GregJ Posted January 3, 2017 Share Posted January 3, 2017 (edited) Just set up my new 1050 Super for 9mm. It appears the Dillon crimp die is not a true Taper Crimp die, as it appears to have the lip to provide a roll crimp. The web pages mentions a Taper Crimp and an Accu-Crimp die. I ran into this when I set up my LNL years ago, I was hoping Dillon would be different. Quote (Taper crimp for autos; accu-crimp for revolvers.) However, there doesnt seem to be an option to specify which one. I will be calling Dillon this am to see, but was wondering if anyone else had run into this. TIA Edited January 3, 2017 by GregJ Link to comment Share on other sites More sharing options...
Hi-Power Jack Posted January 3, 2017 Share Posted January 3, 2017 I've been using Dillon's SDB, and their 9mm dies, for 30 years. Never had a problem with the crimp. Link to comment Share on other sites More sharing options...
GregJ Posted January 3, 2017 Author Share Posted January 3, 2017 Talked to Dillon, the lip I see is never supposed to reached on this die. For semi-autos, the dies are supposed to be in fact taper crimp, for revolver rounds (e.g. 357Mag) the dies are supposed to be "accu-crimp". This came about because I was trying to fine tune my taper crimp, and felt like I might have been bumping into a roll crimp. I guess chalk this up to new to Dillon. Link to comment Share on other sites More sharing options...
mcracco Posted January 4, 2017 Share Posted January 4, 2017 Remember, the 9mm Luger headspaces on the mouth of the case. That is, the open end of the case is what stops its forward movement in the chamber. You want the mouth to have a square edge (hence the taper crimp) and not rolled into the bullet. I always think of it as removing the flare and not crimping. Link to comment Share on other sites More sharing options...
Jeff Phillips Posted January 5, 2017 Share Posted January 5, 2017 Generally I have found that the best crimp is one that removes the flare and just barely allows the cartridge to plunk into a case guage. I then adjust the crimp (if necessary) so I can push the bullet end of the cartridge into a hard surface with a moderate degree of force without suffering any bullet set back. Link to comment Share on other sites More sharing options...
GringoBandito Posted January 5, 2017 Share Posted January 5, 2017 Standard Lee dies make the crimp process much easier and they are worth a look. I swapped out the decapping, seating and crimping dies on my 1050 for lee's and have not looked back. Link to comment Share on other sites More sharing options...
MikieM Posted January 5, 2017 Share Posted January 5, 2017 You should be able to reach the crimp dimension you want before the die starts to roll the case mouth. The measurement you're looking for is .378 inches. Also, the best way to take this measurement is to carefully place the caliper jaws halfway on the case and halfway on the bullet. Link to comment Share on other sites More sharing options...
GregJ Posted January 5, 2017 Author Share Posted January 5, 2017 I think I have this issue resolved. I talked to a bud (he builds my guns) and he has crimped his 9mm to .370, and it works well in all his guns. This, and re-adjusted the sizing die so that is kisses the shell plate seems to have been the fix. I was concerned about the die as the dies that first came with my LNL had a roll-crimp, and that caused me a lot of angst way back then. Link to comment Share on other sites More sharing options...
Brooke Posted January 5, 2017 Share Posted January 5, 2017 It is foolish to crimp to 0.370. That forces the brass into the bullet surface. 0.378 +/- 0.002 is the proper "crimp" for 9 mm. Crimp is a misnomer. All you are doing is removing the flair that you put into brass. Link to comment Share on other sites More sharing options...
rooster Posted January 5, 2017 Share Posted January 5, 2017 Crimp should be Bullet dia. + 2x case wall thickness. .355 Bullet + .011 case thickness x2 = .377 plus or minus .001. At .370 your deforming the Bullet and might possibly do injury to you or your firearm. I definitely would not shoot that in an unsupported chamber. Link to comment Share on other sites More sharing options...
GregJ Posted January 6, 2017 Author Share Posted January 6, 2017 I hear you guys and know what you are saying. The .370 comes from the guy that builds my guns, and is an M in Production. This crimp is with Zero jacketed 124s, and runs in all his single and double-stack guns, including his CZ Shadow. I will be loading some Zeros up this weekend and see how it goes. Link to comment Share on other sites More sharing options...
jhgtyre Posted January 6, 2017 Share Posted January 6, 2017 You should definitely measure your components with calipers before deciding how much crimp to apply. The math isn't hard but this tool is convenient:http://dillonprecision.net/crimp-calculator/ For example I am running some coated 9mm bullets that measure out to .356 and after measuring the case mouths of about 10 of the mixed pieces of brass I am loading I came out with an average of .008 wall thickness. I know with mixed brass you aren't going to be super consistent with that measurement but it is what I have. With those measurements I get these results: SUMMARY Neck tension only_(.000)0.372 Very Light Crimp_(.001) 0.371 Light Crimp_____(.002) 0.370 Moderate Crimp__(.003) 0.369 Heavy Crimp____(.004) 0.368 So IF your components measure out like mine did then .370 isn't so crazy. If they don't then your results may vary. Link to comment Share on other sites More sharing options...
GregJ Posted January 6, 2017 Author Share Posted January 6, 2017 (edited) Quote You should definitely measure your components with calipers before deciding how much crimp to apply. My OCD wouldnt let me do anything but. My digital caliper is the most often used tool on my bench. Maybe more info would be appropriate. I have been reloading for about 10 years. I have been shooting SS Major for the past 6+ years. When I started reloading for my Kimber GM, it needed a tight crimp before it would run reliably. I recently acquired a SS Minor, as well as a PCC (Sig MPX), so I need a butt-load of 9mm. So I got a 1050 with an AmmoBot. My bud (that builds my guns) wants to use my Dillon/AmmoBot, so since it has been years since I have loaded 9mm, and my data is old and not applicable to my new gun, I am trying to use his data. Since we shoot basically the same guns, and to minimize any tweaks between his reloading and mine. If I wind up cranking the crimp up a little, it probably wont be a big deal. I have confirmed that .370 is too much of a crimp from the 115 plated and Precision Delta 124 jacketed I have been running through to get the bugs worked out. Now that the setup is running pretty smooth, I will start loading up my good stuff, the Zero 124s. Edited January 6, 2017 by GregJ Link to comment Share on other sites More sharing options...
rooster Posted January 6, 2017 Share Posted January 6, 2017 Easy to check just pull some bullets. If it's indented in any way it's too much. I've picked up range loads where it took 20 wacks with a puller to separate. Link to comment Share on other sites More sharing options...
Sarge Posted January 6, 2017 Share Posted January 6, 2017 Had a fairly new shooter having problems all season with gun and ammo. Everybody gave him tips all summer but nothing worked. One day he showed clear and kicked a round out and I just happen to pick it up and saw he had fully roll crimped his 9mm ammo. Like 38 special roll crimped! It's a wonder it worked at all. He had no idea what taper crimp was. Link to comment Share on other sites More sharing options...
Brooke Posted January 6, 2017 Share Posted January 6, 2017 I think the OP needs to do 0.370 like he wants to do. Some conditions are terminal. I this is one of them. I just can't help but point out that a 0.355 bullet a case wall of 0.011 or 0.012 wall thickness gives 0.377 to 0.379 total diameter. The "crimp" is a misnomer that causes some people to think it holds the bullet and case together. It does not. Additionally these cartridges headspace against that casing edge and if you reduce it too much it won't work. I will say no more because I think facts are useless here. Good luck to you. Link to comment Share on other sites More sharing options...
MikieM Posted January 6, 2017 Share Posted January 6, 2017 You realize, of course, if you measure the case mouth of a factory loaded round you'll have the solution to this dilemma. Link to comment Share on other sites More sharing options...
bodybag0 Posted April 22, 2019 Share Posted April 22, 2019 This explains why so many Dillon users have roll crimped ammo. It appears they dont know the difference between roll crimp and tapper crimp. Link to comment Share on other sites More sharing options...
noylj Posted April 22, 2019 Share Posted April 22, 2019 (edited) And, as MikieM said: "You realize, of course, if you measure the case mouth of a factory loaded round you'll have the solution to this dilemma" or, just use the factory round to set the crimp and not bother measuring anything. Just do a "plunk" test. Factory ammo seems to only have enough "crimp" to keep taper of case straight and the case mouth does not contact the bullet hard enough to leave a mark. Years ago I played with crimp and found that it did not make a statistically significant or repeatable difference in accuracy. Edited April 22, 2019 by noylj Link to comment Share on other sites More sharing options...
rooster Posted April 22, 2019 Share Posted April 22, 2019 Factory ammo today is real good. It’s made to fit the majority of guns. I set my dies off of measurements made off of premium factory ammo. After your gun runs with this benchmark you can start to change things to better suit your needs, but it is a good place to start. Link to comment Share on other sites More sharing options...
jacala Posted April 29, 2019 Share Posted April 29, 2019 I've been loading 9mm for my Open Major Glock 17 and Standard/Limited Glock 34 (2x of them) for around 15-20 years ??? I just checked the taper crimp on them and they all are .370 . I bullet pull on rare occasions- - they come apart easily. I have 3x different brands of match barrels- KKM, LWD and Storm Lake --all the rounds "plunk" fine in each. I hope this helps someone . These are "range only guns" BTW. Link to comment Share on other sites More sharing options...
Sarge Posted April 29, 2019 Share Posted April 29, 2019 5 hours ago, jacala said: I've been loading 9mm for my Open Major Glock 17 and Standard/Limited Glock 34 (2x of them) for around 15-20 years ??? I just checked the taper crimp on them and they all are .370 . I bullet pull on rare occasions- - they come apart easily. I have 3x different brands of match barrels- KKM, LWD and Storm Lake --all the rounds "plunk" fine in each. I hope this helps someone . These are "range only guns" BTW. .370 is pretty tight Link to comment Share on other sites More sharing options...
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