• Shilen 6mmx47 Lapua Ratchet Twist Barrel Review

    Standard rifling on left, Ratchet Twist on right.Needing a new barrel for my long range Savage I decided to go with a Shilen barrel - but not the normal six groove rifled barrel, rather their “Ratchet Rifled” four-groove profiled land barrel. The Shilen “Ratchet Rifled” (or as I call it, the “Ratchet Twist”) barrel has a radical rifling design that has little publicity or little known about it.

    From a bit of research on the internet I found that Shilen is not the only company that makes profiled land barrels. In fact, I found several barrel makers that have made profile land designs throughout the years. Many individuals give credit to the design of profiled land barrels to Boots Obermeyer from his development of the Obermeyer 5R barrel. I found Broughton and Schneider also have similar barrels. Broughton calls their barrel the 5C or the “Canted Land” rifling, and Schneider calls theirs the P5 or “Polygon Form” rifling. The Broughton barrel has been reported in comparison to have more of a slant on the face of the lands, where the Shilen barrel has a more defined edge. All three companies offer similar caliber and twist choices on these barrels. One thing that stands sure with the aforementioned is that they all have a reputation for being match winning, record setting barrels.

    I contacted Wade Hall at Shilen Barrels and he excitedly told me more about this barrel. He stated that Jim Sommers is one of the quality people that is making their button dies, and Jim wanted to try a new design out. Wade gave him the go ahead, and thus the Ratchet 4 groove rifling was born. The project was tested and they found that while the barrels shot very well, they didn’t shoot any better than the standard six groove Shilen barrels. The project was almost scrapped due to the added cost of manufacturing the ratchet rifle barrel, but then they started getting feedback from customers that they handled the wind better than their standard rifled barrels. Then they thought, “Maybe we got something here.”

    The new Ratchet twist barrel took several world titles in the rimfire 22 category and a theory was developed as to why the world title fell into the hands of this new Ratchet twist barrel. The theory is that when the bullet is fired through a conventionally rifled barrel the lands and grooves leave squared edges on the bullet. As the bullet then travels down range, the square-edge marks left by the rifling gives a surface for the wind to react on. The ratchet rifled barrel leaves a different style of mark and therefore leaves less of a surface for the wind to catch.

    I received the barrel from Shilen and took it to Sharp Shooters Supply where Fred Moreo inspected the bore with a bore-scope. Fred described it as “The profile of the bore and rifling looks like a circular saw blade, as compared to standard rifling looking like a timing belt pulley.”

    I found that there were many different theories located all over the internet; with all the theories of this style of rifling it elevates this type of barrel to “Superman” status. Most of the theories make sense, but some sound outlandish, for example, I saw one claim that the barrel creates a lighter bolt lift. A question that I have is, “Why are there all of these theories to this style of rifling?” My thoughts are that this barrel style must shoot well enough to keep people talking about it. The problem with testing all the found theories is that there are too many variables, and no two identical barrels are the same as each barrel has a personality of its own. I hope that with these tests I can come up with enough evidence to suggest that the theories are either confirmed or plausible. The worst part about these tests, is to be scientific about it, it would take a much larger test section than what we have available, but hopefully I can come up with some good indisputable observations that are repeatable. Some of the myths are that the barrel is easy on break in, it is easier to clean, it creates more speed, and it is less affected by the wind.

    I started load development on a day that was 33 degrees outside with heavy constant 17 MPH winds coming from the west. The wind was blowing on my back and down range. The rounds were loaded with the bullets just touching the lands, all groups shot were three shots at 100 yards.

    The first group was a Berger 108bt bullet on top of 37 grains of IMR 4350. “Wow!” The first two shots went in the exact same hole, and the third shot just low for a .342 group size. The second group was the same combo as the first, “Wow!” Even better a one hole group that measured at .157. The third group was the same bullet on top of 37 Grains of reloader 17, this combo shot about 1 inch lower, the scope was re-zeroed, and the group was two touching with the third left and high measuring at .367. The fourth group was a repeat of the last measuring in at .357. For the fifth and sixth groups I switched to Sierra 107 grain Match Kings on top of 36 grains of H4350. The fifth group measured in at .357, and the sixth group measured in at .332.

    I think we now have a winner of the Berger IMR combo - who would have thought it would be the first combo I would try. I was impressed with the accuracy so far as a 6 group .319 aggregate is not too shabby. When I got the gun home and cleaned it, I found that the feel of the patches down the barrel was super smooth, and the barrel was very easy to clean, but not any easier than any other barrel I have owned.

    On a chronograph I cannot say that I have seen any real velocity benefits of the Ratchet Twist rifling. My finding is that while I can push these bullets faster without running into pressure issues, it’s really a waste as the barrel does not like the increased speed and the faster you go the bigger the groups get. I stopped at 3150 fps (No pressure signs) on a 108 bullet; found that around 2950 is good. I cannot say that this type of rifling created any more speed, and the velocity node I decided on is pretty typical for what the 6x47 Lapau.

    One of the myths of the Ratchet Twist rifling is that its design places a different, less disruptive mark on the bullet, and due to this less disruptive mark it is less affected by the wind (less surface area). So far I have not been able to scientifically prove this. One day that I was shooting at 600 yards, where there was switching winds at 10 to 20 MPH, That day I found that the rifle preformed similar to the other two 6x47 chambered Savage rifles that were shooting with me the same time of day. We all reported about a one MOA movement from the wind.

    I have shot Randy Robinet's (BIB) 108 flat back bullets with great success, and most 1 in 8 twist barrels have one heck of a time with these bullets. Randy recommends nothing faster than a 1 in 10 twist for this bullet. Randy has a theory of what happens with the bullet in a fast twist long barrel. He is thinking the core of the bullet actually becomes molten do to the heat and stress of the bullet during firing. For whatever reason my barrel is very tolerant of his bullets, and so far I have never lost one. It could be because there is less stress on the jacket of the bullet due to the rifling design. It may be other unknown reasons. Randy and I believe that the moly coating on the bullets also contributes this barrel being tolerate of this particular bullet.

    As far as accuracy, “This is truly one of the most accurate barrels I have ever owned!” I believe I got a mystical "hummer" barrel. This thing will shoot 5 shot groups at 100 yards in the .3 area all day long, and at 600 I shot many groups around 2 inches, and even out to 1k it just doesn’t give up. I don’t know about the barrel having a longer life span as I only have around 600 rounds down the tube, but it’s still shooting phenomenally. All I can say is this barrel shoots good enough to nab a single match score win at the 2010 IBS nationals against some of the toughest competitors around, with some of the fastest switching, high mile per hour winds I have ever seen. I would say that this barrel was a contributing factor to my success as the gun shot competitively with all the others.

    In closing, I did not see any proof to suggested that the barrel allowed the bolt to open easier, that it was less disrupted by the wind, that is was easier to clean, or that it created more speed. I can say that I believe that the barrel places less stress on bullet jackets, and the barrel started shooting great right out of the box. I am sold that this is a top notch barrel and that I will definitely be buying another one.

    Warning!” The Shilen “Ratchet Rifled” barrel cannot be gunsmithed backwards.
    Doing so will cause increased pressures resulting in a dangerous situation that could cause injury, death and/or destruction of property.

    Additional Photos:

    By: 82boy

    Shilen Rifles, Inc.
    P.O. Box 1300
    Ennis, Texas, USA 75120
    Phone - 1.972.875.5318

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