 inches of penetration in gelatin is the desired amount for a duty pistol load. I've noted that duty hollow points that commonly stop after about 11-15 inches in gelatin are usually fished out of the third (sometimes fourth) milk jug in the stack. It's not a perfect comparison by any means, but it's probably fair to say a gallon jug of water has about the same braking power as 6-7 inches of ballistic gelatin. The FBI prioritizes penetration over expansion, but states that so long as the penetration levels are there, expansion to 1.5x original diameter is desirable (you see a lot of .70-.95 caliber mushrooms). Obviously, there's no expansion here with the .455 MKIV, but it starts big to begin with, stays on the line it starts on, and penetrates closer to what is probably equivalent to that 18" top end of the spec than the jacketed expanders. I have to conclude that one could do a lot worse than this bit of Late-Victorian tech.
The range was too crowded today for putting groups on paper, but it's minute of dog-food can at 25 yards when the operator does his job. More formal accuracy testing to be done next week. To Be Continued. . .
222558
Fresh from Slovenia with HB and solid base pins, a pair of Cramer rods for each pin, and a steel nose punch. I understand Miha usually makes extras. We were doing both .455 and .457 diameters.
And the end product. . .
222559
To those who aren't familiar with the .455 Webley family of cartridges:
MKI was a 265 grain HBRN atop a longer case than shown using black powder
MKII was this shorter case with the same basic bullet slightly re-shaped to improve stability. This fellow here:
222560
MKIII - aka "The Manstopper" was a 218 grain hollow base, hollow point that was only in military service a little over a year around the turn of the 20th Century due to that pesky Hague Convention nonsense that popped up at around the same time. Sadly, one needs swaging equipment to make those. :(
MKIV is the bullet above under discussion. 220 grains of the regulation 12-1. I cast these of 20-1 and got 228-229 grains. The MKV was the same bullet made of a low-antimony mix. (99-1 says Wiki). These were around from 1900-1914 when supposedly Political Correctness kicked in again and they decided to go back to the MKII.
The MKII stuck around until the FMJ MKVI arrived just before WWII.
Most of what I've gleaned from the libraries of members here is that all the smokeless variants tended to 600 (ish) feet per second.
If you followed our lengthy thread on the later British use of 200 grain bullets in the .38 S&W, there was a lot of discussion on the theory and performance characteristics of both these and the .455. There was much speculation on whether or not they tumbled & I sacrificed a score of stalwart milk jugs to conclude that the probably didn't unless some glancing strike made them.
So. . .another dive into the pond of pre-WWI terminal ballistics. My last batch of MKII bullets were propelled by 3.4gr of Red Dot at the top end of the British military spec of 580 +/- 30fps, so I backed the charge down to 3.2 for these. Have yet to chrono - will report when I do. Targets were a row of gallon pool chlorine jugs - same size and shape but a bit thicker plastic than those for milk at about ten feet. Keeping a trick from my testing of the MKII bullet, I put sheet of typing paper between each of the jugs to provide any evidence of tumbling (they didn't). Here is what I fished out of Jug #4:
222555
Bullet went through in a nice straight line to the back wall of Jug #4, perforated it, dented the front wall of #5 and bounced back into #4. If thinner milk jugs were used, I'm certain this bullet would have been into #5. The nose was slightly compressed and flared out, but really no change to it's profile. Despite the low velocity, there was enough displacement force to split the first jug along one corner.
222556
This is the entry side of the last jug penetrated #4 - nice, round, nose-first entry.
Terminal performance musings: The FBI Jell-O protocols state that 12-18 inches of penetration in gelatin is the desired amount for a duty pistol load. I've noted that duty hollow points that commonly stop after about 11-15 inches in gelatin are usually fished out of the third (sometimes fourth) milk jug in the stack. It's not a perfect comparison by any means, but it's probably fair to say a gallon jug of water has about the same braking power as 6-7 inches of ballistic gelatin. The FBI prioritizes penetration over expansion, but states that so long as the penetration levels are there, expansion to 1.5x original diameter is desirable (you see a lot of .70-.95 caliber mushrooms). Obviously, there's no expansion here with the .455 MKIV, but it starts big to begin with, stays on the line it starts on, and penetrates closer to what is probably equivalent to that 18" top end of the spec than the jacketed expanders. I have to conclude that one could do a lot worse than this bit of Late-Victorian tech.
The range was too crowded today for putting groups on paper, but it's minute of dog-food can at 25 yards when the operator does his job. More formal accuracy testing to be done next week. To Be Continued. . .