Author Topic: RCBS Trim Pro troubles (Read 448 times)

Shane in WI · « **on:** August 18, 2004, 02:47:08 AM »

I bought the full RCBS reloading kit 5 years ago and have been adding tools ever since. One thing that I have never been able to completely iron out is the trimmer station. I have trimmed cases fine, but they tend to vary as much as .004" either way. The setting doesn't seem to move, just depends on how much pressure I put onto the crank. Is this normal? Will it affect accuracy with my 30-06, 22-250, and 338 win mag? I have shot very tight groups with all my hand loads, just always kind of bothered me that I'm having trouble with this step. What is typical tolerance? I have been trimming each reload, but figure I probably wouldn't need to. If none of the cases are over the max length, should I even bother?
Thanks for your help,

KN · « **Reply #1 on:** August 18, 2004, 12:52:45 PM »

I suspect you are not fully trimming some times and that is giving you variations in length. The RCBS trimmer is very good about repeatability. You may want to try the power unit. It sure saves a lot of work. I trim in large lots so I built this trimmer using the RCBS base unit. KN

Val · « **Reply #2 on:** August 18, 2004, 04:40:20 PM »

If you are trimming to the recommended .010 under the max case length you shouldn't have a problem with your reloads, unless you are involved in bench rest competitive shooting. However I get much better repeatability with my Trim Pro without the electric motor option. Be sure that you are giving it enough force to insure the cutter has trimmed all the way to the stop. How good are your calipers? By rotating the case around in the jaws of the calipers variations may be evident if the jaws are not real good. Also try measuring after you bevel the inside and outside of the mouth opening.

Shane in WI · « **Reply #3 on:** August 19, 2004, 03:26:36 AM »

I'll check over all those things, thanks for the idea's. Calipers are good quality, but I haven't tried measuring after bevel/champhering to see if that makes a difference. I do put a drop of oil on the face of the stop and along the shaft, I wonder if that makes a difference?

skb2706 · « **Reply #4 on:** August 19, 2004, 08:35:03 AM »

Two observations with the RCBS trimmer. If you have the collet style shell holder make sure it is very tight on each case...minimizes some variations. Take the friggin crank handle off....throw in trash......replace with allen head bolt that fits the threads.....10-24 pitch I believe. Take a decent rechargable drill and a straight 5/32 allen wrench ...assemble one with the other. You are now prepared to power trim ....do not push hard as the frame will flex a few thousandths if you do.....I bolted mine to a frame I made to reduce this as well. I can usually keep the variation to less than .002".

Bullseye · « **Reply #5 on:** August 19, 2004, 05:52:18 PM »

My trimmer is the older collet style and I have added the electric motor. It will hold the length after trimming before chamfering to .001 all day long. I cannot remember how accurate it was before I put the motor on it.

50 Calshtr · « **Reply #6 on:** August 20, 2004, 05:28:51 AM »

I have my trimmer mounted next to my drillpress and run it with a flex shaft from the drillpress. Works very well, fast and I can use as little or much pressure as the situation demands.