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View Full Version : roll crimping on cast boolits



JWFilips
05-26-2012, 09:55 AM
I was very lucky to get a nice S&W 19-3 for my Birthday a few weeks ago & I'm already geared up and loading casts ( not pouring them yet!) in .38 spec & .357 Mag cases. A friend gave me a couple hundred 125 grain TC boolits to start me out. This is the first cartridge that I ever had to put on a "roll crimp" The boolits have a crimping groove cast in so doing the crimping is easy once I sorted out the case lengths. My question is as I have read here and in other forums, what is the meaning of "light" , "medium" & "heavy" crimp?

I have just been crimping to what I thought looked right but now after a whole lot of reading I'm seen mention of the different crimps for different loads Is there some kind of chart or photo that shows the difference?

Char-Gar
05-26-2012, 10:54 AM
There is no chart nor a standard definition. Turn the case mouth into the crimp groove until you can no longer feel the case mouth with your fingernail and you are good to go. On a sixgun with a very heavy recoil and a heavy bullet you might need to go a little farther to keep the other rounds in the cylinder from "jumping the crimp" during recoil.

sometimes, too much reading can cause more confusion rather than help. Realize that mostly you get in your reading are opinions. Some are informed and some are not. Some are based on personal experience and some are not. Your own experience is much more valuable than the experience or opinions of others, so pay attention to it. If what you are doing works, then there is no need to look farther.

mdi
05-26-2012, 10:57 AM
http://www.exteriorballistics.com/reloadbasics/crimp.cfm This is the only thing I found on degree of crimp. Photo of "slight", "good firm", and too much crimps...

JWFilips
05-26-2012, 11:51 AM
There is no chart nor a standard definition. Turn the case mouth into the crimp groove until you can no longer feel the case mouth with your fingernail and you are good to go. On a sixgun with a very heavy recoil and a heavy bullet you might need to go a little farther to keep the other rounds in the cylinder from "jumping the crimp" during recoil.

sometimes, too much reading can cause more confusion rather than help. Realize that mostly you get in your reading are opinions. Some are informed and some are not. Some are based on personal experience and some are not. Your own experience is much more valuable than the experience or opinions of others, so pay attention to it. If what you are doing works, then there is no need to look farther.

Yes it did seem easier a few weeks ago when I started now you are correct..... I read too much causing doubt & confusion:-(

The first handloads I did for this pistol were great & shot about 2 1/2 " groups at 25yds So I'm excited (Best pistol I ever owned ) Just want to make it shoot as good as I can so I started pulling information from as many sources as I could
Guess trusting my own judgement is the key
Thanks

gray wolf
05-26-2012, 12:35 PM
I would listen to CHAR-Gar

GP100man
05-26-2012, 02:11 PM
We can give opinions, talk, post pics but I believe it all means naught as to what works in YOUR revolver !

I do crimp enuff to be sure of boolit retintion under recoil , some lite loads(fast powders) work better with no crimp (just the flare turned straight ) & then again certain combos work better with a crimp.

But trimming ya cases for a consistent roll crimp is a must.

357shooter
05-26-2012, 02:22 PM
For 38 special and non-magnum loads in 357, all my guns have liked the same crimp. By that, I mean shoot most accurately. Try this:

1 - Size a fired case
2 - Insert is under the crimp die (do not flare it)
3 - Back out the crimp die and raise the ram, the case should not have touched the die
4 - Screw the die in until is touches the case (not first touch, just a little more)
5 - Lower the ram and screw in the crimp die 3/4 turn

That's it, works like a champ. For magnum loads and powders I use one full turn instead of the 3/4 turn.

The minimal crimp approach has never worked in these calibers, in my guns anyway.

This includes light loads with fast powders. Give it a try and see if it works in your gun.

atr
05-26-2012, 02:27 PM
Char-gar has it !
and also BEWARE....some .357 cylinders are shorter than others and that forces you to crimp not in the groove provided but on the upper driving band.....
ALWAYS check a loaded round in your pistol to make sure it fits before you start to "mass" produce.
atr

Char-Gar
05-26-2012, 02:33 PM
Yes it did seem easier a few weeks ago when I started not you are correct..... I read too much causing doubt & confusion:-(

The first handloads I did for this pistol were great & shot about 2 1/2 " groups at 25yds So I'm excited (Best pistol I ever owned ) Just want to make it shoot as good as I can so I started pulling information from as many sources as I could
Guess trusting my own judgement is the key
Thanks

The Smith and Wesson Model 19 (Combat Magnum) is one great sixgun. I have had several but have never managed to hang on to one for a very long time. It is the heavier N frame (27s and 28s) that tended to hang around my house the longest.

I am somewhat ambivalent about this Internet thing. When I started, there was nothing but two or three gun magazines, plus Gun Digest that came out once a year. There were plenty of pictures of loaded sixgun rounds among the pages, and I just tryed to get my crimp to look like the ones in the pictures. That worked so well, I have not given the subject much though in decades.

The writers of the articles mentioned above, mostly knew what they were doing. Their work passed under the eyes of an editor or two, so really dumb and stupid stuff didn't make it into print. Today, if a fellow can turn on a computor and peck at a keyboard, he can wax wise on any subject under the sun. The result is there is an overburden of information out there that varies from excellent to utter drivel. New folks who turn to the Internet have to tip-toe through this mine field of stuff, trying to learn what they can.

At the end of the day, I don't know but what we geezers didn't have it better, at least in this regard. But time marches on, and we have to muddle through with what we have, then as well as now.

44man
05-26-2012, 02:55 PM
How to tell the difference? I use the least needed as long as the last round in the cylinder does not move.
It is hard to see and judge but I try to get the edge of the brass to just reach the bottom of the crimp groove.

MW3840
05-27-2012, 04:23 AM
Author Mike Venturino stated in one of his articles many years back, that when your fingernail no longer catches on the case mouth after roll crimping, the right amount of crimp has been applied.

This has stood me in good stead since.

1Shirt
05-27-2012, 09:44 AM
Threads #10 & 11 make good sense to me!
1Shirt!:coffeecom

just.don
05-27-2012, 10:59 AM
http://www.reloadingtips.com/how_to/crimping_revolvers.htm

pictures from one of the members here

mdi
05-27-2012, 11:37 AM
Another thought; compare your crimp to a factory roll crimp...

JWFilips
05-27-2012, 05:32 PM
http://www.reloadingtips.com/how_to/crimping_revolvers.htm

pictures from one of the members here

Wow not this is pretty informative Thanks for posting. At least this shows me what I'm doing is correct ( when I trusted my judgement) However It was good to see what progressively tighter crimps appear like

Thanks everyone: all have been helpful. I'm sure happy I posted this here....It was the right place!