shilens 4 groove

[calib]

whats the deal with the 4 groove ratchet rifling from shilen. what are the benifits

[calib]

does anyone shoot one of these barrels

[rich44]

I believe and someone correct me if I'm wrong it is supposed to clean up easier and you should get a little more velocity.
I am shooting a Shilen Ratchet rifled barrel chambered in 223 with a 1 in 8" twist and it is by far the best shooting 224 barrel I have and it does cleanup very easy, cant say if its any faster I still haven't replaced my chrono. I have two Shilen 8 twist barrels the same length and chambered in 223 with the same reamer one is ratchet rifled the other is standard six groove as soon as I get a new chrono I'll be able to check the velocity.

[lwink]

I should have a 6mm ratchet rifle 8 twist in about 2 weeks, will put together a post in this forum after a few days at the range. I went through the same thing when I ordered mine a few months ago and I hear nothing but good things, but just very very few things. According to Shilen you theoretically get a bit less wind drift as the jacket is less "cut up" from traditional rifling -- don't know if this will play out in the field or not, but who knows. Also call Jim and NSS on this board and he can tell you a bit about them and get you one for a great price. If it's anything like my other shilen barrel I will be happy as can be.

[calib]

thanks that would be helpfull for some of us

[82boy]

I have been shooting one for a couple of years now. My barrel is chambered in 6x47 lapua, it is a 1 in 8 twist at 28 inches long, it is a #7 contour. The "Ratchet Twist" barrels are a canted land rifled barrel, the concept is nothing new, several manufactures have a version of this barrel. There has been many records set with this style of barrel. Shilen's design is not as radical as others, and and the rifling is not turned as far.

The myths behind this barrel are first do to its design it places a different less disruptive mark on the bullet, and do to this mark it is less affected by the wind. (It has less surface area) So far I have not been able to scientifically prove this. Other suppose benefits is that the barrel produces less heat, that it has a longer life, and is easier to clean.

On the cleaning I don't find that it is any different (easier to clean) than any other premium barrel. I would believe the heat issue I have fires multitudes of round on hot sunny days with the sun beating down on the barrel, and it seams to me that it really takes a beating to get it so hot that I can not touch it. I will say that I have done some experiments with Randy Robinet's Bullets. (BIB) He makes a 108 flat back bullet, that just has one heck of a time in 1 in 8 twist barrels, and especially in longer barrels. Randy recommends nothing faster than a 1 in 10 twist for this bullet, do to all the mega amounts of problem with 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 actuality become molten do to the heat, stress of the bullet during firring. For what ever reason my barrel is very tolerant of his bullets, (Shoots them better than anything else, all I can say is OMG) and so far I have never lost one. It could be because there is less heat generated, it could be that they is less stress on the jacket of the bullet do to the rifling design, it may be other unknown reasons.

On a chronograph, I cant say that I have seen a speed issue, my finding is I can really put the gas on and push these bluets fast without problem, but it is at a wast. The barrels doesn't like speed, and the faster you go, the bigger the groups. I stopped at 3100 fps (No pressure signs)on a 108 bullet, found that around 2800-2900 is good.

On accuracy this is truly one of the most accurate barrels I have. I believe I got a mystical "hummer" barrel. This things will shoot 5 shot groups at 100 yards in the .3 area ll day long, and at 600 I shot a few groups around 2 inches, and even out to 1k it just don't give up. I have not found a bullet this barrel will not shoot, tried 107 SMK's, 105 JLK's, 105 lapua, 115 DTAC Tubbs, 108 Berger, 95gr Starke red mist, and many more.

I don't know about life span, I have only around 400 rounds down the tube, the jury is still out on that one. I have been saying it for sometime now I am doing an article on this barrel, for this site, the problem is I just have not gotten enough data, to prove any of the claims. All I can say is I believe there is something there.

[hotbrass]

A hot barrel is a barrel problem, not a bullet problem. Hot barrels are a problem for any and all types of bullets.

When barrels heat up, they expand and may become distorted. Depending on how much intrinsic stress is being held within the barrel, they could twist or bend slightly which will throw the bullet off or deform the bullet as it makes its way down the barrel. Thus destroying accuracy.

Of course the greater the diameter of the barrel, as is generally seen in bull barrels, the less it will distort and cause flyers.

Also you cannot spin a bullet too fast within the limits of small arms ballistics. In other words, you cannot over-stabilize a bullet. If the bullet is of poor quality or has a thin jacket, and/or core that is not concentric, then you can have a bullet fly apart.

If a bullet could actually become molten in the barrel, I know a few DOD folks that would love to talk to Randy.

[82boy]

A hot barrel is a barrel problem, not a bullet problem. Hot barrels are a problem for any and all types of bullets.

When barrels heat up, they expand and may become distorted. Depending on how much intrinsic stress is being held within the barrel, they could twist or bend slightly which will throw the bullet off or deform the bullet as it makes its way down the barrel. Thus destroying accuracy.

Of course the greater the diameter of the barrel, as is generally seen in bull barrels, the less it will distort and cause flyers.

Also you cannot spin a bullet too fast within the limits of small arms ballistics. In other words, you cannot over-stabilize a bullet. If the bullet is of poor quality or has a thin jacket, and/or core that is not concentric, then you can have a bullet fly apart.

If a bullet could actually become molten in the barrel, I know a few DOD folks that would love to talk to Randy.


I think you need to talk to Randy, he is considered one of the best Ballistic Technicians in all the world. His bullets hold many world records, and has the go to bullet for many competitions shooters world wide with 30 calibers, especially 30 BR. I am sure he would like to know how he is making a poor quality bullet, with junk J4 jackets from Berger, (Same jacket as all custom bullet makers are using.) and his cores that are not concentric.
Here is his information.
http://www.bibullets.com/
Tell the Folks at DOD to give him a call as well.

[hotbrass]

Ok, shame on me. I didnt include design parameters in my little factoid.

I did not say that Randy is making bad bullets. Randy has stated that his bullets perform better at slow twist. He has found what he believes is the proper material and dimensions. If you spin them faster and they come apart, you are taking them outside their design parameters.

As for the molten bullet in the barrel....

Carry on.