Stupid crimp


PDA






kestak
August 16, 2010, 02:09 PM
Greetings,

Lee NORMAL crimp die coming with 30-06 dies.
1 - I screw the die until it touches the top of the case.
2 - I want crimp because it goes into an M1. I screw 1/2 turn more.
3 - Here is what is happening to the brass. For the brass to be ok, I need to turn 1/4 turn.

Can someone please explain me why it collapses the shoulder?

Thank you

http://i445.photobucket.com/albums/qq177/kestak/brass/P1040781.jpg
http://i445.photobucket.com/albums/qq177/kestak/brass/P1040783.jpg

If you enjoyed reading about "Stupid crimp" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
rcmodel
August 16, 2010, 02:31 PM
Seems perfectly normal to me.

1. You screwed it down to the top of the case.
2. You screwed it down another 1/2 turn, or .036".

Thats more crimp then the case & bullet cannelure can take.
SO the shoulder collapsed.

There is no set rule on how far you screw a die down to crimp.
You just have to adjust it to what gives you the amount of crimp you want, with the case length you have.

There can be no set rule on what fraction of a turn that might be.

You will also get shoulder collapse if all the cases are not trimmed to the same length. Just a length difference of a few thousandths will do it.

rc

FeelthySanchez
August 16, 2010, 02:50 PM
Kestak,
Appears that your '06 cases are too long. Have they been fired several times?
Guessing they may need trimming to min empty length after FL resizing.

kestak
August 16, 2010, 02:52 PM
Greetings,

Thank you all for your answers. My cases are all trimmed/deburred/chamferred BY THE BOOK! :D

Like RCModel said, I turned the die too much.

Thank you

rcmodel
August 16, 2010, 02:52 PM
It makes no differance how long they are, as long as they are all the same length.

And you don't screw the seating die down too far, as is the case here.

rc

TonyAngel
August 16, 2010, 03:47 PM
Which crimp die is it that you're using?

rcmodel
August 16, 2010, 03:50 PM
First sentence in first post says:
Lee NORMAL crimp die coming with 30-06 dies.

I take that to mean it is the Lee seating die.

If it were a FCD collet die it couldn't buckle the shoulder.

rc

fguffey
August 16, 2010, 04:01 PM
Screw the die down one half a turn (.036 thousands)!!!??? That means you squatted the case about .034 thousands, the squat bulges the shoulder, the seating die does not offer case support, I have an old Lyman/Ideal reloading book, before the Internet and before anyone on the forms invented it, Lyman said crimping does more to loosen the bullet than it does to increase bullet hold (neck tension).



F. Guffey,

Tilos
August 16, 2010, 04:25 PM
Get a collet crimp die

JimKirk
August 16, 2010, 05:33 PM
Learn what a "good" crimp should look like ... Then you'd be able to say ... "Hell, I over did that" or "Gee, that is not quite enough"!!

Where the heck is common sense nowdays??

ranger335v
August 16, 2010, 06:24 PM
"Where the heck is common sense nowdays?? "

Stupid crimp? Yeah, it hard to find intelligent crimps these days! ;)

USSR
August 16, 2010, 06:32 PM
kestak,

Why crimp? It is totally unnecessary when reloading for the Garand.

Don

kestak
August 16, 2010, 07:05 PM
Greetings,

I shall explains myself. I think after more than 950 posts my common sense has been demonstrated by the various answers and "stupid" questions I asked before doing something stupid... :neener:

I am used to crimp pistols rounds. For rifle rounds, I was just crimping my .223 self defense rounds running into my ARs. The plinking ones, I did not care to have the bullets pushed a little bit when the round is extracted from the magazine (as I discussed here in a past thread). My other rifles are all bolt-action, so no crimp was needed.

In fact, it is not true. I set my dies to just touch the neck a little bit. I found out that when I do that, it reduces the number of occasional flyers.

I read in a reloading book that the M1 Garand/springfield M1A needed a good crimp. While experiencing with the rifle seating/crimp die that I used only to seat the bullets I found out those if turned down too much collapse the shoulder. I never had a collapsing case crimping with my pistol dies: Hence the question here to help me understand how it works.

USSR: Are you sure it does not need any crimp for the M1 Garand in 20-06? Anyone else canc onfirm that? I can't recall in what book I read that, but I am almost sure I read the Garand and the M1A (30-06 and 308 calibers) needed a good crimp to prevent the bullet to be pushed back.

Thank you

Ed Gallop
August 16, 2010, 07:33 PM
I had a similar problem and discovered I overlooked the seating adjustment when tightening the crimp on a Lee seat/crimp die. I now use a factory crimp die and disabled the crimp on the seating die. Wasn't necessary if the adjustments were okay, but I did it anyway. Could be your seating is not complete before crimping begins.

tkcomer
August 16, 2010, 07:37 PM
This is where the Lee Factory Crimp die for rifles shine. You crimp in a separate stage and can add as much or as little crimp as you want. It won't buckle cases and doesn't care what the case length is. It's great for my cast loads where I have to flair the case neck just a tad. Closes that flair right up. And they don't cost that much.

mallc
August 16, 2010, 07:41 PM
I never crimp rifle rounds. Set the neck tension so you can't push the bullet into the case with a fair push on the edge of the bench and be done with it.

My experience is:

1. crimping deteriorates grouping
2. Always listen to RCModel
3. Always listen to RCModel

Scott

USSR
August 16, 2010, 10:07 PM
USSR: Are you sure it does not need any crimp for the M1 Garand in 20-06? Anyone else canc onfirm that? I can't recall in what book I read that, but I am almost sure I read the Garand and the M1A (30-06 and 308 calibers) needed a good crimp to prevent the bullet to be pushed back.

Absolutely. I'm currently feeding 3 Garands. Neck tension (.003 - .004") is all that is needed. Measure the neck diameter of a loaded round with the brass you are using. Then measure the neck diameter of a freshly resized case. If it's not at least .003" less than the loaded round, then you need to polish your expander ball a little to reduce it in diameter. I use bushing dies, so I don't use an expander ball, and I get exactly the amount of neck tension that I want.

Don

Win1892
August 16, 2010, 10:48 PM
If you don't ever crimp rifle rounds then you do not shoot old Winchester levers. I've got a bunch of them and they all demand crimped ammo to chamber properly.

USSR
August 17, 2010, 07:23 AM
There are two situations that require bullets be crimped: the above mentioned lever rifles which use a tubular magazine, and high recoiling big bore rounds. Other than that, neck tension does the job.

Don

rbernie
August 17, 2010, 07:55 AM
I never crimp rifle rounds. Set the neck tension so you can't push the bullet into the case with a fair push on the edge of the bench and be done with it.

My experience is:

1. crimping deteriorates groupingI always crimp rifle rounds. My experience has been that crimping (Lee FCD) lowers SD and modestly improves accuracy in rounds that are NOT tailored to a specific action/rifle. Admittedly, my testing was done at 300 yards or less and there may be bad side effects at 600 yards - I dunno. But at normal hunting distances, crimping works for me.

steve4102
August 17, 2010, 08:17 AM
My experience has been that crimping (Lee FCD) lowers SD and modestly improves accuracy

This. I crimp for all my semi-autos and a few bolt guns with the LFCD. I have yet to find the LFCD degrade accuracy. In most instances accuracy is improved and in a few no change, but never worse. Of course overdoing a good thing can indeed make things worse.

qajaq59
August 17, 2010, 08:46 AM
Yup, you screwed the die down too much. You'll get the feel of the handle as it begins to crimp. Just turn the die down a bit at a time, and check the crimp, until it's what you want. At least it isn't something you'll do twice.

Ed Gallop
August 17, 2010, 10:16 AM
I crimp almost everything and use a factory crimp when possible. I ran many test on several calibers and couldn't find a reason not to crimp, except maybe a hard roll crimp could weaken the brass. I did find reasons to crimp. The only effect on performance was some increase in pressure and velocity, which I wanted, and no negative effect on grouping. I am convinced that everything in the world and beyond, that allows opinions, will have differing opinions. We all must reach our own.

If you enjoyed reading about "Stupid crimp" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!