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View Full Version : crimping and tension



crankycalico
01-18-2019, 10:59 PM
IF you have proper tension to keep the bullet from sliding out when shaken, can you assume that simply removing the flare will be enough to keep the bullet in place indefinitely?

For a rifle with a cast bullet..

lightman
01-18-2019, 11:06 PM
Usually so unless its a rifle with a tubular magazine. Shaking it is not a good test but pushing the nose of the bullet against the loading bench is.

crankycalico
01-18-2019, 11:37 PM
Usually so unless its a rifle with a tubular magazine. Shaking it is not a good test but pushing the nose of the bullet against the loading bench is.

it passes the push test very well. The only thing is that everything I have ever read is that a rifle round needs the crimp.

Even though jacketed slugs in 30-30 don't really get a crimp, cast doesn't always seem to get one online.

44Blam
01-19-2019, 01:11 AM
The way I understand it is that you want a heavy roll crimp on revolvers so the boolit does not move in or out.
Then you need at least a taper crimp on rifles with tube magazines and heavy is fine.
Then magazine fed rounds need very light crimp or just a tight fit...

Please correct me if I'm wrong.

gwpercle
01-19-2019, 10:08 AM
Shaken .... how about pushing in on boolit nose with your thumb or twisting the boolit with thumb and fore finger. Don't go all Magilla Gorilla on the pushing ... another test to preform, after passing the push test , is will it easily chamber and extract from your rifle.
If the boolit sticks in the throat , cast boolits are larger than the other kind, the case comes out, sans boolit and spills powder in the action...now you got a stuck boolit to get out ! Best to do this test with a dummy...no powder, no primer just boolit. Save dummy to set seating dies with next session.
On bolt guns neck tension is usually enough , on lever action I put a little (light) crimp into the crimp groove because of the tubular magazine situation...it pushes hard on the boolits in it .
Gary

toallmy
01-19-2019, 11:01 AM
Recoil in a tube magazine can matter also . I had my dies set up to just remove the flair and it worked fine from my tube magazine 30-30 with my plinking loads , but when I went to a hotter load I noticed occasional telescoping boolits . Just keep a eye on the rounds wile levering them up before chambering them .

crankycalico
01-19-2019, 02:25 PM
I know that in the "older days" before 1970 some people would put a crimp at the case mouth, and "at the bottom of the bullet for lever action rifles like 30-30".
Never figured out how they would be able to do the crimp at the bottom, but it sounded interesting.

The odd thing is the lee collet crimping die CANT do that nice looking roll or taper crimp, just iron out the flare. But I can almost get to see perhaps a 1/64" at the very edge of the case mouth that gets pushed below the rest of the neck so I guess something is working.

HangFireW8
01-28-2019, 08:47 PM
High recoil magazine rifles can pull boolits forward (actually the recoil pulls the cases in the magazine backwards, leaving the bullet forwards).

Feeding from the magazine can force the boolits back in the case.

For that reason a crimp has to work in both directions.

So the answer to your question is "maybe" at best, or "no".

Wayne Smith
01-29-2019, 09:03 AM
Depends on the rifle. Single shots, no crimp, in some cases not even hard neck tension. Box magazines, no to a little taper crimp - depending on recoil. Never had a problem with the 25-20 and no crimp, have had with the 405 Win. Tube mags, always a crimp.

RU shooter
01-29-2019, 07:10 PM
I know that in the "older days" before 1970 some people would put a crimp at the case mouth, and "at the bottom of the bullet for lever action rifles like 30-30".
Never figured out how they would be able to do the crimp at the bottom, but it sounded interesting.

The odd thing is the lee collet crimping die CANT do that nice looking roll or taper crimp, just iron out the flare. But I can almost get to see perhaps a 1/64" at the very edge of the case mouth that gets pushed below the rest of the neck so I guess something is working.
Maybe your crimp did is defective the Lee crimp die I have for my 35 Rem will put one heck of a crimp on a case