I would like some help in assessing the bore on my Garand. The rifle is a 1944 Springfield model with a 1966 VAR barrel. The bore is bright and shiny, with no pitting or corrosion evident from a visual inspection but the rifling looks somewhat worn to me. How do I measure/quantify any wear on the rifling? How do I measure the bore at the muzzle for wear there? Are there any sites with a how-to guide on doing this? Any downloadable documents over at milsurps.com?
Thanks,
Mark
The Danish VAR barrels tend to gauge and shoot well as a result of manufacturing quality and the fact that they were replacement barrels which were lightly used. All of the ones that I have gauged were near new at both throat and muzzle.
Gauges are useful and I have the Fulton MW gauge as well as the Aramor throat gauge for the M1 and the GI throat gauge for the 1903 Springfield. I have just about all of the tech manuals and maintenance/inspection criteria for the Garand, M1 carbine and '03. One common thread through all of the military manuals is that throat erosion and bore condition in terms of pitting, was WAAAY more important than muzzle erosion in assessing the servicability of a bore. In fact muzzle gauges were not used below overhaul level,but throat erosion gauges were used extensively.
For the Garand the servicability criteria on throat erosion was .305 at overhaul level, .306 for issue to troops proceeding overseas, and .310 in the hands of troops (that's a .31 cal rifle
). For the '03 acceptable throat erosion at depot overhaul was .305 while .308 was the reject level for rifles on issue to troops. Depot overhaul specs for muzzle wear on both rifles was that they were re-barreled when muzzles would show a loose fit with a .302 plug gauge. This meant that barrels were considered fully servicable and fit for re-issue with muzzles measuring .302.
There have been a couple of interesting articles on muzzle and throat erosion in recent issues of the Garand Collectors Journal. The findings of one article were that 66,000 strokes of a segmented GI cleaning rod with a deliberate attempt to contact the muzzle were required to advance muzzle wear by one increment on the gauge. An effort was made to rotate the bearing of the rod around the circumference of the muzzle so that wear was reasonably symetrical. Accuracy still beat the acceptance criteria of 5 shots in a 5 inch circle @ 100 yds. Another article illustrates the effect of firing on both throat and muzzle wear. In this case 7000 rds were fired resulting in measured erosion of 1.11 at the muzzle and 3.308 in the throat, a 1:3 ratio which makes sense because of hot gases washing out the throat. Again, accuracy was well within standards.
Most military barrels will benefit from a thorough cleaning/ fouling removal with agents such as JB Bore Paste/Butch's Bore Shine/Sweet's 7.62. The reason for this was that the military never followed a de-fouling routine beyong brushing and patching, so many barrels show a significant build up of crud. In the Lee-Enfield era all that was used was hot water, we got nothing for the FN other than oil, and at present they issue CLP which will remove at least some copper fouling. The key thing about a muzzle crown is concentricity and lack of gouges, dings and other irregularities which will cause a bullet to upset when it exits the muzzle. Often these flaws, which are common on a roughly handled military barrel, can be polished out with a "poor-boy" technique of using a round-headed brass machine bolt loaded with valve grinding compound and chucked in a variable speed drill. I've done this many times with good results.
Gauges and theory aside, the best test for a barrel is shooting from the bench with quality ammo and the rifle well set up for bedding and fit. I thought I'd offer some findings from my range log on barrels which gauged more than 2.5 at the muzzle (Fulton's definition of "poor" on their gauge). 6 Garands exhibiting this degree of wear on the gauge turned in 3 shot groups @ 100 yds of the following average size; 2.24", 1.91", 2.14", 1.99" (this one was .303 plus), 1.88", 2.25", and 1.6" (another one measuring 3,or a .303, on the gauge). A Model 03A3 Springfield with muzzle gauging 3 (another .303) showed an average of 40 3shot groups at 2.13". Just for fun I once tested a M1903 with a barrel gauging .307 at the throat and .303 plus at the muzzle and still got 3 inch groups from what was a reject barrel.
All things being equal, a new or lightly worn barrel is preferable, but folks shouldn't despair because the muzzle doesn't read well on the gauge. Get some good ammo, get the rifle properly set up, work on your bench technique, and go shoot it!
