Author Topic: Just Another Ballistic Article!  (Read 1730 times)

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Taurian

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Just Another Ballistic Article!
« on: July 30, 2016, 02:02:32 PM »
I have to admit that I am tired after writing several of these articles on ballistics. But, like the trooper that I am, I just posted a new article titled, "Working the (Ballistic) Angles?

I hope that you find the article useful, if not a reason for taking a well-deserved nap.

You can find the article at:
 
Working the (Trajectory) Angles?: http://guntoters.com/blog/2016/08/02/working-the-trajectory-angles/

You will also find a link to one of the articles written by M1911A1 that I do recommend reading.

Comments are welcome, as long as they do not address spelling, grammar, and the content of the article - just kidding!
« Last Edit: August 02, 2016, 08:10:43 AM by Taurian »
The fact that the GOVERNMENT would even consider removing the natural right to bear arms is the very reason why the 2nd Amendment was written.

M1911A1

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Re: Just Another Ballistic Article!
« Reply #1 on: July 30, 2016, 03:48:09 PM »
A Few Supplementary Notes:

1. The original specification for the .45 ACP cartridge was that it should produce the same exterior ballistics (i.e., trajectory and point-blank zero) as did the .45 revolving-pistol cartridge in use by the Army at the time. This older cartridge was not the .45 "Long" Colt, but rather the .45 S&W Schofield (because it fits both revolvers). Nevertheless, the exterior-ballistic differences among the three were quit small.

2. The Army's required "75-yard zero," as applied to the Colt's Single-Action Army (SAA) revolver, seems to me to actually have been a point-blank zero, in which the POI would fall somewhere within a 10-inch circle around the POA at 75 yards. This matches-up quite well with the results of your experiments.

3. If one were to read the actual Army manual explaining the use of the SAA, especially by the Cavalry from horseback, one might be appalled. The technique absolved the user from any sort of aiming effort. It is a complete mystery to me, how anyone using the approved technique ever made any hits at all, particularly from horseback. And when the M1911 was adopted, the very same shooting technique was approved and taught.
Steve,
retired leathersmith and practical shooter


"Qui desiderat pacem, pręparet bellum."

Taurian

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Re: Just Another Ballistic Article!
« Reply #2 on: July 31, 2016, 03:56:26 AM »
And, just to add to your accurate points: The .45 Schofield used a 1:24 twist rate; whereas, the .45 Colt (and subsequently the .45 ACP) uses a 1:16 twist rate.

Even through the .45 Schofield could be fired in the Colt SAA chambered for .45 Colt, the rim of the Schofield cartridge was slightly larger in diameter and caused some loading issues in the Colt SAA. That leads me to wonder if the .45 Schofield cartridge could have been shot in lever-action rifles chambered for the .45 Colt.  I would assume that if the breech wall would allow the .45 Schofield cartridge, but would the loading tube and cartridge pick-up mechanism allow it to be used without modifying the rifle?

I had read somewhere that there were many Spencer Carbine conversions to center-fire cartridges and the .45 Schofield was one of those conversions.

Ah, the wandering mind!
The fact that the GOVERNMENT would even consider removing the natural right to bear arms is the very reason why the 2nd Amendment was written.

M1911A1

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Re: Just Another Ballistic Article!
« Reply #3 on: July 31, 2016, 02:40:03 PM »
...That leads me to wonder if the .45 Schofield cartridge could have been shot in lever-action rifles chambered for the .45 Colt...

I believe that the difficulty inherent in using the .45 Schofield cartridge in some lever-action rifles, in particular in Winchester M.1873 reproductions chambered for .45 "Long" Colt, hinges upon the case length, not the rim diameter.
The length of the cartridge lifter of the M.1873 has to pretty exactly match up to the length of the cartridge being used in it.
In a '73 arranged for .45 "Long" Colt, the lifter is too long for the Schofield cartridge. Thus the lifter will try to accept more than one Schofield cartridge (perhaps 1.375 of them?) from the magazine tube, and will jam against the breech end of the tube on its way up.

The M.1892 Winchester uses a very different cartridge-lifter system, and it may work properly with the shorter cartridge.
But, purely as a thought experiment, I don't think so.
Steve,
retired leathersmith and practical shooter


"Qui desiderat pacem, pręparet bellum."

Taurian

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Re: Just Another Ballistic Article!
« Reply #4 on: July 31, 2016, 02:57:19 PM »
I suspected as much.  That issue seem to be prevalent with some models of the lever-gun, even today, that are intended for multiple cartridge use like the .38 Special/.357 Magnum and .44 Special/.44 Magnum.  The Rossi rifles are especially troublesome in that respect. Trust me, I know, because I traded off two of them due to that issue (both were .38 Special/.357 Magnum versions). It does seem; however, that the single-caliber versions (like the .45 Colt  and the .30-30 versions) have less issues.
The fact that the GOVERNMENT would even consider removing the natural right to bear arms is the very reason why the 2nd Amendment was written.

Taurian

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Re: Just Another Ballistic Article!
« Reply #5 on: August 01, 2016, 10:39:16 AM »
ARTICLE REMOVAL:

Part of my assignment as a "Global Moderator" is to notify members of offending material; whereupon, providing them an opportunity to correct things.  Well, I had to post notice to myself about my recent article "Working the (Trajectory) Angles?"

As I was preparing a follow-up article, I noticed some serious discrepancies in  "Working the (Trajectory) Angles?" that I felt needed to be addressed. In short, I was incorrect in some areas and decided to pull the article rather than offend you with my ignorance.

The article will be re-published at a later date with the corrections, and adjusted content, made where necessary.
The fact that the GOVERNMENT would even consider removing the natural right to bear arms is the very reason why the 2nd Amendment was written.

M1911A1

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Re: Just Another Ballistic Article!
« Reply #6 on: August 01, 2016, 12:05:46 PM »
The problems couldn't've been all that bad.

I'm sorry that you pulled the entire piece, rather than simply adding a note at its top telling the reader that some changes would soon be made.
Steve,
retired leathersmith and practical shooter


"Qui desiderat pacem, pręparet bellum."

Taurian

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Re: Just Another Ballistic Article!
« Reply #7 on: August 02, 2016, 05:08:23 AM »
I'll be posting it soon after corrections are made, and it should be at the same location a the site.

I realized, that after a range session this past weekend, that I was way off in my stated "natural" zero for the Rock Island Armory FS 1911 Tactical. I need to correct that, but I also want to ensure that the rest of the information in the article is valid.
The fact that the GOVERNMENT would even consider removing the natural right to bear arms is the very reason why the 2nd Amendment was written.

Taurian

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Re: Just Another Ballistic Article!
« Reply #8 on: August 02, 2016, 08:11:51 AM »
UPDATE!

The original article has been updated and can be found @ http://guntoters.com/blog/2016/08/02/working-the-trajectory-angles/
The fact that the GOVERNMENT would even consider removing the natural right to bear arms is the very reason why the 2nd Amendment was written.