Linstrum
08-24-2008, 08:53 AM
The John C. Garand Match requires Garand rifles that are in basically as-issued during World War Two and Korea configuration. The chambers and barrels can be match cut since these fall within mil spec for sniper use. Leather or canvas slings can be used and the stocks must be wood.
More years ago than I care to think about I bought two unissued Garand receivers. They had been removed from rifles that had sat in storage in Korea for probably 40 years and had minor cosmetic damage below the wood line and I only paid $50 each for them. I already had one functioning Garand and an M1A, so these parts just sat on the back burner. When I got the receivers I had also picked up a set of barrel and receiver wrenches for the Garand as well as all the “innards” to complete one action, minus the barrel, wood, and the hardware to go on the wood.
A couple of months ago I started the process of rebuilding my one already functioning Garand and turning my piles of parts back into two more functioning Garand rifles. My functioning Garand I got working quite accurately by installing a new or maybe slightly used World War Two era barrel (I suspect it is new since we used corrosive ammo and this barrel is PRISTINE inside, no copper, carbon, rust, just pure bright shiny steel!). For my parts I purchased another pile of “innards” for the one receiver needing them, and two match grade military profile barrels and a match chamber reamer from Criterion to complete the working components. I got two new walnut stocks and some necessary additional parts via the recommendations of fellow Cast Boolits members BruceB and Garandsrus plus a few others and night before last completed the first functioning rifle from parts after probably twenty hours work. It is missing one minor piece of stock hardware that did not get sent with my stock hardware shipment.
The last step in completing the assembly of parts back into functioning machines was chambering the barrels since they are manufactured with “short-chambers”. Even with Eli Whitney, Jr's concept of interchangeable parts and Springfield Armory's impeccably tight manufacturing tolerances during World War Two, Criterion takes no chances on sending a barrel that costs more than 100 gallons of gas that is out of tolerance for a customer's particular rifle. Since I had a reamer the next step was to “do it to it” and finish cut the chamber for the rifle I had just assembled. I used a set of three chamber gauges so I could tell where I was in cutting the chamber. The first gauge is the minimum fit and corresponds to SAAMI minimum CARTRIDGE dimensions, the second gauge corresponds to the minimum CHAMBER dimensions, and the third corresponds to the maximum CHAMBER dimensions or the “hey, you just destroyed a $300 match barrel and it is now just a regular .30-06 ”. I used a 3/8” open end wrench to turn the chamber reamer, backed up with a plastic handled screwdriver for pressure to feed the reamer. I have worked as a machinist since 1958 so I have used a reamer a few times before and I trust my “feel” for how things are going. As soon as the first go gauge would barely fit but the second one wouldn't fit I stopped and chambered a sized empty cartridge, which the bolt had difficulty closing on. I re-cut a trifle more and stopped as soon as the bolt would close on the sized cartridge by tight finger push on the right side bolt locking lug. I have three sets of sizing dies for the .30-06 and the three different cartridges sized using my three dies were the same feel at closing the bolt. Kind of amazing, speaks highly for Lee Precision since that die set cost 1/3 of the others!
Once the bolt would close on a cartridge it was time to go to the range. I looked outside and it was just getting light in the east and I saw the sun rise at the range up at Dry Canyon. Two mule deer with nice racks were waiting for me, standing next to the 100-yard target backstop. I honked the truck horn to get them out of my way, I didn't want to spoil some guy's chance at them in the upcoming deer season by shooting near them and getting them forever spooked by close gunfire. I had set the sights by just lining them up with the alignment marks stamped on the gas cylinder dovetail and receiver rear and the first eight shots were all on paper! The same thing happened when I re-barreled my first Garand. I didn't bother to set the sights, that would be for another day when I wouldn't be so tired. The condition of the cartridge primers indicates high pressure since the primer indentations are all heavily cratered and the primers are totally flat with sharp edges. These are the same 147 grain fmjbt using 44.4 grain IMR4895 and 180-grain Lee 0.309 with 42 grains IMR4895 hand loads I use in “Utah”, my first Garand, that show no signs of pressure in that rifle with its original World War Two mil spec barrel. From the evidence I need to re-cut the chamber a bit more since the tight chamber limits internal powder space volume by preventing the very slight but critical initial expansion of the brass to fit inside the chamber volume when the primer and powder first ignite but the projectile hasn't started to be pushed out of the case neck yet. The same phenomenon is responsible for high pressure when the case neck is crimped very tightly and resists bullet movement that normally occurs when the primer pops. Powder charges are determined using chambers cut to SAAMI commercial specifications and what I am dealing with is the equivalent of using a cartridge case with very thick walls, another known cause of high pressure. The same principal is at work and re-cutting the chamber closer to match specs will help since I intend to use my regular .30-06 loads that have the correct pressure-time curve for the Garand.
rl400
More years ago than I care to think about I bought two unissued Garand receivers. They had been removed from rifles that had sat in storage in Korea for probably 40 years and had minor cosmetic damage below the wood line and I only paid $50 each for them. I already had one functioning Garand and an M1A, so these parts just sat on the back burner. When I got the receivers I had also picked up a set of barrel and receiver wrenches for the Garand as well as all the “innards” to complete one action, minus the barrel, wood, and the hardware to go on the wood.
A couple of months ago I started the process of rebuilding my one already functioning Garand and turning my piles of parts back into two more functioning Garand rifles. My functioning Garand I got working quite accurately by installing a new or maybe slightly used World War Two era barrel (I suspect it is new since we used corrosive ammo and this barrel is PRISTINE inside, no copper, carbon, rust, just pure bright shiny steel!). For my parts I purchased another pile of “innards” for the one receiver needing them, and two match grade military profile barrels and a match chamber reamer from Criterion to complete the working components. I got two new walnut stocks and some necessary additional parts via the recommendations of fellow Cast Boolits members BruceB and Garandsrus plus a few others and night before last completed the first functioning rifle from parts after probably twenty hours work. It is missing one minor piece of stock hardware that did not get sent with my stock hardware shipment.
The last step in completing the assembly of parts back into functioning machines was chambering the barrels since they are manufactured with “short-chambers”. Even with Eli Whitney, Jr's concept of interchangeable parts and Springfield Armory's impeccably tight manufacturing tolerances during World War Two, Criterion takes no chances on sending a barrel that costs more than 100 gallons of gas that is out of tolerance for a customer's particular rifle. Since I had a reamer the next step was to “do it to it” and finish cut the chamber for the rifle I had just assembled. I used a set of three chamber gauges so I could tell where I was in cutting the chamber. The first gauge is the minimum fit and corresponds to SAAMI minimum CARTRIDGE dimensions, the second gauge corresponds to the minimum CHAMBER dimensions, and the third corresponds to the maximum CHAMBER dimensions or the “hey, you just destroyed a $300 match barrel and it is now just a regular .30-06 ”. I used a 3/8” open end wrench to turn the chamber reamer, backed up with a plastic handled screwdriver for pressure to feed the reamer. I have worked as a machinist since 1958 so I have used a reamer a few times before and I trust my “feel” for how things are going. As soon as the first go gauge would barely fit but the second one wouldn't fit I stopped and chambered a sized empty cartridge, which the bolt had difficulty closing on. I re-cut a trifle more and stopped as soon as the bolt would close on the sized cartridge by tight finger push on the right side bolt locking lug. I have three sets of sizing dies for the .30-06 and the three different cartridges sized using my three dies were the same feel at closing the bolt. Kind of amazing, speaks highly for Lee Precision since that die set cost 1/3 of the others!
Once the bolt would close on a cartridge it was time to go to the range. I looked outside and it was just getting light in the east and I saw the sun rise at the range up at Dry Canyon. Two mule deer with nice racks were waiting for me, standing next to the 100-yard target backstop. I honked the truck horn to get them out of my way, I didn't want to spoil some guy's chance at them in the upcoming deer season by shooting near them and getting them forever spooked by close gunfire. I had set the sights by just lining them up with the alignment marks stamped on the gas cylinder dovetail and receiver rear and the first eight shots were all on paper! The same thing happened when I re-barreled my first Garand. I didn't bother to set the sights, that would be for another day when I wouldn't be so tired. The condition of the cartridge primers indicates high pressure since the primer indentations are all heavily cratered and the primers are totally flat with sharp edges. These are the same 147 grain fmjbt using 44.4 grain IMR4895 and 180-grain Lee 0.309 with 42 grains IMR4895 hand loads I use in “Utah”, my first Garand, that show no signs of pressure in that rifle with its original World War Two mil spec barrel. From the evidence I need to re-cut the chamber a bit more since the tight chamber limits internal powder space volume by preventing the very slight but critical initial expansion of the brass to fit inside the chamber volume when the primer and powder first ignite but the projectile hasn't started to be pushed out of the case neck yet. The same phenomenon is responsible for high pressure when the case neck is crimped very tightly and resists bullet movement that normally occurs when the primer pops. Powder charges are determined using chambers cut to SAAMI commercial specifications and what I am dealing with is the equivalent of using a cartridge case with very thick walls, another known cause of high pressure. The same principal is at work and re-cutting the chamber closer to match specs will help since I intend to use my regular .30-06 loads that have the correct pressure-time curve for the Garand.
rl400