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Posted: 7/3/2026 5:57:52 PM EDT
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Some of you may remember this thread: https://www.ar15.com/forums/General/Commercial-ammo-in-garands-test-results-/5-2734055/ Well after some thoughts and comments from others we decided to test a different way. Not that the testing above didn't show that port pressures were very similar between milsurp and commercail ammo. However others pointed out the bolt speed velocity was more important than port pressure. So there is a new test setup and we've run prelimnary tests to calibrate and validate the system and see what all we can "see". Comments from Ken: This is a time in the program where I've got my nose to the grind-stone. I've shot several different loads now IN the instrumented M-1 Garand; measuring bolt speed velocity, and time between port impulse and the start of op-rod movement. I have validated the test set up, which includes a test sled on linear bearings, non-contact laser micrometer, piezo-electric transducer, charge amplifier, power supply, mounting locations for all the gadgets on the rifle, multi-channel oscilloscope (with all the correct settings), etc. The laser micrometer processor speed is capable of taking measurements every 0.33 MILLISECONDS, which provides for ample data points along the charging handle movement path. I've also witnessed already some interesting phenomena that have not been clearly noted before in any M-1 Garand study I've read. First, the signal from the port pressure transducer occurs 2.7 milliseconds BEFORE the charging handle STARTS to move. Doing the math, given a projectile moving at 2750 fps, and a port located 1.5 inches before the end of the muzzle (you can do the math too....), the projectile is down-range by 8 FEET, before the charging handle starts to move. This phenomenon MAY indicate that there is a lot of "time" to de-pressurize the system before the op rod activates. This MAY likewise indicate some level of self-regulation of maximum port pressure, given the variety of loads shot through a gun with a port located only 1.5 inches from the muzzle. (Kudos to "whoever" designed this rifle.....LOL) Another phenomenon witnessed was that I can clearly see the "time" it takes for the bolt itself to unlock, after the rifle is fired. There is a distinct shape along the front time/distance curve that occurs during EVERY shot recorded (M1, M2, standard CMP ball, commercial ammunition, etc). The third phenomenon witnessed was a fairly consistent correlation between the port area under the pressure/time curve (area under the curve) in the Mann test barrel, and the resultant bolt speed velocity OF THAT SAME AMMUNITION in the actual M-1 rifle. ----- So where we are right now is on a slight pause as Ken is back doing work that pays the bills and I am gathering more commercial ammo for testing purposes and I still have a fairly large stock of milsurp 30-06 all the way back to 1927 that is still servicable to shoot. End result it looks like the results are same that commercail ammo is fine, just proven a different way via bolt speed. Plus we are going to do some other tests with this setup with the rifle in various condtions or lubrication and wear. |
RIP MSgt Adam F. "Benji" Benjamin (EOD) KIA Helmand Prov 18 Aug 2009 Semper Fi bro' and save me a seat.
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
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NRA pistol, rifle and shotgun Instructor
| I use a Schuster DCM adjustable gas plug. |
So... I find comfort in the fact that if Trump has to work so hard to go to Heaven, then there is a shit load of Democrats that have no f-cking chance to go anywhere but HELL. Sometimes it is entirely appropriate to kill a fly with a sledge-hammer.
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Originally Posted By DasRonin: I use a Schuster DCM adjustable gas plug. |
RIP MSgt Adam F. "Benji" Benjamin (EOD) KIA Helmand Prov 18 Aug 2009 Semper Fi bro' and save me a seat.
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
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So chastize me on proceeding with caution! M1 Garand operating with caution to prevention to possibly damaging the operation rod... so shoot me! I hope to say your right... but I proceed to operate as if your are wrong! |
So... I find comfort in the fact that if Trump has to work so hard to go to Heaven, then there is a shit load of Democrats that have no f-cking chance to go anywhere but HELL. Sometimes it is entirely appropriate to kill a fly with a sledge-hammer.
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Originally Posted By DasRonin: So chastize me on proceeding with caution! M1 Garand operating with caution to prevention to possibly damaging the operation rod... so shoot me! I hope to say your right... but I proceed to operate as if your are wrong! You dont have to hope. Look at the data he shows. The gunstore myths has 0 evidence or data. |
Do Good
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Zzzzz. The old wives tale of "You'll bend your, checks notes, solid steel and thick ops rod, by using anything but M2 ammo!!!" Seemingly, no amount of data or even statements from the CMP will put this to rest. It's in the same category as "You know, those commies were smart in that they designed their AK's to be able to use M16 ammo in a pinch!" |
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For the OP, have you posted these current tests on M14forum.com ? And Thank you for the updates !! |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
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TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
"I Find Your Lack of Faith Disturbing"
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Originally Posted By bfoosh06: For the OP, have you posted these current tests on M14forum.com ? And Thank you for the updates !! I've got an ammo shipment almost completed to send in for testing. Wait on a few more different boxes to arrive. |
RIP MSgt Adam F. "Benji" Benjamin (EOD) KIA Helmand Prov 18 Aug 2009 Semper Fi bro' and save me a seat.
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
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Originally Posted By Jeremy2171: No this post and there are where we stand currently. I've got an ammo shipment almost completed to send in for testing. Wait on a few more different boxes to arrive. Originally Posted By Jeremy2171: Originally Posted By bfoosh06: For the OP, have you posted these current tests on M14forum.com ? I've got an ammo shipment almost completed to send in for testing. Wait on a few more different boxes to arrive. Unfortunately I tried to follow the back and forth on the M14 forum but gave up after a dozen pages. The vast majority couldn't seem to accept the results, questioning the test, the method, or the expertise. I applaud the OP @ Jeremy2171 for looking into bolt speed as another factor to test. |
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Originally Posted By Jeremy2171: No this post and there are where we stand currently. I've got an ammo shipment almost completed to send in for testing. Wait on a few more different boxes to arrive. Very Nice ! Thanks for all your efforts ! |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
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The commercial ammo we are planning on shooting in the next round of bolt velocity testing. Attached File Attached File |
RIP MSgt Adam F. "Benji" Benjamin (EOD) KIA Helmand Prov 18 Aug 2009 Semper Fi bro' and save me a seat.
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
NC CCH Instructor
NRA pistol, rifle and shotgun Instructor
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Originally Posted By Jeremy2171: The commercial ammo we are planning on shooting in the next round of bolt velocity testing. https://www.ar15.com/media/mediaFiles/51024/1000005906_jpg-3797304.JPG https://www.ar15.com/media/mediaFiles/51024/1000005933_jpg-3797305.JPG Thanks again ! |
*Hold on to your AR-15s. Their magic must be very powerful, or they wouldn’t want them.*
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
JAFOM.... Just another fat old man.
________________________________
TOGC,IADC
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