T/C venture with 5r rifling, can some one explain??

[fox fire]

 I,ve seen the T/C rifles ( venture and the icon ) and they talk up ther 5r rifling, I read ther advertisements and it explaned it some but thought ya'll mite have some more info, just kinda wundered if 5r rifling was actually any better or not.
   ( also why not in the encore? )                                               
                                                                                 Thanx guys.

[trotterlg]

Not better but different I guess.  There are two left and two right, three right and a lot of 4's either way, 6's both ways, and only 12's right as far as I can find.  They all do the same thing which is to spin the bullet.  Probablly the more inportant measuremts are the twist rate and the area percentages of the lands and grooves.  Unless you are cutting really fine detail, the bottom line is that it just doesn't matter.  Larry

[gunnut69]

Have to agree with larry here.. Rifling types don't really seem to make much difference. The MicroGroove rifling system from Marlin seems to make sense but it's not enough to matter or the benchrest crowd would ne all over it. Left, Right spin directions some say have an effect at extreme reanges but for most they are irrelavent. The Springfield 2 groove barrels I've seen shoot BETTER with cast slugs than the 4 groove... so Marlins clain that their rifling is better because it destorts the bullet less has some holes too,.. In my opinion its the same as the argunment that a cases shape can make a cartridge perform better. I've even heard it said that the short cased magnums can produce less recoil for the same verlocity/bullet combo.. While there is some truth to the short mahs producing a tiny bit less recoil with identical loads that's not the fault of the case.. It's due to the much higher pressures these rounds are loaded to. It allows the use of faster powders and higher pressures to reach the same velocity as a longer cased mag. The slightly reduced weight of the powder charge does in reality produce tiny reductions in recoil energy.. The problem is that these rounds high pressure levels are in actions that originated with the larger cased rounds, just shortened a bit.. The higher pressures remove some of the built in safety margin. Someone is gonna get hurt with them yet..

[fox fire]

Gotcha, thanx for breakin it down for me,  I hadnt heard of it till I saw ther ad and figured that some one here could fill me in.

[roper]

Here is a clip from sniper hide on the 5r barrels "the 5R describes the type of rifling. In non-5R rifling the lands join the grooves with a relatively sharp angle. The 5R type has a small radius at the root of the lands. Supposed to have less gas leakage, less stress on the jacket material, etc and here is clip from Broughton barrels on their 5C barrels "Shooters are reporting more velocity, great accuracy, longer barrel life, reduced bolt pressure and ease in cleanability with the Broughton "5C ®" barrels".

Shilen makes a "Ratchet" twist barrel it's radius/cant one side of the lands.

Obermeyer has a trade mark on the name 5R and has lend it to other barrel manufactors.  Mike Rock used it first and set uo Rem with there 5r barrels and latest is Kreiger is now making 5r barrel.

I don't want to get into a contest with anyone but anytime you can get a better bullets seal and stop gas leadage your going to get better velocity using published loading data.  I think they also help with some of the longer bearing surface bullets VLD etc.
I used a radius barrel 1/12 twist on my 300WSM  and to me recoil felt the same as when it was a factory rifle and I used a heavier contour barrel same length.  I did get an increase in velocity over published  data.

Here is a clip from Obermeyer on cut rifling "Over the year I have noticed button barrels often have a short life when compared to cut barrels. I believe the main reason for this is that some button-rifled barrels have shallow rifling due to the mechanics of the process. Cut barrels are normally cut to full depth -- remember it is the lands that drive the bullet."

I just ordered a Kreiger 5r 1/11.25 twist for another 300WSM and I use a Bartlen 5r for one of my 30-06 and have one up the gunsmith now for a new 280AI.  I also use a Shilen Ratchet barrel for my 30x280AI and 30-06 those only come in 1/13 twist barrels.  I used one of Lawton barrel for my 270WSM.

I've got some pretty nice cut barrels that shoot pretty good without the 5r.  If you look at the result for the BR 2009 Super Shoot  the top 20 ishooter n light  use 17 cut barrels and heavy used 14 cut barrels acouple use Bartlein gain twist.

The 5r/5c barrels I'm using I like they there easy to tune a load for and it come down to how you want to spend your money.  You have to stop and think alot of custom barrel guys and more and more are going to 5r barrels, Obermeyer started Kreiger,Chanlynn,Rock Bartlein got it's start from Kreiger list goes on where those guys learned.

You look at the rifle Mel Forbes from NULA builds using Douglas barrels he get around $3k for one of his rifles.

As to the # of grooves that has been a contest or should say ongoing everyone has a theory.  Lilja makes a pretty nice 3
groove 1/11 twist 30 cal barrel and Rock is making 5r/7r barrels so might be something to odd # groove vs even.

[fox fire]

 I had no idea that barrels were this technical, I've been playin with guns since I was a kid and thought that the rifling was the same (as far as type) except the twist.

 Glad I asked, learn somthin new every day.

[gunnut69]

I'm no expert with rifling mechanics but if sealing is the goal the landless design used but some such as HK would seem to be even better... No land groove connection at all as the hexoganal bore itself is twisted to impart spin. Reminds me of the ads touting the greatness pf the various super short rounds that are just as fast as the xxx. Not better just shorter. Those calibers are mostly dieing now. The gentlemen you named (and some others) produce very high quality barrels. Whatever design they make will be the best it can be and that's likely very good indeed. Is that design better than another of the same quality? I would bet the difference is not provable. The business they are in however is very competative though and if something becomes the 'latest' in the game they weill most likely make it too..

[roper]

I'm no expert with rifling mechanics but if sealing is the goal the landless design used but some such as HK would seem to be even better... No land groove connection at all as the hexoganal bore itself is twisted to impart spin. Reminds me of the ads touting the greatness pf the various super short rounds that are just as fast as the xxx. Not better just shorter. Those calibers are mostly dieing now. The gentlemen you named (and some others) produce very high quality barrels. Whatever design they make will be the best it can be and that's likely very good indeed. Is that design better than another of the same quality? I would bet the difference is not provable. The business they are in however is very competative though and if something becomes the 'latest' in the game they weill most likely make it too..

What is the latest I guess is that companys like Bartlein,Krieger,Broughton,Rock and others is they offer a choice in riflings to someone who plans on buiy a barrel. 

Lots of shooters that purchase after make barrels like me don't always buy a 5r rifling barrels not that they cost anymore Kreiger is the only one that want $30 more for his 5r barrels.  The other 30-06 that I got new in 2008 has a Lilja 3groove button rifling.  This year besides the 30-06 with the Ratchet rifling from Shilen I had a 257Wby build using a plain old Shilen barrel and 270 with a Lilja barrel.

Comparing my Lilja barrel 30-06 to the Bartlein 5r barrel in accuracy they both shoot pretty nice they were cut from the same chamber reamer and same reamer was used on the Shilen barrel 30-06.   

When I first started shooting BR Hart/Shilen were the top barrels used in the top 40 at the super shoot only seen 3 Shilen barrel and I'm sure alot of the cut barrels uses weren't 5r riflings.  Back then the cut barrrel were mainly used for highpower shooting only cut barrel used were from Mark Chanlynn.

Who knows who is making the 5r barrels for the t/c venture?  Afew custom guys making 5r barrels here is specs on one
Barrel:
4150 Mil-B-1159F Vanadium alloy (machine gun rated)
70 Rockwell case hardened heat treated "5R" polygonal barrels are 2 times harder than Mil-Spec & hammer forged barrels
Corrosion resistant and 10 times thicker and hardness than Mil-Spec chromed lining
“5R” Polygonal right handed 1x10 twist cut button rifled barrels from Rock Creek Barrels, Inc.
BC-A5 Muzzle device
Chamber: 7.62X51 mm NATO (.308 Cal.)


Rock Creek barrels is owned by Mike Rock and he makes what's called OEM barrels same as Kreiger who makes barrels for Wby rifles.  Like I said Mike set up Rem for their 5r barrels and they use that for the m-24 sniper rifle.  Navy SEALS Knight’s SR25 Sniper Rifle  they used Obermeyers 30 cal 5r barrel and I think that enough proof as to how good the 5r barrels are when it come to arming US snipers.  Obermeyer been gear for the last few years suppling 5r barrel to the military.

gunnut69, don't mind me saying this but the 5r barrels been around long time and there not for everyone but they have a purpose.  The good thing about our system is if you don't like it don't buy it.

[gunnut69]

Amen to that!! I don't know but with the makers you list making them I have no doubt they are very good barrels indeed, but I don't believe they are a great advance.. Still God bless our abundance of choice, it's what makes us the greatest country in the world.. at ;east for the time being..

[fox fire]

 Thanx gents, gettin educated I am, realy enjoyin the tutoring, think I'll google some barrel info to get a visual on some of this.