5R Rifling Opinions and Experiences????

[jimfinn]

I am going to have a barrel made to go on a switch barrel rifle of mine. I am going to have it chambered in 7-08. This is a hunting rifle based on a Model Seven action and the barrel is going to be medium sporter,same as Lilja's #4) contour.
Does anyone have experience with 5R rifling? My understanding is that it can reduce copper fouling and also lower pressures. I just don't know anyone who has direct experience with it.
I found the following statement by doing a web search. If the 1.5 caliber bearing surface requirement is true, it sure would influence a persons decision.
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"If the lands have an angle on their sides instead of being vertical, the jacket won't be stressed as much. Obermeyer's 5R rifling has this; it was developed several years ago for the thin-jacketed Sierra 7mm match bullets. Seems those bullets had high incidents of jacket separation with conventional rifling, so Boots Obermeyer figured that if the side of the land was angled, the jacket would be less stressed at the edges of the lands. This works very well for bullets with bearing surfaces longer than 1.5 calibers,bullet diameter times 1.5). But bullets with bearing surfaces shorter than 1.5 calibers, conventional, square-sided lands seem to be the best for accuracy."
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Why ask about this for a hunting rifle? I guess I'm just curious and like to try different things
Thanks
Jim

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Last edited by jimfinn : Today at 08:02 AM.

 

[WayneShaw]

I have no direct experience with 5R rifling, but I can't imagine why any one of the top barrel makers product won't serve you extremely well. Being installed on a Model 7, any good stainless match grade barrel wil be hands down a vast improvement over the stock barrel.

Of course, trying new and different things is always fun.

 

[babyrou]

Just had a Broughton 5C canted land 4# medium sporter instaled on Sako 75 in 300 ultra mag which is somewhat similar to the 5R. Used the 1 shot clean afer every shot for the first 5 shots, 2 shots clean for the next 10, 3 shots clean for next 15. The first 4 shots copper fouled bad, started to clean up @ 5, @ at 15 shots it was barely fouling + now after barrel break in copper fouling is almost non existent. With factory barrel it took 101.5 grains of retumbo to get 3350fps with 180g bullet slight signs of pressure. With Broughton Barrel currently shooting 3375-3400fps with 97 grains of same powder absolutly no signs of pressure. I can't afford my Mcmillan stock yet so I dropped it back into the factory injection moulded stock that the recoil lug doesn't even touch + the screws bind + shot only 1 target @ 100 yards. 5 shots outside to outside of 1 hole group measures .453 with a .308 diameter bullet. EXTREMELY PLEASED, FLABERGASTED, CAN'T BELEIVE IT, WOW. I really don't have a lot of experience yet with this barrel but so far these words describe how happy I am. You really should call Broughton + talk to Tim North, like I did, before you make your decision.

 

[Spotcheck_Billy]

I've been shooting an Obermeyer 5R .308 barrel in my Terry Cross M40A1 tactical rifle since late 2001. It's been great! Copper fouling is next to nonexistant after break-in and it has held competition accuracy for more rounds than I ever expected.

Boots runs a one-man shop and his barrels are often difficult to get unless you don't mind waiting. You can also get excellent 5R barrels from Border Barrels,O K Webber is the US distributor) or from Mike Rock,Rock Creek Barrels).

HTH,
Alan

 

[frankgreen]

As far as cleaning goes. The only thing for sure is from a carbon fouling standpoint they are easier to clean. This is because the side of the lands are angled down to the groove. The patch isn't trying to get down into a 90 degree corner on conventional rifling. If you pay attention to cleaning and how you clean though I don't feel this is really a problem.
The 5R rifling can possibly help with copper fouling but I have seen 5R type barrels that have copper fouled so bad that they had accuracy problems and we're tough to clean from a copper fouling stand point. The 5R rifling doesn't guarantee you won't have a problem barrel from a copper fouling stand point. Please keep in mind that there are a lot of factors involved that can cause fouling. The style of rifling isn't a guarantee.
If memory serves me right, the R in 5R is because it's a Russian design. The R doesn't stand for Radius. Boots was the first person to do it here in the States to my knowledge. Also have to give him alot of credit also for being one of the few guys to keep single point cut rifling alive and prove it's many benefits vs. other rifling forms.
I believe it can help with jacket failure. Again there are many things that can cause jacket failure in bullets. One is velocity, another is the thin jackets on some bullets, and another is bore size. My last two kriegers I've had in 6mm Rem. chamber and 1-8 twist barrels would both blow up Berger 105gr. VLD bullets. But I could shoot 107gr. Sierra bullets in them all day long with no problems. The Sierra's are a tougher bullet/jacket than the J4 in my opinion. Like I said before though I think there we're 3 things working against each other here. Both barrels we're tight bore 6mm's,.236 bore size), thin jacket bullets and I'm pushing them close to 3200fps. When shot at long range,1000yds) about 1 in every 8-10rds. would come apart on me around 600-700yds. Like I said the 107 Sierra's I wouldn't lose any. The last barrel is still on one of my guns and is an excellent barrel but I won't shoot any Berger's thru it.
My 7mm barrel is a standard 4 groove barrel and I haven't lost any Sierra or Berger match bullets to jacket failure. But it's not a tight bore and I'm not pushing them hard veloctiy wise either.
Accuracy wise I don't see a difference between the 5R rifling and conventional rifling. Nor do the different number of grooves effect in any way barrel life, or getting more velocity.
I've got another 6mm in 1-8 twist with the 5R type rifling and am playing with it. It's only been shot in 1 match at a 1000yds. and some shooting at short range for testing my loads for accuracy and velocity. At a 1000yds. my wifes oldest son shot my Krieger barreled gun and I shot the other one on the same day. We used the same amount of windage on both guns and we're shooting the 107 Sierra's. The loads we're identical and the velocity between the two barrels was only 30fps. difference. I've got some more ammo loaded with 105 Bergers and hopefully soon before the weather gets worse I will get a chance to shoot them at a 1000 and see if I loose any to jacket failure. The 5r 6mm barrel is a tight bore 6mm,.236) also. Standard bore size is .237. Talk to you later and hope this info. helps. Tried to keep it short and I have to go. Talk to you later, Frank at Bartlein Barrels.

 

[Bobs243Ackley]

Hi Jim,

FWIW, I have a cut rifled Satern five groove with a 5C setup. This is a 6.5" twist barrel that I had chambered up in .22BR to shoot the 90gr., and 100gr., bullets that are available. This barrel was "broken in" in seven rounds. This has been one of the easiest cleaning barrels that I have ever shot! I clean with the TM Solution and it cleans up with no carbon left behind, and no traces of copper showing to the naked eye at the muzzle. The other thing that I have noticed is that I have not had any of the problems of breaking any of the 90gr. Sierra MK's that I have had people report to me using a non-canted setup. I am shooting these bullets at just about 3,000 fps, and every one of them has made it to the targets with no signs of coming apart.

Cordially,
Bob Blaine