Crimp for 40sw

[dearslayer]

Look at the Pic. The Crimp is where the Black Line is at the mouth of the case. You can see that it only extends about .015 below the case mouth.

The Area below that on this case measures .423 where the bullet is Seated.

Just below the Base of the Bullet, the case measures .419 which is the product of Full Length Sizing the Case. The whole case was .419 before the bullet was seated.

When the bullet is seated it forces the case open to .423 That is .401 bullet +.011+.011 case wall thickness, which gives this Cartridge a Neck Tension of .002 per side

The top edge of the case where the crimp digs into the boolit measures .417 at the very top edge. This all means that the Crimp intrudes into the bullet .003 all the way around and creates a step on the bullet that prevents Bullet Set Back during Recoil and or Chambering.

Read this, and Re-Read this until you firmly understand it, This is all there is to it.

Hope this helps your understanding of this subject. Sorry about the pic, the site will not allow it to be erected.

Randy

Thanks for all this info Randy, and thanks for having the patient to hold my hand through this sort to speak. I think I kind of understood it for the most part but with so much conflicting info it begins to cloud the understanding. Hopefully I'll have some time tomorrow night to check this all again. One question though ... When you say the crimp intrudes the cast boolit all the way round should I not be worried about that causing leading in the barrel whereby the powder coat is now essentially cut with the edge of the case. Would this be considered the same as shaving of the lead or would the .003 not be enough to break through the powder coat? Again please understand I'm trying to learn.

[justindad]

I just quickly seated a boolit,no powder or primer and then pulled the boolit to measure without crimping at all. The boolits measures 0.401 same as before being seated.
Excellent! This is what you want, even after you apply an adequate crimp.

Now remember the taper crimp die is NOT swaging down the boolit if I adjusted it to just removed the bell on the case and apply the slightest crimp. My previous post whereby the bullet was swaged down .008 was only due to the fact I was trying to get the diameter of the case down to 0.416- 0.418 as suggested earlier so to achieve that, I had to turn the taper crimp die down quite a bit.
That was a misunderstanding, which I believe you now understand. See the image below - only the portion of the case labeled “crimp length” should be affected.

That was the experimental part of this equation. When I get more time I will do a dummy round with the taper crimp die just removing the bell and I will cycle it through the action 3 or 4 times to see if there's any boolit setback. Right now unfortunately I have to run out the door for another 12-hour night shift. Work sure does get in the way up the fun stuff.

Refer to the first image below. The gage diameter at location #1 is where the crimp is applied. Mine measures 0.420” - some folks do a few thou more and some a few thou less. The crimp length for this pictured round is 0.035” long. It depends on your particular crimp die, but a crimp length anywhere in the range of 0.015 - 0.050” would not surprise me.

When I mentioned that you pivot the cartridge in the jaws of the calipers, the pivot point is where the crimp length ends (0.035” away from the case mouth for this exact round). The arrows at gage diameter #1 are directly on the case mouth. Notice that you can see light between the very edge of the case mouth and the calipers - that gap is only a few thou wide. The pivot axis could also be located at gage diameter #3, depending on meaningless imperfections, or intentional brass taper, etc. more often than not, my rounds pivot at the end of the crimp length.

Gage diameter #2 shows where the brass has sunk into the lube groove. Whether or not this is visible depends on your brass and the lube groove width. This is not meaningful if the case is not swaging down the boolit.

Gage diameter 3 is at the bottom driving band of the boolit. This could be the pivot axis instead of at the very end/bottom of the crimp length. Either location is fine, so long as the case mouth is not on the pivot axis.

Some folks might prefer that the round pivots on the case mouth. I don’t. Consider what you’ve read, test for proper feeding & chambering in your gun, and decide for yourself.



In this next image you can see how the case mouth is measured. I try to gasp the round so that only half the thickness of the caliper jaws is touching the case. If your calipers are tilted at all, the measurement will be off - that is why this measurement is tricky to get right. Also keep in mind that the crimp length is tapered, making it nearly impossible to truly contact the case mouth.

[dearslayer]

Everything is starting to become more clearer with each post. Thanks to all who contributed to this thread. I really appreciate all the help.

[justindad]

The pictures I posted were crimped with a Redding Taper Crimp die. I do not have the Lee FCD in .40 S&W. There may be some nuanced differences as a result.

The boolit is the RCBS 10mm-200-SWC sized to 0.401”. Alloy is COWW + 1% Sn.

[dearslayer]

As mentioned in an earlier post I had to stop using the factory crimp die as the cases were too large to go past the bottom carbide sizing ring without a pretty noticeable thump. Once it was in the die and I tried to remove it, the bullet would be loose and I'd be able to turn it by hand. I believe it was swaging the bullet and the brass was bouncing back allowing everything to be loose.

[45_Colt]

This over-sizing can occur with the carbide FCD. Sometimes they come through on the small side, which isn't good.

You are correct about the boolit being swaged down and the brass bouncing back (spring back). Same can happen if there is too much of a taper crimp. And this is a crimp just being at the case mouth. As shown by justindad, just a smidgen of ironing out the mouth flare is all that is required.

Once this area is squared away can work on getting the empties to exit to the right. Odds are the extractor is clocking or the tension is wrong.

45_Colt

[W.R.Buchanan]

OF: Yes it works the exact same with with PC'd Boolits I have loaded thousands of Cast Boolits for .45 ACP (Lyman 452374) that were PC'd. First off PC is Polymer Based Paint and it is flexible. But since you are only impressing into it .003-.004 per side it in a tapered line is not cutting into the PC, only displacing it. My PC runs between .0005-.001 per side.

I don't know what is going on with your FCD but My loaded Cartridges don't' get expanded enough to be sized by the Carbide Ring at all. In fact I use my FCD with the Taper Crimp Parts removed as a Push Thru Die to Debulge .40 S&W cases. Been doing that for quite a few years. Then they get F/L sized during the loading OP.

This was originally done to Debulge the portion of the case that was expanded into the Feed Ramp on Gen 2 Glocks. They corrected the Chambers in Gen 3 Glocks and the problem mostly went away. However there are still plenty of Gen 2 Glocks out there (Mostly Police Trade ins) so you have to look for severely Bulged Cases if you are reloading Range Pickups, Especially from Police Pistol Ranges. I posted a pic of a Blown Out case in another thread recently and warned about reloading Federal Cases marked "FC" and "FC10". That was picked up after an officer blew his Gen 2 Glock at our range, and it was a factory loaded round..

I have never seen any of the problems you state in your "News for Newbies' paragraph. The cartridge shown in the picture was run into a Lee FCD as the final step. I was looking for a Cast Boolit round that I loaded a few weeks ago but I guess I shot them all up. Those Boolits were only sized and lubed (WW) but the dimensions were the same as the Plated Bullets because I backed the crimp off a couple of .000. I'd have to take the Expander out of the Powder die to measure it, but mistakes I have pulled have still measured .401 after going in the cases and then being removed with a hammer type puller. My WWW boolits run around 14-15 BN.

Justindad,,, Exxxcellent picture of the caliper jaws at the right place on the case mouth. How many hands do you have?

Randy

[W.R.Buchanan]

As mentioned in an earlier post I had to stop using the factory crimp die as the cases were too large to go past the bottom carbide sizing ring without a pretty noticeable thump. Once it was in the die and I tried to remove it, the bullet would be loose and I'd be able to turn it by hand. I believe it was swaging the bullet and the brass was bouncing back allowing everything to be loose.

See the part in my last explanation about taking the internal parts out of the FCD die and running all your cases thru that as a push thru die. That is called "De-Bulging." Lee sells a "Bulge Buster Kit."

De-Bulging .40 S&W cases when you first acquire them is a good idea as it finds all the deformed cases for you.

Then you will Full/Length Resize the cases as the first operation of the Loading Operation. This will reduce the outside diameter of the case further and then it gets opened back up a little when the Expander/Flaring Die is used before charging the case. Then you seat the boolit, then you crimp the boolit in place.

Randy

[dearslayer]

See the part in my last explanation about taking the internal parts out of the FCD die and running all your cases thru that as a push thru die. That is called "De-Bulging." Lee sells a "Bulge Buster Kit."

De-Bulging .40 S&W cases when you first acquire them is a good idea as it finds all the deformed cases for you.

Then you will Full/Length Resize the cases as the first operation of the Loading Operation. This will reduce the outside diameter of the case further and then it gets opened back up a little when the Expander/Flaring Die is used before charging the case. Then you seat the boolit, then you crimp the boolit in place.

Randy

When you say remove the internal parts from the factory crimp die you don't mean remove the carbide sizing ring at the bottom of the die right? That's what resizes the case correct? So I would be just removing the adjustable knob and the internal part on top for crimping correct?

[W.R.Buchanan]

Yes. You don't remove the Carbide Ring as that is what is doing the De-bulging. Look at the Lee Bulge Buster kit. It comes with Pusher and a Collection Bottle.

The only cartridge that needs this operation is the .40 S&W.

Randy

[dearslayer]

Yes. You don't remove the Carbide Ring as that is what is doing the De-bulging. Look at the Lee Bulge Buster kit. It comes with Pusher and a Collection Bottle.

The only cartridge that needs this operation is the .40 S&W.

Randy

So the bulge buster just pushes it through to collect in the bottle, whereas without it, I would have to use the shell holder and retract each case but does doing it this way accomplish the same thing, or does the buster just do it faster without any other benefit?

[popper]

Bulge buster was for (old) glock fired brass.
Ballistic engineer specifies that 30 cal seating force is ~70 lb. for jacketed bullet. Less for 40sw. Taper crimp should be applied by just applying a crimp to the top 10 thou of the case. As 40 brass shortens after several firings and NOT wanting to trim pistol brass, I just use the SS press handle to 'eyeball' it. Drop handle till it just 'hits', then a skosh down press. No problems for several thou rnds. cast. Lee pistol FCD has the bulge buster carbide ring, rifle doesn't.

[W.R.Buchanan]

So the bulge buster just pushes it through to collect in the bottle, whereas without it, I would have to use the shell holder and retract each case but does doing it this way accomplish the same thing, or does the buster just do it faster without any other benefit?

NO,,, you must push the case all the way thru the Die in order to remove the bulge which is at the bottom of the case right above the Extractor Groove. You will need a pusher that goes into the ram of your press. (Lee) the bottle isn't a must as you can catch the cases as they go thru the die. But it makes it easier. Just buy the Kit and another Carbide Factory Crimp Die, then you won't have to futz with taking your existing die apart and changing all your previous settings.

Here's the cheapest and fastest place to get it.

https://www.midwayusa.com/product/1012847155?pid=882261 Bulge Buster Kit

https://www.midwayusa.com/product/1011209519?pid=289675 Carbide Factory Crimp Die. Total about $35. Then you have everything you need.

Randy

[GONRA]

GONRA sez - use MICROMETERS for diameters, CALIPERS for LENGTHS .

[dearslayer]

I have the stem from the Lee 40sw sizing kit and I tried using it this morning to push a case all the way through the crimp die. Damn I thought I would snap the lever on the little Lee press that I use for decapping and sizing. The case went in most of the way easily but then stopped. It took a lot of force till it finally thumped through with a BANG. I don't think I'd want to doing ANY cases like that. Is this normal????

[justindad]

I tried using the Lee Carbide FCD as a sizer for .45 ACP. The case would not go all the way through - I had to hammer it out. Maybe it’s the old simple lever press with small leverage, maybe I did something wrong, maybe my die is too small for my brass. Doesn’t really matter, I was just tinkering after I found out that was possible.
*
Redding makes a bulge buster for .40S&W / .357Sig only. Takes far less force to use. Redding’s die is almost certainly more accurate & precise for this purpose. If you need to fix a bulge in a .40, consider the Redding G-RX die.

[dearslayer]

I tried using the Lee Carbide FCD as a sizer for .45 ACP. The case would not go all the way through - I had to hammer it out. Maybe it’s the old simple lever press with small leverage, maybe I did something wrong, maybe my die is too small for my brass. Doesn’t really matter, I was just tinkering after I found out that was possible.
*
Redding makes a bulge buster for .40S&W / .357Sig only. Takes far less force to use. Redding’s die is almost certainly more accurate & precise for this purpose. If you need to fix a bulge in a .40, consider the Redding G-RX die.

Wow I just checked and that Redding die here in Canada on Amazon.ca is $173.00!!! That's a little steep.

[justindad]

That’s pretty high. I bought mine before 2019… swear to god I wouldn’t have paid that much… unless I was drinking. I probably did.
*
Edit: I got mine on sale for 97USD. I’ve done dumber things…

[W.R.Buchanan]

OK guys there is a difference between A "Full Length Sizing Die" and a "Lee Carbide Factory Crimp Die." You need to figure out which ones you have? I can't do that for you. A .40 S&W case will NOT go all the way thru a F/L Sizing Die! Period! The Web of the case is too Big to "Swage down" or Compress, to go thru the die. It will however go thru a Lee Carbide Factory Crimp Die with the guts removed.

The ID of a .40/10MM F/L sizing die is .417 or .418 I have 2.

The ID of the FCD is .423 A case will go thru that one, but it runs thru easier if you lube the cases, but there is still some resistance... I use Dillon Case Lube and my RCBS Rock Chucker for that operation..

The Lee Carbide Factory Crimp Die is $20, used to be $15 when I got mine.

I actually bought one of the Redding Dies and it was $65 at the time and I sent it back because it was so poorly machined I couldn't stand to have it near me in my shop!!! Especially for 4X the price. I was truly insulted ! All of the knurling was double struck,,, Meaning whoever set it up on the Machine didn't know what they were doing. Redding states they are the worlds finest Reloading Dies, I beg to differ !!! And IMO they damn sure aren't worth the prices they ask. And the funny thing is that Lee dies will do anything a Redding die will do for 1/5 the cost !!!. Hard to argue with that !!!.

So after you get your Lee Carbide Factory Crimp Die and Lee Bulge Buster Kit we can continue.

I just noticed something that might have played a part in your negative crimping experience. The sleeve that actually does the crimp has two ends. The ID on one end is tapered, that is the end that goes in the die facing down. The other end is NOT Tapered, it goes up to ride against the Adjustment Cap.

Randy

[dearslayer]

Fair enough but I'm not using the full length sizing die to de bulge. As mentioned earlier I stopped using the FCD because it was swaging my boolits and making them loose in the case and also it was extremely difficult to get them through the carbide sizing ring sooooooo that's why I put it aside and ordered and replaced it with the lee Tapered Crimp die. I'm now doing as suggested which is to remove the top adjustment screw and internal crimp bushing ( if thats what it's called ) and that die now sits in my Lee de capping and sizing press. This is where I had the problem with almost getting the case stuck ... IN THE FCD. I hope I'm not the one confusing everyone. If I am the please say so. I thought I was putting as much info as I could put there as to not confuse the readers.

Also I did have the proper tapered end down when I was using the FCD previously. I just looked to be sure.