Well, I am needing to acquire a case trimmer. I haven't made up my mind which yet. I was looking at a couple that will allow me to turn or ream case necks. I hardly know the difference, even though I get the general idea. What are the two processes? Are they really that important?

develdogs
neck reaming removes metal from the inside of the neck. The reamer follows the existing hole and removes a uniform amount of metal. But not many case necks are of uniform thickness. So you end up with the same varations in thickness as when you began, just a thinner neck.

Neck turning is done on the outside of the neck aginst a mandrel. This produces a thinner neck of uniform thickness.

Both techniques are used when converting a case to another smaller caliber, or shortening a case to convert to another cartridge. Both of these operations can produce a fairly thick neck that must be thinned.

Another use is if you have a tight necked chamber. Again you must thin the case neck.

Some reloaders neckturn cases in order to produce a more concentric case for a standard chambered rifle. This is done to gain consistancy, therefor accuracy. This last one is somewhat controversial. This is (in my opioion)due to the fact that an off the shelf factory rifle with a "factory" chamber will not likely be accurate enough to show what fine differences this technique may yeild.

Are these really important. Yes. If you chamber a cartridge with a too thick neck it can/will pinch the bullet, delaying it's release. This will cause increases in chamber pressure. Possibly catastrophically high chamber pressure.

muck

Excellent post muck

I think that most of us don't really get into neck turning or reaming, just buy quality brass and it should not make a difference in hunting load accuracy.

However, all of us need to trim occasionally, more so if you use dies with expander balls. The best method, IMHO, is to use the Lee system which will automatically set the trim length for your caliber and is quick and easy. You will need to get one of these

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=930066

in each caliber. You can use it in a drill if you get one of these

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=476992

or in a

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=515804

and get one of these

http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=136199

which in my opinion is the easier way. Attach the Zip Trim to your bench or to a piece of 2x4 and vise it. Quick and easy. I have a Lyman trimmer and wore blisters on my hands and ruined a few cases before I switched. Now is gathers dust and I haven't used it in years.

You can also use the Lee Zip Trim to clean your cases and not have to buy a tumbler.

Hope this helps.

I've used the Forster trimmer with neck turning tools for many years. For the amount of use you seem to have it should be adequate. There are more sophisticated tooling to be had but it may not be what you need. roger

I would have two tools.....a trimmer (Wilson is the best IMO) and a neck turner.....

Making one tool do both is not a good idea IMO.

Sinclaire seems to be the guys with the neck turning tools.

I actually use a lathe and a live mandrel to do this when it needs to be done.....but not everyone wants to buy a lathe to do this.

I have an RCBS rotary case trimmer with the collet holder. I will sell it for $25 including the shipping.