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Few errors in that article:

1) IMR 4895 is actually a mid to late war development, M2 ball was developed with IMR 1185 and later used IMR 4675 or IMR 4745.
There is zero mention of those two powders anywhere on the internet...did you mean IMR 4676? I'd like to see the data sheets for that powder and what ammo it loaded.
 

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Wow! Every time this topic comes up there's an argument. I actually love the heated discussion. Last time I was involved in one of these I got blasted by a number of forum members for using Hornady Superformance in one of my Garands WHILE ALSO USING a Garand Gear gas plug. I'm glad to see Garand Gear data being cited in this discussion, as in the past it was blown off on this forum.

Not trying to start a fight here. I do think it's an interesting discussion and, admittedly, one I have to brush up on (again). There are folks here who really do know what they're talking about. There are also folks here that will smugly tell you if you use anything other than M2 ball you're a communist and a pedophile and your rifle is gonna blow up in your face and frankly they don't care if you die if you're that stupid - without any data to support what they're saying.

Great discussion here folks!
 

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There is zero mention of those two powders anywhere on the internet...did you mean IMR 4676? I'd like to see the data sheets for that powder and what ammo it loaded.
That is a typo, the two propellants are IMR 4746 and IMR 4745.

They are listed in the report on muzzle pressure for the M1 Garand I referenced.
Apparently you missed the test reports from SA I posted above.
Well, that doesn't state they are safe or unsafe, just that one lot of M2 Ball averaged a bolt velocity of 26.28 fps . . . It also does not mention how the lot was packaged, 8 or 5 round clips, belts or loose. Not all M2 Ball is equal, it was segregated by intended use.

Maybe if you gave the rest of the details of the report or information such as the title, author, date, etc.
 

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Wow! Every time this topic comes up there's an argument. I actually love the heated discussion. Last time I was involved in one of these I got blasted by a number of forum members for using Hornady Superformance in one of my Garands WHILE ALSO USING a Garand Gear gas plug. I'm glad to see Garand Gear data being cited in this discussion, as in the past it was blown off on this forum.

Not trying to start a fight here. I do think it's an interesting discussion and, admittedly, one I have to brush up on (again). There are folks here who really do know what they're talking about. There are also folks here that will smugly tell you if you use anything other than M2 ball you're a communist and a pedophile and your rifle is gonna blow up in your face and frankly they don't care if you die if you're that stupid - without any data to support what they're saying.

Great discussion here folks!
So true about the bashing

garand gear data has some issues but it's a start.
 

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That is a typo, the two propellants are IMR 4746 and IMR 4745.

They are listed in the report on muzzle pressure for the M1 Garand I referenced.

Well, that doesn't state they are safe or unsafe, just that one lot of M2 Ball averaged a bolt velocity of 26.28 fps . . . It also does not mention how the lot was packaged, 8 or 5 round clips, belts or loose. Not all M2 Ball is equal, it was segregated by intended use.

Maybe if you gave the rest of the details of the report or information such as the title, author, publisher.
M2 ball is M2 ball...packaged differently or not..it's still M2 ball.
 

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M2 ball is M2 ball...packaged differently or not..it's still M2 ball.
No, sorry, its not. As I stated ammunition was/is segregated by intended use. There is a difference between boxed and clipped M80 Ball and belted M80 Ball, besides M13 links . . .

And, you also intermix average velocity with peak velocity as if they are the same. In the spread sheet you referenced as "proof" that 220 gr is 'safe' it is the average velocity, yet the SA report page notes peak velocity. An average velocity of 27 fps might have a peak velocity of 32 fps

And, yes the velocity in the spread sheet is the average velocity over the first three inches as the video quality and the markings on the stock do not allow for better resolution. You cannot accurately measure 25 to 30 fps over a 2 to 3 millisecond interval with a one inch scale. He measured the time it took (number of frames) to move one inch. And since the big hump of the peak velocity seen on the graph all happens within and inch, he has measured the average velocity.
 

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No, sorry, its not. As I stated ammunition was/is segregated by intended use. There is a difference between boxed and clipped M80 Ball and belted M80 Ball, besides M13 links . . .

And, you also intermix average velocity with peak velocity as if they are the same. In the spread sheet you referenced as "proof" that 220 gr is 'safe' it is the average velocity, yet the SA report page notes peak velocity. An average velocity of 27 fps might have a peak velocity of 32 fps

And, yes the velocity in the spread sheet is the average velocity over the first three inches as the video quality and the markings on the stock do not allow for better resolution. You cannot accurately measure 25 to 30 fps over a 2 to 3 millisecond interval with a one inch scale. He measured the time it took (number of frames) to move one inch. And since the big hump of the peak velocity seen on the graph all happens within and inch, he has measured the average velocity.
We aren't talking about M80 ball...we are talking about M2 ball.

M2 ball is M2 ball..period. Is one lot is more or less accurate than another sure... but it's still made to the same specs and fully interchangeable..

Actually 220s moving the oprod at the same velocity as garand ammo is how I come to say that 220s are fine
 

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So true about the bashing

garand gear data has some issues but it's a start.
There are a handful of guys on here that really know their s#!+ on this topic, and Lysander is one of them. I can count on one hand the others. There's tons of poor information out there that guys swallow whole. Takes a discerning eye to parse through it.
 

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(SNIP)
Actually 220s moving the oprod at the same velocity as garand ammo is how I come to say that 220s are fine
Not according to the tests in the video I posted. (post #39)

What about their conclusion from the high speed photography that the 220gr projectile at a lower velocity still exceeds normal op rod velocity don't you think is accurate?
 

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Not according to the tests in the video I posted. (post #39)

What about their conclusion from the high speed photography that the 220gr projectile at a lower velocity still exceeds normal op rod velocity don't you think is accurate?
Using substandard M2 ball from the late 60s is purposefully misleading.

Same test duplicated here shows vastly different results..


 

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The velocity of the M1 oprod might not be a good indicator of the STRESS (bending force) exerted on the oprod in the micro seconds after the bullet passes the gas port. Another consideration is whether (and to what extent) the cartridge remains pressurized enough to delay extraction (and oprod movement) while the gas cylinder is pressurized.
My guess is that the initial high pressure 'smack' on the oprod causes the 'oprod bending troubles'.

Jay
 

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The velocity of the M1 oprod might not be a good indicator of the STRESS (bending force) exerted on the oprod in the micro seconds after the bullet passes the gas port. Another consideration is whether (and to what extent) the cartridge remains pressurized enough to delay extraction (and oprod movement) while the gas cylinder is pressurized.
My guess is that the initial high pressure 'smack' on the oprod causes the 'oprod bending troubles'.

Jay
Good point... also what does lubrication (grease) play into this?
The oprod is in effect "floating" under spring pressure until it moves about 3/8" and the oprod cam starts to engage and unlock the bolt lug.
At this point the lack of grease comes into play.

A dry rifle vs a greased rifle showed about a 10% decrease in oprod velocity all because of friction.

Friction causes stress....

Grease your rifle properly.

Good springs...and properly greased all are important aspects of keeping your rifle running safely.
 

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Well the only ammo I use either 308 win 150gr fmj or 7.62 nato 150gr fmj with no problems. And I've installed a Sadlak op rod
 

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you can shoot any SAMMI spec 30-06 in a M1 garand it will not blow up. Can some ammo produce excessive port pressure that can potentially damage parts, yes.
but even a op rod can and will bend from M2 ball ammo. Especially if the op rod is already worn/fatigued/seen abuse before you get it.
Other than the " I want to get a deer this season with my M1" I see no reason to use a M1 for hunting? Thats the fine part of "my gun" you get to do what you want.
I had a old timer tell me when they where allowed to shoot their own ammo( for matches) lots of guys shot 220 grain bullets loaded to pressure signs and then back off a bit.
he also said thats when you could get op rods by the bucket full along with buckets of inexpensive bullets and we still shot out to 800-1000 yards with the M1.

also there plenty of lighter 30-06 hunting ammo out there depending on your needs. Lots of great bullets also that will deliver more take down ability than say bullets made 40 years ago.
 

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Good point... also what does lubrication (grease) play into this?
The oprod is in effect "floating" under spring pressure until it moves about 3/8" and the oprod cam starts to engage and unlock the bolt lug.
At this point the lack of grease comes into play.

A dry rifle vs a greased rifle showed about a 10% decrease in oprod velocity all because of friction.

Friction causes stress....

Grease your rifle properly.

Good springs...and properly greased all are important aspects of keeping your rifle running safely.
Lubrication actually plays very little in the bending stresses in an M1 or M14 operating rod. Inertia is the biggest factor. The operating rod accelerates with very little resistance until it contacts the bolt cam, then in a millisecond it has to accelerate the bolt to 20 to 25 fps.

Unlocking takes about 1 millisecond, you can calculate the minimum acceleration, and thus the forces involved. But remember, this is a low estimate, as much of the time the bolt is rotating, but not moving rearward.

You can also figure the additional force required to boost the bolt velocity beyond 25 fps.

Going from 23 fps to 28 fps sees a 22% increase in force.

And, greasing the rifle would actually increase the bolt velocity, less resistance to a constant force (for a given ammunition) and all.
 

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Lubrication actually plays very little in the bending stresses in an M1 or M14 operating rod. Inertia is the biggest factor. As you state, the operating rod accelerates with very little resistance until it contacts the bolt cam, then in a millisecond it has to accelerate the bolt to 20 to 25 fps.

Unlocking takes about 1 millisecond, you can calculate the minimum acceleration, and thus the forces involved. But remember, this is a low estimate, as much of the time the bolt is rotating, but not moving rearward.

You can also figure the additional force required to boost the bolt velocity beyond 25 fps.

Going from 23 fps to 28 fps sees a 22% increase in force.
And dry is much worse than when greased....hence my point. A dry oprod cam and bolt lug will increase the friction and stress on the rod.
 

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Nope, not even close. I am more suggesting hand loads up to 180 with the proper cautions taken to establish safe operations.
There are many super commercial loads that are designed specifically for bolt guns. With any semi, caution is the name of the game. Do the research, it can save a lot of healing in the future.
I think if I was to use my M1 for hunting I would load up a 150gn RNSP with 50 grains H4895.... Growing up I thing 150 gn RNSP took down more stuff in more cals than I could count.
 

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We aren't talking about M80 ball...we are talking about M2 ball.

M2 ball is M2 ball..period. Is one lot is more or less accurate than another sure... but it's still made to the same specs and fully interchangeable..

Actually 220s moving the oprod at the same velocity as garand ammo is how I come to say that 220s are fine
Sorry, no, it's not and just because you repeat yourself, it doesn't make it true. Interchangeable, in a pinch, yes, but not exactly the same.

Belted ammunition is tailored to reduce bore erosion, so it uses a different propellant.

And besides, the specifications for .30-06 never specified muzzle or port pressure, so manufacturers are free to use slower less erosive propellants (and bump up muzzle pressure) for belted. And since ammunition packaged in belts almost never was broken down into M1 clips (as clips were never procurable as a separate item), the risk was minimal.
 
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