Case Trimmer Problems

F

Fox1

New member
Last week I posted about problems chambering reloaded cartridges and it turned out to be a shoulder length problem. I resized the casings a little deeper and it cleared that problem up.

At that time I didn't have a case trimmer yet, so I was going through my casings and just loading ones that fell below the Max. Case Length. Well I have been wanting to get a Hornady case trimmer but, because I was worried that my cartridges not chambering may have been a case length problem, I grabbed an RCBS case trimmer at Wal-Mart. (I have to order and wait on the Hornady trimmer.)

I set up the RCBS trimmer last night and as I was setting the trim length, I noticed that the spindle didn't line up correctly with the case mouth. I had to pull the case mouth toward me while sliding the spindle into it. After I trimmed the first case to length and locked the stops down, I measured the case twice and got 2 different lengths that were about .003" different. I put the case in the "jaws" of my caliper and examined it, loosened the caliper, turned the case 1/8 of a turn then measured it again. At one point I could see that the case mouth was tight in the caliper on one side and there was a gap on the other side.

After another case with the same result, I unscrewed the trimmer from my bench and flipped it over and adjusted the "base" end that holds the bottom of the casing so that the casings are in a straight line with the cutter/spindle.
With the spindle aligned correctly and sliding right into the case mouth, I trimmed some more cases but when measuring them, the lip of the mouth is still beveled, or cut at an angle less than 90 degrees.

First Question: Will a .003" bevel on the case mouth matter or am I being too picky?

Second Question: Has anyone ever run into this problem before and how do you correct it?

I've heard a lot of battles over "Hornady vs. RCBS" or even Lee or any other manufacturer and it's just as useful as 9mm vs. .45 arguments. This thread isn't intended to stir up that debate.
In this instance, I am just really not happy with the quality of the RCBS trimmer and I'm wondering if this is normal or could I have gotten the one bad trimmer that was made on a Wednesday during the World Series Playoff.
 
Doesn't sound normal to me. I'll make an inexpensive recommendation, and that is to do as I do and use the Lee trim system. I'm not talking about that cheesy ziptrim thing with the pull-string, but rather the cutter/pilot, where you can chuck the shellholder assembly in an electric drill. Cuts mouths perfectly, and to the correct trim-to length for the caliber you're reloading.
 
First Question: Will a .003" bevel on the case mouth matter or am I being too picky? Too picky, unless you are a EXPERT or above.

Second Question: Has anyone ever run into this problem before and how do you correct it? Re-trim with a better trimmer.


Lee tool in drill press works well. Wilson tools are great, too.
 
I believe that concerns of trimming exactly square, or to any specific length, is overly analysing the situation. By the time the base of a bullet passes the mouth of the case pressure has effectively sealed the neck onto the chamber wall, effectively making it a closed chamber and a non-issue for the bullet.
 
It's not clear to me from your post whether you are using a pilot on the case trimmer or not. If not, you have to put a pilot for the caliber you are trying to trim on the cutter to make sure the case is properly aligned and keep the neck steady while you trim it.

If you are indeed using a pilot, then the problem ahs to be under the base of the cartridge where the collet is grabbing the case, but that still doesn't seem right since the case would still be centered.
 
My thoughts are you did not have the caliber specific pilot installed in the trimmer. Trimmers are pretty precise once the learning curve is covered.

Your post makes me question whether or not you really understand the whole reloading process? And, to skip procedures really is not a healthy thing to do.
Do you have a couple hard cover manuals to consult for a review of the process?

There is no substitute to doing things right! And, that takes time.

I would always check the size but un primed / powdered case in a gun to make sure the brass will chamber.
 
Scorch

It's not clear to me from your post whether you are using a pilot on the case trimmer or not. If not, you have to put a pilot for the caliber you are trying to trim on the cutter to make sure the case is properly aligned and keep the neck steady while you trim it.

If you are indeed using a pilot, then the problem ahs to be under the base of the cartridge where the collet is grabbing the case, but that still doesn't seem right since the case would still be centered.
Click to expand...

I am using a pilot and it is the correct one. When it lines up, it slips right in the neck mouth *snugly* not flopping around or with room to spare.

The end with the collet is the end I had to re-align just to get the case straight in line with the trimmer/pilot.


cgaengineer
Of topic...but what kind of Wal-Mart sells reloading gear?
Click to expand...

I live in Nebraska and I know of 3 Wal-Marts that sell reloading supplies and equipment. Strange but true!


rn22723
My thoughts are you did not have the caliber specific pilot installed in the trimmer. Trimmers are pretty precise once the learning curve is covered.

Your post makes me question whether or not you really understand the whole reloading process? And, to skip procedures really is not a healthy thing to do.
Do you have a couple hard cover manuals to consult for a review of the process?

There is no substitute to doing things right! And, that takes time.

I would always check the size but un primed / powdered case in a gun to make sure the brass will chamber.
Click to expand...

I see that you are a senior member here, so I say the following with respect.
I do understand the reloading process. I will be the first to admit that I am new to it and still have a lot of questions, but I am meticulous every step of the process and I ask a LOT of questions and ALWAYS start out at the minimum charge. As stated before, the pilot is the correct size. I understand that trimmers are suppose to be precise, that is why I'm posting here. I'm wondering if I got a lemon or if anyone else has experienced this with the RCBS trimmer.

I'm not sure what procedures you feel I skipped. I did state that I didn't have the trimmer so I couldn't trim casings, but I did size all of them and only loaded the ones that were at, or slightly below, recommended trim length already. I do have a manual and I read the specs 4 or 5 times during each loading session.

Again, I mean no disrespect as I am here to learn, but if you see a place where I'm skipping something I should be doing, please tell me what it is because I do want to do things correctly.
 
If you are saying that the case is being trimmed at an angle (ie: not perpendicular to the mouth of the cartridge) then to me, that would indicate that the pilot is not perpendicular to the cutting teeth. I'm no engineer, just my piddly .02 worth as a first post. Cool forum, BTW.....
 
I know how the RCBS trimmer works. Is it possible you did not have the shellholder installed correctly? This alone would cause things to be off kilter. Now, with all due resepct........you will always have some variance case to case with trimming...........

I tend to think what you wrote made me suspect your lack of understanding of the process.

How did you size the shoulder a little deeper? That statement alone makes me think you do not understand how set the dies to size cases? Either you are full length sizing the cases as presecribed in how to set up the FL sizer or you are not? It is an yes or no question. No grey area.

Are you trying to neck size cases that were not fired in your gun? Neck sizing only works when using a bolt gun, and it is a good idea use a Neck sizer die to accomplish that mission.


A person needs to have cases trimmed to a uniform length especially when a person is crimping the bullets? Are you crimping and trying to seat in the same pass? They are two seperate operations. Seat all the ammo first, then crimp them.
 
rn22723
I know how the RCBS trimmer works. Is it possible you did not have the shellholder installed correctly? This alone would cause things to be off kilter. Now, with all due resepct........you will always have some variance case to case with trimming...........

I tend to think what you wrote made me suspect your lack of understanding of the process.

How did you size the shoulder a little deeper? That statement alone makes me think you do not understand how set the dies to size cases? Either you are full length sizing the cases as presecribed in how to set up the FL sizer or you are not? It is an yes or no question. No grey area.

Are you trying to neck size cases that were not fired in your gun? Neck sizing only works when using a bolt gun, and it is a good idea use a Neck sizer die to accomplish that mission.


A person needs to have cases trimmed to a uniform length especially when a person is crimping the bullets? Are you crimping and trying to seat in the same pass? They are two seperate operations. Seat all the ammo first, then crimp them.
Click to expand...

The shell holder on this case trimmer is the flat plate with keyhole's and there are 2 studs on the base so I don't think the shell holder plate is on crooked. I double-checked it and the plate dropped down all the way on both sides.

Resizing the shoulder deeper.
I was full-length sizing these cases; not neck only sizing them.
I think this is where I may have gotten in trouble on that particular step. I didn't test fit the empty casing in the rifle first and then I full-length resized a LOT of .223 casings. I'm using Hornady dies in a Texan press. I installed the resizing die according to the instructions: raise the ram with shell holder to the top of it's throw BEFORE it cams over then twist the die down until it touches the shell holder. I thought that was where you tightened the die down. Another member here suggested lowering the die just a bit more (I went a 1/4 turn deeper) and it pushed the shoulder down enough that they chamber correctly now. There is some pressure at the top of the stoke but the casings aren't sticking in the die and they will chamber now.

I'm blaming this on being a rookie because I was resizing pistol brass to start out with and I resized a LOT of that and then it's ready to go when I want to load some. But pistol brass doesn't have the neck and shoulder so that is why I got away with resizing a lot before hand. Not so with bottle-necked casings which are more particular to the chamber.

Crimping
I'm not crimping these reloads because they are going in my bolt action but now I have another question about crimping. I do want to make some loads in this caliber for an AR so I will crimp them.
You said above that seating and crimping are two separate operations. The Hornady manual for the die said it will seat then crimp in one pass. Is this something unique to these dies? I do see at the bottom that Hornady notes that the cases need to be trimmed to a uniform length in order for the crimp to be even.

I took the RCBS case trimmer to a friend who's reloaded for years and he can't find anything out of whack and he says the cutter looks and measures straight but the thing is still trimming cases with a bevel. Talking about it, we also decided that even if the cutter was shorter on one or two "blades" it should still cut the case neck square to the sides because it is cutting in a rotary motion so only the high "blades" would touch the casing but they would cut all the way around.
He said he's stumped too.

Thank you again for the help!
 
SEEING AS TO HOW IT IS RCBS EQUIPMENT ,,,

Give them a call . They are located in Oroville California and are in my opinion the most customer oriented people in the reloading business . They go way beyond most folks expectations in helping to solve a problem or replacing any incorrect parts . I have delt with several companies in the past and they have always been the best . I was traveling through their area a few years ago and dropped in to see if I could get a replacement primer tray for my hand primer tool telling them I had dropped it and broke it and to my surprise they handed me a new one free of charge ! They have custom tweeked my dies free of charge and replaced other parts as well over the years . Wal Mart will indeed give you a new one but they surely wont have a clue as to what may be wrong ,,,,
 
Rcbs trimmer problem

I also had problems with my Rcbs trimmer and am looking to go with Lee or a a better system. The entire head piece that holds the shell is super wobbly. I get inconsistent trim lengths +/- 7 thousandths. Their square as far as I can tell but it's extremely in accurate and I have to measure them 10 times and it takes forever to get them down to 2.40 +/- .002. I need to pull it off yh3 bench and see if I can tighten the head up. It's brand new I have done maybe 50 cases with it using the correct pilot.
 
Fox1,

A bevel is only possible if either the cutting teeth aren't ground at 90° to the axis or if the pilot is not square to the teeth, which would produce an outside bevel, as shown in the first position below. Remember, this is a lathe tool, so all around the mouth it passes the same cutting edge, so the result will be symmetrical, whatever it is.

Case%20Bevel%202016-08-30_14-20-59_zpsvwdrnlf5.gif


From your measurement description, though, I don't think you have a bevel, but rather what seems to be an angled trim across the case mouth, leaving the case taller on one side than the other. A lathe type tool can't make that form of cut because of the inherent symmetry of its cuts due to revolving the cutter. Instead, I suspect your caliper picked up a slight unevenness in the case head. This can be due to an an extractor mark on the head, a rim bend by the extractor, or an out-of-square head.

One way to look for that is to drag a case head across a little sandpaper lying on a flat surface like a piece of glass (scrap plate glass is great for this) and seeing where it marks the brass. High spots can be brought down this way, too. If you have them, try to flatten them by rotating the case a quarter turn after every drag over the paper to even out any tilting. Once they are gone, try trimming and see if that correct the uneven length issue.

In theory, the grip on the head of the case by the trimmer doesn't have to be wobble-free. It only has to prevent it from slipping as it cuts. The pilot corrects the alignment. But you do want the thing bottomed out in the case chuck.
 
I'm using the RCBS Case trimmer for over 25+ years. The case shell holders are numbered depending what case your using, make sure you are using the right case, also remember when installing the shell holder THE NUMBERS ARE FACING OUT. On the adjusting dials , the main adjustment knob that tightens to main cutting shaft is backed away slightly so micro dial can be adjusted to fine tune your trim length. The cutter will cut accurately when set up correctly. Read the instructions, practice on some beat up cases. It's a good trimmer. Double check , the right she'll holder with numbers facing out , with the right pilot, make sure your case bottoms, the piolet should fit perfectly into case mouth or somethings not right. Hope I Helped
 
Seating dies will both seat the bullet and crimp it in place. Problem is that as it is seating the bullet it is also trying to crimp leading to some slight variations in OAL. Some of us will unscrew the seating die just a little so that it does not crimp while seating. After we get the seating that we want we can then use a LEE Factory Crimp Dies or remove the seating plunger from the seating die and use the seating die just to do a final crimp. That way you are not trying to do two operations at the same time. Adds a step and another hour to the process.
 
PA -Joe
Crimp seating die is a little off subject, but then again, all cases must be trimmed to the same length to seat & crimp the bullet properly. If not your crimps will be to tight & to loose, never the same unless your cases are the same. The crimp & seating dies work perfect when set up right.
 
What Dufus said, my Forster has a collet type clamp that let's me place my brass in it, and then I extend cutter pilot assembly into the case mouth and with a few turns and applied hand torque it sets my case straight and then clamps it tight while I trim to a perfect measurement.. (been using mine since 86).
 
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