Star guage?

sourdough1938 · March 6, 2015, 09:37 PM

I believe it was the springfield that had star gauge barrels. If I remember the barrels were stamped with a star on the muzzle if they passed inspection with perfect barrel or near perfect. Can anyone correct me if I am wrong or add more info about them? Were they used on match rifles or sniper rifles? Were any of them used in Combat? Thank you in advance for any info.
Sourdough1938

Jim Watson · March 6, 2015, 11:50 PM

Springfield 1903 National Match and Sporter barrels were star gauged. I don't know if any service models were star gauged. Maybe as a spot check.
The muzzle was stamped with the star (actually a little circle with rays representing the gauge points) and the rifle shipped with a yellow card showing bore and groove diameters at every inch down its length.
I guess there is a statistical chance that a NM could have seen combat in WWII.

CAUTION: Gun show entrepreneurs have made star stamps and printed gauge cards. You, too can have a star gauge Springfield except it never was actually gauged.

James K · March 7, 2015, 06:59 PM

And they were only on M1903 Springfields and (very late) on Krags. Not on M1903A3's or M1917 Enfields or M1 rifles.

To backtrack a bit. A star gauge is an instrument for measuring inside diameter of a tube/barrel. It is essentially a long hollow rod with two pads on one end that are forced outward by a pointed internal rod with a caliper handle (like a micrometer) on the other end. The pads are narrow enough that they can measure either lands or grooves

In use, the gauge is inserted into the muzzle end of the barrel and readings taken every inch. The readings must be within the specifications for those barrels or the barrel is rejected.

In the slow days of peace, apparently every barrel was gauged before being installed. If one proved especially correct and even all the way through, it was stamped with a number on top, a star-gauge mark was made on the muzzle at the 6 o'clock position, and a star-gauge card filled out with the measurements. It was then set aside for use with match rifles.

In wartime, no one had time for such nonsense, and it was eliminated altogether in WWII, not only because it was time consuming but because air gauges were developed for routine inspection. Also, production methods had improved so much that almost all barrels were as good as the best from the star-gauge era.

Jim

Bart B. · March 8, 2015, 11:48 AM

Springfield Armory made the first National Match Garand in the early 1950's; they weren't available during WWII.

http://www.thegca.org/m1-national-match-summary

The remark in the above link mentioning that the NM Garand would hold its own against other service rifles is a bit misleading. Nothing equaled the accuracy of the 7.62 NATO Garands rebuilt by the USN Match Conditioning Unit in San Diego made in the mid 1960's. Barrels for them were selected from regular broach rifled arsenal barrels air gauged to verify uniform groove diameters about .3078" +/- .0001". Military rifle team shop rebuilding the .30-06 ones could get them to shoot about 2 MOA at 1000 with good commercial match ammo or handloads. Those M1's in 7.62 NATO from the USN shop with the same type of ammo would shoot almost 1 MOA at 1000. The Army and Marine Corps M14NM, reworked, would shoot as well.

James K · March 8, 2015, 04:24 PM

A couple of additional notes on star gauges. The gauges themselves were made at Frankford Arsenal. The device was not used in Europe, where plug gauges were pushed through the barrel to do the same thing. Later air gauges took the place of both.

Air gauges work differently. A plug is inserted in one end of the barrel and forced through by air pressure; the pressure at the other end is monitored and an increase indicates a loose spot in the barrel while a drop indicates at tight spot. While it might seem less precise than a "real" gauge, in fact it is more precise. The old star gauge depended a lot on the skill of the user and there have been suspicions raised that inspectors marking a star gauge card were more accurate with their pencils than the barrels would be.

Jim

Bart B. · March 8, 2015, 05:27 PM

Star gauges, or deep hole micrometers, can reveal an out of round bore. Air gauges cannot do that.

James K · March 8, 2015, 05:41 PM

They can reveal a problem but not exactly what it is, as a deep hole micrometer can. But a round plug in an oval barrel will allow more air to escape than it should, showing a problem at that spot. Out of round bores are not real common, though, unless I happened to sit on the barrel.

Jim

sourdough1938 · March 9, 2015, 05:33 PM

I want to thank all of you for taking time to answer my questions, which you all have more than done. I am astonished and overwhelmed with the knowledge of the people that frequent this forum!
Sourdough1938

James K · March 9, 2015, 10:55 PM

With your kind permission, a couple more small notes. AFAIK, the "between wars" preparation by the U.S. Army for sniping was simple - there was none. I can recall no mention of sniping in the decision to adopt the M1 rifle (a very poor rifle for that task) or of any plans to expand or improve the sniping capabilities of the M1903. The sole step forward on any sights was the use of the peep sight on the M1, at last superseding the absolutely awful M1905 sight on the M1903 rifle.

Since star-gauge markings were put only on barrels to be used for match rifles or sporters, I don't think many were used in combat. There are, though, reports that at least some soldiers and Marines took personally owned M1903 match rifles to war, so it is possible that some "star gauged" rifles were unlucky stars for a few enemy troops.

Jim

highpower3006 · March 15, 2015, 10:13 AM

According to Brophy, different operators can get different readings on the same barrel. He mentions that he and a friend tried checking several star gauged barrels and couldn't get the same readings that were on the card.

National Match rifles that were used at a match but weren't purchased by a competitor, were returned to Springfield Armory and reconditioned then put into regular service, so it is possible that a "regular" service rifle could have a star gauged barrel.

March 6, 2015, 09:37 PM	#1
sourdough1938 Member Join Date: October 2, 2014 Location: lampasas.tx Posts: 25	Star guage? I believe it was the springfield that had star gauge barrels. If I remember the barrels were stamped with a star on the muzzle if they passed inspection with perfect barrel or near perfect. Can anyone correct me if I am wrong or add more info about them? Were they used on match rifles or sniper rifles? Were any of them used in Combat? Thank you in advance for any info. Sourdough1938

March 8, 2015, 11:48 AM	#4
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Springfield Armory made the first National Match Garand in the early 1950's; they weren't available during WWII. http://www.thegca.org/m1-national-match-summary The remark in the above link mentioning that the NM Garand would hold its own against other service rifles is a bit misleading. Nothing equaled the accuracy of the 7.62 NATO Garands rebuilt by the USN Match Conditioning Unit in San Diego made in the mid 1960's. Barrels for them were selected from regular broach rifled arsenal barrels air gauged to verify uniform groove diameters about .3078" +/- .0001". Military rifle team shop rebuilding the .30-06 ones could get them to shoot about 2 MOA at 1000 with good commercial match ammo or handloads. Those M1's in 7.62 NATO from the USN shop with the same type of ammo would shoot almost 1 MOA at 1000. The Army and Marine Corps M14NM, reworked, would shoot as well. Last edited by Bart B.; March 8, 2015 at 12:00 PM.

March 6, 2015, 11:50 PM	#2
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,537	Springfield 1903 National Match and Sporter barrels were star gauged. I don't know if any service models were star gauged. Maybe as a spot check. The muzzle was stamped with the star (actually a little circle with rays representing the gauge points) and the rifle shipped with a yellow card showing bore and groove diameters at every inch down its length. I guess there is a statistical chance that a NM could have seen combat in WWII. CAUTION: Gun show entrepreneurs have made star stamps and printed gauge cards. You, too can have a star gauge Springfield except it never was actually gauged.

March 7, 2015, 06:59 PM	#3
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	And they were only on M1903 Springfields and (very late) on Krags. Not on M1903A3's or M1917 Enfields or M1 rifles. To backtrack a bit. A star gauge is an instrument for measuring inside diameter of a tube/barrel. It is essentially a long hollow rod with two pads on one end that are forced outward by a pointed internal rod with a caliper handle (like a micrometer) on the other end. The pads are narrow enough that they can measure either lands or grooves In use, the gauge is inserted into the muzzle end of the barrel and readings taken every inch. The readings must be within the specifications for those barrels or the barrel is rejected. In the slow days of peace, apparently every barrel was gauged before being installed. If one proved especially correct and even all the way through, it was stamped with a number on top, a star-gauge mark was made on the muzzle at the 6 o'clock position, and a star-gauge card filled out with the measurements. It was then set aside for use with match rifles. In wartime, no one had time for such nonsense, and it was eliminated altogether in WWII, not only because it was time consuming but because air gauges were developed for routine inspection. Also, production methods had improved so much that almost all barrels were as good as the best from the star-gauge era. Jim

March 8, 2015, 04:24 PM	#5
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	A couple of additional notes on star gauges. The gauges themselves were made at Frankford Arsenal. The device was not used in Europe, where plug gauges were pushed through the barrel to do the same thing. Later air gauges took the place of both. Air gauges work differently. A plug is inserted in one end of the barrel and forced through by air pressure; the pressure at the other end is monitored and an increase indicates a loose spot in the barrel while a drop indicates at tight spot. While it might seem less precise than a "real" gauge, in fact it is more precise. The old star gauge depended a lot on the skill of the user and there have been suspicions raised that inspectors marking a star gauge card were more accurate with their pencils than the barrels would be. Jim

March 8, 2015, 05:27 PM	#6
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Star gauges, or deep hole micrometers, can reveal an out of round bore. Air gauges cannot do that.

March 8, 2015, 05:41 PM	#7
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	They can reveal a problem but not exactly what it is, as a deep hole micrometer can. But a round plug in an oval barrel will allow more air to escape than it should, showing a problem at that spot. Out of round bores are not real common, though, unless I happened to sit on the barrel. Jim

March 9, 2015, 05:33 PM	#8
sourdough1938 Member Join Date: October 2, 2014 Location: lampasas.tx Posts: 25	I want to thank all of you for taking time to answer my questions, which you all have more than done. I am astonished and overwhelmed with the knowledge of the people that frequent this forum! Sourdough1938

March 9, 2015, 10:55 PM	#9
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	With your kind permission, a couple more small notes. AFAIK, the "between wars" preparation by the U.S. Army for sniping was simple - there was none. I can recall no mention of sniping in the decision to adopt the M1 rifle (a very poor rifle for that task) or of any plans to expand or improve the sniping capabilities of the M1903. The sole step forward on any sights was the use of the peep sight on the M1, at last superseding the absolutely awful M1905 sight on the M1903 rifle. Since star-gauge markings were put only on barrels to be used for match rifles or sporters, I don't think many were used in combat. There are, though, reports that at least some soldiers and Marines took personally owned M1903 match rifles to war, so it is possible that some "star gauged" rifles were unlucky stars for a few enemy troops. Jim

March 15, 2015, 10:13 AM	#10
highpower3006 Senior Member Join Date: July 30, 2011 Location: Savannah TN Posts: 1,220	According to Brophy, different operators can get different readings on the same barrel. He mentions that he and a friend tried checking several star gauged barrels and couldn't get the same readings that were on the card. National Match rifles that were used at a match but weren't purchased by a competitor, were returned to Springfield Armory and reconditioned then put into regular service, so it is possible that a "regular" service rifle could have a star gauged barrel.