Ratchet Twist ?????

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  • Last Post 28 June 2019
Brodie posted this 24 June 2019

Does anybody have any experience with Shillen's "Ratchet Riffling " or any information at all on how this four groove cut works with cast bullets?

B.E.Brickey

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Ken Campbell Iowa posted this 25 June 2019

hi ... i think the 22rf bench guys still use these a bit ... those were just coming in when i retired from that ... they shot well, but that was 15 years ago .  22 rf bullets are kinda like cast ... ( g ) ...

ken

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Brodie posted this 25 June 2019

Thanks Ken,.....I am toying with the idea of replacing the 6.5 Creedmore barrel on my Savage with a .308, and noticed that Shillen offers this rifling in a four groove configuration in a 1:13" twist.  So I thought that I would ask around before dropping about $400.00 bucks/   I guess if it worked alright with 22rf it should work well with cast center fire bullets.

B.E.Brickey

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M3 Mitch posted this 26 June 2019

I had never heard of "ratchet rifling" so looked up online, the general opinion seems to be that it is not any better or worse than any other rifling form.  My 1948 M70 in 30-06 has 4-groove rifling and has always been one of my best shooters.  So I don't think your question has a definitive answer.

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Brodie posted this 27 June 2019

Mitch,  I really was not looking for a definitive answer, unless several people said: " I tried it and it wouldn't hit the side of a  barn from the inside.".  Four groove has proven to shoot just as well and any other.  At least to me.  The reason for the post was Shillen's picture of the rifling was odd enough that I thought I would ask the opinion of the membership.  Thanks for your answer.

B.E.Brickey

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John Alexander posted this 27 June 2019

There has always been a lot of hocus pocus about types of rifling. Advantages of 5 grooves anybody? It seems that everything from 2 up has been made to work well.  I have two old Sakos and both have 12 grooves (I think -- they are hard to count) and shoot both jacketed and cast very well.  Not to mention polygon and oval bores. 

I have always been intrigued by the idea that match grade bore with a high ratio of land circumference to groove circumference (WWII 2 groove military rifles) might be an advantage for bore riding bullets and some think they are in 03a3s. 

I have also wondered why the bottom of grooves still have sharp corners for fouling to hide in instead of rounded.  I semi-understand why this might be hard in cut or button rifling. But with many, maybe most, now being done by hammer forging it should be easier than sharp corners.

John 

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Ken Campbell Iowa posted this 27 June 2019

in my 22rf benchrest days, shilen came out with 2-groove ... wow, we thought ...  we finally decided that they shot great indoors, but not as well as " standard " outdoors.  weird, eh ?   based on 2 or 3 top shooters and barrels.  terrible to think we rejected 1/2 minute barrels .

btw, my best barrel ... was a chrome moly douglas ... special match and cryoed ... regular 6 groove ... but i think it was just a lucky draw.

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Brodie posted this 27 June 2019

When I looked at the illustration of the rifling on Shilen's web page I found the shape of the lands intriguing.  It looked more like a tooth on a circular saw blade than the square topped lands I am used to looking at.  I thought that it may reduce pressure somewhat with jacketed bullets, and I wondered if it would hold as well with cast bullets as our usual rifling. 

I am thinking of re-barreling my 6.5 creedmore to 308 Win. to shoot cast in since the Savage barrel system allows for easy changing of the barrels.  Naturally, I want to put a barrel on that will shoot well, and the Shilen 1:13" barrel seemed like a good candidate, but boy did those lands look funny.  If not the 1:13 ratchet then the 1:12" regular rifled barrel.  Any way thank you all for your thoughts and opinions.

B.E.Brickey

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John Alexander posted this 27 June 2019

Brodie,

 

Why not the 6.5 creedmore as a CB rifle.  The 8" twist would stabilize a long CB and if of the right shape could have a higher BC than a lot of 30 caliber bullets giving you less wind drift.

Less recoil, less torque = easier to shoot well and less punishment/fatigue. 

Just wondering.

John

 

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Brodie posted this 28 June 2019

I have thought about it John, but that fast twist has kind of got me spooked.  I know that some (Larry Gibson) have had success with the 6.5x55 Sweede and it has an even faster twist.  Since I am taking (forcibly I might add, no tag) this Fall off from big game hunting I guess that I'll give it a go.  I have a couple of 6.5 moulds.  We'll see after my dismal failure with the 8x57 (and I am not done) It's kinda hard to take on a new fairly unknown project caliber.

B.E.Brickey

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John Alexander posted this 28 June 2019

I have had good luck in competition with the 8" twist in my Tikka in 223.  Faster twists do magnify the effects of out of balanced bullets but my TFS articles about how little, if any, even base defects or big wrinkles affect accuracy at the 1 moa level were done with 8 and 9" twist rifles so I have quit worrying about it.

Whatever you do with your project the main thing is to enjoy it. Good luck, I will be interested in how it turns out.

John

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