1st batch of 380 failing plunk test

[BondoBob]

I ordered the Lyman M expander die. Hopefully that does it. If I end up needing to replace the FCD as well, Ill return the Lee aet and start over with another
brand.

[Aguila Blanca]

Originally Posted by Geezerbiker

Do yourself a favor and get a RCBS taper crimp die. I've found that Lee factory crimp handgun dies to more harm than good... I'm not Lee bashing either. I have a lot of Lee tools that I think are both clever in design and well made.

Yeah, I know someone else who keeps telling me that.

All I know is that I have loaded many thousands of rounds of handgun ammo, all except maybe a dozen .44 Colt Original prototypes done with Lee factory crimp dies. I haven't experienced any issues that would suggest to me that the FCD is doing bad things, so my view is ... "If it ain't broke, don't fix it." I'll keep on using the FCD unless/until circumstances take me in another direction.

[BondoBob]

I fired the rounds that did come out ok yesterday. They worked great. Fed, fired and ejected just as good as store bought ammo. They did seem pretty hot compared to box ammo though, due to the shorter COAL I guess. So, I think downloading from the minimum powder charge a bit might have been better. But they seem to be at what would have been the max.

I ordered the M die. I'm pretty sure the problem is my technique not getting all the bullets in strait. Hopefully the Lyman M die will help with that.

[scatterbrain]

Looking quickly through these posts, and having similar issues in the past I would check the length of your fired brass to see that it is the SAME length. Length controls the amount of bell on the case. Next thing, how can you test the the sized case, with bell, in your chamber, I never could. With large diameter bullets on short cases I needed more bell to get them straight and they wouldn't drop in until crimped.

[Aguila Blanca]

Originally Posted by BondoBob

They did seem pretty hot compared to box ammo though, due to the shorter COAL I guess.

What shorter COAL? You're considerably longer than the bullet manufacturer calls for, and just .002" under the SAAMI maximum COAL for .380 ACP.

[m&p45acp10+1]

Bondobob have you tried turning the seating die down half a turn, and repeating that until offending rounds do chamber? Also seat that longer bullet a wee bit deeper. I had the same problem with my LCP and the Berry's 100 grain bullets. My Browning .380 1911 feeds them without problem. If they are too long my LCP chokes on them.

[kmw1954]

My experience with the 380acp with both plated and cast lead bullets.

My 380acp is loaded on an junk antique Lee 3 hole Turret Press with simple Lee Carbide 3 die standard pistol die set with the Lee powder thru flaring die so I can use the Lee auto powder measures.

On this setup I have loaded Xtreme 100gr RNFP, Berry's 100gr FBRN and Berry's 100gr HBRN plated bullets. For cast bullets I've loaded a 35692 RN from unknown mold, Lee 356-95 FP and a Lee 356-102-R1. Some of the cast lead 95gr and 102gr Lee bullets had been powder coated. Also checking my log book I have loaded the Lee 356-102 sized at .356", .357" and as cast at almost .358" With the plated and cast bullets I've used lengths from .955" to as long as .970".. The cast Lee 95gr FP was loaded to .930"

Again all of these finished with just a 3 die set and the seating and crimping all done in one stroke, All rounds loaded are also done with sorted head stamps just for consistency.

At this point I am trying to understand why these are not passing the magic Case Gage of whatever manufacturer. Also knot understanding why the Lee Carbide Factory Crimp Die is not post sizing these rounds.

I have shot these in 380acp rounds in 4 different pistols with the setting point being that the length must fit the shortest chamber.

BondoBob I surely hope you can get this sorted out.

[Unclenick]

I think because he was seating too shallow and getting the bullets started in canted and didn't have a seating die ram that tended to straighten the bullet nor had enough seating depth for the sides of the case to do some degree of straightening, he got the bulge in the case over top of the bullet base that has the rub marks in his photo. The M-die will stop it regardless of his seating depth. Why the CFCD didn't iron it out is a good question. It may just be springing back.

[kmw1954]

Agreed that I believe his seating depth is too shallow. In my mind for the Berry's .356" 100gr RN even at .970" is too long.

He states the empty sized case will drop right in and right out so the sizing die appears to be working correctly. I always adjust the Lee powder thru flare die as per Lee's instructions. As I have tried one cannot over flare with this die and in some cases with cast bullets I wish it would flare more. So I suggest setting the die per Lee's instructions and start with a new clean dummy round.

This is more work but may prove the fault. Adjust the seating die out so there is no crimp and try seating a bullet to .970".. At this point the bullet should not drop into either the barrel or your test gauge because of the flare. Now back the seating stem out so it will not make contact and then slowly turn the die down to start removing the crimp. Here you can raise the round into the die and slowly turn the die until it makes contact. From there lower the ram, turn the die 1/4 turn and continue this until it will drop into the case.

From here you may have to adjust the bullet seating depth a little deeper if the bullet is hitting the lands/rifling and is sticking or won't chamber completely in the barrel or will not fall out when turned upside down.

Also try this W/O the Lee CFCD.

[BondoBob]

What shorter COAL? You're considerably longer than the bullet manufacturer calls for, and just .002" under the SAAMI maximum COAL for .380 ACP.

Aguila, I was referring to the fact that I used Jacked bullet data for a plated bullet. I didn't have any powders on hand that were listed in my load data for plated. The Min COAL (as Lee Manual States it) was. .980 for Jacketed bullets with Universal powder. It did not occur to me to use the .960 COAL that Lee stated for the plated bullets with other powders. Lee lists a min OAL not an average or a maximum. So, I assumed that going deeper could create over pressure. I decided to experiment with this load erring on the side of caution. After reading the responses here, I went back to the press and re-seated them down to .960 then went to the range. I did not re-crimp only pushed them in .022. Best 380 rounds I ever shot.

I didn't even try chambering in my guns the rounds that failed the chamber checker. I'm very new to reloading (less than 500 rounds under my belt) so I'm being very cautious.

The case lengths checked out ok.

Thy Lyman M die should be here in a week or two. I'll return and post results here.

Shooting for 100% success rate (pun intended) like I get with 38 and 357.

[74A95]

Originally Posted by BondoBob

I didn't even try chambering in my guns the rounds that failed the chamber checker. I'm very new to reloading (less than 500 rounds under my belt) so I'm being very cautious.

You're overly cautious. Whether or not your loaded ammo fits the chamber checker is irrelevant. All it does is determine if the round fits the dimensions of the reamer used to cut the chamber checker. The reamer used for your barrel might have different dimension and still be within SAAMI specs.

Your ammo has to fit your barrel's chamber. And it has to fit your magazine and feed reliably. That's all. Really.

You won't be shooting the ammo from your chamber checker, so, and this bears repeating, whether or not your loaded ammo fits the chamber checker is irrelevant.

Really, it would be okay to throw away or put the chamber gauge in a drawer and forget about it. People get confused by chamber gauges and think their ammo MUST fit it. It doesn't.

Just because a round DOES fit the chamber gauge does not mean it will fit your barrel. People see this happen, too, and get confused about it and think they have a bad barrel. They don't. Companies use different reamer dimensions for their barrels. It does not mean the barrels are defective (although that does happen).

[BondoBob]

74A95, I tried them in the barrels. Most don't drop in. Some did, but need a little push and failed to drop out. I suppose I could try firing them. But these pocket pistols are finicky as it is. I believe that this indicates the chamber checker I have, while less forgiving, is pretty darn close to the Kahr PM380 barrel. The Sig P238 is a tad wider but not much, almost the same results.

[HiBC]

BondoBob....

Imagine you are making replacement aircraft parts that will be sed to keep them flying in a combat zone.

You don't have the plane in question(a chamber) to try your part on.
The mechanic needs a part that fits any aircraft built to specs. Done right,engineering and tolerance study allows a gauge to be built so that if it passes the gauge it should fit any airplane.

Same with guns,reloading,and guages. SAAMI documents the standard dimensions for USA ammo and guns.

Your gauge is the last word that your ammo passes SAAMI dimensions and should run in any SAAMI gun. (for the dimension(s) the gauge is designed to check)

Your gauge is not junk,and IMO,it would be a mistake to retire it to a drawer.

Am I correct,you have more than one .380? What if you buy another? Do you want to discover you loaded 1000 rounds that fit your first gun,but won't run in your new gun?

If the ammo fits your gauge,it shoulf fit any gun made to SAAMI spec.

If your gauge won't accept the ammo,you have a problem to correct. Tilted bullets and distorted cases.

You are taking steps to correct that problem. Great!!

To not fully solve the tilted problem,you have ammo the gauge rejects.
Because your chamber has some diametral tolerance,it accepts some reject,non SAAMI ammo. You can use your chamber to sort reject ammo.

Or you can refine your skill and process to make only good,SAAMI ammo.

The gauge is a good tool to assure your ammo remains quality.

You are new to reloading. You get to decide if you produce quality,or mediocre ammo you have to sort.

[Aguila Blanca]

Originally Posted by HiBC

Same with guns,reloading,and guages. SAAMI documents the standard dimensions for USA ammo and guns.

Your gauge is the last word that your ammo passes SAAMI dimensions and should run in any SAAMI gun. (for the dimension(s) the gauge is designed to check)

Your gauge is not junk,and IMO,it would be a mistake to retire it to a drawer.

Good explanation.

Originally Posted by BondoBob

74A95, I tried them in the barrels. Most don't drop in. Some did, but need a little push and failed to drop out. I suppose I could try firing them. But these pocket pistols are finicky as it is. I believe that this indicates the chamber checker I have, while less forgiving, is pretty darn close to the Kahr PM380 barrel. The Sig P238 is a tad wider but not much, almost the same results.

If you have stated which chamber checker you have, I missed it. It shouldn't matter. All the chamber checkers I'm aware of are made to the SAAMI minimum chamber dimensions. This means, as HiBC explained, that ammo passing the chamber checker should function in ANY firearm that meets SAAMI specs -- which have a tolerance for both ammo dimensions and for chamber dimensions.

Which means that the way you expressed the situation is reversed.

"I believe that this indicates the chamber checker I have, while less forgiving, is pretty darn close to the Kahr PM380 barrel. The Sig P238 is a tad wider but not much, almost the same results.'

What you're really saying is that the Kahr barrel is closer to SAAMI minimum chamber dimensions than the Sig P238 barrel. You should be judging the barrels relative to the chamber checker, not judging the chamber checker relative to the barrels.

[hammered54]

never have done 380 but I have done a $h*t ton of 9mm....you said your using the Lee FCD.....in my dealings and looking at your photo....you may have it crimping it to much....looks like its slidding pass the lip it should head space on ( to me)
also make sure seating die is set to not add a roll crimp to it before you use the FCD....
also on the 9mm FCD it resizes it again in and out of the die...so any bulge is gone....it really shouldn't be this difficult.

[BondoBob]

Thanks for all the great feedback. I have and use a Lyman chamber checker for all the rounds I make. I'll continue to use that. I agree with you HiBC that it's the gold standard. 74A95 I appreciate your point, but I want my ammo to fit any 380 in case I upgrade a barrel or trade in a gun down the line. Also, I just want it to be the best I can make it, not just good enough.

Hammered 54, I also believe it should not be this difficult. I have no such issues with revolver cartridges. Since half of my rounds come out perfect and the other half fail, I believe it's my technique getting tilted bullet seating. I don't think it's the FCD because those rounds really struggle to get in and out of that die, while the others glide through smoothly. The bullets are just tilted, there's barely any contact to seat, they are so damn small.

I expect the Lyman M expander die to remedy this. If it were a bad die, I should get 100% failure or close to that, right. Since the Lyman M die also works for 9mm, It's a good value. I expect I may have a similar issue when I start reloading those (soon).

I'll return here and post back the results of my first batch with the Lyman M expander die. We'll see if that does it.

[74A95]

Even when using the Lyman M die, you must be careful to manually get the bullet started straight. If it starts crooked it will stay crooked.

Crooked bullets can cause a problem fitting in the chamber, but they might not have much impact on accuracy. You might find this article interesting:

https://americanhandgunner.com/gear/...-and-accuracy/

What is the diameter at the bulge of the rounds with crooked bullets that don't fit the gauge?

[Bayou]

Don't know if this is a factor or not in OP's issue, but I had a problem with my RCBS 380 flare die a while back. It would apply a very minimum crimp, and when adjusting for a bit more crimp, the flare stem would place buckles on the body of the brass.

The seater stem was marked 38 caliber rather than 380 caliber. I called RCBS about this. The RCBS CS rep said RCBS was familiar with these complaints and had redesigned the flare stem for the 380 die set. A new stem was mailed to me at no cost. The new, redesigned stem was, this time, marked 380 cal.

The new flare stem does not buckle the brass and will apply a generous flare with no issues.

Not sure if this could be a factor in OP's problem, but I thought it would be worth mentioning.

Bayou

[Unclenick]

BondoBob,

I expect the M-die to fix the issue for you. Per the article 74A95 linked to, you need to place the bullets in and see that they are upright, and not just drop them in place, but you will get used to the feel of it rapidly. You will get a much more even bulge all around the case (though runout in neck wall thickness will still make it a little uneven in some cases). You can also look at range pick-up brass with calipers. A thinner neck wall (Remington is thinner in 45 Auto and may also be thinner in 380; you can check) will be less prone to producing an interference fit with a tilting bullet, but it also work-hardens from resizing more because it can expand more in the chamber, so it may not last as many reloadings.


74A95,

That article echoes my experience, though mine is with 45 Auto. I could never see an alignment effect on accuracy with jacketed bullets, but with soft swaged lead bullets, getting them aligned with the bore by seating them out to headspace on the throat reduced groups by about 40% and, as a bonus, greatly mitigated leading. Jacketed bullets seem to be tough enough to avoid the extreme distortion the softer bullets have scraping against the mouth of the throat and can straighten themselves on the way into the bore without distortion issues of any significance.

I think the author of the article was hoping that what applied to rifle bullets would apply to pistol bullets, but a little math shows it won't work out for several reasons. One is that rifle bullets generally have a longer aspect ratio than pistol bullets, especially in the ogive. A typical 7.62 ball bullet is almost 3 times longer in calibers than a typical 45 HP. That moves the center of gravity of the bullet further forward of the geometric center of the bullet bearing surface by a factor of that length ratio. A given in-bore-tilt angle around the bearing surface center of that rifle bullet produces 3 times the eccentricity of the bullet center of mass's spin around the bore axis of an equally tilted HP pistol bullet. As a result, the lateral jump caused by that eccentric spin is three times greater for the rifle bullet, even if you load it down to the pistol bullet's velocity in a barrel with the same rifling pitch. But that's not normally what you have. Normally the rifle barrel pitch is faster and its velocity greater. That means the rifle bullet is generally spinning faster than a pistol bullet. At exit from the muzzle, a 7.62 ball round from a 10" or 12" pitch barrel is spinning roughly four or five times faster than a round of 45 hardball from a standard 16" pitch barrel. That increases the speed of the lateral jump and its resulting lateral drift that stays with the bullet to the target. (This effect is the principal reason for not using an unnecessarily fast rifling twist in a rifle.) When the two differences are taken together, even if you assume the same time of flight to the target for the drift to work, the rifle is typically going to exhibit around a factor of 12 to 15 greater drift from bullet tilt than that pistol bullet does. If a tilted 30 cal rifle bullet can produce up to 1 moa of group growth, as A.A. Abbatiello, an Oak Ridge National Laboratories engineer found in his early 1960s study of Lake City NM ammunition, then the 45 will produce about 0.07 to 0.1 moa of difference from that source of error, which, for statistical reasons, is very hard to discern.

The reason the author's tilted bullets actually shot better in that article's test is something I can only make speculative guesses about. Some of the tilted round may have randomly centered their cartridges in the chamber better. No other reason occurs to me at the moment.

I've never had a Ransom Rest produce pistol groups as tight as I could get off bags by hand. I believe this is mainly because it registers on the grip frame of a gun, where a shooter registers on sight alignment. If a barrel fits up into the slide well, sight and barrel alignment should be consistent, but if the slide is not fit to the frame, registering on the grip frame still allows alignment of the bore and target to shift around by as much as the slide and frame can shift. I've seen it suggested that spring-loaded plastic rollers bearing on the side of a slide might help the Ransom Rest maintain alignment better, but I don't know anyone who has tried it.

[74A95]

Originally Posted by Unclenick

The reason the author's tilted bullets actually shot better in that article's test is something I can only make speculative guesses about. Some of the tilted round may have randomly centered their cartridges in the chamber better. No other reason occurs to me at the moment.

You're assuming that bullet tilt matters for the typical bullet at a typical range of 25 yards. And you're guessing that it was a random fortuitous alignment of the stars (in this case bullets) that was responsible? That's not exactly the most parsimonious explanation.

Another explanation is that bullet tilt doesn't matter for the typical bullet at a typical range of 25 yards

[Aguila Blanca]

Lyman M die update:

As a result of this discussion, I learned that Lyman offers a powder-through version of the M die. It's a multi-caliber set, with one die body and plugs for multiple handgun calibers. It sounded good, and the Lyman web site says, "Fits all standard powder measures."

Fortunately or unfortunately, depending on your perspective, I have learned to never accept any "Fits all" statements as infallible. I reached out to Lyman's marketing director and I asked if the #7767901 Multi-Expand Charge Die System will work with my Lee Autodisk powder measure. I just received a response:

Here is our tech’s answer to your question:

No, it does not accept the Lee Autodisk. It will work with other standard powder measures with a 7/8”x14 mounting thread.

Hope that helps!

Yes, that helps. It means I get to save $47.95 (plus tax and shipping).

It also means I need to look for alternatives if I want to get the advantages of the M die expander. I'm considering buying some Lee expander plugs for slightly larger calibers and turning them down on my hobby lathe.

[Unclenick]

Originally Posted by 74A95

ou're assuming that bullet tilt matters for the typical bullet at a typical range of 25 yards. And you're guessing that it was a random fortuitous alignment of the stars (in this case bullets) that was responsible? That's not exactly the most parsimonious explanation.

Another explanation is that bullet tilt doesn't matter for the typical bullet at a typical range of 25 yards

Saying there is nothing to see here is only the parsimonious explanation when the group differences are small enough to ignore. So you're assuming there is no statistical significance between the group sizes produced by the Redding die (which the author said straightened bullets pretty well) and the group made by the crooked bullets. But the range between the two is about twice that of the 95% confidence level that their averages are not just randomly different in either direction. If the difference is likely real, then it is likely there is an explanation. As I said, mine is speculative. I await something better.

I suppose one path around the statistic of the significant difference would be to argue the top right hole in the Redding die group is an outlier, due, perhaps, to a bullet defect. Dropping that hole brings the size down to just about that of the Lyman group which is just barely under the 95% confidence level difference (about 1.089 times the smaller group size for this sample size). But one normally has to make a pretty good argument for discarding a point in the data because doing so leads to having to show why the most extreme holes in the other groups shouldn't be tossed, too.

[74A95]

Originally Posted by Unclenick

Saying there is nothing to see here is only the parsimonious explanation when the group differences are small enough to ignore. So you're assuming there is no statistical significance between the group sizes produced by the Redding die (which the author said straightened bullets pretty well) and the group made by the crooked bullets. But the range between the two is about twice that of the 95% confidence level that their averages are not just randomly different in either direction. If the difference is likely real, then it is likely there is an explanation. As I said, mine is speculative. I await something better.

I have questions about how useful it is to calculate 95% confidence intervals when looking at group size.

Let's test it. If a gun shoots a 5-shot group that is 0.85", what are the predicted sizes of subsequent 5-shot groups.

If you'd rather not work with 5-shot groups, how about a 15-shot group that measures 1.07"?

[Unclenick]

There are tables for these numbers. The Lyman #47 has a good article on basic stats for shooters that includes the information for 95% confidence intervals. For five-shot groups, 95% will between 65% and 153% of the first group you fire. The remaining 5% can be bigger or smaller. The center of those groups will move around, with 95% being within two times the standard deviation divided by the square root of 5.

The main limitation of these kinds of numbers is they assume the shooter is consistent. That makes them underestimate variation if the shooter gets tired or the light changes or the shooter occasionally flinches. But with a machine rest's data, they tend to run true.

[74A95]

Originally Posted by Unclenick

There are tables for these numbers. The Lyman #47 has a good article on basic stats for shooters that includes the information for 95% confidence intervals. For five-shot groups, 95% will between 65% and 153% of the first group you fire. The remaining 5% can be bigger or smaller. The center of those groups will move around, with 95% being within two times the standard deviation divided by the square root of 5.

The main limitation of these kinds of numbers is they assume the shooter is consistent. That makes them underestimate variation if the shooter gets tired or the light changes or the shooter occasionally flinches. But with a machine rest's data, they tend to run true.

Thanks for those numbers.

So, with the 0.85" value I gave, 95% should be within 0.55" and 1.30".

That value is from this article (https://www.ssusa.org/articles/2019/...ve-shot-group/) in which 10 5-shot groups were fired at 25 yards with the same ammo with the gun in a Ransom Rest, which meets your criteria, " . . . with a machine rest's data, they tend to run true."

According to the 95% interval rule of thumb only 5% should be outside that range. But using the data from the article, 7 groups (70%) of those values are outside that range.

It I apply it to the first group fired (as you specified), which is 2.29" and was the largest of 10 groups fired, the 95% interval is 1.49" to 3.50". From that article, 5 groups (50%) are outside that range.

It looks like the 95% intervals method does not match the actual data.

It sounds like the method assumes that the first group fired will be more-or-less in the middle size range of subsequent groups fired. Seems like a bad assumption.