.308 vs .30-06, and an M1 question

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Nightcrawler

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Does modern loaded .30-06 have any performance advantage over .308? I know it can use heavier bullets (220 grainers).

I know you can't use the hot loads in an M1 Garand, right? 150 grain ball only? What about 168-ish grain stuff?

What about that vented gas nut for the Garand? Can you use heavier loads with it then? What about the 220 grain bullets?

I fired some 220 grainers through a Remington 7400. Knocked something loose on the inside, methinks.

There's a shortage of .30-06 autoloaders. There needs to be a military grade (i.e., reliable and easy to field strip/clean) .30-06 semiauto that has 5 and 10 round box magazines, that can use all loads from the lightweight varmint stuff to the 220 grain elk bullets.
 
According to Jim Thompson, heavier bullets are fine in the M1 Garand as long as you understand what you're doing. Using a vented gas cylinder lock is important, as is the proper use of heavy grease along the receiver channels/bolt lugs.

Not only will the vented gas cylinder lock prevent pressure from becoming too great, but the heavy grease will compensate for the fact that the op-rod and op spring are in the rear position for up to twice as long as with M2 ball.
 
The only thing that matters with the Garand is that the pressure at the gas port be the right amount for the op-rod system. The Force on the piston is the product of gas Pressure x piston Area, so any method or device which allows control of the pressure lets you vary your loadings. (F = P x A)

The GI round's chamber pressure is about 47,000 psi; modern commercial runs some 10% higher. There is a particular pressure curve with IMR 4895, but loads with the heavier bullets commonly use slower-burning powders; these have higher pressures at the gas port.

Art
 
"I know you can't use the hot loads in an M1 Garand, right? 150 grain ball only? What about 168-ish grain stuff?"


168's and 173 work fine. Stick with 4895 powder.
 
I have loads using Hornady 150 FMJBT and 168 BTHP Match bullets. All shoot fine out of my M1
 
Military and civilian HP match shooters have put millions of rounds down the barrels of M1's using 168 and 173 grain match bullets with no harm to the rifle.

The key is to use a propellant that keeps the gas port pressure down to within the design limits of the M1. IMR 4895 is the propellant for which the M1 gas system was tailored. but some other propellants with similar burning characteristics will work equally well.

BTW--180 grain slugs are starting to get a bit heavy for use without a modified gas system, so if you want to go that heavy, you will need to get an adjustable gas cylinder plug.
 
You mentioned elk,so....
Another option is loading the Garand with lighter weight premium bullets such as X-bullets,Nosler Partitions, or Winchester FailSafes to ensure more controlled expansion in lieu of the 180-220gr bullets normally used for elk,moose and bear.
 
There's a shortage of .30-06 autoloaders. There needs to be a military grade (i.e., reliable and easy to field strip/clean) .30-06 semiauto that has 5 and 10 round box magazines, that can use all loads from the lightweight varmint stuff to the 220 grain elk bullets.

5-10 round mags? Eh. Personally, I'd love to see an AR-10 in .30-06 that takes $3 surplus BAR 20 rounders...
 
Nightcrawler, to the first part of your questions: The '06 beats the .308 for a handloader, mostly. Back when the factories reported pressures in psi, I recall seeing .308 at 53,000 psi, but the '06--due to so many older rifles--was loaded to 47,000 psi. Handloading lets you make up the difference.

The heavier bullet deal has to do with overall length. The 180-grain bullets and heavier are longer. To maintain proper length, they gotta stick farther back into the case of a .308--and you can't load as hot without getting too high a pressure.

For 150- and 165- grain bullets in today's 18" to 22" barrels, the .308 is easily the equal of the '06, and might in some cases do better. '06 handloads in a 24" or 26" barrel will have the advantage.

Art
 
5-10 round mags? Eh. Personally, I'd love to see an AR-10 in .30-06 that takes $3 surplus BAR 20 rounders...
Click to expand...

You know you can have your M1 Garand converted to accept BAR magazines for around $250, do you not? It can also be converted to accept M14 mags for $200.
 
I'd love to have a Garand modified to take a BAR magazine. It's been a fantasy for years.
 
Til your fantasy comes true you could always pick up the next best thing.........one of those .308 Italian Garands that takes M-14 mags, the BM-59 I think it is called.
 
Clayton, of West Texas Ordanance, does the work. You can check him out, here.

http://groups.msn.com/WestTexasOrdnance

Though the work is not listed on his site, he does do the work and even quoted those prices for me. The reason he does not list the work on his site is because of his reluctence to destroy the scaracer and scaracer M1 recievers on the market.

On converting an M1 receiver to M14 mags, it can be done. It's not that hard to do, it just takes time. I would rather not make the conversion, simply because the stocks of good Garand receivers are drying up and I don't want to contribute to it, but if you want a conversion built I can do it. Price for converting a Garand is $200 for a .308, and $350 for a 30-06.
Click to expand...
 
Well, if you don't want to destroy an original Garand (an understandable attitutde), this seems like a good project for one of those newly made Springfield Armory M1s, or that IAI M1 clone, if it ever hits the market...
 
Er.....NO! The entire point of converting the M1 Garand to accept mags is to have a legal forged reciever M14 type rifle!
 
shoot 12 more rounds before reloading
Click to expand...

That really doesn't seem worth the hassle of getting an M1 converted.

Okay, so in order to really appreciate the M1 and the advantage the .30-06 cartridges has, not only am I going to have to acquire an M1, I'm going to have to start handloading, too? And be good at it?

Yikes, this is getting complicated, LOL.

So this vented gas cylinder. Who makes it, how easy is it to install, and how easy is it to adjust? Adjustable gas systems don't bother me in the least, being a fan of the FAL and all.

Oh, and I heard someone say that the USGI M1 didn't have a chrome lined barrel. Is this true?
 
You do NOT have to handload to use an M1, but it WILL help you get the most out of the rifle. Allow me to explain:

Most commercial .30/06 ammo (Federal, Remington, etc.) is loaded a bit hot for the M1, in that the pressures at the GAS PORT on the M1, when using this ammo, will be higher than is desireable. Since the gas piston on an M1 is part of the operating rod, which is VERY long, it's possible that these types of loads can bend the rod in repeated use.

To solve this, most casual shooters focus on using nothing but surplus military ammo that approximates the U.S. military M2 ball round. Unfortunately, much of the surplus ammo available is not in real good shape from years of poor storage, or was made by contractors in 3rd world countries where quality control is not up to U.S. mil standards.

The ultimate solution, of course, lies in "rolling your own." It is very easy to duplicate the U.S. military ball round with several propellants and bullets.

If you do not want to pursue this route, and want to stay with high quality commercial ammo, the adjustable gas system is the solution. This consists of a modified gas cylinder plug into which adjustable exhaust vents are installed. This can be had from several sources, including Fulton Armory, who is on the web.

The new gas cylinder plug screws in in place of the original one, and can be changed back and forth in about 15 seconds.

U.S. military barrels for the M1 never were chrome lined. It's no big deal, unless you plan on shooting lots of corrosive ammo through the barrel, and don't plan on cleaning it often, as the chrome makes the barrel more resistant to corrosion.

Since modern ammo is non-corrosive, chrome lining is not necessary. By the way, a chrome lined barrel is NOT as accurate as one that is not chrome lined, all other factors being equal.
 
Yeah, I know, but I thought chrome lining was considered a "must" for military arms. The M14 had a chrome lined barrel, didn't it? I know the M16 does.

I found out that my FAL (with Austrian barrel) has a chrome lined chamber, but no chrome lined bore. Hmm.

How hard is it to adjust the gas cylinder for a given load? How do you figure out what setting to set it to?
 
The adjustable gas system for an M1 consists of a special gas cylinder plug and a bunch of smaller interchangable exhaust ports that screw into a hole in the gas cylinder plug itself.

The gas exhaust ports are a small screw-in plug with a calibrated hole in it to let gas out. Adjusting them is a matter of screwing in these ports with sucessively smaller exhaust holes until the system reliably locks open on single shot, much akin to the way you adjust a FAL gas system.

The FAL is easier to adjust, in that you don't have to remove and install any parts, but it's only one small gas jet, and that is replaceable without any disassembly of the rifle, so it's pretty easy to do it at the range.
 
Oh, I see. That's cool. I was wondering if it wasn't going to be like terribly overcomplex, or something.

Now all I have to do is get myself a Garand. I don't want a CMP rifle, though. I want a new one (on original receiver, though). I don't think I can afford one anytime soon, though. :(

Still, I dream of an Orion 7 Select Grade...
 
Night...

Yeah, I know, but I thought chrome lining was considered a "must" for military arms.
Click to expand...
Is this because, even with non-corrosive ammo, the barrel will last longer in a weapon with full-auto or burst capability if it's chrome-lined? If that's important, it becomes "not an issue" for most of us.
 
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