US M65 .22 Hornet ctg question


#1

Hello,

I’m looking for a source listing the velocity of the 45grain M65 .22 Hornet ctg, as it was when fired from the M4 air crew survival rifle. Can anybody point me in the right direction (preferrably without spending the bucks for a copy of Jane’s or something like that).

Unfortunately, NFA restrictions have made the M4 difficult to study in person, but I need to understand its performance for a research project.

And correct me if I’m wrong – the M4 would have been a .223 diameter bore, rather than .224, and with a 1:16 twist rate?

Much obliged,

Charlie DeArmond
charlie.dearmond@gmail.com
www.kegisland.com


#2

Bore diameter of the M4 is .2225-.2245 with a twist rate of 1 turn in 16 inches (6 grooves).


#3

Maybe it’s me missing something but I don’t see a bullet weight in that data sheet.

gravelbelly


#4

The numerical figures mentioned in this thread (.2225-2245 and .223) do not refer to bore (land-to-land) diameter but to groove to groove diameter. Jack


#5

Bullet is 35.0 -2.0 grains. Dwg B7553666


#6

Land to land diameter is .2165-.2175.


#7

Fede,

I believe that data sheet is from TM 43-001-27, which was a 1994 US Army publication. I appreciate the reply with data sheet, but this info is for a later variant of the M65 load. What I need to determine is the speed of the older 65 grain / 2,9g weight FMJ spitzer flat base M65 load that the M4 produced with its 14 inch barrel.

The lighter bullets used in the newer load were most likely adopted to flatten the trajectory of the cartridge a bit to reduce the potential for missing due to range estimation and correction errors in a survival situation. The Army also sometimes issued hollow point and soft point loads for survival rifles, but the specific load I need to understand is the earlier FMJ that would have been around in the WWII and early post-war period.

I could cut a barrel down to near the legal limit and counter-bore the muzzle to hit the right length internally in order to measure this directly, but it’d cost me to do this and the weapon modified would probably lose a third to half of its market value. Still hoping someone will know where to find this old technical data.

Thanks to all for your replies so far. Sincerely,

Charlie DeArmond (Anselmo)
charlie.dearmond@gmail.com
www.kegisland.com


#8

The first adopted load was a 45 grains FMJ designated M39 and there was also a “Ball, Soft Point” without model designation. Early 1959 manuals still list these but not the M65, which was already in production. An early 1963 document list both M39 and M65 but not the soft point.

This is a M4 bore drawing:


#9

In checking my collection and notes I came up with these, listed in apparent chronological order: (a.) SUPER SPEED 22 HORNET, with soft nose bullet (113 gr. total weight), removed from military box cautioning against anti-personnel use; (b.) SUPER SPEED 22 HORNET, with FMJ spitzer bullet (101 gr. total); my notebook, probably citing a dealer’s list, calls this a T200E1; (c.) RA 50, FMJ spire point bullet (92 gr. total); (d.) WCC 58, with FMJ spitzer bullet 100.5 gr. total). The total weight of (a.) suggests a 45 gr. bullet. I can’t account for the low weight of (c.). Jack


#10

Jack, test number designation of the M65 was T200E1. The one headstamped RA 50 should be RA 59.


#11

Fede: Thanks for the info. The Remington round’s headstamp is tiny–I can’t see it now & obviously couldn’t see it when I cataloged it all those years ago! Any idea why the total weight is so low? Jack


#12

Jack, it looks like your cartridge has no propellant at all (there are two different boxes for that headstamp identifying it as a M65 load). Maximum weight specifications for the M65 are: total 103.0 grains; case 53.0 grains, propellant 12.6 grains, bullet 35.0 grains (jacket 12.5 grains and slug 22.5 grains) and primer 3.5 grains.


#13

Does anyone have a muzzle velocity for the M39?


#14

Now we’re getting somewhere. I’ve got some WCC 1960 mil surplus FMJ on the way. Going to break down and collect data on a round. Will then test for speed consistency. If burn consistent will then record speeds in 22.5" bbl, then in 1.0" increments, down to 16.5". I need to at least be able to closely extrapolate speed with 14" bbl, but can’t counter bore to do this more directly as I need standard crown for following acoustic data collection. Catch up with you guys in a while. Thanks for assist.

Charlie


#15

Not sure what the importance of the precise data is, especially the sound signature, but for a round this size, a velocity could probably be reasonably approximated by measuring MV in whatever barrel length you have and subtracting something in the range of 30 to 40 fps for each inch less of the original barrel length from which the MV was taken.

Do you know anyone having a T/C Contender with a .22 Hornet barrel you could use as a test bed? I think T/C will make up about any barrel length and chambering you want.


#16

DennisK,

T/C contender. An excellent point. I can get a 14 inch Contender pistol in .22 Hornet and test that, rather than butchering a rifle and still not getting it quite right.

Reason for the need to get this thing nailed down and the reason I need unusual data on it is a bit off topic for this forum, but I will very briefly lay it out, as the question has been asked.

I’ve been digging deep into the ballistics and forensics of the JFK assassination. At first, in working through all the nasty bits related to the head shot, I thought I might wind up vindicating the Warren Commission. But as I worked back through the time scale and overlayed various types of evidence things got progressively wierd.

When I dug into the shot that hit JFK in the upper back / base of the neck I ran into something I really didn’t expect. I found that the entry wound was small enough to be inconsistent with the 6.5, that the wound itself was far less severe than should be expected with a medium power FMJ, that there was no evidence that the bullet did any damage after exiting via the president’s necktie knot, and that the impulse on the DPD dictabelt didn’t match those of the known medium power rifle shot impulses. When I dug into the DPD dictabelt using Cornell’s Raven Lite acoustic analysis software I found five similarly-shaped forms on the spectrograph. Three correspond to times at which there is reason to suspect a shot has been fired (behaviors, etc). Two are still kinda hanging around with no supporting evidence that I’ve been able to locate. In a nutshell, what I suspect I might be seeing in the evidence are indicators that a low power small caliber weapon was fired five times at JFK between the time the limo was about halfway through its turn from Houston onto Elm and the time of the back/neck shot. The only way this makes sense is if the energy was low and the muzzle report just intense enough to be captured on the dictabelt recording. You can find more info on the reasons I’m making these statements and my process or working through the various elements on my website, kegisland.com.

I want to stress that I’m not trying to spin a new theory. I’m just trying to square the evidence. It’s really the evidence itself that’s stubbornly presenting a very odd picture of what was actually flying through the air during the assassination.

My interest in the M4 is due to:
-Credible claims that I am in process of evaluating that its FMJ bullet roughly matches the general description of the stretcher bullet a Parkland Hospital administrator received from one of his orderlies. This administrator pointedly stated that this bullet did not look like the 6.5 later presented to him by investigators seeking to confirm witness statements and chain of custody of evidence.
-The odd combination of a relatively strong muzzle report for the Hornet and a relatively low terminal ballistic effect for the Hornet in evidence related to the assassination. A short barrel woud tend to swing these elements in those directions.
-The fact that the Hornet itself is arguably the best chambering of its day for reliable and accurate low power small caliber rifle work, due in large part to its low case volume and very tight throat design.
-The compact nature of the M4
-The relative ease with which the M4 might have either been fitted with optics or used with open iron.
-The fact that both rifle and cartridge were available as proven factory-made products.
-The simple fact that in order to conduct acoustic testing of this general type of cartridge, I need to work with a standard – so I might as well chose the standard that seems most likely to fit the evidence insofar as I currently understand it.

Please understand that I fully understand there is no way I can prove that either this particular cartridge or rifle was in use. I just need to either show a correspondence or lack of correspondence between the acoustic fingerprints of this combination and the signatures I’ve isolated on the DPD dictabelt. Either way, the data leads to the truth – and that’s what I’m after, no matter what it turns out to be.

Okay. That should do. I don’t mean to be obscure in my questions, but I do want to stick to the core purposes of this forum, and that is a big reason I simply began with the technical questions at hand rather than getting into the context.

Sincerely,

Charlie


#17

I can’t delve into the many ballistics mysteries of the JFK assassination, but I suspected your intent was of that nature.

Anyway, I went into my internal ballistics software package (Quickload) and ran a simulation of MV vs. barrel length for typical .22 Hornet loads. Here is what I calculated for fps/inch for 33, 40, and 45 grain bullet weights, respectively:

22"-20" 26;22;20
20"-18" 29;26;24
18"-16" 34;30;27
16"-14" 40;36;32

e.g., the MV loss (delta V) for a 40 grain bullet when reducing barrel length from 18" to 16" is 30 fps/inch. For a 45 grain bullet it is 27 fps/inch. For a 33 grain bullet it is 34 fps/inch.

I make no claims for accuracy, only that these results are at least educated guesses. However there is considerable experimental data indicating that for the .223 Remington, delta V averages out to between 40 to 50 fps/inch over a wide range of barrel lengths and loads.


#18

The JFK assassination is not a subject I’ve ever looked into, but I do recall reading in WW2 accounts that, unlike pointed FMJ bullets, the round-nosed Carcano FMJ does not yaw on impact and was notorious for making only a very small wound channel. Unless the bullet hit something vital, people wounded by one were usually out of hospital and back in action quite quickly.


#19

Dennis, OK. Thanks for running the sim. It’ be interesting to see if the M65 45 gr exhibits approx 27 fps loss per " MV on chrono between 22" rifle and 14" pistol.

Tony, yeah - 6.5 Carcano rn FMJ is deep penetrator, but it can yaw and violently disintegrate if it hits bone at high vel, and even when it holds together upon striking bone it can create a bone fragment shower fanning out along the wound tract. One thing worth considering as well is that GIs that lived long enough to receive surg care may have been disproportionately suffering soft tissue wounds in less critical areas. Good to bear in mind the fact that the 6.5 x 54 that was nearly the ballistic twin of the Carcano was used to great effect by big game hunters in Africa.

I’m going to leave my forensics notes intact on this thread, but don’t think this is the right place to dig into that topic. Thanks for the assist. I’ll come back later to post data in order to add to the info on this site.


#20

True, but that’s because it penetrated deeply and in a straight line, so was good for brain-shots against the big beasts. Those hunters were good enough to get very close and place their shots with great precision.

The theory of bullet terminal effectiveness suggests that a long round-nosed FMJ will (other things being equal) do a lot less damage than a spitzer FMJ, and what I’ve read about the combat performance of the Carcano bullet backs that up. The same problem was discovered with the round-nosed .303 bullet, leading to the brief adoption of a hollow-point version before this was banned by the Hague agreement. In contrast, the 6.5mm Arisaka Type 38, which had a spitzer bullet, was noted for being surprisingly destructive and lethal, as was the .303 Mk VII spitzer load.