Crimp for 40sw

[dearslayer]

A while back I enquired on here regarding the 40sw and Win231 powder and an issue I was having with the FCD,and I haven't really reloaded any since that time. Not enough time to do everything that needs doing in life I guess. So I have managed to step into it again and I went back to that older thread and someone had mentioned that it's important that the crimp measure .0416-0.418. Given the issue I was having with the FCD I decided to crimp using the seating die and it seemed to be going ok until I revisited that thread and checked the current crimp. The boolits are not moving this time round and I thought the crimp looked ok but when I measured, the crimp was 0.425. The plunk test in my barrel works fine and drops freely in and out. What am I missing. Should I try to squeeze the crimp to 0.416-0.418?? Perhaps I had best check the calibration on my caliber today to be sure it's correct. Can't do it now cuz I'm at work.

[fredj338]

Dont bother measuring. IF it chamber checks, good to go. What I do though is do a dummy round, pull the bullet & measure the bullet after crimping. Too much crimp reduces the bullet dia & you can get key holes.

[dearslayer]

Well I loaded and shot about 60 rounds this evening and everything cycled and went smoothly. I just have to concentrate on accuracy now because at the time it wasn't my main concern. Accuracy wasn't bad but I was more concerned with making sure the gun cycled and fed okay. I'll load some more and test for accuracy. The only thing I don't like is I'm still having the same issue as before whereby the cases are coming back to hit me in the face. The last time I mentioned this I explored the ejector and such and everything seemed fine so I still don't know why it's popping empty cases directly back at my head. Doesn't seem to be every round but the majority.

[Der Gebirgsjager]

I have found the casing in the face problem to be caused by one of two things: Either the angle of the ejector hook which controls the angle at which the case will be ejected out of the port, or the load itself. You might find that a more powerful, less powerful, or load with a different powder will solve the problem, as the velocity and timing of the slide changes with the load. I'd start with trying different loads before I got out the file for the ejector.

I've usually had great luck with the FCD in all cartridges and calibers tried, but folks loaded very good ammo without it before it came along. If your standard crimp die works satisfactorily, stick with it.

DG

[gwpercle]

You don't need to measure squat ... put a moderate Taper Crimp on the boolit , with the seating-crimping die that came in the set .
Take the round out and press on the boolit with your thumb ...hard ... if it moves , add more crimp ... if it don't move , press the boolit nose against the edge of your bench ... firmly but not all Magilla Gorilla on it ... if it moves , add just a little more crimp ... if it holds firm , you got it .
So many times people post / books give dimensions but fail to take into cosideration boolit diameter .. that dimension is only good for that diameter boolit and cast boolits are larger than J-Words ... taking measurements is a waste of time ...testing the boolit with thumb and bench edge ...that will tell you the story ! I've loaded handgun ammo for 50+ years and never needed a FCD ...the die that comes in the box will work fine if you adjust it correctly ... Dummy Rounds can help you set adjustments (case with boolit , no powder - no primer ) once you get seating depth then crimps worked out semi-auto's can be seat/taper crimp in one step .

If you don't have one , a Kinetic Bullet puller can be used to pull those bullets that slide back into the case ... a couple light taps brings them forward and you can add more crimp (turn the crimp die down) and try again .
Gary

[popper]

SA try to eject sideways but slide speed (controlled by load power) will get them going more vertical. What is your bullet weight and 231 load & pistol? Yup, taper crimp works fine, ditch the FCD for pistol.

[dearslayer]

I've ordered a plain old Taper crimp die and it should be here Thursday. I'm using a Para Ordnance 16/40 Limited. Using 4.7gr of Win 231 under a cast 165gr boolit from my MP mold ...402-165 TC. After powder coating and sizing I believe it's around 168gr give or take.

[fredj338]

You may get better results with softer load but often cases in the face are extractor/ejector issues. What pistol?

[mdi]

FWI; I don't crimp any semi-auto handloads. I just deflare with a deflaring die (aka taper crimp die) and plunk test. Many handloads of 4 different caliber semi-auto, I have had zero problems. Neck tension keeps bullets in place...

[dearslayer]

You may get better results with softer load but often cases in the face are extractor/ejector issues. What pistol?

It's a Para Ordnance 16/40 limited.

[35 Rem]

I'm new to the 40 S&W but I just measured some of my loads and the case diameter at the crimp is .422. These are used in 2 different Glocks and are loaded with some Berrys plated bullets. I've only fired about 150 so far but have had no problems with bullets moving or easy chambering. The loaded rounds fall into the chambers when holding the bare barrel in hand to do a plunk test.

[1006]

For a 1911, a recoil spring is easy enough to change. You could order a calibration pack from gun springs.com, Wilson Combat, etc, or just acquire a few different weight springs and try them. I would try a 14, 16, and an 18; see what happens. They are cheap, and you may be due for one, anyway. Or, if you are running a shock buffer, simply take it out. You may not be using one, but if you are, try it without it installed—the slide will travel a little further and sling the brass a little differently.

My personal set up with standard or reduced loads (not extra hot loads) with a factory gun in 40 is a 14 pound recoil, 18 pound main/hammer spring-no shock buffer.

https://www.gunsprings.com/cID1/mID1/dID1#799

[W.R.Buchanan]

If you are at .425 you have NO CRIMP WHATSOEVER! Your bullet is .401 +.011+.011 for the case wall thickness on both sides = .423! if your case wall thickness is .012 per side then that =.425

If your Case Wall thickness is .011 and you are getting .425, you have not removed all of the Flare you put in the case mouth, and only part of the case neck is holding the bullet in place !!.

IE: Only the "Neck Tension" is holding the bullet in place. That may, or may not, be enough?

I'm the one who told you about .416-.418 measurement across the case mouth with the caliper blade half on and half off the case mouth.

This is not and easy measurement to take with calipers and takes some practice and you must get repeat readings several times to insure that You got a valid reading in the first place..

Using the correct .416-.418 measurement IE: .417-.401= .016/2=.008 -.011 =.003 per side that the case mouth is pressed into the bullet locking it in place, which in turn means that there is .008 of the case mouth left to head space on the chamber.

The reason why all this matters is because this cartridge runs at 35,000 psi. And if the bullet gets set back during recoil or chambering it will cause a Pressure Spike which may have a negative effect.

Just because a gun will run with no crimp doesn't mean it will never have a problem. All it means is that you got away with it.

If it didn't matter, then every factory loaded cartridge in existence would not be Crimped! The .40 S&W is the one cartridge where all of this matters !!! I can't emphasize this enough!

My Last .02 on this subject!

Randy

[justindad]

Adding to what Randy said… I read on here one time that factory ammo uses some sort of a coating on either the bullets of inside of the brass to increase the friction between the two, thereby reducing setback. I had previously figured this was the case, based on some .357 Sig ammo I had seen.
*
Close the case mouth just to the point that it is no longer the largest diameter. You can over-crimp to the point that it will weaken the joint and increase setback (due to poisson effect).
*
Measuring the diameter of the case mouth is tricky, and dependent upon your brass thickness. As shown in the image below, I like to hold the round in the jaws of a caliper to confirm the mouth is just ever so slightly crimped. Looking at the bottom jaw of the calipers, and you can see light passing between the jaw and the case mouth. Another thing that can be done here is to pivot the round while in the jaws of the caliper (pivot in an axis perpendicular to the case’s cylindrical axis); the pivot point will be where the largest diameter is. If the case mouth pivots outside of the jaws, then the largest diameter is behind the case mouth.

[dearslayer]

If you are at .425 you have NO CRIMP WHATSOEVER! Your bullet is .401 +.011+.011 for the case wall thickness on both sides = .423! if your case wall thickness is .012 per side then that =.425

If your Case Wall thickness is .011 and you are getting .425, you have not removed all of the Flare you put in the case mouth, and only part of the case neck is holding the bullet in place !!.

IE: Only the "Neck Tension" is holding the bullet in place. That may, or may not, be enough?

I'm the one who told you about .416-.418 measurement across the case mouth with the caliper blade half on and half off the case mouth.

This is not and easy measurement to take with calipers and takes some practice and you must get repeat readings several times to insure that You got a valid reading in the first place..

Using the correct .416-.418 measurement IE: .417-.401= .016/2=.008 -.011 =.003 per side that the case mouth is pressed into the bullet locking it in place, which in turn means that there is .008 of the case mouth left to head space on the chamber.

The reason why all this matters is because this cartridge runs at 35,000 psi. And if the bullet gets set back during recoil or chambering it will cause a Pressure Spike which may have a negative effect.

Just because a gun will run with no crimp doesn't mean it will never have a problem. All it means is that you got away with it.

If it didn't matter, then every factory loaded cartridge in existence would not be Crimped! The .40 S&W is the one cartridge where all of this matters !!! I can't emphasize this enough!

My Last .02 on this subject!

Randy

Dang!! ...I"m just a newbie compared to the lot of you more experienced folks.The way you explained this makes perfect sense.I have about 100 rounds loaded so should I run them through the taper die till I achieve the suggested measurement??

[45_Colt]

If the crimp on 40 S&W is so important to prevent set back. Then why aren't the bullets cannalured? And the case crimped into it?

45_Colt

[Tim357]

If the crimp on 40 S&W is so important to prevent set back. Then why aren't the bullets cannalured? And the case crimped into it?

45_Colt

because it's a rimless case that should headspace on the case mouth. if you have a good extractor hook, it may headspace on the hook. too much crimp, not enough extractor hook and the case will sink to far into the chamber, causing either a misfire or a huge increase in chamber pressure caused by the bullet being pinched in the throat at ignition

[dearslayer]

Adding to what Randy said… I read on here one time that factory ammo uses some sort of a coating on either the bullets of inside of the brass to increase the friction between the two, thereby reducing setback. I had previously figured this was the case, based on some .357 Sig ammo I had seen.
*
Close the case mouth just to the point that it is no longer the largest diameter. You can over-crimp to the point that it will weaken the joint and increase setback (due to poisson effect).
*
Measuring the diameter of the case mouth is tricky, and dependent upon your brass thickness. As shown in the image below, I like to hold the round in the jaws of a caliper to confirm the mouth is just ever so slightly crimped. Looking at the bottom jaw of the calipers, and you can see light passing between the jaw and the case mouth. Another thing that can be done here is to pivot the round while in the jaws of the caliper (pivot in an axis perpendicular to the case’s cylindrical axis); the pivot point will be where the largest diameter is. If the case mouth pivots outside of the jaws, then the largest diameter is behind the case mouth.

I just used your method and my pivot point is at the case mouth indicating that it's larger in diameter then the lower case and will require more crimp. Just wondering if it will swage the boolit.I will try a dummy round and pull it to measure.

[45_Colt]

because it's a rimless case that should headspace on the case mouth. if you have a good extractor hook, it may headspace on the hook. too much crimp, not enough extractor hook and the case will sink to far into the chamber, causing either a misfire or a huge increase in chamber pressure caused by the bullet being pinched in the throat at ignition

Then the crimp isn't to prevent set back. But for removing the slight flare on the case mouth.

45_Colt

[Dusty Bannister]

Sometimes we forget that commercial ammo is mostly jacketed bullets and completely out of control by the maker once sold to the consumer. And usually are of smaller diameter. Too many times I am reading of issues caused by trying to follow the Jacketed bullet "rules" when dealing with our own cast bullets.

One needs sufficient neck tension to hold the bullet in place in the case, but not to the point of compressing the bullet smaller.

The comment mentioned why no crimp groove. No such feature in the no lube groove bullets that are so popular with the PC crowd these days. Not hearing a lot of issues from that practice.