Spiral cut reamers

[LVLAaron]

I've got a spiral cut rougher from JGS for 308 family cases. It is really a joy to use (especially with the barrel flush) -The chips all break (straight reamer with a flush you can get long chips that don't break and wont "flush" even with a lot of pressure)... It just makes me smile when I use it because it cuts so clean and fast.


Has anyone used spiral cut finish reamer? Is there any disadvantage that I'm not thinking of? They are 3 flute... would that create a "5R 4 flute" chatter type problem?

 

[ggshoots]

I'm glad you brought this up as I was just looking at a couple of reamers and saw the spiral flute option. All of mine are straight as well so I cant voice an opinion.

 

[Walt Krafft]

I use a lot of the piloted core drills from JGS to rough chambers. I have 1 spiral flute finishing reamer from Clymer. It is a 6 flute. Cuts fine. I don't think it adds enough to pay extra for it. I would pay extra to go carbide first.

 

[LVLAaron]

I use a lot of the piloted core drills from JGS to rough chambers. I have 1 spiral flute finishing reamer from Clymer. It is a 6 flute. Cuts fine. I don't think it adds enough to pay extra for it. I would pay extra to go carbide first.

Not concerned about the cost.

 

[TaperPin]

I’m a fan of how easily the faces of a straight reamer can be lightly hand stoned to keep edges as sharp as possible. With a larger budget, the ability to have spiral reamers sent off for touch ups would be nice.

I wouldn’t hand stone the top of a spiral reamer for any reason - it’s just too hard to keep a consistent angle. However, I wouldn’t hesitate to take a few tenths off the diameter of a straight reamer if it needed it. In a perfect world reamers would be the ideal shape and dimension, but in my limited exposure to chamber reamers it seems there is a wide range somewhere between no schitts given and pretty good.

 

[X Count]

Only used one on a new barrel. A spiral flute carbide reamer and it cut real nice in that one setup. Not enough data to be definitive.

 

[WayneShaw]

I have one piloted spiral throating reamer. For some reason, it does not like RPMs. I have to keep it below 100. Cuts OK though.

 

[55fairlane]

As a die maker, when I gave a "critical "hole, I use a spiral (machine) reamer. The spiral design, gives you more flute in contact with the bore, helping to eliminate chatter, keep the holes concentric & produce a better finish

 

[59FLH]

As stated above in general spiral reamers offer advantages that straight flute reamers do not. Their biggest advantage is in an interrupted cut.

 

[jackieschmidt]

We use a lot of shell reamers in the 2” to” 3” diameter for steering pin bushing holes. They are not an actual spiral, but angle fluted.
They tend to avoid chatter better than straight fluted reamers.

 

[LVLAaron]

These are for sure spiral.

 

[GenePoole]

Actually, helical.

 

[LVLAaron]

For the curious reader... Those 3 flute helical reamers are a little tough to get started without a huge chattery mess. I found pre-boring a half inch or so and then cutting a 15 degree chamfer maybe 150 thou for the reamer to meet up with solves it.