HALLAUSTIN
New member
I am wondering what the number of grooves does in a rifle. I found a neat gun, but its a 2 groove... What does that even mean.
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What does the number of grooves do?
- Thread starter HALLAUSTIN
- Start date
HALLAUSTIN
New member
I worded this bad. I ment to ask how does it affect the performance?
To the average non-match shooter such as myself- absolutely no difference in performance at all. It's my understanding that the 2-groove was an effort in cost savings when the 1903's were being simplified with stamped parts and being re-born as the 1903A3. I have a 2-groove that out-performs- well actually, it out performs quite a few of my rifles. I was going to say that I have a number of 03's and 03A3's but it's plain to me that I achieve better groups consistantly with the 2-groove.
There's more contact area on the bullet, I guess it could get hot quicker, and I don't really think it would effect cleaning to a degree that us average folk would even notice. I do suspect that if we were back in the day when cupronickle projectiles were still in use- that stalactite fouling would be a bigger issue. But then again, I don't think 2-groove bbls were around when the US was still using cupronickle.
My guess is that unless yours was heavily used and abused- it ought to be a fine rifle. Is yours on a 1903 or 1903A3? Still in full military dress?
There's more contact area on the bullet, I guess it could get hot quicker, and I don't really think it would effect cleaning to a degree that us average folk would even notice. I do suspect that if we were back in the day when cupronickle projectiles were still in use- that stalactite fouling would be a bigger issue. But then again, I don't think 2-groove bbls were around when the US was still using cupronickle.
My guess is that unless yours was heavily used and abused- it ought to be a fine rifle. Is yours on a 1903 or 1903A3? Still in full military dress?
Ideally, the rifling would impart a spin to the bullet while leaving it pristine. However, that's not possible since it takes a good deal of force to impart the high spin-rates necessary for stabilization during the short trip down the barrel.
The rifling needs to engage the bullet in such a way as to prevent it from slipping or skidding--basically it has to deform the bullet so that it fits the rifling so tightly that it can't skid.
You could do that with only one rifling land, but it would have to be big in order to stand up to the force involved and that would mean more deformation on the bullet. As you go to more and more lands, they can be proportionally smaller and therefore each land doesn't have to deform the bullet as much. You can keep the same amount of rifling surface area driving the bullet to spin without having to deform the bullet as much.
Ideally you'd want a lot of very small lands for minimum bullet deformation, however as the lands get very small they can wear faster and they may also not work well with very soft bullet material because they don't bite deeply enough to prevent skidding. Marlin used a "microgroove" rifling in their rifles for awhile but ran into problems with some of their guns when people tried to shoot lead bullets and found that the bullet size had to be carefully matched to the bore to get decent accuracy with the small lands and grooves.
Somewhere in the neighborhood of 5-6 lands/grooves seems to be a common compromise.
2 lands was done on some U.S. military rifles as a wartime cost/time savings measure. If the lands are more prominent than they would be in a typical multigroove/multiland system then they will deform the bullet more and could compromise accuracy to some extent--at least theoretically. If they aren't more prominent, then they will likely wear faster than normal rifling because the amount of rifling area actually doing the work of spinning the bullet would be less than in a more typical system.
Some collectors probably want to have a sample of each kind of bore and that may be part of why the rifling type was called out in the ad. Alternatively, some shooters may not want a 2 groove bore. If I had my choice, as a shooter, I'd probably take the conventional approach over a 2 groove bore, but that's the engineer in me talking. From a completely practical perspective I doubt it would be possible to measure the difference in performance/durability without extensive testing on a number of specimens.
The rifling needs to engage the bullet in such a way as to prevent it from slipping or skidding--basically it has to deform the bullet so that it fits the rifling so tightly that it can't skid.
You could do that with only one rifling land, but it would have to be big in order to stand up to the force involved and that would mean more deformation on the bullet. As you go to more and more lands, they can be proportionally smaller and therefore each land doesn't have to deform the bullet as much. You can keep the same amount of rifling surface area driving the bullet to spin without having to deform the bullet as much.
Ideally you'd want a lot of very small lands for minimum bullet deformation, however as the lands get very small they can wear faster and they may also not work well with very soft bullet material because they don't bite deeply enough to prevent skidding. Marlin used a "microgroove" rifling in their rifles for awhile but ran into problems with some of their guns when people tried to shoot lead bullets and found that the bullet size had to be carefully matched to the bore to get decent accuracy with the small lands and grooves.
Somewhere in the neighborhood of 5-6 lands/grooves seems to be a common compromise.
2 lands was done on some U.S. military rifles as a wartime cost/time savings measure. If the lands are more prominent than they would be in a typical multigroove/multiland system then they will deform the bullet more and could compromise accuracy to some extent--at least theoretically. If they aren't more prominent, then they will likely wear faster than normal rifling because the amount of rifling area actually doing the work of spinning the bullet would be less than in a more typical system.
Some collectors probably want to have a sample of each kind of bore and that may be part of why the rifling type was called out in the ad. Alternatively, some shooters may not want a 2 groove bore. If I had my choice, as a shooter, I'd probably take the conventional approach over a 2 groove bore, but that's the engineer in me talking. From a completely practical perspective I doubt it would be possible to measure the difference in performance/durability without extensive testing on a number of specimens.
Ideal Tool
Moderator
Remember..there was a war on..anything to speed production was done. Dad worked at the old AC Spark Plug plant during the war as a Machine Repairman..they would complete the days production of Browning .50 M.G.'s...take them underground to the testing range..clamp e'm down & feed a belt in e'm. He said he remembered late at night lying in bed hearing that deep slow Thump..Thump..Thump of those big .50's being tested. One night, one got loose..bullet went thru couple cement block walls, thru a brick one & smashed into a building across the street! Nobody hurt..bet someone got wrote up on that one! He said him and his buddies had to run production with a sandwich in one hand..as they couldn't even take time for lunch..they were being pushed so hard for the war effort..then they all got real mad when they heard on the news of how the Italian workers were getting a siesta for their lunch!
Here something on the 2 groove barrel
http://longrangeshooter.com/2012/01/benchmarks-two-groove-308-barrel/
http://longrangeshooter.com/2012/01/benchmarks-two-groove-308-barrel/
Rifleman1776
New member
The number, style, depth and twist of grooves in a barrel has been a subject of expermentation and debate since the first hand gonne went bang many centuries ago. Yours is just one of many curiosities that have evolved over the centuries. If it works, enjoy.
I'm not smart enough to explain why, but the number of lands/grooves determine the bullet make up, or one bullet will be more accurate then another.
An Example: When I started shooting for the NG, we had M14s with 4 groove barrels. We were using M118, which was the military 173 grn Match Boat tail.
We started Mexican Matching the M118, meaning we pulled the 173s and replace them with 168 SMKs. We found that the 168s shot better with a 6 groove barrel.
The 6 groove barrels didn't like the SMKs, but did shoot the M118.
The Army then came out with M852 which is Match ammo loaded with 168 SMKs.
We still got both, M852 and M118. What I had to do was issue two M14s to each guy on the Rifle Team. The 4 groove Military Match barrel when we got the M118s, and a rifle with the commercial (Barrnett) 6 groove barrels for when we got the M852.
But like I said, you're gonna have to find someone a lot smarter the me to explain why.
You either have to pick the barrel that fits the bullet you want to use, or you pick the bullet to match the barrel.
An Example: When I started shooting for the NG, we had M14s with 4 groove barrels. We were using M118, which was the military 173 grn Match Boat tail.
We started Mexican Matching the M118, meaning we pulled the 173s and replace them with 168 SMKs. We found that the 168s shot better with a 6 groove barrel.
The 6 groove barrels didn't like the SMKs, but did shoot the M118.
The Army then came out with M852 which is Match ammo loaded with 168 SMKs.
We still got both, M852 and M118. What I had to do was issue two M14s to each guy on the Rifle Team. The 4 groove Military Match barrel when we got the M118s, and a rifle with the commercial (Barrnett) 6 groove barrels for when we got the M852.
But like I said, you're gonna have to find someone a lot smarter the me to explain why.
You either have to pick the barrel that fits the bullet you want to use, or you pick the bullet to match the barrel.
madcratebuilder
New member
Many different war time mil-surps rifles well have 2, 4, 5 and 6 groove barrels. It was found early on that a 2 groove would meet the same accuracy requirements the 4, 5 and 6 groove barrel achieved, with much less machine time.
I would be more concerned about overall barrel condition than the number of grooves.
Some mil-surp may have a substantially higher value because of the number of grooves the barrel has.
I would be more concerned about overall barrel condition than the number of grooves.
Some mil-surp may have a substantially higher value because of the number of grooves the barrel has.
semi_problomatic
New member
It tells you how groovy you are.
Jim Watson
New member
What kind of "neat gun" are you talking about?
Two groove barrels were standard on Remington 1903A3s from 1943 on.
A lot were used as replacements on 1903s and other .30-06s.
The British even made some for .303s.
Two groove barrels were standard on Remington 1903A3s from 1943 on.
A lot were used as replacements on 1903s and other .30-06s.
The British even made some for .303s.
HALLAUSTIN
New member
The barrel in question is a 1903 A3 repro. I think it is neat and yes, there is another thread about this exact rifle, but I didnt want to hijack the thread or steer it off course. I am starting a WWII collection. Im only 19, but it is a life goal including an 03a3, garand, m1carbine, mosin, 98k, SMLE, and an arisaka. It seems odd, but I really like older guns. Not all that into the new stuff, dont know why. I know there is better, newer stuff, subMOA out of the box, but I want the old stuff.
A two-groove barrel resulted from increasing barrel..
production during WWII, the War Dept. found that two-groove barrel met the same accuracy requirements of a standatd four-groove barrel.
The barrels involved were those specifically used on the 03A3 and model of 1917 [Enfield].
NOTE: some idiots have offered two-groove barrels for the M1 Garand.
AVOID them, as they are salvage and notsafe to shoot.
British military rifles used the five-groove and it was thought it was better to have a land opposite a groove.
Most commerical sporting barrels us the four -groove rifling, some .22 will have six.
That basically in a nutshell.
production during WWII, the War Dept. found that two-groove barrel met the same accuracy requirements of a standatd four-groove barrel.
The barrels involved were those specifically used on the 03A3 and model of 1917 [Enfield].
NOTE: some idiots have offered two-groove barrels for the M1 Garand.
AVOID them, as they are salvage and notsafe to shoot.
British military rifles used the five-groove and it was thought it was better to have a land opposite a groove.
Most commerical sporting barrels us the four -groove rifling, some .22 will have six.
That basically in a nutshell.
True- Very True. That has been my major burn so far in my collecting experience- still have the thing. Odd part is that before I found out it is unsafe- the rifle has provided better accuracy results than any other M1 I've fired. The way they do it is ruther slick- I just wish they could have found a safe way to do it.NOTE: some idiots have offered two-groove barrels for the M1 Garand.
What they did to mine was cut off the chamber area of an M1 bbl, ream it out to accept a milled down portion of a A3 bbl which had the correct sight splines and a gas hole milled. Then, it's my unnerstanding they simply silver soldered the two portions together.
When will you get a chance to shoot your 1903A3?
Ideal Tool
Moderator
Hello, Hall,Austin. Some of the early lead-bullet masters liked a 7 groove..this placed a land opposite a groove for which they thought it gave bullet better support. From the targets shot with Pope rifles, it certainly didn't hurt!
Ignition Override
New member
I've owned six Enfield #4/Mk. 1s and stiil have five.
The Longbranch had a shiny bore and seemed to have good rifling. I have no idea, but there could have been some muzzle wear (?).
The problem was that using new Prvi Partizan ammo, most of which has boat tail bullets, all impacts from 100 yards were very flat "keyholes". Most comm. 303 ammo has BT bullets, which is very ironic.
This did not happen to me with flat base bullets, therefore I traded the Longbranch for a Faz. ('42) #4 built in England. All Savage and Longbranch #4s, plus a small fraction of those built in England have two groove rifling.
This is described in the Enfield #4, #5 book by Charles Stratton.
The Longbranch had a shiny bore and seemed to have good rifling. I have no idea, but there could have been some muzzle wear (?).
The problem was that using new Prvi Partizan ammo, most of which has boat tail bullets, all impacts from 100 yards were very flat "keyholes". Most comm. 303 ammo has BT bullets, which is very ironic.
This did not happen to me with flat base bullets, therefore I traded the Longbranch for a Faz. ('42) #4 built in England. All Savage and Longbranch #4s, plus a small fraction of those built in England have two groove rifling.
This is described in the Enfield #4, #5 book by Charles Stratton.
I'm convinced the groove count has something to do with how bullets are reshaped as they enter the rifleing. Best accuracy has always happened when the bullet diameter is a few ten-thousandths larger than a barrel's groove diameter. So, every bullet fired through one is swaged down a bit in diameter as it upsets when forced into the barrel. As long as this is consistant and uniform from shot to shot, best accuracy is at hand.
My experience and observations of accuracy regarding groove count in 30 caliber barrels used by top marksmen with the best ammo follows:
The military M2 172-gr. FMJBT match bullet (originally a machine gun bullet developed in the 1920's) shot best in 4-groove arsenal barrels fitted to M14NM rifles used by the Army and Marine Corps rifle teams and in M1 rifles rebarreled to 4-groove 7.62 NATO arsenal used by USN and USAF rifle teams. When used in Winchester Model 70 post '64 match rifles with its 4-groove hammer-forged barrels, it was equally as accurate. Remington's 40X rifles in .308 Win. 6-groove barrels never shot this bullet well.
Sierra Bullets' 30 caliber match bullets from 168 through 200 grains performed best when shot from 5- or 6-groove aftermarket match barrels. They shot more accurate from the arsenal 7.62 NATO 4-groove barrels in USN and USAF M1's than the military 172-gr. FMJBT match bullet. But for some reason, the Army and USMC M14NM's arsenal 4-groove barrels didn't shoot them all that well. When aftermarket 5- or 6-groove barrels were used in M14NM's, the Sierra's shot the best. Which, in my opinion, was why those team members had two M14NM's; a "Lake City" one with a 4-groove barrel for M118 match ammo and a "Sierra" one with an aftermarket 5- or 6 -groove barrel for ammo loaded with Sierra's match bullets. These bullets were also the best ones to use in Remington's 40X 30 caliber 6-groove barrels. And bolt action match rifles typically used 5- or 6-groove aftermarket barrels for best accuracy with Sierra. One barrel maker used 3-groove rifling that also shot Sierra match bullets very accurate, but I've no data on how they performed with the military M2 match bullet.
In 1991 when Sierra's 155-gr. 30 caliber Palma bullet was introduced, top competitors soon learned it shot best from 4-groove barrels. Not surprising as other long range marksmen around the world had been using 4-groove barrels for best accuracy with the 7.62 NATO ammo's 147-gr. bullet.
My experience and observations of accuracy regarding groove count in 30 caliber barrels used by top marksmen with the best ammo follows:
The military M2 172-gr. FMJBT match bullet (originally a machine gun bullet developed in the 1920's) shot best in 4-groove arsenal barrels fitted to M14NM rifles used by the Army and Marine Corps rifle teams and in M1 rifles rebarreled to 4-groove 7.62 NATO arsenal used by USN and USAF rifle teams. When used in Winchester Model 70 post '64 match rifles with its 4-groove hammer-forged barrels, it was equally as accurate. Remington's 40X rifles in .308 Win. 6-groove barrels never shot this bullet well.
Sierra Bullets' 30 caliber match bullets from 168 through 200 grains performed best when shot from 5- or 6-groove aftermarket match barrels. They shot more accurate from the arsenal 7.62 NATO 4-groove barrels in USN and USAF M1's than the military 172-gr. FMJBT match bullet. But for some reason, the Army and USMC M14NM's arsenal 4-groove barrels didn't shoot them all that well. When aftermarket 5- or 6-groove barrels were used in M14NM's, the Sierra's shot the best. Which, in my opinion, was why those team members had two M14NM's; a "Lake City" one with a 4-groove barrel for M118 match ammo and a "Sierra" one with an aftermarket 5- or 6 -groove barrel for ammo loaded with Sierra's match bullets. These bullets were also the best ones to use in Remington's 40X 30 caliber 6-groove barrels. And bolt action match rifles typically used 5- or 6-groove aftermarket barrels for best accuracy with Sierra. One barrel maker used 3-groove rifling that also shot Sierra match bullets very accurate, but I've no data on how they performed with the military M2 match bullet.
In 1991 when Sierra's 155-gr. 30 caliber Palma bullet was introduced, top competitors soon learned it shot best from 4-groove barrels. Not surprising as other long range marksmen around the world had been using 4-groove barrels for best accuracy with the 7.62 NATO ammo's 147-gr. bullet.