Icefire Posted December 3, 2006 Share Posted December 3, 2006 (edited) Well found out the hard way that I wasn't really crimping my ammo (new reloader).. Jam after jam after jam... 1 out of 5-7 rounds, stovepipe, double feed, failure to go in battery. How much should I crimp? I just made some test and I wounder which way should I go? I got a CZ75b, Lee pro 1000, 1.135" AOL. I don't want to buy the Factory crimp since I would have to crimp them one by one after. Left is my ammo before, next is rim just taper enought to remove the belling, next to are taper crimper more. Crimp is : .417 .413 .398 .398, wall is .417 thanks Edited December 3, 2006 by Icefire Link to comment Share on other sites More sharing options...
Jon Merricks Posted December 3, 2006 Share Posted December 3, 2006 Holly Crap! Your taper crimp should look like the 2nd from the left. The others look like your going to blow something up. My general rule for crimping is to measure the case wall multiply by 2 then add your bullet dia. My 40 crimps are aroundt .420 The only reasons you need to crimp is keep the bullet from pushing back when it hits the feed ramp and to keep the edge of the case from dragging when doing the same. Your problems sound to be more with the gun than ammo. Shoot factory ammo and see what she does then if it works try loading to that ammo's specs. Disclaimer: Try all the about at your own risk. Link to comment Share on other sites More sharing options...
Larry White Posted December 3, 2006 Share Posted December 3, 2006 Depending on wall thickness I like .418 or .419. All yours are too tight.--------Larry Link to comment Share on other sites More sharing options...
Jon Merricks Posted December 3, 2006 Share Posted December 3, 2006 One more thing, really think about getting a Dillon. Link to comment Share on other sites More sharing options...
Icefire Posted December 3, 2006 Author Share Posted December 3, 2006 (edited) Well those were minor load, probably 130-140pf (4.2gr Universal Clay, 180gr plated). I have a 14lbs spring in the gun vs the 16lbs factory. The wall thickness in mid height is .416-.417 so getting .420 would be asking for trouble no? Those were just a test, to see what crimp I could be getting with my lee pro 1000. I too find the second round a bit better than the first, and the last one feel really smooth (no edge praticly). But the last to are ROLL crimp, not taper crimp like the first two. Edited December 3, 2006 by Icefire Link to comment Share on other sites More sharing options...
Jon Merricks Posted December 3, 2006 Share Posted December 3, 2006 The wall thickness in mid height is .416-.417 so getting .420 would be asking for trouble no?Those were just a test, to see what crimp I could be getting with my lee pro 1000. I too find the second round a bit better than the first, and the last one feel really smooth (no edge praticly). But the last to are ROLL crimp, not taper crimp like the first two. The wall thickness should be around 0.010" maybe a little more or less. Again understanding the meaning of why we need crimp try 0.420" and if your can squeeze it by hand and push the bullet back go a little tighter. Once you get where you want it pull the bullet and see if you crimped so thight that it left a ring around the bullet and if so loosen it up just a little. Also a forum search might will show you something we have missed. Link to comment Share on other sites More sharing options...
George Posted December 3, 2006 Share Posted December 3, 2006 About halfway between #1 and #2 should be about right. You really should not crimp more than what it takes to just flatten the case mouth back against the bullet. The round on the left looks to almost be right. The second from the left looks like it has too much" crimp on it. The ones on the right are crimped dangerously tight! Link to comment Share on other sites More sharing options...
HHjr Posted December 4, 2006 Share Posted December 4, 2006 I agree with George ..... and notice George does not spit out a number for a crimp. Look at the crimped round, stop when you see a burnished edge reflecting in the light. That is all you need. Forget trying to get to a certain number. HHjr. Link to comment Share on other sites More sharing options...
unclez Posted December 4, 2006 Share Posted December 4, 2006 (edited) Start at .420 and work from there. I would say anything below .418 is too tight and anything above .423 is too loose. The crimp I run with Zero JHP's is .420 to .421 Zack Edited December 4, 2006 by unclez Link to comment Share on other sites More sharing options...
George Posted December 4, 2006 Share Posted December 4, 2006 notice George does not spit out a number for a crimp. Look at the crimped round, stop when you see a burnished edge reflecting in the light. That is all you need. Forget trying to get to a certain number Abso-Frickin'-Luteley. There is NO SUCH THING as a magic crimp number for any round. Brass thickness, bullet diameter and amount of case mouth flare all contribute to this being a variable, NOT a constant. Derive it by trial and error for YOUR brass, bullet, case flare combo. You can measure bullet and brass thickness, then add the bullet diameter to twice the brass thickness and test to see IF that is OK, but that typically winds up being a starting point for a dynamic adjustment that is finalized by eye, feel and testing. That is all! Link to comment Share on other sites More sharing options...
Icefire Posted December 4, 2006 Author Share Posted December 4, 2006 From Lee Precision: Dummy cartridge #2 would be the correct crimp (counting from the left). The two on the right look like the bullet seating die is adjusted too far down, and the case mouth is actually passing through the crimp shoulder, while the one on the far left has no crimp at all. Link to comment Share on other sites More sharing options...
unclez Posted December 4, 2006 Share Posted December 4, 2006 Did you give them the crimp size you had for each of those or did they just see the pic? According to your measurement they would be reccommending a .413 crimp? Link to comment Share on other sites More sharing options...
Icefire Posted December 5, 2006 Author Share Posted December 5, 2006 I sent both the pic and mesurement.. I agree with George ..... and notice George does not spit out a number for a crimp. Look at the crimped round, stop when you see a burnished edge reflecting in the light. That is all you need. Forget trying to get to a certain number. HHjr. That exactly it according to Lee as the 2nd round in my pic. Link to comment Share on other sites More sharing options...
Overkill Posted December 7, 2006 Share Posted December 7, 2006 Here's my procedure. Measure the OAL with a caliper. Put the nose of the finished round against the reloading bench, put your thumb behind it and lean into pretty hard. Then measure it again. Keep tightening up the crimp till the round doesnt shrink any under heavy thumb pressure. That leaves it as tight as it needs to be to avoid being set back if a round gets rechambered, without driving up pressure or degrading accuracy. Link to comment Share on other sites More sharing options...
Hank Ellis Posted December 7, 2006 Share Posted December 7, 2006 My feelings on straight wall pistol cartridge crimps circa May of 2004 and still holds true. 3 and 4 should be buried in a very deep hole. Don't want anyone to shoot anything like this. 1 is a bit undercrimped and 2 is a bit overcrimped. Or to simplify it, what George says. Link to comment Share on other sites More sharing options...
revchuck Posted December 10, 2006 Share Posted December 10, 2006 A quick, easy way - take a round of factory ammo that works reliably in your gun, back your crimp die off a good bit, run the round of factory ammo all the way up and screw the crimp die down until it firmly touches the factory round. Use that as a starting point. Mine are .420. Link to comment Share on other sites More sharing options...
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