Re#16 and the M-1 Garand

[fyrewall]

Yea but the 06 is real good - lots of deers and elks every year are killed with them and the resale potential for 06's is enormous - I sold my 06 bolt gun for lots of $ in 2 weeks. Please grant me a modicum of grammatical leeway as English was not my families natural language as my parents came from a foreign country and spoke their native language during my formative development stage. Besides the word "deers" implies lots of them - just think - a huge bunch of deers, including huge bucks, roaming your allocated hunting area and you having a .30-06 bolt gun stoked up with 52 grains of H4895 and a nice 150 grain bullet, like right from the Sierra manual.

Mr. Garand must have some thoughts about port pressure equating to pressure and a commensurate expansion of expanding gas to drive closed system M1 gas system piston. I believe more gas would gush through a M1 gas port to generate higher forces against a piston, at rest, (Newton) with a higher pressure load, like 56K psi than a lower pressure load as shown in the Hornady manual (M1 Garand) which would probably be in the sub 50 k psi range; Hornady has a max load of 46.4 using H4895 for 150 grain bullets. Once the piston started to move the volume inside the cylinder would rapidly increase thus the expansion would be minimized.

In regard to using to using a slower burning powder like H4350 or Re 16 the pressure peak would occur further down the barrel and would generate more pressure at the gas port.

"loose" does this mean floppy and about to fall off? A gentle correction would be "lose", meaning the inability to ascertain credibility in this particular instance regarding my modest attempts to prevail in this discussion.

Got to go now - next to be discussed is forum responsibility.

 

[fyrewall]

Ya' all are funny. I love the old "that's the way we did it back then..." argument.

In general, the 52gr rule is a pretty safe way to do business.

Actually the problem with bent op rods isn't really port pressure, it's impulse and momentum. Port pressure limits are a simplistic way of monitoring potential forces that reach the op rod. You actually need to know how fast the powder expands in the gas cylinder so that you can determine what the Impulse and momentum forces are. If you can calculate those forces then you would be able to determine what powders will damage the op rod. What the gas port pressure is isn't a true picture of what the gases are doing in the gas cylinder. But in reality we all know that nobody but the federal government would have the tools and money to do that kind of work and so the 52gr rule is a good substitute because that limitation on the powder charge relates to how much gas port pressure is developed which, in turn, relates to how much impulse and momentum the op rod experiences.

Oh, and yes, I'm one of those old guys too (62 years old this year) but tend to try to keep up with science behind the shooting sports.

P.S. - when you criticize people and software for being inaccurate it would behoove you to check your spelling and sentence structure. Otherwise your comments loose credibility. The plural of the words deer and elk are; deer and elk, not deers and elks.

Please see above.

 

[fyrewall]

Hello Mr. rammac,

On "that's the way we did it back then..." argument." I really like "love" olde stories from folks that have had hands on experience. For example, Donny, one of my sport's pals, father was subjected to some real bad stuff in WWII. Any how Donny's dad claimed a Garand could completely penetrate some J type enemy combatant and kill at least one J type next in line. Another story that I heard, when at boot camp, was my Marine DI stating a hit from M1 Garand could disable a tank should a part of the tread be hit. Interesting but short on ammo specifics.

On the deers vs. deer imagine a translation of "a herd of deer" to "troupe de cerfs communs" Please note the use of "s" in cerfs.

This forum has an excellent spell checker but permits syntax errors like "loose" vs. "lose" . We all incur momentary lapses in spelling but this might be explained by a momentary seizure or tremor that might cause a double strike of the letter "o".

As far as the actual loading or approved ammo for the M1 Garand the data appears to be loosely organized. I have the impression that GI M2 ammo is loaded with a 150 grain bullet using 50 grains of IMR 4895 at an MV of 2740 fps. Upon doing a limited search of the Newton Impulse stuff I discovered that the max permissible impulse, as a force applied to the gas piston in pound m seconds is between 274 and 305. Varying force and varying times might equate to equal pound seconds. All this happens real fast (very short duration), maximum pressure within the stainless steel gas cylinder should be less than 1,000 psi. Some pressure loss occurs due to leakage around the gas piston. Operating damage is likely to occur because of high pressure in the gas cylinder but it is unable to use barrel pressure as an indication of gas cylinder pressure because of the constricted gas passage or gas port but gas pressure inside of the cylinder is a fact. It is impossible for powder to expand in the cylinder. Gas is bled into the cylinder, impacts the piston, (pound m seconds) and begins the process of moving the piston, operating rod, and spring compression. As volume in the cylinder increases due to piston movement pressure decreases.

The following link should augment this discussion:

https://www.garandgear.com/m1-garand-ammunition

Note that many varieties of commercial ammo exceed the 274 and 320 pound m seconds Garand limit. Lots of stuff to move, piston, operating rod, and spring compression. The link ID's high pressure in the gas cylinder as a cause of operating rod damage

Looking at some .30-06 ammo at my LGS I see two boxes labeled as suitable for "Garand", one is the American Eagle ammo with a 150 @ 2740 fps. Then upon looking at the data in my Hodgdon magazine/manual for the 150 bullet with some Garand suitable powders I see that 49 grains of IMR 4895 produces 49,400 psi and a max load of 53 grains for 56,700 psi. The U.S. Army stuff specifies a load of 50 grains if IMR 4895 for the M2 load. Pressure gradients appear to be rather steep for each grain of powder. 52 grains is just one grain less than the max recommended load of 53 grains. The type of firearm is not specified but possibly Hodgdon anticipates folks will load their Garand rifles with this data. Loading slower burning powders under 52 grains, like H4350 would produce what I think would be called a "squib" load. Many load manuals recommend H4895, and such for Garand use.

To me the 52 grain rule appears sort of arbitrary in that it is over the M2 load limit *. The link - "when possible choose ammunition that does not exceed M2 ball in both peak pressures and total impulse". Varied use in different environments could affect ammo pressure. Of interest none of the M1 Garand loads in the Hornady manual approach 52 grains. Many are constant and independent of bullet mass - like 46.4 to 46.1 from bullet weights from 150 to 178 grains, this makes me think that these loads are developed to give approximately equal port pressures independent of bullet weight but having equal powder amounts provide equal gas volumes.

For me - if M2 ammo was the standard it is good enough.

In closing I choose to use "I" messages vs. "you" messages.

An other helpful link:

https://en.wikipedia.org/wiki/Malware

This popped up when I attempted to access "masterpostemple.bravepages.com", IPA 66.219.202.10 - Malwarebytes labeled this as "Malware". The two links that are attached to this post were accepted.

Possibly I might get some help in looking at the 52 grain stuff. Various relatively low budget research operations routinely play around with stuff more involved than Newtonian physics.

edit - * my failure to understand 52 rule only ID's powder types not charges.

 

[Beau]

Malwarebytes used to be good, but sucks anymore. Microsoft has a better, free antivirus called Security Essentials.

And, as has been said multiple times in this thread, the 52gr rule is NOT permission to run max boltgun loads through an M1, it's just an indicator that the powder is suitable for the M1 at appropriate charges.

 

[scubohuntr]

I've never seen a need to use anything but 4895 in mine, although I wouldn't hesitate to use 4064 if I had it around. Also, I won't load bullets heavier than 160 grains for the Garand. I have a bunch of assorted brass, half an eight pound jug of 4895, and half an ammo can full of 147 gr pulldown bullets. I'm set for M1 loading for a while. It all comes down to physics, and not hitting that forged op rod harder or faster than it can take. It's an M1 for God's sake, there is no need to load it hot, heavy, or fast. It was designed to shoot M2 Ball ammo. Anything beyond 600 yards, even in a match accurized M1, is area fire. If I need to shoot further, I pull out the Palma rifle. If I need to hit harder, I have a .375 H&H. If I need accuracy, AR-15. But at the range, all of those only come out of the truck when I am out of .30-06. Nothing else I own is as much fun to shoot.

 

[fyrewall]

Just trying to clean my stuff up a little more.

I have both the M-S free "Security Essentials" & Malwarebytes. Are evaluations objective? Malwarebytes nailed "masterpostemple.bravepages" real quick. Experience running the higher rated Norton showed Norton not equal to Malware in regard to some issues like hijack - "server.shoofie.tv", and PUP "config.hfreeformsnow.com". In these cases Security Essentials failed to act also. M-S insists on periodically updating Windows 10. Seems like computers in every room. "Security Essential" android use?

I remember "It is said that any powder that uses ~48-52 gr. under 150 bullet is suitable for the M1". After looking at this, I finally figured this just ID's the powders, but does not specify charge weights. Looking at my Hodgdon manual I must agree. Suitability might not equate with optimum results. Noticeably missing powders are: H4350, IMR 4350, H414/W760, H380. The much used olde favorite IMR 3031 falls under with loads of 43.0 and 46.7. These are from the Hodgdon manual. H380 is an interesting powder, my olde Speer manual marked this powder with an * meaning they OKed it for gas guns. I have the impression that H380 was a surplus powder and that led to thinking that it was developed for the 7.62X51 (.308) and possibly .30-06. For years I used H380 in the .30-06 and .308 happily being ignorant of the 52 rule. I noticed the Hornady manual for M1 Garand loads, followed the 52 rule and in addition the powder charges were very similar across bullet weights of 150 to 178 grains and this makes me think gas volume is an important consideration. H380 appears to be an "orphan" powder now.

Getting into the impulse stuff. Blow by blow or shot by shot. Compulsive/impulsive to check out more.

1 Bullet passes gas port and high pressure expanding gas is jetted thru gas port into cylinder
2 Surging gas enters gas cylinder and slams into piston which is at rest, initiating Newton stuff (equal and opposite action/reaction)
3 Gas hammers fixed weight piston from a stop to some max speed, then a stop in a real short time - speeding piston - momentum ( mass * velocity).
4 Gas escaping around piston and increasing volume inside cylinder due to moving piston limit piston travel.
5 Math wizards describe events and evaluate momentum process as impulse in pound ft. micro seconds (lbf-ms)
6 Math wizard's thinking goes graphic and inside their heads a graph is drawn, the X axis being time, and the Y axis being momentum (mass * velocity)
7 As time progresses, real fast in micro seconds, the momentum rapidly increases from zippo as velocity increases then back to zippo when velocity quits.
8 The math wizards describe this event as "impulse", more Newton stuff, and produce some sort of lop sided graph, skewed kind of toward the left (asymmetrical); then, using an esoteric process of integration from the start to end time, to determine "total impulse" using the area under the graph and derive a total impulse value - pound feet - micro seconds
9 The bullet has now exited the barrel but powder gasses continue to enter the gas cylinder thru the gas port because the pressure in the barrel is greater than that of the cylinder.
10 The cycle is repeated.
11 The bullet zips forward and is intended to penetrate or impact some target. The possibility of extinguishing an enemy combatant's succession is real. General Patton praised the M1 Garand that was developed in the 1930's.

How could this be screwed up? The link, "Garandgear", that pitches a modified gas plug, gets into peak pressures and total impulse. That link is happy with impulse values of 274 to 305 pound ft. - m seconds (lbf -ms) and maximum pressures inside the gas cylinder not to exceed 1 thousand psi. A whole bunch of graphs are displayed for different brands/types of '06 ammo. Damage to the operating rod is suggested if gas tube pressure exceeds 1000 psi by some extent or if ancillary factors limiting operating rod movement occur such as distortion resulting in binding or inadequate lubrication. The link suggests using M2 ball ammo that complies with both peak pressures and total impulse. Should the impulse values be under a certain level, 192 (lbf-ms) the possibility of short cycling exists. If the impulse values get excessive, like approaching 400 damage might occur. The only variable affecting the action inside an mechanically unchanging cylinder is the ammo. This then gets into specific ammo having 52 rule powders, permissible peak pressures, and impulse values.

I used the Hornady M1 Garand data, and as mentioned powder charges across a range of bullet weights are quite similar.

Anticipating a big community of deers, I developed a load of 53 grains of IMR4320 with a Hornady 150 grain bullet, using Winchester brass and CCI large rifle powders for use in my Win M70. While sighting in with another guy who had a Rem 740, he asked to try one of my rounds. Excessively violent ejection occurred. Pressures were probably about 59.5 K psi. The Rem 740 has some similarities to the Garand. While the IMR4320 was on the 52 go list a working load probably would have been 48 grains. As far as the 52 rule, that I have yet to see - I think - "certain powders are suitable for use in the M1 Garand, these powders provide working pressures in the 48 to 52 grain range for a variety of rifles but actual allowable M1 Garand charge weights would be less".

I apologize for my misunderstanding but give me credit for not being able to read about the 52 grain rule.