lucas Posted August 26, 2015 Share Posted August 26, 2015 I have forgotten the measurement. Link to comment Share on other sites More sharing options...
dr2e Posted August 26, 2015 Share Posted August 26, 2015 i crimp just enough to take the "bell" out and it is usually measures .420". Link to comment Share on other sites More sharing options...
FortyOverUnder Posted August 26, 2015 Share Posted August 26, 2015 I'm at .421-.422 avg. Link to comment Share on other sites More sharing options...
noylj Posted August 26, 2015 Share Posted August 26, 2015 Why measure? As long as the flare is removed, you are good to go. Since chambers all vary, someone's "ideal" might not be ideal in your gun--if there is even an ideal. If one wants to measure, and taking it to the next step, then one should adjust for varying case wall thickness if it is so important. Don't over-think taper crimp. Link to comment Share on other sites More sharing options...
darkvibe Posted August 26, 2015 Share Posted August 26, 2015 I'm at .421-.422 avg. This is where I am too. Link to comment Share on other sites More sharing options...
DougM Posted August 26, 2015 Share Posted August 26, 2015 +1 on the 0.421 - 0.422 final. Link to comment Share on other sites More sharing options...
Amoore1960 Posted August 28, 2015 Share Posted August 28, 2015 Why measure? As long as the flare is removed, you are good to go. Since chambers all vary, someone's "ideal" might not be ideal in your gun--if there is even an ideal. If one wants to measure, and taking it to the next step, then one should adjust for varying case wall thickness if it is so important. Don't over-think taper crimp. I just pulled several 10mm loads that had bad PMC brass and it made me reevaluate my crimping. I was thinking 10mm needed to crimp tight so I put a .003 taper crimp on it but by the time it would actually measure .003 difference I was crushing the bullet. I didn't know that until I pulled these rounds. Since, I have lightened up to .001 or .002 and still have plenty of neck tension and I want to believe a more accurate round...we'll see. I just started loading them back up. But I like to measure and know what I have going on yes there is variance between case length and thickness but I believe an average can be had. JMHO Link to comment Share on other sites More sharing options...
TDA Posted August 28, 2015 Share Posted August 28, 2015 Crimp does not set the neck tension. Neck tension is a function of the bullet fit in the case. The function of "crimp" in an auto loading pistol is simply to remove the flare that is needed to fit the bullet into the case so that it doesn't get shaved. Link to comment Share on other sites More sharing options...
GrumpyOne Posted August 28, 2015 Share Posted August 28, 2015 If you forget again, here is a good rule of thumb. Measure the bullet, should be around .400-.401. Measure the case wall thickness of the brass at the mouth. Multiply that by two. Add the bullet measurement to the case wall x 2 measurement. That should get you very close to where you want your "crimp", which isn't really a crimp, it's just a removing of the bell/flair of the case mouth you did to make the bullet seating easier. Link to comment Share on other sites More sharing options...
cactusbrew Posted August 28, 2015 Share Posted August 28, 2015 I am at .421. Link to comment Share on other sites More sharing options...
zzw26n Posted August 28, 2015 Share Posted August 28, 2015 I'm glad you asked, wealth of info on this site. Link to comment Share on other sites More sharing options...
Roons Posted August 28, 2015 Share Posted August 28, 2015 Since chambers all vary, someone's "ideal" might not be ideal in your gun--if there is even an ideal. Truth. I have to run mine at .419 for a custom build. I would get feeding issues if I went with .420. However, I used to run .420 when using a Brazos Edge. Link to comment Share on other sites More sharing options...
captain037 Posted August 28, 2015 Share Posted August 28, 2015 I find that I need more with lead bullets and way less with jacketed. So, it really does depend on the bullet. With jacketed, I just take the bell out. With lead I have to crimp a lot to make them function. Link to comment Share on other sites More sharing options...
Poppa Bear Posted August 28, 2015 Share Posted August 28, 2015 All of mine "crimp" to .421" does not matter if it is coated, jacketed, or whatever. The chamber diameter will not make have an impact on the diameter of the case mouth as long as it is below the bullet diameter (.400") + 2 wall thicknesses (.011 x 2= .022) .422". Above that number you will likely not be removing the bell which could lead to a sharp edge grabbing the edge of the chamber. The two major areas that cause chambering problems are the over all length being to long and the bullet hitting the rifling, and the case not being sized properly and the base of the case being larger than the chamber diameter. I have had cases that measure as much as .432". You can size the top of the case but if you do not take the base down to less than the chamber diameter you will have feeding issues. My chamber measures out to .426" which is very close to the SAAMI minimum for a chamber diameter, and ALL of my finished .40 rounds have a max diameter of .423". Link to comment Share on other sites More sharing options...
RPatton Posted September 1, 2015 Share Posted September 1, 2015 Crimp does not set the neck tension. Neck tension is a function of the bullet fit in the case. The function of "crimp" in an auto loading pistol is simply to remove the flare that is needed to fit the bullet into the case so that it doesn't get shaved. +1 I wonder how many times this will be have to be repeated in the forum. Link to comment Share on other sites More sharing options...
noylj Posted September 2, 2015 Share Posted September 2, 2015 >Crimp does not set the neck tension. Neck tension is a function of the bullet fit in the case. The function of "crimp" in an auto loading pistol is simply to remove the flare that is needed to fit the bullet into the case so that it doesn't get shaved. >+1 >I wonder how many times this will be have to be repeated in the forum. As long as the word crimp is used and folks don't read their manuals in depth. Link to comment Share on other sites More sharing options...
GrumpyOne Posted September 2, 2015 Share Posted September 2, 2015 More likely, it will continue until manufacturers stop calling them crimp dies, crimp stations, etc. Either way, everyone here knows what was meant by it, so no need to drive it into the dirt. Link to comment Share on other sites More sharing options...
RPatton Posted September 7, 2015 Share Posted September 7, 2015 More likely, it will continue until manufacturers stop calling them crimp dies, crimp stations, etc. Either way, everyone here knows what was meant by it, so no need to drive it into the dirt. Maybe so but bullets with a cannelure will SOMTIMES need a real crimp, i.e. the 44mag, 454, 460 etc. and that is why they are called "crimp" dies. Maybe some dies should be labeled "case wall straightening dies" instead of crimp dies. This topic has already been driven into the dirt. Maybe it should have its own section in the forum rather than being a "topic" in General Reloading. Link to comment Share on other sites More sharing options...
ruleyoutoo1911 Posted September 9, 2015 Share Posted September 9, 2015 Just started loading .40 myself and set mine at .421 Worked great, this forum has the best info! Link to comment Share on other sites More sharing options...
zipper046 Posted September 15, 2015 Share Posted September 15, 2015 .422 for my Berry's plated and Zero FMJ...works well.. Link to comment Share on other sites More sharing options...
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