can you actually deflare without crushing front driving band?

[guy_with_boolits]

1911 45 acp

cast boolits (MP-452-200)

I'm seating and deflaring as separate steps

By deflare I mean taper crimp die but only enough to where it will headspace on case mouth in chamber

My question is..is it possible to deflare in this situation without slightly crushing the front driving band?

I mean I go to alot of trouble to make sure these bullets, after PC'ing and sizing, are .4525

Even a small amount of crushing will waste that

I notice the case wall is .009". So x2 = .018. + .4525 = .4705.

If the case wall is .0005" thicker, now my bullet gets crushed .001"

This seems like a very tight dance to play....is it even possible? Does it even matter? After all its the front driving band getting crushed by this deflare, not the rear driving band which does the gas seal.

This pic exemplifies what I'm talking about, you can see how the slight deflare crimp has crushed the front driving band enough to where its not touching the barrel.

[onelight]

It does not matter to me , the base of the bullet is more important and I consider a crimp important , and it is going to size when it enters the barrel.
Unless your cases are exactly the same length the long ones will crimp more than the short or you will not remove all the flare and the short won't plunk . It's a compromise you probably can't see on paper .
You need enough crimp that they all plunk.

[Ed_Shot]

Agree with onelight, your cases are not all the same length. Your rounds actually headspace on the extractor not the case mouth.

[35remington]

It does not matter. Most of the bullet is unchanged. The bullet is still guided and still seals as it is supposed to.

The cases do not headspace on the extractor. Those with understanding of 1911’s in particular know this to be false. The extractor gap sees to it that it does not do this, and allows the case to be well clear of the breechface by design.

[Char-Gar]

The purpose of a taper crimp is to keep the case mouth from striking the feed ramp in the rounds trip from the magazine to the chamber. As others said, the headspace is controlled by the extractor. I know zero about those silly painted bullets, but setting the taper crimp is very easy and does not "crush" anything. Setting the taper crimp is very easy, and here is how to do it.

1. take a factory loaded 45 ACP round, place it in the ram and run it to the top of the press stroke.
2. Screw the taper crimp down on the loaded round unsinging only hand force.
3. Set the die lock ring and you are done.

[megasupermagnum]

Most of my pulled bullets show at least a tiny indent. All I do when I set my taper crimp dies is I measure somewhere down the case, say it measures .472". I then tighten the die in until it crimps so that I can pull my calipers up the case without it catching. The way you are doing it is correct. A taper crimp is not a crimp. Anything from straight sided, down to a tiny bit inward is acceptable.

More important is figuring out why your powder coating is failing.

[35remington]

Gents, do some relevant measuring and get back to me on whether the extractor headspaces. For those needing some guidance I’ll tell you where to look.

Nothing like finding out by doing it yourself.

Sorry for any drift.

[charlie b]

My purpose in crimping the bullet is to keep the bullet from moving during the trip from the magazine to the chamber. I've had some, mainly when I used lubed bullets, that would get shoved back in the case if not crimped a bit.

After setting the crimp die I check it with a plunk test. Remove the barrel from the pistol and drop the round in. It should chamber on the case mouth (not the extractor).

And, yes, that means the forward drive band under the crimp area would be sized down a little. Never affected accuracy.

[45-70 Chevroner]

Agree with onelight, your cases are not all the same length. Your rounds actually headspace on the extractor not the case mouth.

I think you need to look up headspace for simi autos. The case actually does headspace on the mouth of the case, that is why you only taper crimp. If they headspace on the extractor you would be replacing extractors all the time.

[44MAG#1]

Are you wondering about the cases headspacing or accuracy of the bullets because of being squeezed down slightly?

[JimB..]

So if I chamber a round in a 1911 with the extractor removed from the slide do have infinite headspace, no headspace, or a tear in the time-space continuum?

Yes, some guns will headspace on the extractor, but it just means that the extractor geometry is wrong, the cases are less than min length, or you’re way overcrimped.

[35remington]

He’s wondering about accuracy. We are causing thread drift trying to argue about extractor headspacing or lack thereof.

Even a fairly viciously overcrimped case or a plausibly short case won’t do so. All this requires is a knowledge of extractor/breechface gap tolerances and chamber/case dimensions.

What is not realized is a 1911 extractor lets a case get quite a long way from the breech before it can stop its forward movement.

Quite a long way. Well before then the chamber shoulder has stopped the cartridge, not the extractor.

[44MAG#1]

I, as a standard thing, crimp with a fairly heavy taper crimp. I know, I know, everyone will tell me I am wrong but I do it with results that please me.
And so it goes.

[charlie b]

FWIW, I used the maximum taper crimp on some of my .45acp rounds a while ago. They still head spaced properly and I could tell no difference in accuracy. FYI, I am not an olympic level shooter. 6" groups at 25yd is about as good as I can do.

[tja6435]

I, as a standard thing, crimp with a fairly heavy taper crimp. I know, I know, everyone will tell me I am wrong but I do it with results that please me.
And so it goes.

Same here, eliminates failure to feed in 9mm and .45 auto for me. Just flattening the bell isn’t near enough for my guns.

[mdi]

Yes, do it with all my semi-auto ammo...

Regarding head spacing and case length. I haven't measured any 45 ACP or 9mm cases in a very long time, but as I remember my mixed brass varied in length no more than .005" max., so not enough deflaring variation to matter at all. There are some that will measure the case and sort to +/- .002" and measure case mouths post crimping, again holding +/- .002". Good for them, it's their ammo, their guns and their time. For me (and the one competitor I knew that shot 45 ACP Bullseye) my targets show no improvement/reduction in group size, and I still get 99.99% feeding/firing/extraction...

[AZ Pete]

RE: heavy taper crimp....that is subjective. My experience is that if the taper crimp is "too heavy" with my 200 g. SWC's the exposed portion of the front driving band will be swaged up so as to prevent chambering. So for me, crimp just enough to pass the "plunk test", but not so much that you fail the "plunk test". Your dies, bullets and experience may vary.

Regarding the your concern about swaging the front driving band down... That may be academic, the best test is how they shoot.

[kayala]

More important is figuring out why your powder coating is failing.

That would be my first priority as well.

[W.R.Buchanan]

The Taper Crimp on a .45 ACP should be .468-.470. Don't you guys "Measure" this when you are setting up?

Why not? Are you just eyeballing it?

Randy

[guy_with_boolits]

The Taper Crimp on a .45 ACP should be .468-.470. Don't you guys "Measure" this when you are setting up?

Why not? Are you just eyeballing it?

Randy

Measuring the crimp diameter to a meaningful precision is difficult because its an angled ring only about 0.020" long. You can't use a micrometer so you are left with calipers and getting .001" with the blade edges on an angled thin ring seems like eyeballing / wishful thinking to me even though you are using a measuring tool.

I've resorted to setting up by adjusting the crimp die until the completed cartridge plunks in the actual barrel of the pistol and moves freely, then I turn in the crimp slightly more to account for case variances and press sloppiness.

I then plunk each completed round. This is not practical however since I'm learning anyway its good for me to see exactly how all my produced rounds are chambering.

I suppose the proper way to guarantee chambering is to use a factory crimp die which sizes the entire round to a guaranteed-will-plunk diameter.

However that doesn't seem like its going to work for cast boolits. I'm already expanding the case so they wont get crushed. Forcing them to be crushed after that makes no sense, so I'm left with a taper crimp to deflare. And in that case its very sensitive as described above.

So basically my setup for producing cast boolits is:

a) not progressive compatible as I've found COAL and deflaring (plunking) vary WILDLY from round to round if done on the load master, as the forces wobble everything around..we are talking .010" variances
b) not factory-crimp-die compatible since it will crush the boolit I went to all the trouble of not crushing by expanding the brass
c) requires me to use my APP and single stage presses with breech locks to do final boolit seating and deflaring as two separate operations

Now the situation with FMJ boolits would be different. I could use the FCD, and if I allow for some COAL variations, probably do the entire thing on the progressive load master as its supposed to be and live the dream...I will attempt that in the near future

So, let me make a statement and let the hive mind review it:

If you are:

a) expanding the case so the boolits dont get crushed

you therefore cannot logically

b) use the factory crimp die which crushes the entire case and the boolit

so you are forced to

c) taper crimp/deflare, which is only consistent enough to do on a single stage if you truly want it to be just a "deflare", and then only with brass thats relatively similar in length and wall thickness

EDIT: all the above assumes when using the FCD that the taper portion is screwed all the way out so that only the sizing ring is acting