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Sarco is advertising a group of garand parts that they say were made for Italy and can be used to convert a garand to 7.62x51. The group consists of a barrel which is 1/2 inch shorter than standard and chambered for the nato round, a shorter op rod and stock. Have any of you seen these parts? Is the conversion possible and is it likely to result in a functional rifle?
CAB
Yes, they do run OK. The Italians did a good job. However, you need pile of correct parts to make them run. Or, you could simply buy a Wilson .308 barrel and be in business. (I bought a Wilson barrel).
It's better to do as Calif-Steve says and NOT do a Conversion to .308. Having a proper .308 chambered barrel installed is cheaper and far better than any conversion work done on the rifle with one of those kits. I have a .308 Garand that I had rebarreled by Fulton Armory and I'm happy with how it shoots (and that it's got standard parts in it).
Danny
Quote:
Originally Posted by Calif-Steve
Sounds interesting, What is involved in fitting a wilson barrel?
What parts would need to be changed?
CAB
All that you really need is a properly fitted and properly chambered standard (regular size/length) M1 Barrel that is offered in many places such as from Dean's Gun Restorations (DGR) among others. The gas port may have to be enlarged to reflect what's needed for a .308 rifle, depending upon how the barrel comes, but I don't mess around with M1 Rifles as much as I do M14 types, so that part is a bit unclear to me. Someone here should have a better handle on how the gas ports typically come from the various manufacturers, but that wouldn't be an issue if you were having it installed for you. The builder should be worrying about that. It's just more for your information that I tell you this. I REALLY like the M1 in .308. I've shot more .308 out of an M1 than I ever have .30-06.
Danny
Quote:
Originally Posted by cab32
Taken from U.S. govt M1 Garand blueprints.
Gas Port for 30-06 M1 Garand - 0.0790" dia + 0.0015" - this equates to between a #46 and #47 drill bit.
Gas Port for 7.62X51 MM Army M1 Garand - 0.1050" dia + 0.0015" - this equates to between a #36 and #37 drill bit.
Gas Port for 7.62X51 MM Navy M1 Garand - 0.1065" dia + 0.0015" - this equates to a #36 drill bit.
Plagiarized from various sources.......FWIW.
Mike D
I do not doubt the above information that the 7.62/308 M1 requires a larger gas port than does the 30-06 M1 but my question is WHY? It would logically seem to me that both the 7.62 and the 30-06 develop approximately the same chamber pressure (~50K PSI) and the bore length from the chamber to the port is approximately the same (though the 7.62 case is approximately ¼ inch shorter than the 30-06). Perhaps someone can tell me why the larger port is required for the 7.62/308.
Just curious.
In theory , the smaller volume of gas produced by a smaller powder charge in a smaller case -- forced thru a same diameter ( but slightly longer ) rifled part of the bore produces lower port pressure .
In my experience the Italian Typo 2 conversions do not have and do not need the larger gas port , It is possible that the conversions have slightly greater volume in the gas cylinder when the rod/piston is at rest. The distance from case mouth to gas port may also be a factor.
Springfield Armory used to rebuild Garands in the Mid 90;s w/ standard & match grade .308 barrels. ( I had a rifle rebuilt by them, with a match grade .308 barrel, but not to match grade spec's, limited funds at the time) Of course this was the time to grab all the spare parts you could from other vendors to attempt to built that correct garand, when parts were plentiful. The Sarco --spare--parts kit come from the Italian BM59 version of the M1 Garand, that had been built to use magazines, basically a precursor to the M14. It was an economical way to upgrade the garand design.
The BM59 was built by Beretta after the M14.
Thanks for the answers
Using the measurements provided by “mdoerner, I made the following calculations:
For the 30-06- 0.0790” the area of the port is 0.0049 Sq In
For the Army 7.62-0.105”, this is 0.0087 sq in or a 76% increase in port size.
For the Navy 7.62 – 0.1065”, tnis is 0.0089 sq in or an 81% increase in port size
These seem to be quite drastic changes. Were they computed or developed empirically?