Hart prototype 5 groove?

[Joe Salt]

butch Boots was doing Military work and you are right about the shape it's to reduce powder fouling! He got from the Russians.

Joe Salt

 

[butchlambert]

butch Boots was doing Military work and you are right about the shape it's to reduce powder fouling! He got from the Russians.

Joe Salt

Joe, I won't argue that with you and you are probably right. My post was about the shape of the land. I have a piece of a military barrel of about 80mm +or- and it is an 8 groove with the 5r rifling. I was told it was WW11 in origin. I can't verify that.

 

[JRS]

That trough shape, "R", has been around since the turn of the century. The Russians use it in their 4 groove barrels. Boots Obermeyer simply used the design after examining the Russian barrels, but went to 5 grooves. Hence the 5R (R= Russian) designation.

 

[butchlambert]

That trough shape, "R", has been around since the turn of the century. The Russians use it in their 4 groove barrels. Boots Obermeyer simply used the design after examining the Russian barrels, but went to 5 grooves. Hence the 5R (R= Russian) designation.

If you look at the profile of the land it has 5 radii. You can call it Rooshin if you choose.

 

[jamesdmock]

I have shot a 5R barrel and I thought that the design as started by Obermeyer had a "radius" at the bottom of the lands rather than being square. This is not a new concept because the Japanese did something similar 70 or more years ago. As far as an advantage, I did not notice any. With the premium barrels that we have today, we are blessed in that a vast majority clean easily and most are very accurate. Personally, I prefer 4-groove standard lands for long range and short range shooting. Good shooting.....James

 

[JRS]

If you look at the profile of the land it has 5 radii. You can call it Rooshin if you choose.

It's nothing new, Butch, and wasn't designed by Boots Obermeyer. The early Enfield's used it. There were 30 caliber 7R barrels, and 3R 22 caliber barrels made with it. Boots Obermeyer started using the 5R in the barrels he supplied for the Navy/Knights Armament SR25 program.

 

[butchlambert]

I have shot a 5R barrel and I thought that the design as started by Obermeyer had a "radius" at the bottom of the lands rather than being square. This is not a new concept because the Japanese did something similar 70 or more years ago. As far as an advantage, I did not notice any. With the premium barrels that we have today, we are blessed in that a vast majority clean easily and most are very accurate. Personally, I prefer 4-groove standard lands for long range and short range shooting. Good shooting.....James

James, I believe a good barrel is a good barrel. Lands and grooves don't make them a great barrel. The 5R barrels start with a radius from the groove to the upward leg of the land, a radius at the top of the land, a radius in the top of the land as it drops off, a radius from the top of the short side of the land, and finally from the bottom of the land to the groove. A barrel company needs to make money, so if enough customers ask for it, they will build it.

 

[butchlambert]

It's nothing new, Butch, and wasn't designed by Boots Obermeyer. The early Enfield's used it. There were 30 caliber 7R barrels, and 3R 22 caliber barrels made with it. Boots Obermeyer started using the 5R in the barrels he supplied for the Navy/Knights Armament SR25 program.

Hey feller, I don't believe I posted that any barrel maker was the designer. I don't know who the great designer was. Read my post above. I have a World War11 barrel cutoff that is a 5r shape. Now, where can we read of a 7R or 3R barrel aside from your post?

 

[JRS]

Hey feller, I don't believe I posted that any barrel maker was the designer. I don't know who the great designer was. Read my post above. I have a World War11 barrel cutoff that is a 5r shape. Now, where can we read of a 7R or 3R barrel aside from your post?

That 8 groove barrel you have would be 8R. The "R" configuration has been with us since the turn of the century. The "R" doesn't care whether it is attached to a 5 groove barrel, or a 3 groove barrel. You can read about it from a number of books sitting on my 18 shelf bookcase. The configuration has been around for a very long time. Boots Obermeyer was the first person to use it in the U.S.

 

[butchlambert]

That 8 groove barrel you have would be 8R. The "R" configuration has been with us since the turn of the century. The "R" doesn't care whether it is attached to a 5 groove barrel, or a 3 groove barrel. You can read about it from a number of books sitting on my 18 shelf bookcase.

No, it would be an 8 groove barrel with a 5r land configuration.
Give me a list of the books that relate to what you are stating.
I would like to read them if I don't already have them.

 

[Joe Salt]

This is real easy, Call Boots he is very nice man and still doing barrels a 80 years old!
Back in the 80's and 90's his barrels were hard to beat. Then he started make them for the Military, don't remember exact date.
but I have one now and its a shooter!

Joe Salt

 

[butchlambert]

This is real easy, Call Boots he is very nice man and still doing barrels a 80 years old!
Back in the 80's and 90's his barrels were hard to beat. Then he started make them for the Military, don't remember exact date.
but I have one now and its a shooter!

Joe Salt

Joe, I think Boots is on top of the barrel making. If not I wouldn't have a 308 blank in 11.25 waiting for me to decide what to do with it.

 

[msinc]

It is my understanding {as per U.S. Army instruction at Aberdeen Proving Grounds} that the radius on the drive side of the rifling was done by the Russians for use with their steel jacketed "issue" bullets. It was noted that steel jackets, dead soft annealed as they were, caused wear on the drive corner of the lands. The russ-skis, at some point decided that if it wanted to wear round why not make it that way to start with??...since the wear tended to slow way down after a certain "roundness" or radius was achieved. Somewhere along the way they also decided that hard chrome was a good thing to add to the bore as well. I can't say if all captured or imported SKS rifles have it, but all AK communist block weapons do. If the barrel of some imports don't have hard chrome then it was likely made in China for the sole purpose of bringing American dollars east.
Maybe 5R does clean easier, but none of mine ever did {none ever shot any better either}. That is probably a rumor started right here in the USA. If anyone feels like they need to request some sort of "proof" as to the origin of this info.....don't read it.
This is what I was taught and I agree with it. The idea that barrel makers to the country not only with the largest Army in the world, but also the largest supplier of arms to the third world, would worry about making rifling that "cleans" easier powder residue wise just don't seem to hold up to the steel bullet excuse. Further, the primary weapon in which this rifling is found is not exactly noted for how much it "needs" to be cleaned anyways.

 

[BoydAllen]

This is getting way too complicated. I am pretty sure that Boots said that the R stood for Russian since he first noticed the canted land design on a Russian military firearm and then started making barrels with that type of rifling. The five is a reference to the number of lands, or grooves if you prefer. I believe that he was the first barrel maker in this country to use the particular label to describe rifling that has lands with both sides canted in combination with five grooves. Since then others have brought out their own versions. IMO radii are a separate matter. To my knowledge no barrel manufacturer has used R to describe the shape of rifling that did not have canted lands.

 

[jamesdmock]

Here is an illustration of the standard rifling versus 5 R rifling. This is for the Obermeyer version. I am sure that other makers like Broughton, Bartlein or Krieger may be a little different. Obermeyer was the first US maker that I know of that offered this option. Good shooting....James
http://obermeyerbarrels.com/faq.html

 

[Tim JN]

Here is an illustration of the standard rifling versus 5 R rifling. This is for the Obermeyer version. I am sure that other makers like Broughton, Bartlein or Krieger may be a little different. Obermeyer was the first US maker that I know of that offered this option. Good shooting....James
http://obermeyerbarrels.com/faq.html

This is exactly the same as a Broughton 5C® in pulled button or Krieger Obermeyer 5R in cut rifling. The great barrel maker Boots Obermeyer started it all in Wisconsin.

Tim North
Broughton 5C® Rifle Barrels

 

[jbhotrod]

FWIW apparently Rock Creek has done some 6R and/or 7R stuff, IIRC it was actually Dan Muller while he was at RC that was doing it..?? Also, as for button vs cut rifled barrel life; High Power shooters seem to have the opposite opinion. Across the board, most all High Power competitors seem to have the consensus that cut rifled barrels last ~6000 rounds while button barrels will go for ~3000 rounds in .223/5.56, while holding match winning precision at 600yd.