Colombian 7.62mm NATO M1 Garand Conversion

This rifle sold for $2,070 at Rock Island on December 1, 2018.

After World War Two, Colombia adopted the .30-06 cartridge as standard, purchasing a thousand .30-06 FN49 rifles and 19,000 surplus American M1 Garand rifles. With the subsequent development of the 7.62mm NATO cartridge, Colombia experimented briefly with converting their existing Garand rifles to the new NATO round. In 1990 a large batch of Colombian surplus arms was purchased by Springfield Sporters, and it included 12 Garand’s converted to 7.62mm. The conversion was done by cutting about a half inch off the chamber end of the barrel and cutting a new 7.62x51mm chamber. The handguards, stocks, and operating rods were cut down by the same amount, allowing the use of the existing gas port. In addition, the stock and hand guard were drilled with a pattern of quarter inch holes, to provide visual and tactile indications that the rifle was no longer in its original caliber. Clearly this conversion was not deemed efficient enough to adopt en masse, as only this small batch of test rifles has been seen.

22 Comments

  1. There is also a Yugoslavian almost adopted M57, sort-of BM59 that used M1 Garand rechambered to 7.9x57mm, with ZB-26/30 magazine.

  2. Reason for turning 30.06 calibre rifles into 7.62 Nato does not surprise me a bit. Having recently shot rifles in both calibers is convincing enough. I would not want to soldier with the former.

    • “I would not want to soldier with the former.”
      ???
      So far I know, the story was that in 1950s 7,62×51 NATO cartridge was created which was shorter, but thanks to newer powder, roughly equivalent to older 7,62×63 cartridge.
      Fact they did not made further conversion thus did not surprise for me – after all while such conversion might be relatively cheap, advantages achieved (excluding cartridges compatibility if you use another 7,62×51 NATO chambered weapons) are small.

      • Sure you can compare bullets weight and their velocities, but subjectively speaking it was not pleasant experience. But neither was 8mm Mauser. It makes me think what punishment soldiers have gone thru, just short of being wounded or killed.

        Today’s grunts just blast happily away with their small-bores.

        • But by end of 19th century standards or so around 8 mm was small-bore (in comparison to earlier black-powder cartridges). Notice that important reason to introduce smaller cartridges was to cut mass (per one cartridge) so you can carry more of them. That is true both in end of 19th century and half of 20th century.

      • The .308Win in two or three; one was very heavy special target rifle, the other Remington 700. That target rifle was at least 7kg heavy, accuracy probably better than 1/2 MOA. For 30.06 it was Winchester 70 made in 1948. Real nice rifle. Shooting 8mm Mauser was done from custom German made hunting rifle with excellent Hensoldt scope. I do not own any of them.

        • “Remington 700(…)Winchester 70”
          Wasn’t that former heavier? What was barrel lengths for both? Muzzle devices used if any?
          Anyway, IIRC from past discussion here, during Great War, .30-06 cartridge performed poorly when used in machine gun (at bigger distance) when compared to 7,9×57 Mauser (with schweres Spitzgeschoß?), so while it might looks “powerful” at muzzle it do not have to be so great at range.

          • Those two are good representative of common hunting rifles and fit for comparison. One was in .308 the other in 30.06. You can find barrel length and mass if interested; there were no modifications on them. No muzzle devices on them either.
            With the mentioned special (.308), this is beyond bounds of common rifle – custom made from non-standard components. It would need whole page to describe it. But even with that one I felt some kick. I am very comfortable with my 7.62×39 carbine though; it a breeze to shoot and close to my sentiment.

            The 8mm strikes me with its wisible efficiency. Yes it is bit brutal for woosie like myself, but it did do the job. Russians were lucky with their own 7.62x54R, an excellent round which proved itself so many times.

          • “Russians were lucky with their own 7.62x54R”
            Just opposite, it rimmed nature means a lot of problems with box magazine, especially of greater capacity. There were attempts to replace it yet in dawn of 20th century, one which did go relatively far was 6,5 mm Fyodorov cartridge
            http://ww1.milua.org/bullets1916.htm
            for more data regarding 7,62×54 R problems inside bigger box magazine see chapter Магазин под патрон с закраиной и без — проблемы разработки here:
            https://www.kalashnikov.ru/pulemyotnaya-drama-krasnoj-armii-2/

    • Yes. The Navy method was simply to turn a steel bushing roughly 5/8″ long to fit into the front of the .30-06 chamber, silver-solder it in, then run a 7.61 x 51mm chambering reamer into it to establish correct shoulder contour and thus headspace. Just as safe and effective, and much less involved than the Columbian procedure.

      Incidentally, back in the 1950s, several U.S. importers used a similar bushing procedure on FN M1903 Grande Modele automatic pistols in 9 x 20SR mm Browning (aka “9mm Browning Long”) to convert them to 9 x 17SR mm Browning alias .380 ACP. Note that without using a weaker recoil spring, it took some fairly “stiff” loads in .380 to reliably cycle the Grande Modele action, according to Dean Grennell. “Stiff” as in “sometimes reaching +P or +P+ levels”.

      cheers

      eon

    • Yes they did. According to Bruce Canfield (American Rifleman 1/2014) they did bush the chambers as eon notes. They also put a spacer block in the magazine well, and opened up the gas port for reliable cycling. Unfortunately the bushing would occasionally be extracted along with a fired case. The solution was to rebarrel the rifles.

      Incidentally the opening up of the gas system suggests that the pressure curve was different and undergassed when using 7.62 NATO. Quite the opposite from what happened with the M16 when the army switched powders in the 5,56 ammo. This might tie in with what Denny was talking about in the difference between .30-06 and 7.62 NATO.

  3. The Italians also converted M1s to 7.62 NATO. They did theirs with new barrels and stocks one inch shorter. Op-rods were shortened. I acquired a kit of parts to convert my worn out M1. Had relieve the gas port to get it to function reliably.

    • I have one of those too. About 8 or 9 years ago the CMP was selling some beat up Winchester M1s without stocks and rear sights. I bought one and one of the Italian kits from Sarco, plus a spare rear sight assembly The barrel was in like-new condition and the stock was also very nice.

      Had the rifle rebarreled using the kit and everything refinished. It looks like a brand new gun now and works great.

  4. Some Small Arms Firing School attendees at Camp Perry in 1977 were issued Garands in 7.62 NATO because of not enough M-14s to go around.I remember that these were chamber sleeves versions.

    • All else being equal, weight of the gun heavily influences felt recoil. Also the Garand is gas operated which reduces felt recoil, energy is used to operate the mechanism.

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