.380auto Taper Crimp

[vaalpens]

I have started reloading 380auto a while ago and has another thread dedicated to the test loads and results. This thread is specifically about the 380auto taper crimp, so I don't want this question to get lost in the other thread.

To be honest, I have been a bit underwhelmed with the accuracy of the 380auto cartridge. Accuracy is obviously not very good with a pocket pistol, but I do expect some consistency. This is why I started looking at my reloading process to see if I can make any improvements.

My process is basically to sort by headstamp, and then also sort by case length to get some consistency over at least 5 test rounds. Even with this process I have found that my ES and SD numbers are not very good.

One thing that I have realized is that when I pull some bullets for whatever reason with an RCBS impact puller, the bullet would come out very easily. My method I always use is to do two light taps, and then a heavier tap. With the 380 the bullet would come out even before the heavier tap. For other cartridges the bullet would normally fall out by the second or third heavier tap.

This made me think that maybe I am not crimping enough. I basically just remove the bell with my taper crimp, but maybe for the 380 it is not enough.

An article from Loaddata that I found, indicate that for the 380auto, they apply a taper crimp to get the case mouth to .3670" to .3695". This to me seems like lot of crimp. I did a few dummy loads to this crimp and found that pulling the bullets felt more normal now, but I could see the crimp marks on the bullet after they were pulled.

So my question basically is, do you crimp to SAAMI specs of .3730", or closer to the .3695" that LoadData uses. The article available to everybody is at:
https://loaddata.com/Article/LoadDevelopment/Top-10-Reloaded-Handgun-Cartridges-7-380-Auto/703

I am definitely going to test this out, and obviously do the normal plunk and cycle/setback test before loading any live rounds, but it will be interesting to find out what everybody else does regarding the 380auto taper crimp.

Please note that I mostly load 95gr FMJ RN bullets.

 

[SingleActionAndrew]

I might consider the sizer and expander, brass and bullet size if neck tension is a concern but not increase taper crimp on a bullet with a real jacket

 

[Zygodactyl]

I found that I don't need a lot of crimp. I just crimp enough so that the bullet is not forced back into the case when chambering. I use a Lee Factory crimp die but adjust it so it doesn't leave marks on the bullet.

 

[mdi]

Check mouth diameter after sizing, and mike your bullets. Semi-auto bullets are kept in place by neck tension, not crimp. Make sure case mouth ID is around .003"-.005" smaller than bullet diameter. My semi-auto handloads, includimg 380 ACP, are not crimped, just deflared (using a deflaring die, aka taper crimp die). Many times excess taper crimp loosens neck tension...

 

[CQB45ACP]

Check mouth diameter after sizing, and mike your bullets. Semi-auto bullets are kept in place by neck tension, not crimp. Make sure case mouth ID is around .003"-.005" smaller than bullet diameter. My semi-auto handloads, includimg 380 ACP, are not crimped, just deflared (using a deflaring die, aka taper crimp die). Many times excess taper crimp loosens neck tension...

This is oft forgotten and bears repeating...taper crimping an auto cartridge does not increase tension.

 

[lordpaxman]

For other cartridges the bullet would normally fall out by the second or third heavier tap.

This made me think that maybe I am not crimping enough.

And again, neck tension is set by the sizer and expander.

You may want to check factory ammunition to compare how many whacks it takes to dislodge bullets. In fact, you mentioned accuracy (precision?) so how do your reloads compare to factory ammo?

 

[entropy]

I have started reloading 380auto a while ago and has another thread dedicated to the test loads and results. This thread is specifically about the 380auto taper crimp, so I don't want this question to get lost in the other thread.

To be honest, I have been a bit underwhelmed with the accuracy of the 380auto cartridge. Accuracy is obviously not very good with a pocket pistol, but I do expect some consistency. This is why I started looking at my reloading process to see if I can make any improvements.

My process is basically to sort by headstamp, and then also sort by case length to get some consistency over at least 5 test rounds. Even with this process I have found that my ES and SD numbers are not very good.

One thing that I have realized is that when I pull some bullets for whatever reason with an RCBS impact puller, the bullet would come out very easily. My method I always use is to do two light taps, and then a heavier tap. With the 380 the bullet would come out even before the heavier tap. For other cartridges the bullet would normally fall out by the second or third heavier tap.

This made me think that maybe I am not crimping enough. I basically just remove the bell with my taper crimp, but maybe for the 380 it is not enough.

An article from Loaddata that I found, indicate that for the 380auto, they apply a taper crimp to get the case mouth to .3670" to .3695". This to me seems like lot of crimp. I did a few dummy loads to this crimp and found that pulling the bullets felt more normal now, but I could see the crimp marks on the bullet after they were pulled.

So my question basically is, do you crimp to SAAMI specs of .3730", or closer to the .3695" that LoadData uses. The article available to everybody is at:
https://loaddata.com/Article/LoadDevelopment/Top-10-Reloaded-Handgun-Cartridges-7-380-Auto/703

I am definitely going to test this out, and obviously do the normal plunk and cycle/setback test before loading any live rounds, but it will be interesting to find out what everybody else does regarding the 380auto taper crimp.

Please note that I mostly load 95gr FMJ RN bullets.

Do not use a powder measure and expect perfect measurements every time. Hand throw each charge on a beam scale and you will eliminate the one variable that will cause more accuracy deviation than any of the other things you've mentioned. The smaller the charge, the more important this is, and
380s take small enough charges to make hand throwing charges worth it.
If you're already doing the other things you mentioned, it's clear this isn't just range fodder, or if it is, you clearly have a worthy level of reloading OCD.

 

[lordpaxman]

I respectfully disagree hand weighing each charge is going to decrease accuracy deviation wrt powder throws with a semi-auto 380 at 10-20 or even 30 yards.
Given the powder meters well, +/- a tenth or two, and the rest of the process is dialed in, it just doesn’t factor into accuracy or precision. Especially if you’re not using a ransom rest to test it.

 

[entropy]

Then why the concern about neck tension? As long as the bullets aren't backing upon firing, it will affect accuracy less than charge weight.
Just for giggles, I looked up AA#5 with a 95 gr. FMJ, and found a min. of 4.3 gr producing 784 fps to 4.8 gr. going 891.
While it may not follow exactly, that comes to .1 gr equalling @ 21.4 fps.

I'd worry more about uneven seating before neck tension. As I said, exact charges are a variable that is easier to control, and that's what accuracy is about, eliminating variables.

I believe unless you're loading for a fixed barrel .380, even that's a small gain for the work.

Setting the die to COAL for the bullet used should give proper taper crimp. If not, time to whack test some of your loads.

 

[fxvr5]

As I said, exact charges are a variable that is easier to control, and that's what accuracy is about, eliminating variables.

Velocity extreme spread and standard deviation are not correlated to accuracy at typical handgun distance. Obsessing over charge weight in handguns isn't fruitful.

Consistent Velocity = Accuracy - American Handgunner

It’s been said consistent velocity produces greater accuracy. That is, the more consistent the velocity is between shots, the tighter the group. The more the velocity varies, groups will get larger.

americanhandgunner.com

 

[lordpaxman]

Neck tension prevents bullet setback upon feeding/chambering/firing and you do not want setback on such a small volume cartridge. It also helps with powder ignition and burn prior to the bullet even jumping.
I’ll try to find the article but someone actually attempted to seat bullets crooked and compare that to straight and found it really didn’t make a difference. This is with semi-auto pistol at limited range.

 

[fxvr5]

Neck tension prevents bullet setback upon feeding/chambering/firing and you do not want setback on such a small volume cartridge. It also helps with powder ignition and burn prior to the bullet even jumping.
I’ll try to find the article but someone actually attempted to seat bullets crooked and compare that to straight and found it really didn’t make a difference. This is with semi-auto pistol at limited range.

found it;

Crooked-Seated Bullets and Accuracy - American Handgunner

How important is it to seat the bullet perfectly strait in the case? What if the bullet is seated crooked? Read the full article...

americanhandgunner.com

 

[Blue68f100]

Adding crimp will decrease neck tension, like others have said. Neck tension is increased when your putting a bullet into a smaller hole....

If you want to maximize your neck tension try seating a bullet without using the expander. If you have beveled the case mouth, no expander should be needed since most all jacketed bullets have a small radius on the base. Just got to make sure you start them straight.

btw, I never liked loading the small 380's or smaller. With narrowed powder range it just give you more variations.

 

[jmorris]

Please note that I mostly load 95gr FMJ RN bullets.

Who sells those?

 

[jmorris]

I basically just remove the bell with my taper crimp,

That is what I do, hold the bullet with neck tension of the case.
Once you crimp enough to distort the bullet, you can forget about accuracy. Why they are selling these, they don't want their name of the box the ammunition comes out of to gain the crummy reputation.

My process is basically to sort by headstamp, and then also sort by case length to get some consistency over at least 5 test rounds. Even with this process I have found that my ES and SD numbers are not very good.

I'd start your process with good factory ammunition, head stamps will already be sorted and you can see what numbers machines, costing thousands of dollars more than what we have, can produce. Speaking of numbers, I try and quantify things as much as possible. "Good/bad" are fine when we have two things to compare but even then there is no idea of how much better or worse something is.

Having ES and SD numbers that are "not very good" also doesn't mean that much to me. At pocket pistol ranges, I'm not even sure they matter unless they are in the 4 digit range.

What is the range to target? I know I am going to have something like 13 feet of drop with a .22 lr at 300 yards, so I can see the benefit of low ES/SD. However, shooting my NNA at 3 yards, it's inaccuracy isn't because wildly different trajectories caused by different exit speeds of the bullets...

 

[Walkalong]

Velocity extreme spread and standard deviation are not correlated to accuracy at typical handgun distance. Obsessing over charge weight in handguns isn't fruitful.

That's what I have experienced as well. I had a bad time with .380 in the beginning, but finally bought a set of RCBS .380 dies and it solved my lack of neck tension issues.

I like AA #2 and W-231 in the .380, they shoot about as well as I can shoot with small pistols. Well enough that after all these years and all the new powder options I haven't tested any further. I use enough taper "crimp" to remove the bell, maybe a hair more on longer cases, just like other auto cases.

Some 95 Gr soft point over runs I bought, they don't shoot as well in 9MM as some other
95 Gr bullets I bought, so I relegated them to .380 where all we do is up close practice.
If I was going to get serious about .380 again, I would try N-310 & WST.

 

[Tall]

I have a Browning Model 1911 in 380 ACP. With factory PMC 95 grain FMJ it is not reliable. Maybe one malfunction per magazine. I am going to try my handloads they must give an improvement or I will sell the gun. I have a Lee FCD carbide die that will do a taper crimp on them.

 

[buck460XVR]

I might consider the sizer and expander, brass and bullet size if neck tension is a concern but not increase taper crimp on a bullet with a real jacket

Yep. I had similar issues as the OP when first starting to load for .380 and it came down to the Lee sizing die not sizing the brass enough. When I contacted Lee, they said this is a common issue with their .380 die and suggested I buy the "undersized" die. Took care of my issue, but seems to me if they know their regular die has issues, why even sell it in their 3/4 die sets? Now I have enough neck tension, that all I have to do for crimp is take the flare out.

 

[Charlie98]

I would either try a different headstamp brass, or a different sizing die... like others have mentioned.

@shoebox1.1 and I were just having this discussion about some of his .38SPC brass... some of the brass would allow you to just push the bullet in. Sure, you can crimp it to hold the bullet, but that's not really the solution.

 

[vaalpens]

I just want to thank everybody for your responses with recommendations. It will take a bit of time to go through all of them, but I will and will respond to each one of them.

Just based on what I have read so far, it seems we all are doing the same way regarding taper crimping. Just remove the flare but do not crimp jacketed bullets. It is just strange to me that LoadData would crimp the jacketed bullet to .3670" to .3695". I will probably still do a test load and compare it against a load with my normal crimp process.

 

[mdi]

Perhaps we should change the name/nomenclature of the final step die to make it easier for newer reloaders. I no longer think of it as a taper crimp die, but a deflaring die. I just touch the mouth of the case, removing any flare, enough to get good plunk testing. Has worked on my 32 ACP up through m 45 ACP handloads for quite a while...

 

[Walkalong]

I just want to thank everybody for your responses with recommendations. It will take a bit of time to go through all of them, but I will and will respond to each one of them.

Just based on what I have read so far, it seems we all are doing the same way regarding taper crimping. Just remove the flare but do not crimp jacketed bullets. It is just strange to me that LoadData would crimp the jacketed bullet to .3670" to .3695". I will probably still do a test load and compare it against a load with my normal crimp process.

I'm doubtful more crimp will affect the ES/SD numbers significantly, or increase accuracy, I would be more concerned with good neck tension, but I'm looking forward to your results.

 

[vaalpens]

I would either try a different headstamp brass, or a different sizing die... like others have mentioned.

@shoebox1.1 and I were just having this discussion about some of his .38SPC brass... some of the brass would allow you to just push the bullet in. Sure, you can crimp it to hold the bullet, but that's not really the solution.

Thanks for the comments. This issue is with all the headstamps I have as far as I know. I ma going to order the undersized sizing die and see if it makes a difference.

 

[vaalpens]

I'm doubtful more crimp will affect the ES/SD numbers significantly, or increase accuracy, I would be more concerned with good neck tension, but I'm looking forward to your results.

The more crimp will probably just help with any possible setback, but not neck tension. I am planning on ordering the undersized sizing die, and then do some testing.

 

[vaalpens]

Yep. I had similar issues as the OP when first starting to load for .380 and it came down to the Lee sizing die not sizing the brass enough. When I contacted Lee, they said this is a common issue with their .380 die and suggested I buy the "undersized" die. Took care of my issue, but seems to me if they know their regular die has issues, why even sell it in their 3/4 die sets? Now I have enough neck tension, that all I have to do for crimp is take the flare out.

Thanks for the comments, and yes, you are correct. Why sell something that you know you have an issue with. I am planning on ordering the undersized die.