Can anyone tell me the various pros/cons between these diffrent types of rifling???

1: Conventional cut rifling

2: Polygonal rifling.

3: Eliptical rifling.

And then of course there are methods of manufacture.
- button
- broaching/cutting??
- EDM
- Hammer forging

I would really appreciate a rundown. Thanks.

Wes

I find your signature line most disturbing! Is there no hope for me then?!
When it comes to rifling forms I'm assuming that we are speaking of the use of jacketed bullets. It is beneficial to minimize distortion of the bullet jacket. To this end it would seem that narrow lands and grooves of the same radius as the diameter of the barrel are best. The only drawback to this is that the jacket seldom obturates sufficiently to fill the corners of the grooves so there is always some gas leakage. The polygon form can perhaps provide a better seal but it does this by distorting the jacket to a greater extent. Since the jacket metal springs back a bit when the bullet exits the barrel, the result is a loose core and the potential for imbalance. Elliptical rifling would do the same thing only worse. The shilen "ratchet rifling" form could be described as a modified polygon and is, in reality, conventional rifling with 4 funny shaped lands.
It has been said many times by many people that the method of manufacture is meaningless and the best of all types are equal. This is probably true.
A cut rifled barrel is probably more dependent for results on the skills of the barrel maker than any other. This can of course be good or bad depending on the maker! Some of the finest barrels produced now or ever were, and are, cut rifled but so were some of the worst. In general, the best makers produce barrels that are a result of a "hands on " approach where each step is performed and controlled by the maker. the resultant product is dependent on the maker's pride in his workmanship. A good cut rifled barrel will be consistent in diameter from end to end and the reaming will have been so well done that lapping is almost unnecessary.
A top quality button rifled barrel is drilled and reamed the same as it's cut cousin but the rifling is swaged in one pass of a carbide button. This button can iron out reamer marks to a certain extent but in a good barrel these marks didn't exist in the first place. Again the drilling and reaming is probably the most important aspect of the manufacturing process. Lapping is as much a cleaning procedure as anything and is done to provide a desired surface finish rather than to correct any dimensional deficiencies.
Broaching is cutting all at once and if the blank has been well drilled and reamed and if the broach is perfect, the resulting barrel will be as well. Broaching is not used though by any of the top match grade barrel makers I'm aware of.
I look on the hammer forged barrel as the product of an engineer rather than a craftsman. I don't mean this in any derogatory sense. In hammer forging the result is determined by the quality of the steel and, apart from that, it is all up to the machine. The best hammer forged barrels are probably every bit as good as any other and may even, in some respects, be better. The surface finsh can be superb as can straightness. The barrels are remarkably stress free and consistent in dimension. The primary influence on the final resultant quality is probably the quality control employed in the final inspection.
The Winchester match barrels as well as barrels from Steyr and from Swiss Arms are excellent barrels. The internal finish in some Remington hammer forged barrels could well be described as grotesque! Some look like a corduroy road!
An important requirement for a good barrel is that it be stress free in blank form. This ensures that machining operations carried out subsequently can be done without changing the dimensions of the bore or affecting the straightness of the barrel.
I really like cut rifled barrels just because they are a great example of barrelmaking as an art. The barrel maker's abilities are showcased better than in any other type.
I must confess though, if I want a barrel that I want to be able to give me a 1/8 moa BR rifle I will always choose a button rifled barrel from Hart or Shilen.
I will, in the near future, be fitting and testing some pretty good looking barrels which are hammer forged by Swiss Arms. These barrels are much harder than those by other makers and may provide better life but we shall see. Regards, Bill.

Ive got a button rifled 30-06 that shoots anything up to 180 grns quite nicley but it wont stabelize a 200 grn bullet. I believe its a 1-10" twist. I also have a cut rifled Mauser 8X57 that handles as much as 220 grns just fine and also 200 grn bullets at nearly the same velocity as the 06. I believe it has a 1-9.5" twist. My thinking (flawed as it may be) is that the mass and impetus of the bigger bullets may not engage the button rifling in the throat area as readily as compared to the much coarser ballard type rifling in the 8mm, which doesnt give the bullet a choice. This in effect may be reducing the rate of twist on the bullet. Is there anything to this or am I off track?

I think off track would be one way of putting it. If the barrel will not stabilize 200s it is because the twist is too slow. If it a 10 twist it is not too slow. A bullet that is understabilized will, at some point in it's flight, be travelling sideways.
Harry Pope claimed he could rifle a barrel using a lap charged with coarse emery and it would, for a short time, be capable of giving good accuracy. Regards, Bill

Bill,

Thank you very much for your explanation!! I really enjoy when members like you take the time to share info on their experiences. Very interesting and informative.