HOO-RAH!! SHOUT out to Krieger and Sierra!!

[JBT47]

This is not an isolated incident of bullets blowing up in four groove barrels. Frank Green at Bartlein has been talking about this on forums for years how the 5R land geometry is easier on bullet jackets. Fast twist, heavy for caliber bullets, high velocity in a 3 or four groove barrel disrupts the jacket integrity more than a 5R or 6 groove barrel.

 

[600yards]

I have a Bartlein 5R 1-7.5” Twist 1.250” str 30” long chambered in 6.5-284 and I’m going through load development now. Using Seirra’s new 150 grain load data that’s on the daily bulletin the Retumbo max load in this barrel is running 3042 ft/sec. with a es of 35 ft/sec. .6 inch 5 shot groups at 100 yards. The accuracy load so far is Reloader 23 max load running 2930 ft/sec with a es of 18 ft/sec .4 inch 5 shot groups at 100 yards. I have used about 150 Bullets without any coming apart yet so I’m hoping the 5R rifleing will work.

 

[ShootDots]

I’m using a Bartlein 5R 1-7.5” Twist 1.250” str 30” long in 6.5-284. Going through load development now. Using Seirra’s new load data on the daily bulletin the Retumbo max load in this barrel is running 3042 ft/sec. with a es of 35 ft/sec. .6 inch 5 shot groups at 100 yards. The accuracy load so far is Reloader 23 max load running 2930 ft/sec with a es of 18 ft/sec .4 inch 5 shot groups at 100 yards. 150 Bullets fired without any blowing up yet.

You won't get ANY blow-ups with the 5R rifling.. THe reason why the 2930f.p.s. shoots so well is that that IS the accuracy node!

 

[Snuggie]

I’ve never used anything but Bartlein 5 R barrels. Never had a prob with the 80’s or now the 90 Berger’s. I think the 5R configuration stabilizes the bullet just that much more. And when you’re shooting a .223 it helps!! They’ve proven to be a large factor in me winning matches. I also use a 5R on my 6.5X47L. Btw, hi Ben!

 

[ShootDots]

I’ve never used anything but Bartlein 5 R barrels. Never had a prob with the 80’s or now the 90 Berger’s. I think the 5R configuration stabilizes the bullet just that much more. And when you’re shooting a .223 it helps!! They’ve proven to be a large factor in me winning matches. I also use a 5R on my 6.5X47L. Btw, hi Ben!

Hey Dwight! How is Palo Alto been treating you? I know the weather has kept some matches from happening! Yukk!!

 

[Snuggie]

Hey Dwight! How is Palo Alto been treating you? I know the weather has kept some matches from happening! Yukk!!

Ben, it’s either been 3 degrees or rain out since OCT !! Most have not shot since!
My trigger finger is getting numb, LOL! Hoping for March!

 

[jonbearman]

Good for you Ben and I hope your new 5r is a hummer. I have a 5r in 6br and it shoots really well.

 

[22BRGUY]

You won't get ANY blow-ups with the 5R rifling.. THe reason why the 2930f.p.s. shoots so well is that that IS the accuracy node!

Great job of problem solving for us all! Thanks Ben.
Can't help but wonder now if that "2930" node couldn't be achieved with a 260AI and Re 26??

 

[ShootDots]

Great job of problem solving for us all! Thanks Ben.
Can't help but wonder now if that "2930" node couldn't be achieved with a 260AI and Re 26??

There is only one way to find out! I tried getting the 150s going with a .260A.I. before I chambered the 6.5 x 284. I used RL-16 and 44.3grs>>>I could only muster 2820. I could have gone just a bit higher. However, it was doubtful I could have reached 2900 without pushing the limits of the brass.. BUT I never did try RL-26>>>with that it may very well be possible! Like I said, there is only one way to find out!

 

[JBT47]

There is only one way to find out! I tried getting the 150s going with a .260A.I. before I chambered the 6.5 x 284. I used RL-16 and 44.3grs>>>I could only muster 2820. I could have gone just a bit higher. However, it was doubtful I could have reached 2900 without pushing the limits of the brass.. BUT I never did try RL-26>>>with that it may very well be possible! Like I said, there is only one way to find out!

If I had a 260AI I would also try Viht N560. I have gotten great velocity with 560 in several cartridges.
I would also consider N550 but it may be a little quick for the 150’s.

 

[ShootDots]

If I had a 260AI I would also try Viht N560. I have gotten great velocity with 560 in several cartridges.

VV N560 is a GREAT powder. However, with my first 6.5 x 284 back when I first started on F-Open, I used it for the first barrel. It gave me PHENOM velocity, some of the BEST accuracy>>>but it killed my barrel in about 900-1000 rounds. The next barrel I went with a 6.5 x 284 again, however, I went with H1000. Got excellent accuracy and 1500 rounds barrel life!

 

[Mulligan]

@ShootDots
Ben, Any updates? The silence is killing me.
CW

 

[ShootDots]

@ShootDots
Ben, Any updates? The silence is killing me.
CW

I got the barrel last week. It will be chambered soon.... When it is, I will let everyone know how the 150SMKs are doing..

 

[Mulligan]

I got the barrel last week. It will be chambered soon.... When it is, I will let everyone know how the 150SMKs are doing..

Thank you!!!
CW

 

[Dusty Stevens]

I was wondering what was going to happen with the trading a chambered barrel for a blank- i guess you had to just eat the cost?

 

[Bart B.]

When Sierra introduced its 168 grain HPMK 7mm match bullets, its thinner jacket (compared to hunting bullets) was engraved enough by lands that hotter loads spun with 9 inch twists oft times flew apart. Conventional rifling weakened jackets too much. Boots Obermeyer started his 5R rifling shape for 7mm match barrels which solved this problem.

Sierra split a production lot of their 30 caliber 168 HPMK bullets shipped to the US Army International Rifle Team and the US Navy Rifle Team. Navy team rebulleted 7.62 M118 match ammo with them; several flew apart shot from Garand's 1:12 twist barrels. Army Int'l team put theirs in reduced hand loads for their 1:12 twist barreled 300 meter free rifle's 308 Win ammo. Sierra replaced the USN's bullets and offered to do same with the Army's 168's. Army said no thanks, they were the most accurate 168's they ever had.

I was shooting Norma 26 caliber 139 grain match bullets in 264 Win Mag ammo in a 600 yard match. My scorekeeper watched 2 more of them fly apart at close range after seeing one of my early record shots fly apart about 50 yards downrange.

 

[Bart B.]

Their 5R rifling was set up by Boots Obermeyer. He did their tooling and gave them permission to use the 5R label.

I think Obermeyer's 5R rifling was patterned from the Russian design.

 

[Mulligan]

@ShootDots

Anything to share yet?
CW

 

[Ned Ludd]

You won't get ANY blow-ups with the 5R rifling.. THe reason why the 2930f.p.s. shoots so well is that that IS the accuracy node!

Not true. I've have jacket failures with Berger 90 VLDs in a 5R barrel. The 5R rifling pattern may well be easier on jackets than some other types of rifling, but the rate of twist and velocity of the load itself are also factors. The faster the twist rate and the harder you push the bullet, the more likely you will experience jacket failure. I hope for your sake that the new 5R barrel does the trick, but only extensive testing will reveal whether the jacket failure issue goes away completely, or is simply "lessened". From personal experience, even one jacket failure is too many, because it will almost certainly happen in the middle of an important match. After that, it becomes difficult to ever fully trust that rifle again for competition.

 

[ShootDots]

Not true. I've have jacket failures with Berger 90 VLDs in a 5R barrel. The 5R rifling pattern may well be easier on jackets than some other types of rifling, but the rate of twist and velocity of the load itself are also factors. The faster the twist rate and the harder you push the bullet, the more likely you will experience jacket failure. I hope for your sake that the new 5R barrel does the trick, but only extensive testing will reveal whether the jacket failure issue goes away completely, or is simply "lessened". From personal experience, even one jacket failure is too many, because it will almost certainly happen in the middle of an important match. After that, it becomes difficult to ever fully trust that rifle again for competition.

What you are saying is absolutely true. I have friends that had MANY .223 90 grainers blow up. Nearly impossible to stop>>>but they were running 6.75 twists I believe. I am hoping that the slower, as in 7.5 twist will mitigate the blow-ups with the 5R.. Only time will tell..