Crimp...diddilyimp

[MissionaryMike]

I used to be put a very light crimp while reloading with BBI 147 grain bullets. Unfortunately, I don't recall the measurement. A week ago, I picked up the EGW U-die, and again followed BBI's instructions on how much crimp to start with. For the sake of context, BBI suggests starting with 1/8 turn crimp, while the instructions for the Lee FCD say to start with a 1/2 turn for a "light" crimp. I wasn't getting clean plunk and spin tests, at least not consistently. So, I kept increasing the crimp more and more. My results were getting worse and worse.

This morning, I decided to case gauge, as well as plunk and spin dummy rounds (no powder/primer) WITHOUT crimping at all. These dummy rounds case gauge perfectly. They also plunk and spin perfectly. Without actually running through my FCD, the case mouths are measuring about 0.379-0.3805", which I think is an okay crimp diameter for coated lead bullets, but I'd like some confirmation on this.

If it sounds good to y'all, then I'll set my FCD to crimp to about 0.380, and run the cartridges through so that I can get that diameter consistent across my ammo.

As always, thank you,

MM

[PiratePast40]

My understanding is that you should only be removing the bell on 9mm, not actually crimping the case. That's what I have set and all of my coated 147g bullets are good through the case gauge and pass the plunk test. They're also accurate when I do my job right.

[TDA]

A quick search for "crimp" would most likely turn up about 678,300 threads asking the same question.

But, yes, all you need with a pistol round is a straight case wall. No bell and no "crimp".

Edited November 11, 2015 by TDA

[wav3rhythm]

Thanks TDA, I was searching for "Crip" and I didn't think these guys were into reloading.

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[Hi-Power Jack]

I case gauged, as well as plunk and spin dummy rounds WITHOUT crimping at all. These dummy rounds case gauge perfectly. They also plunk and spin perfectly.

Sounds to me, like:

1. you may not be expanding your case enough to get lead bullets into the case

2. you have at least enough crimp, but just because the plunk / spin doesn't mean that you're

not crimping too much

3. Your next test should be accuracy (too much crimp can affect accuracy, adversely).

Reloads have to feed properly (Plunk Test) and be accurate.

[IDescribe]

Your crimp should be .377-.378.


That said, while many use the FCD with great success, they're unnecessary -- they fix problems that don't exist if the rest of your process is sound, and they're known for causing troubles with lead and coated. Maybe it's time to buy a regular crimp die.

[MissionaryMike]

A quick search for "crimp" would most likely turn up about 678,300 threads asking the same question.

But, yes, all you need with a pistol round is a straight case wall. No bell and no "crimp".

^ I hear you, and yes, it's been asked many times over. Almost too many times that it just takes too much time to weed through it all.

Your crimp should be .377-.378.

That said, while many use the FCD with great success, they're unnecessary -- they fix problems that don't exist if the rest of your process is sound, and they're known for causing troubles with lead and coated. Maybe it's time to buy a regular crimp die.

Thanks, ID. These are the type of hard numbers I was hoping to get as a response. For now, I'm going to stick with the .379-.380". They are plunking and spinning well @ this diameter in my barrel. If they produce good and consistent shots, then I won't change.

I hear what you're saying about the FCD, as I've read that a few times over as well. I guess I was one of those that thought he knew what he was doing with the FCD, at least until I got a U-die. It threw my reloads off a little bit, but I think I can manage, especially since I can bounce ideas and questions off you more experienced guys here on BEnos. I don't take that for granted. I've learned lots....and much more to learn.

Thanks, gentlemen,

MM

[TDA]

"Hard numbers" are not always the ideal situation as they can be dependent on measuring technique and other factors.

Using .45 for an example, you can get bullets in .451". .452", and .453" which will result in different case diameters. In 9mm, Blue 147's are a different diameter than Acme 147's.

That's why I suggest a straight case wall rather that a hard number.

[MissionaryMike]

"Hard numbers" are not always the ideal situation as they can be dependent on measuring technique and other factors.

Using .45 for an example, you can get bullets in .451". .452", and .453" which will result in different case diameters. In 9mm, Blue 147's are a different diameter than Acme 147's.

That's why I suggest a straight case wall rather that a hard number.

I'm right there with ya. But numbers can certainly serve as a reference point. The 0.380" is not so far off than ID's suggested 0.378", so I feel more confident in moving forward with what my personal experience yielded. If, however, my crimp diameter was something like 0.415", then at least I would know that I'm way off the mark, and I can look to correcting whatever user error might be the cause.

Again, I appreciate all your guys' help.

[TDA]

I wasn't meaning to imply that there was a right or wrong method, just putting it out there for consideration.

[dave33]

Mike, for reference, my plated or jacketed loads usually measure out to .377-.378, coated lead bullets up to .356 usually measure .3785-.3795, and coated lead bullets up to .358 usually measure .3795-.3805. I use mixed head stamp brass, lots of random range pickup stuff, and there is most certainly going to be some variation due to that.

I also use the FCD, properly adjusted it works as good as any thing else and wont harm the lead. What die are you using to seat your bullets? If using the Lee seater die you may have it screwed in enough to be taking out the flair and passing the case gage.

[9x45]

Only enough to remove the bell, try this. Mark a load before crimp, then run it thru. It should wipe about .005" of the case.

[adamge]

Good tip x45, thanks.

[IDescribe]

Keep in mind that different case manufacturers make the cases to different lengths. If you're not sorting by headstamp, consistent crimp isn't going to happen.

[Sarge]

Just another reason I sort my brass.

[tcazes]

While that is very true I pick the shortest piece I can find in my stash relatively quickly, then flare to suit. Make sure you flare enough to get a good initial seat of the bullet then ONLY crimp to remove the flare bacj to uniform. Too much crimp will cause plunk failure and case gauge failure as will not enough.

[MissionaryMike]

Mike, for reference, my plated or jacketed loads usually measure out to .377-.378, coated lead bullets up to .356 usually measure .3785-.3795, and coated lead bullets up to .358 usually measure .3795-.3805. I use mixed head stamp brass, lots of random range pickup stuff, and there is most certainly going to be some variation due to that.

I also use the FCD, properly adjusted it works as good as any thing else and wont harm the lead. What die are you using to seat your bullets? If using the Lee seater die you may have it screwed in enough to be taking out the flair and passing the case gage.

^ Thanks, Dave33. I am using coated bullets, and I did a batch last night and was consistently getting 0.3790". With an OAL of 1.1185", I'm getting 100% case gauging, as well a plunk/spin testing. As far as my seating die, I'm using the one that came with the carbide 4-die set. I have the seating die backed out enough not to crimp at all during that station.

Keep in mind that different case manufacturers make the cases to different lengths. If you're not sorting by headstamp, consistent crimp isn't going to happen.

^ I sort all my brass by headstamp.

I need to go chrono the ammo, as well as check accuracy, but it looks like I have a good load here w/ good dimensions. You guys have been a great help. Thank you.

[thermobollocks]

A crimp that's just enough to remove the bell should yield a total diameter at the case mouth of 2 x case thickness at the mouth + bullet diameter. Since my cases are around .010-.011" thick, that means with my .356" bullets, my crimp should be at .376-.378.

[Miranda]

My FCD always swages my lead bullets.

so first a word of warning make sure your lead and plated do not set back

because quite a few of mine did.

win and FC case mouths measure at 11 thousands.

all the others I have measured are 12 thousands.

Welcome to calipers...thermobollocks and I are not really in disagreement.

for win and FC the two case walls add to 22 thousands

.380 inches is the max size for the diameter of the case at the mouth.

.380

minus

.022

is 358.

most 9mm bullets I have measure at .356.

so with win and FC I crimp to .380 .379 and things are good

as long as I use the 38 powder funnel for the lead bullets.

I recall reading a while ago that the lee FCD is not recommended with lead bullets

I can't find that instruction now.

I have tried the plain ole taper crimp die and it seems good for lead bullets.

miranda

[Red Ryder]

Keep in mind that different case manufacturers make the cases to different lengths. If you're not sorting by headstamp, consistent crimp isn't going to happen.

SOOO true! I use the Redding micrometer crimp die. Love it. Very easy to make slight adjustments.

[MissionaryMike]

I'm currently loading FC and *FC* (sorted them together) and the 10 that I just measured avg. out to 11.5-12 thousands of an inch (0.0115-0.012").

(0.0115 x 2) + 0.356 = 0.379" and (0.012 x 2) + 0.356 = 0.38"

I think I'm ok. But again, I'll see how it all runs with the chrono and targets, and to make sure it all goes "pew pew".

[noylj]

Sorting and consistent crimp are about as needed as bicycles for fish. A taper crimp will "crimp" enough for all cases and you'll never see it on target--you aren't shooting benchrest or long-distance rifle, you're shooting, at best, 12 MOA.

From OPs post, it sounds as though the crimp was FAR too much and the cases were actually being crushed.

One veery important thing NOT mentioned was pulling a bullet and inspecting after seating and crimping. I'll beat if the OP pulls a bullet from one of the cases that won't gage, the bullet will have been swaged down in diameter and have a severe crimp ring in the bullet.

The Lee FCD is a solution to NOT setting up your dies correctly and not preventing the bullet from being seated crooked. Better to buy a $10 Lee taper crimp die if you are using lead bullets.

If you want accuracy, size all cases, measure all cases, and set all the long ones aside for when you need accuracy--longer cases = less head space.

Unless you are into "Precision Pistol" shooting, all cases are "the same" and crimp is only to get rid of the case mouth flare and that is ALL it is for.

Much more important to try to push the bullet into the case with thumb or finger after seating to be sure there is enough case tension on the bullet.

Crimp is really a very unimportant thing, beyond getting the rounds to feed and chamber. Your pistol just isn't accurate enough to ever show any variations due to crimp.

[thermobollocks]

Consistent crimp is necessary for feeding, avoidance of setback, and not damaging the bullet. You should be measuring it when you fiddle with your dies just as you'd measure OAL. A couple of thousandths caused by the variation of case thickness isn't even A Thing for PPC shooters, but you should have some idea how much you're crimping in the first place. That said, since my crimp changes approximately never, I don't worry too much about it.

I rolled with the old fingertip micrometer for a while, but why in the world would you halfass it when measurement is so easy?

[MissionaryMike]

Used my loads from the OP w/ crimp the diameter set at 0.379-80" at my very first USPSA match. No problems at all with 120 or so rounds I fired. And thank goodness, too, b/c there's already enough to think about during a match.

[Sarge]

Used my loads from the OP w/ crimp the diameter set at 0.379-80" at my very first USPSA match. No problems at all with 120 or so rounds I fired. And thank goodness, too, b/c there's already enough to think about during a match.

Absolutely! If you take the time to make quality ammo that's a huge piece to the puzzle! That's a very good lesson to learn early on.