38SC Crimp

[Joe139]

I was told to use a light crimp on a 38 SC I'm setting up my press and was wondering what a light crimp measured if my case is .378 should my crimp at the mouth be .377 or what.

Edited November 13, 2011 by Joe139

[superdude]

I was told to use a light crimp on a 38 SC I'm setting up my press and was wondering what a light crimp measured if my case is .378 should my crimp at the mouth be .377 or what.

you'll get different opinions on this but yes, a crimp of .001 to .002 inches smaller than the case wall ought to do it.

[Pat Miles]

Damn near impossible to measure that on the cartridge. I like to set my crimp to just get rid of the burr on the front of the cartridge. You should see a sliver of bright brass at the case mouth.

Pat

[Aircooled6racer]

Hello: I measure down 1/8" from the case mouth then measure using a vernier caliper with half the blade measuring the case mouth. 0.002" less is what I like but I am younger than Pat and can see Thanks, Eric

[noylj]

1) shiny ring around the case mouth

2) no visible flare/bell when looking at the case against a white background

3) able to slide your thumb down the bullet ogive and NOT feel a sharp change at the case mouth. (practice feeling with and without flare).

4) Does the round easily chamber?

If measuring a taper crimp was THAT important, there would be a market for tools to do so.

[CocoBolo]

Hello: I measure down 1/8" from the case mouth then measure using a vernier caliper with half the blade measuring the case mouth. 0.002" less is what I like but I am younger than Pat and can see Thanks, Eric

I can't see as well as either of you, I turn the crimp die down 1/2 turn after contact, then give it the thumb test. Measure the OAL, press the round against the bench with the thumb, measure it again, if it is shorter it needs more crimp. When I was young I could gap points visually and they would be spot on, now cars don't even have points.

[Pezco]

Yup, I target .378 which works great for my SV 38 SC IMM Open guns.

[Joe139]

Thanks for all the info

[DougCarden]

Another quick and dirty way to do it is to make a dummy round. Put toolhead down and screw down the crimp die til it touches. Put it up and turn a 1/8 more or so. Crimp it. Pull the bullet and look at the bullet. You want a faintline on the bullet, not digging into the jacket, but a faint line. You also want the lip or belled edge to be smooth. Another thing to do is just adjust the crimp until the round drops smoothly into the case gauge and drops back out. This works really well with 9mm.

Hope this helps.

DougC

[Pat Miles]

Hello: I measure down 1/8" from the case mouth then measure using a vernier caliper with half the blade measuring the case mouth. 0.002" less is what I like but I am younger than Pat and can see Thanks, Eric

Young whippersnapper!

Pat

[Joe139]

Thanks guys I remeasured my cases they were .379 at the loaded bullet I crimped to .378 1/2