Needing Experienced Gunsmith opinions on a project

[Ridge Runner]

I have a wild ass idea of converting an M1 Garand to a 8mm, 9.3, 375, 358, 45-70 caliber.

Using an adjustable op rod screw to control safe operation of the op rod, is it possible to convert the 30-06 M1 Garand into a caliber other than the standard 308 NATO or 30-06?

And maintain the standard 30-06 magazine well.

If need be, modification of the 30-06 mag well, should it be required.

Why? You ask. I just have an idea to convert a perfect weapon into a better perfectly good weapon of a larger caliber for my personal shits and giggles at the range and for hunting.

While we are at it, how about your opinions on just the opposite: of converting the M1 Garand to a smaller caliber like the 22-250, 260, 6mm, 243, 7mm-08, or other caliber(s)?.

Or maybe using the M14 as a platform with the box magazine would be better for converting?.

 

[bruce moulds]

a 280 rem garand would be well worth having.
for a bigger challenge, a 9.3x64 might be interesting.
finding charger clips for different rim diameters could prove another challenge.
bruce.

 

[USMA84DAB]

Bad Juju Tarzan - no go that way!

i cannot claim to be a Garand "expert" - however, during my younger days at USMA I was instructed by Art Alphin in History of Military Technology where we invested a great deal of time understanding the development and the fielding of the Garand. It is one thing to design a great weapon - another level of game entirely to design that weapon such that it can be mass produced with interchangeable tolerances to the tune of millions of copies during war time. Your desire to play with the DNA of a masterpiece promises only frustration and lots of money.

1st - no one makes a barrel for a Garand other than in .308 and .30-06. 8mm-06 would work except no one makes 8mm Garand barrels

2nd - While I was employed at GA Precision, I asked one fo the riflesmiths to work on an M1A (son of Garand) for me - to just bob the barrel and get rid fo the extra 4" that are not needed. No one would touch it because of the timing of the splines on the barrel that are used to mount the front sight/gas block. The tiniest of mistake and the barrel is ruined. I sold the standard length rifle and bought a scout squad version.

3rd - why ruin a piece of history? If it isn't worth the history to you/has already been bubba-ized, then just start with a better donor rifle - the complexity of the Garand/M1A is great for being the first mass produced battle rifle - designed to the specific task - now you would be inviting problems for gas port size, recoil spring strength, Oprod bend, feeding geometry, the magazine or en block not being designed for the cartridge you select. I just replaced an Oprod for a Client that had been battered by some AP ammo he found and fired. He refinished the stock and sanded too much away, so now the action slides 1/8" back and forth in the stock - which results in one round of the 8 not firing due to the slippage. There is no ordnance shop available to rebuild the gun from wear and tear/your mistakes - you get to foot the bill every time you exceed the design parameters and break something. Could one do it - probably - the cost would be insanely more than I would want to invest - I could buy ten other rifles for the bill this one will take.

The AR platform is being experimented with in the manner you describe. I recently built a .358 Win AR-10, as well as a 7mm-08. NEMO makes ARs in .300 WIN MAG. Cheaper & available barrels, parts, easier design to manipulate than the Garand.

Your proposed task is somewhat akin to moving from St. Louis to Las Vegas via a straight line through the crust of the earth. Could it be done - sure. I would rather fly over the Rockies vz. tunnel through.

No ill will here intended - just trying to illustrate the herculean can of worms you are asking to open. Hope my limited experience/insight helps you see things in a better perspective.

 

[ve7poi]

Well put

 

[Wyatt Smith]

35 Whelen would be very cool. And more American.

 

[fourfive8]

2nd run at this idea I'd pick an older, functional Garand with a semi worn out bore for the project then go for it! Probably doable with little difficulty simply converting to something based on the '06 like the 35 Whelen. But radical changes would require someone who knew what they were doing. There is nothing gentle about the cycling of the Garand, so IMO, first rule would be imperative- correct, positive head spacing between ammo and chamber. The remains of the last attempt like this I saw was on display in our LGS a few years ago... Someone tried to rechamber and convert a perfectly functional 30-06 Garand into a 308 "tanker model". The acton area of the rifle was expanded in all directions and the only thing holding it together were slivers of wood Some kind of miscalculation I'd think.

 

[Areaonereal]

Not to be offensive....
but WHY.

 

[Ridge Runner]

Not to be offensive....
but WHY.

Why?
You asked.
I have run across a few odds and ends pieces of Garand parts. And thought about building a "wildcat" of sort Garand.

I need more than just "a few" more parts to put this together. But hey let see what some of the "old hand" gunsmith think.

Use an adjustable gas cylinder lock screw valve to control gas pressure and timing.

Find a "shot out" barrel to rerifle or add a chrome bore sleeve to reduce bore size.

Preferably use and maintain the original 30-06 receiver with original "mag" configuration, thereby necking up or down 30-06 brass to 25-06, 257, 375, 9.3 or 358/-06.

If its practical and feasible: Why not?

 

[Ray B]

One of my places of service while in the USMC had M1 Garands as the duty weapon (this was in 1969). During that time I had opportunity to compare the M1 with the M14. One of the main improvements of the M14 was a change in the gas porting system. The M1 ported the gas near the muzzle and the pressure was the duration of time with the passage of the base of the bullet from the port to the muzzle. The M14 had the port closer to the breech and used a piston to regulate the gas utilized to push the piston.

So to your idea, In order to get your rifle to function properly you would need to use a load that would duplicate the amount of pressure of service ammo when the bullet is in the bore from the gas port to the muzzle. I don't know what the numbers are but the M1s that we used were very particular and loads where the pressure differed resulted in either insufficient or excess pressure on the operating rod.

 

[Wheels]

I can’t help you with your question. What I will mention is if anyone is interested in the M1 Garand or other USA military rifles and happen to be around Springfield MA, you might stop in at the armory. It is very interesting

just don’t carry a weapon when you go in

 

[8x68]

Well I found this: https://www.thefirearmblog.com/blog/2015/07/06/oood-mccann-industries-458-win-mag-garand/
Sacrilege to wreck a M1 Garand but if you got money....

 

[Ridge Runner]

Well I found this: https://www.thefirearmblog.com/blog/2015/07/06/oood-mccann-industries-458-win-mag-garand/
Sacrilege to wreck a M1 Garand but if you got money....

It's not about wrecking an M1 Garand, it's about building an M1 Garand in a different caliber, using extra parts and only buying parts to complete the project. Taking a worn "shot out" barrel, rerifling the barrel into a larger caliber or lining the barrel to a smaller caliber.

 

[Bob Nelson 35Whelen]

I have a wild ass idea of converting an M1 Garand to a 8mm, 9.3, 375, 358, 45-70 caliber.

Using an adjustable op rod screw to control safe operation of the op rod, is it possible to convert the 30-06 M1 Garand into a caliber other than the standard 308 NATO or 30-06?

And maintain the standard 30-06 magazine well.

If need be, modification of the 30-06 mag well, should it be required.

Why? You ask. I just have an idea to convert a perfect weapon into a better perfectly good weapon of a larger caliber for my personal shits and giggles at the range and for hunting.

While we are at it, how about your opinions on just the opposite: of converting the M1 Garand to a smaller caliber like the 22-250, 260, 6mm, 243, 7mm-08, or other caliber(s)?.

Or maybe using the M14 as a platform with the box magazine would be better for converting?.

@Ridge Runner.
Forget the Garand for anything that's not on the 06 case due to the enbloc mag. It would be very expensive to do any mag mods. It has been done to the 35 Whelen so I can't see the 9.3x62 not working. The 270 and 280 May develop to much pressure.
The M14 should be a good candidate to nearly all the T65 derivatives. It would be an awesome hog rifle in 338 federal or 358 Winchester and a 20 found mag.
Why not go the full deal and convert a Remington 7400 to 458 win mag. A semi auto 458 would be fun.
Bob.

 

[Bob Nelson 35Whelen]

a 280 rem garand would be well worth having.
for a bigger challenge, a 9.3x64 might be interesting.
finding charger clips for different rim diameters could prove another challenge.
bruce.

@bruce moulds
The enbloc clips would have to be custom made for other than 06 derivatives.
Bob

 

[Bob Nelson 35Whelen]

One of my places of service while in the USMC had M1 Garands as the duty weapon (this was in 1969). During that time I had opportunity to compare the M1 with the M14. One of the main improvements of the M14 was a change in the gas porting system. The M1 ported the gas near the muzzle and the pressure was the duration of time with the passage of the base of the bullet from the port to the muzzle. The M14 had the port closer to the breech and used a piston to regulate the gas utilized to push the piston.

So to your idea, In order to get your rifle to function properly you would need to use a load that would duplicate the amount of pressure of service ammo when the bullet is in the bore from the gas port to the muzzle. I don't know what the numbers are but the M1s that we used were very particular and loads where the pressure differed resulted in either insufficient or excess pressure on the operating rod.

@Ray B
The Garand runs at around 52,000 psi as you said it is very intolerant to pressure so converting to cartridges like the 270 at over 60,000 psi really upset it. The Garand has very successfully been converted to 35Whelen due to very similar pressure parameters.
Bob

 

[bruce moulds]

i believe that powder burn rates are also critical to function of the action.
bruce.

 

[Ridge Runner]

@Ridge Runner.
Forget the Garand for anything that's not on the 06 case due to the enbloc mag. It would be very expensive to do any mag mods. It has been done to the 35 Whelen so I can't see the 9.3x62 not working. The 270 and 280 May develop to much pressure.
The M14 should be a good candidate to nearly all the T65 derivatives. It would be an awesome hog rifle in 338 federal or 358 Winchester and a 20 found mag.
Why not go the full deal and convert a Remington 7400 to 458 win mag. A semi auto 458 would be fun.
Bob.

I had a worn out barrel 742 a friend wanted it so I traded.

Perhaps if I have various parts for an M14 instead of a Garand I would convert an M14.

I was looking up various calibers based off the -06 brass and saw the 338-06. Been doing a whole lot of consideration into it.

As for pressures, since I am reloading for the Garand, I replaced the stand cylinder lock screw valve with an adjustable cylinder lock screw valve and I don't reload to max loads.

As a side note: the C.O.A.L for the standard 30-06 is 3.210, military ammo that I have measures 3.318-3.320.

If I'm not mistaken there is already an OP here on AH referencing an M1 Garand or M14 being converted to 458WM and the person or company that did the conversion.

 

[Ridge Runner]

i believe that powder burn rates are also critical to function of the action.
bruce.

Correct.

From the research I have done so far too slow or too fast of burn rate will cause pressure/timing problems that can/will cause various types of internal/external damage. Another concern is over heating the barrel and gas cylinder.

Not all but some of these problems can be solved by replacing the standard cylinder lock screw valve with an adjustable cylinder lock screw valve. And refraining from reloading max loads.

 

[CoElkHunter]

Well I found this: https://www.thefirearmblog.com/blog/2015/07/06/oood-mccann-industries-458-win-mag-garand/
Sacrilege to wreck a M1 Garand but if you got money....

That’s what I’m talking about! Maybe with a binary trigger so each time you pull the trigger a round is fired, and each time you release the trigger a round is fired. Closest legal to full auto you can get. I fired a friend’s AR with that trigger. Pretty awesome! I’ll WATCH someone shoot it in the WM though. Ha! Ha!

 

[Ridge Runner]

@bruce moulds
The enbloc clips would have to be custom made for other than 06 derivatives.
Bob

I have skimmed through some of this so I can't say what calibers would or would not require custom made or just a modification to standard clips.

Since I have narrowed my options down to the 25-06, 338-06 and an 8 mm. I don't think I need to consider custom made clips at this point.