Thoughts on crimping Semi Auto Pistol Reloads

perry shooter

#2 Crimping for Semi Auto Pistol reloads. With a semi Auto reloading brings an entirely different set of problems.

Because the Cartridge must feed into the chamber the case mouth must form a smooth transition into the chamber but it must also prevent the bullet from being pushed deeper into the case which can cause increased pressure when the cartridge is fired. At the same time Most semi auto rounds Head Space on the case mouth.

A roll crimp on a semi auto pistol Cartridge does not work well for 3 reasons. One because any variations in case length "Straight walled semi Auto cases tend to get shorter each time they are fired" a long case will have too much crimp "with resulting case Budge and possible damage to the bullet" and short case will have too little crimp allowing the bullet to be pushed deeper into the case causing increase in chamber pressure when fired.

You should have a Belling die for semi auto cartridges and this die should be adjusted so the shortest case will have a slight bell at the case mouth "too much bell will cause short case life and too little bell will cause the case to shave the sides of the bullet when seating into the case.

You must set the seater die to meet two criteria one it must fit in the magazine and two it must chamber in the barrel. I like my Cartridges as long O.A.L. as possible with the above two criterias met.


The O.A.L. is set with the seating die and the case bell still visible. Now with the bullet seated to the proper O.A.L. it is time to adjust the Taper Crimp Die.

Start with the taper crimp die turned out and adjust down 1/4 turn at a time until you see the case mouth bell start to be squeezed closed. Now with a dial caliber or Micrometer measure the Diameter of the loaded round about 1/4 inch down from the case mouth then adjust the die down 1/4 turn at a time until the case mouth is .0005-.0015 inch smaller then 1/4 inch below case mouth. Now you will have an undamaged bullet that will group well. It will be less likely to lead. The cartridge will not hang up on a sharp case mouth when trying to chamber. The Bullet will not push deeper into the case on chambering. It will have proper HEAD SPACE.

coledigger4

Thank you, Bert. I found both crimping posts interesting.

v35

.357 Sig really needs a good crimp because their short necks don't offer enough grip resistance to resist bumping up steep ramps of short barreled semi autos. I suspect it's a matter of time before bullet setback kabooms some short pistol and factory ammo gets modified.
Note how similarly short Comnibloc military 7.62x25 necks are punch marked to supplement the grip of their short necks.
.30 Luger, with equally short necks, doesn't have that problem as Lugers don't have tilt barrels that steepen their feed ramps.

niechen861102

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CHEVELLE427

Perry.

have you had any experience with the lee carbide factory crimp die, it seems to work good for me ,

it resizes the loaded round in case there is something out of whack and crimps the bullet also, even says you can crimp bullets with out a crimp grove.

i have run some lead 45acp through a case gage and it passed but wouldn't chamber to full battery in my 1911.

i then ran the same round in the carbide seat die and i felt some drag as it went in and out but it chambered in the 1911 after that.

any yes / no - right / wrong rout to go?

norgexxx

Chev; know the question is for Perry, but i'll drop my two cents also. I really like the lee carbide sizer/crimp die and have gotten them for just about everything I reload, that said lets re-examine a couple of things. Most semi-autos space on the case mouth. If the case is too long from too many firings it will not go full battery. Just the opposite can occur with to much of a roll or taper crimp as that distorts the case-mouth dimensions. The Lee die in question is a FACTORY CRIMP die, not taper, not roll, but factory, hence if used properly, (ie; a light factory crimp) on correct length cases, it still spaces on the case mouth. The added benny here is the carbide sizing ring in the bottom of the crimp die is a fail-safe design that will let all but severly distorted rounds chamber. I am not a fan of all things Lee by a long shot, but...the Lee factory crimp die is one of the best new products out there, consistent crimps contribute more to accuracy then most will acknowledge, and can offer some forgiveness (accuracy-wise)if you are a tiny bit short on your COAL. Listen to Perry, but this is my contribution to the thought processes taking place here also.

norgexxx

Chev; also you are correct in that the Lee factory crimp die will make its own 'cannulere' in the bullet under the factory crimp. Of course the depth of cannulere is dependent on the severity of the crimp. In my own experience, only a light crimp is needed with semi-auto pistol. I will sometimes use a heavier factory crimp on some rifle rounds when using 'non-cannulered' projectiles (especially with tubular magazines). These Lee factory crimp dies (IMHO) let you expand your selection of projectiles for just about anything you shoot.

jade30

have you had any experience with the lee carbide factory crimp die, it seems to work good for me rade ,

it resizes the loaded round in case there is something out of whack and crimps the bullet also, even says you can crimp bullets with out a crimp grove.

i have run some lead 45acp through a case gage and it passed but wouldn't chamber to full battery in my 1911.

i then ran the same round in the carbide seat die and i felt some drag as it went in and out but it chambered in the 1911 after that.

perry shooter

Hello Jade 30 I have never tried the Lee Crimper.I do have reservations about any thing that would be strong enough to form/deform the jacket of a jacketed bullet. Seems like it could mess up the jacket to core area.I dont like a heavy crimp on lead bullets because I like the bullets to be slightly over size to the bore on as much of the bearing surface as possible. But it is an interesting concept that I might test in the future. I load with two thoughts on my Pistol loads . I have a number of star progressive presses. I want to be able to load 300-400 MATCH GRADE rounds an hour, this includes the time to lube the bullets in a Star lubersizer. I shoot about 5000-7500 45acp a year.I do a lot of ransom rest testing to get the smallest group size as possible within reason of time spent on loading.

v35

Recently, I loaded some 357SIG and 9mm using .356, 125 gr truncated cone, hard cast lead bullets having crimp grooves .
Both calibers were given visable roll crimps using Lee's standard carbide die set.
The object was to check feed function in a P11 in both 9mm & 357Sig calibers.
Accuracy wasn't evaluated.
Both calibers exhibited no setback of bullets despite bullets hanging up on the ramp.
These P11 & P3ATs do jam once their feed ramps get smoked up.
A high degree of polish doesn't resolve the problem.
Five rounds of a factory box of 357SIG had serious bullet setback .
A meaningful headspace issue didn't come up in these tests.
The crimped 9mm ammo was also fired in a P2000 and a P35 BHP without issue.
One 357 actually buckled its shoulder but the bullet remained in place.

widowshooter

I am having problems with .45ACP rounds seating fully into the chamber of my Sig. 1911. A friends reloads and factory rds lock up fine and shoot great. Mine, not everyone, but most of them stop about an eighth of an inch from complete lockup in the chamber..I miked the outside dia. at the web and they came in 3 thousandths under the max.,same for the crimping area of the mouth. Overall length is fine, as is case length...I am at my end here and can't figure out whats going on..these are both 200gr.ball, and 185gr.HP jacketed bullets.
Any ideas?

perry shooter

Hello we need to diagnose the problem one step at a time. Not knowing you or being able to look at your ammo in person. Let me ask are you able to disassemble the pistol as far as removing the barrel ? If so that would be my first step . Then with both Factory and your reloads try by holding the bare barrel with muzzle facing down try to let a round chamber . It needs to Fully Chamber under it's own weight. You should not need to push it in at all . Fully chambered is so the rim is flush
with the end of the barrel Hood.If they do not then your ammo is the problem. and we will need to take steps to find out what is the problem
. However if your reloaded rounds fully chamber from their own weight then most likely we have Extractor adjustment problems.For now I will assume we have an ammo problem. First step is on a flat surface like a piece of flat glass or other hard surface "Kitchen counter top" take two factory rounds and two of your reloaded rounds put the two factory rounds side by side facing straight up. slide the two rounds so they touch now take two reloaded rounds and on another place put them touching. now with a flash light behind one pair shine the flashlight at both rounds . Stoop down to have you eye level with counter top look at where the pair of Factory rounds touch each other You should not be able to see any sliver of light between the two cases or if you do ONLY .oo1 and the same from top to bottom. Now try the same test with your reloads . Pay very close attention to the area where the Bullet stops and the case mouth starts . If the cases touch just at the mouth but not 1/4 inch below the case mouth then your case is being bulged during the Crimping stage and you have found problem. I am going to sign off for now but will monitor this post to see what your results of this test. Cheers Perry Shooter

widowshooter

I place two handloads and two new factory loads side by side and they seemed to be very close with min. gap between the cases. The only thing I can find is my reloads when measured are 3 thousandths larger in dia. at the mouth than the other reloads that will chamber,but mine are still 3 thousandths under the max. in the 49th edition of Lyman reloading manuel. Help me out here...

perry shooter

Your Pistol MAY have a chamber on the small side of SPEC. Did you try the chamber fully on their own weight with barrel removed. . It sounds like your sizing die is TOO big . Do you have dial indicator . What is the case size of one of your reloads3/8 inch below case mouth. The case mouth itself should be .469 inch . If your read my Sticky again you may notice some brands of Brass have thicker sidewalls then others some Bullets you buy for reloading are slightly different one brand may be .450 and others .451 or .452 Now you size a case with thick side walls and .452 bullet and a thin case with .450 bullet You might have one round as much as .479 and another at.469 . You need to do the fully chamber under its own weight in a bare barrel removed from the pistol test. Try with 20 or even 50 rounds of reloads. If some work and others don't. See if it is one brand of Brass that causes all the problem.

widowshooter

Perry, this is a Sig. 1911 C3 and I would think the quality control is pretty good on it's manufacturing tolerance, however I might have one that the barrel was reamed with a very old reamer and it did in fact cut a smaller dia. chamber. I will do some more measuring and will take the barrel out and try and drop several different reloads and see what happens. Thanks for the input and I will try and get some more data for you to evaluate.

perry shooter

Will wait for your report . Karl.

widowshooter

Karl, so far what I got last night was that my reloads are .470-.472 at the case mouth while my other reloads,not done by me, are .469-.470. Now at the case web, mine are anywhere from .472-.473 while the other reloads are a max. of .470. The bullets are hornady 185gr. HPs. and measure an advertised .451 dia. Cases are winchester, once fired from new box of 230gr. ball.
I am suspecting, on my own, right now that my RCBS carbide resizing die is not resizing the cases to the correct Outside dia. at the web. Did not take the barrel out last night..too many other out of tolerance measurements on the loaded cases..but I'm no expert with .45ACPs.With powder and bullets costing so much, I sure do hate this...I loaded 30-40 of these on my dillan before I quit.

perry shooter

Yes it looks like RCBS dies in your dillon may be slightly over size. One thing you can try in the meantime is see if you have some Remington Cases or TZZ cases they have thinner wall thickness so after a bullet is seated they will be .003-.005 smaller then the
Winchester also read about the TAPER crimp dies on my original post STICKY. A taper crimp die will solve most ALL feed problems. that way you will have a nice smooth transition between the round in the magazine up the barrel feed ramp and into the chamber. I have shot pistol matches for over 40 years at 5000 - 7500 rounds of 45ACP per year. YOU just can't beat taper crimp.

widowshooter

Please excuse my ignorance, but I was under the impression that the .45ACP seating die was of a taper crimp design, not roll crimp as all my other dies. I have shot heavy magnum loads for 40 years and of course had to use heavy roll crimping to stop bullet jump during recoil. I have lots of brass, including alot of win., so will have to go through them and see what I can find..
Thanks so much for the help..think I might call RCBS and see if their customer support can give me any insite as to my problem.

perry shooter

Hello. IMHO One should never try to load semi auto pistol ammo by seating and crimping at the same time. Look at it this way the seating die nose punch is pressing the bullet into the case all the way that the press handle is on the down stroke now if you try to crimp at the same time the case mouth scrapes lead or brass at the same time you are seating the bullet to correct OAL A better way is to set up your progressive press to Seat in one station and crimp in the next station or Seat with seating plug turned down and die body turned up then turn plug up and die back down. You most likely will never get the .469 case mouth trying to seat and crimp at same time . I bet if you buy a dedicated TAPER CRIMP DIE your problem will soon be long forgotten.

widowshooter

Ya know, its amazing what you can learn if you can just talk to the right fellow..I never thought of that crimping issue..all my experience crimping has been with roll crimping and it is no problem when loading revolver loads..
Thanks my friend, I will talk to dillon and maybe even try that Lee crimping die that I have heard about.

perry shooter

The LEE is NOT what I had in mind I use star reloaders and loaded over 350,000 rounds of 45acp. In matches we can't afford malfunctions. RCBS also make separate TAPER crimp dies that work well. Please don't think I am a hard nose old man But I was Va. state team capt. for over 20 years at Camp Perry . We have had as many as 38 shooter on any given year . I mentored people on setting up and using all kinds of loading equipment... Once the bullet is seated in the correctly adjusted seating die the taper crimp die never touches the bullet . If you try to crimp with a lee die it will deform the bullet. Group size goes to pot. remember Revolvers need a roll crimp to keep bullet from going forward out of the case . Semi auto. Need to keep bullet from being pushed back into the case when bullet nose hits the feed ramp on the way to the chamber you want a smooth transition. NO sharp edges on a case mouth.. Feel free to email me direct .
karlwoerner@vatractor.com I can then send some pictures. Cheers Karl.

widowshooter

Well, I have, I think found my problem. I do not have a crimp die, just a seating die..so I talked to a reputable gunsmith and he looked at my reloads. He suggested I back out my seating die, since there was a bulge in the case around the bullet. I did this and guess what....they seat. I may buy a custom seating die, but right now, this is and was my problem..I wanted to pass this on to you since you tried so hard to help me with me problem.

Mike

perry shooter

Hello Glad you found your problem.[:)][^] However IMHO you would have never had this problem in the first place if YOU would use a Taper Crimp die. You really need to be sure the case mouth is small enough to firmly Hold the bullet to prevent the bullet pushing back in the case when it hits the Feed ramp of the barrel . Check your fired cases carefully if you see any signs what so ever of a bulge near the case head stop shooting immediately and get a taper crimp die to prevent a KABOOM

widowshooter

Thanks, I think I will get intouch with Midway and pick me up a good crimping die..do you have any preferences?

perry shooter

I like RCBS just make sure it is a taper crimp Not roll crimp.

v35

I had the same problem with my Kahr which has a slightly undersize chamber, lands and grooves. That's why the previous owner sold it to me.
It shot factory ammo OK but not his or my reloads. I found my reloads slightly bulged at the crimp.The bulge was just enough to jam in the undersized chamber.I was surprised a roll crimp would bulge thick 45ACP brass. It wasn't visible to the eye but was to the caliper.
I bought a Lee factory crimp die that resized my finished handloads and put a taper crimp in the neck, ending the issue.