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Educate me on trimming brass

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13 September 2007, 10:08
Blackhawk83
Educate me on trimming brass
What insights can you guys provide to me to help me ensure that I get my brass trimmed to same length on multiple cases. I am using hand powered RCBS trimmer.
13 September 2007, 11:18
JAL
Why wouldn't you get them all the same? Mind you, I have got many different lengths, but I'm not normal.

IE If you lock your trimmer up it should stay cutting the same length. (Mine moved because it wasn't tight enough.)

If you change calibres like I do it's a problem to get exactly the same setting even using measurements or a master case (for length.)

Then you can use trial and error and minor adjustments on some cases until it's right.

But then I don't worry too much about a couple of thou. as I'm not into bench rest.

So, why do you need them exact?
13 September 2007, 11:48
GSP7
Sneak up on the trim length of your first one(take brass out and measure it), adjust the trimer, then tighten the hex head screws and you are set. Have at the rest of em!

Get rid of that hand crank knob on that RCBS and hook a cordless drill to that sucker! clap
13 September 2007, 14:15
Wink
Do you have one of the Lyman case length guides? The one that is basically a metal card with cutouts for maximum case length? It is a good way to quickly check which case you should trim. I ask because sometimes only some of the cases will be longer than your "trim length" as set up on your case trimmer. In that case you will end up with some of your cases shorter than others, even after trimming.


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13 September 2007, 14:20
Rikkie
I use a Lyman trimmer, but unless I'm very much mistaken, the same should apply to RCBS.

I found that my locking collar moved ever-so-slightly as it worked up against the base. I removed the collar, and now do the following: Mike, trim, de-burr, mike. I got the feel of 'speed and feed' just right, and am able to hold miniscule if any tolerances. It DOES take forever though, but that's half the fun (I think!) Roll Eyes
13 September 2007, 17:55
Jim C. <><
First, if your case lengths are varing only 4-6 thousants, that is "exactly the same" to the rifle.

To the best of my knowledge, only the Wilson and Lyman "Universal" trimmers firmly hold a case against a solid steel stop to insure the potential for uniform trim length.

Trimmers that use tapered "draw-in" collets or common shell holders to secure the cases are certain to trim to varying lengths no matter what you do. Even then, as said above, it won't make any real difference so long as you trim enough to prevent jamming into the end of the chamber, and that's not likely to happen.
13 September 2007, 18:44
Hot Core
The only way I know to get them extremely close to the same length is to use the very inexpensive Lee Trimmer/Gauge.

You can "Power-it-Up", but that just ruins the inexpensive Cutter very quickly. Or you can sit back with a trash can between your legs, watch some Football and trim away with the Lee.

They even offer a Cutter with a Ball handle on it now. I've got one and totally forgot I had it until I was putting the stuff up just yesterday. Roll Eyes So I can't say how well it works. Feels fine in your hand though.

The most expensive is not always the best way to get a job done.

Best of luck to you.
14 September 2007, 01:55
Dwight
If you don't mind spending the money the Wilson case trimmer will get them exactly the same every time no matter what caliber. Just buy the Wilson with the Mic installed on it. You will never need another trimmer.
14 September 2007, 22:49
Pete E
Gents,

Why is there a need to trim cases to different lengths? I presently use the Lee, which gives fixed results, so what am I missing out?

Regards,

Pete



Men of Harlech
15 September 2007, 01:59
Jim C. <><
quote:
Why is there a need to trim cases to different lengths? I presently use the Lee, which gives fixed results, so what am I missing out?


Pete, you really aren't missing anything but a little speed if you are using the Lee trimmer system.

The only advantage common, adjustable trimmers offer is that they can be set for any length or cartridge you wish.

Those who think it's critical to trim cases to a specific length, plus or minus zero, and the mouths cut perfectly square, will likely be very disappointed if they check again after that precise brass is loaded and fired.
15 September 2007, 07:44
ireload2
If you have one of the first model RCBS trimmers wit the draw in collet it will cause the case length to vary if the head diameter varies.
RCBS later changed this and they will replace part of your trimmer if you have the old style.

Trimming is some what over rated, most chambers are .030 to .040 longer than the case. I just like to keep the case mouth square and smooth.
My trimmers get used mostly to shorten formed cases.
15 September 2007, 19:46
vapodog
quote:
Originally posted by Jim C. <><:
First, if your case lengths are varing only 4-6 thousants, that is "exactly the same" to the rifle.

To the best of my knowledge, only the Wilson and Lyman "Universal" trimmers firmly hold a case against a solid steel stop to insure the potential for uniform trim length.

Trimmers that use tapered "draw-in" collets or common shell holders to secure the cases are certain to trim to varying lengths no matter what you do. Even then, as said above, it won't make any real difference so long as you trim enough to prevent jamming into the end of the chamber, and that's not likely to happen.

Good post.....actually with the Wilson toolI can do a bit better than this but it takes some getting used to!

If you want then to +/- .001 you're in for some frustation!


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15 September 2007, 19:59
Eric
I've used a Forster trimmer for years (with a collet shell holder) and it always trims to about plus or minus .001 if I do my job right.

I make sure that the case rim is not burred or otherwise damaged, everything is clean, and I seat the case into the collet by applying slight pressure with the cutting arbor when tighting the collet.

I also used the fixed Lee case trimmer for some cartridges with excellent results. As the man said, plus or minus a couple of "thou" won't mean squat.

Regards,

Eric


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16 September 2007, 14:50
Saeed
The very best case trimmer is the Wilson with the Sinclair micrometer adjustment.

Once you set it, it will trim cases EXACTLY the same.

We have tried Lee, Lyman and RCBS trimmers. None of them comes even close to the Wilson for accuracy.


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17 September 2007, 05:58
D Hunter
I have been using the RCBS X-die for my 30-06. It is supposed to eliminate the need for trimming. I have not checked the brass length since using it but all the rounds have chambered. Has anyone used the x-die and measured for brass length consistency?


Although cartridge selection is important there is nothing that will substitute for proper first shot placement. Good hunting, "D"
17 September 2007, 08:01
BigJakeJ1s
The very best trimmer is the one that works for you. I like the cost, effectiveness, and falling-off-a-log simplicity of the Lee.

Andy
17 September 2007, 11:29
sonar59
Hi Blackhawk83, I also use the RCBS hand trimmer. Mine is of the older variety with the draw in collet setup. I tend to keep retired cases around for setup of sizing die and trimmer setup. Do you chamfer the case mouths before you resize your die? Do you chamfer case mouths just before trimming? If there is debri in the case mouth that may cause trimm variation. Things I would check is if the cutter is spun tight onto the handles' shaft. Also snug hex screws good when you get it setup. Lastly I would try to use the same amount of tension in fixing down the collet onto the base of the case with the cutting arbor inside the case mouth to get the best alignment.
The RCBS instructions that came with mine stated that if the cutter needs to be sharpened, RCBS will do it free of charge! Haven't tried it yet, but sure sounds good.


Sonar59