Sizing questions


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scythefwd
May 20, 2010, 11:24 PM
All,
I just did my first resizing. After I got done, I used the lee hand trimmer/pilots to trim to length. I then deburred/chamfered the mouths. I then measured my work...rut roh.

All of my cases but 1 (I only did 10) measured .005-.003 inches short of max case length. Their other dimensions are dead on. I'll chock that up to the case trimmer pilot. There was a spread of .002 (from 2.289 - 2.291) inches that I can attribute to variance in how tight I had the shell holder tightened into the trimmer base. Then there was that one shell.. it measured 2.278 OAL so far. All dimensions are exactly with the others except the neck is .011 inches shorter than the rest. I suspect that I really cranked down on the base of the holder to do that. I will have to make sure I am paying more attention to that.

Here are my questions...
The lee manual only has max dimensions, so what are the minimum dimensions? AKA What is the allowed variance in case length, minimum to maximum length?

Would you just load up the short round and not worry about it? This is not match ammo

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JimKirk
May 21, 2010, 12:22 AM
The short case will not matter unless you are crimping in a cannalure. I would set it aside unless I really had to have it.
I'm not sure how you got the differing lengths as the pilot to lock stud is always the same, it is a set length. You may not have cut all the way down as I have done the same thing... thinking I was finished cutting when I lacked a few more turns being finished. Once you get the feel for the "finished" cut it become easier.

Jimmy K

Randy1911
May 21, 2010, 12:41 AM
When I do my trimming, I try to listen for the scraping sound the cutter makes and keep cutting until I don't hear it anymore. This works for me.

degunner
May 21, 2010, 01:46 AM
when you say "it measured 2.278 OAL so far" that was for a completely assembled round?
What are you loading?
Lyman Reloading Handbook 49th Edition will be able to answer the min. case length question for you

Doug b
May 21, 2010, 02:43 AM
Al .011 is nothing to worry about in this instance.

snuffy
May 21, 2010, 12:57 PM
All,
I just did my first resizing. After I got done, I used the lee hand trimmer/pilots to trim to length. I then deburred/chamfered the mouths. I then measured my work...rut roh. rut-roh? WTH is that

All of my cases but 1 (I only did 10) measured .005-.003 inches short of max case length. Their other dimensions are dead on. I'll chock that up to the case trimmer pilot. There was a spread of .002 (from 2.289 - 2.291) inches that I can attribute to variance in how tight I had the shell holder tightened into the trimmer base. Then there was that one shell.. it measured 2.278 OAL so far. All dimensions are exactly with the others except the neck is .011 inches shorter than the rest. I suspect that I really cranked down on the base of the holder to do that. I will have to make sure I am paying more attention to that.

Here are my questions...
The lee manual only has max dimensions, so what are the minimum dimensions? AKA What is the allowed variance in case length, minimum to maximum length?

Would you just load up the short round and not worry about it? This is not match ammo

We still don't know what/which caliber-round you're talking about.

As for the l\Lee trimmers, they're pretty much fool proof. You have to make sure the pilot is firmly tightened into the cutter head, AND STAYS TIGHT! Then, you have to make sure you turn it until it's finished cutting. The pilot pin HAS to contact the case spinner stud or it will leave it long. How tight the shell holder is has nothing to do with how much it cuts,(except if it's so loose that you can't hold onto the case).

My method for using the Lee system is to chuck the stud in my cordless drill. Then I have the wood ball end on the cutter/pilot assembly. The shell is tightened lightly into the case holder, then a quick jab of the drill trigger trims the case. Then I pick up the chamfer tools, do the inside and outside chamfers. If I'm de-burring the flash holes, I do it then while the case is still in the spinner. Also a quick swipe with 4-0 steel wool will shine them up.

scythefwd
May 21, 2010, 04:58 PM
Jimkirk - I kept spinning until there was no resistance.

Randy1911 - doing the same

degunner - I have not assembled any cartridges... only resized the cases. I know I used OAL wrong. Sorry for any confusion. I don't have the lyman book. If you have it, would you mind posting the actual allowed deviations?

Snuffy - as to allowable deviation, caliber shouldn't matter too much, but these are .30-06 rounds.
The cases are brass, and you have a lot of mechanical advantage using the screw on base. One could compress the base of the case a hair (.003 inches is hardly noticeable without measurement tools). I don't get why you highlighted "this is not match ammo". Are you saying you would or wouldn't use the case. I know it doesn't have to be as tight of tolerances, but my question is WHAT are the tolerances. Rut roh - watch an episode of scooby doo and you'll get your answer to that one. It's something that has stuck from my childhood.

JimKirk
May 22, 2010, 01:17 PM
Even if you "could" compress the case head, which I don't think you can, the measurement would still be from the top of the lock stud which contacts the base of the case to the cutter blades. If you move the base up then the cutter would move up by the same amount.

The only way to change the length would be to shorten/lengthen the trimmer shaft pilot pin which goes through the primer flash hole.

You may be able to distort rim of the case with the stud, but you'd have to bear down with some big pliers, even so, the stud would still be in the same position.

30/06 Springfield Max. Case Length: 2.494" Case Trim Length: 2.484"

Jimmy K

R.Clem
May 22, 2010, 09:20 PM
In the manufacturing of brass cases the primer holes are punched in, this leaves a burr on the inside. There is a tool for removing this burr, during said process I have noted some cases have a considerable amount of burr while others have virtually none. As the Lee trimmer rides on this burr, that could very well be the problem.
It has been noted by gun-writers over the years that all cases the same length is more important than all cases being trimmed to max or minimum.

Ray

ranger335v
May 22, 2010, 09:54 PM
SAAMI specifies the max case length. How short we cut them is up to us. The normal recommended "trim to" length is 10 thou less than max but that's no law.

Sunray
May 23, 2010, 01:31 AM
"....005-.003 inches short of max case length..." That'll do. As long as they're between the trim-to and max length. You really want 'em all the same though. Mind you, 2 thou isn't a lot.
"...2.278..." Way too short for a .30-06. Trim-to is 2.484". You're 206 thou under. That's 2/10" under. Necks will be too short to hold the bullet properly.
"...compress the case head, which I don't think you can..." Hammer. Works like stink. snicker.

JimKirk
May 23, 2010, 01:36 PM
Sunray
A Hammer will shorten too long of case also....faster than a Lee trimer!

But I don't really think you could compress a case head(with the Lee lock stud & shellholder) enough to change the operation of the Lee trimmer.

Jimmy K

snuffy
May 23, 2010, 03:40 PM
scythefwd

Snuffy - as to allowable deviation, caliber shouldn't matter too much, but these are .30-06 rounds.
The cases are brass, and you have a lot of mechanical advantage using the screw on base. One could compress the base of the case a hair (.003 inches is hardly noticeable without measurement tools). I don't get why you highlighted "this is not match ammo". Are you saying you would or wouldn't use the case. I know it doesn't have to be as tight of tolerances, but my question is WHAT are the tolerances. Rut roh - watch an episode of scooby doo and you'll get your answer to that one. It's something that has stuck from my childhood.

Oh yeah scooby doo saying uh-oh! As for why I put that in bold, I dunno.:confused: I DO know I was in a hurry to get down to the garden.

Sunray made me go look up the specks on 30-06! He's right! How the devil are you trimming with a Lee trimmer that's trimming .200+ thousandths too short?

2.484
-2.278
______
=
0.206
Are those measurements of yours misprints? Might I suggest you re-measure those?

As for the comment/opinion that the Lee pilot rides on a flash hole burr, that's nonsense. The pin that goes through the flash hole is plenty long to reach the lock stud without coming near the top of the flash hole.

JimKirk
May 23, 2010, 05:28 PM
Snuffy.... That is what I thought about the pilot pin length too, I just hadn't made it out to measure my pin, I had remembered it to be long enought not to hit anything other than a major burr.

I keep repeating this statement a lot lately: Something ain't right here!

Jimmy K

scythefwd
May 25, 2010, 03:04 AM
snuffy, you are right- it was a misprint. It's 2.478 inches, or .026 inches less than max length and .016 inches less than "trim to lengths". I think I'm going to use the case (again, it is NOT .2 inches short but .02 inches short) with a light load. That should bring it back into specs.

As to the .003 inches difference in the others, it was a new trimmer and it could be there as a small burr on the cutter... which wore away as I trimmed the first 1-3 cases. Then everything normalized at the longer length. I could be wrong, but that seems to make the most sense to me. My typo.

JimKirk
May 25, 2010, 08:08 AM
Now we get the correct information, I knew that there was no way to cut a case .2 too short, if you were using the trimmer correctly! .02-.03 is OK, more than likely user error, but it is within an acceptable range. The Lee trimmer is a good product and like all products, it is possible to have burrs.

Glad you got all the "burrs" out and are getting good results with the trimmer now.

Jimmy K

scythefwd
May 26, 2010, 01:07 AM
Jim, the last 2-3 cases I trimmed with it were exactly the same length... so I hope that is the case.

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