45 ACP Crimp OD?

[SteelCityShooter]

I'm going to help a friend set up his new Dillon XL 650 for .45ACP.  I have one myself but only use it for 9 mm and .38 Special so I'd appreciate some advice for setting up his crimp die. What OD of the  loaded rounds' case mouth am I looking for?  

[IGOTGLOCKED]

16 minutes ago, SteelCityShooter said:

I'm going to help a friend set up his new Dillon XL 650 for .45ACP.  I have one myself but only use it for 9 mm and .38 Special so I'd appreciate some advice for setting up his crimp die. What OD of the  loaded rounds' case mouth am I looking for?  

Been running mine @ .471 brother...

[Steve RA]

Basically, you just want to straighten the case walls.  Crimps are for revolver rounds where the bullet has a crimping groove.

[MAC10]

dead nuts .470 taper for 45acp

[SteelCityShooter]

2 hours ago, Steve RA said:

Basically, you just want to straighten the case walls.  Crimps are for revolver rounds where the bullet has a crimping groove.

Yeah, I know that.  I was just looking for guidance as to what diameter means the belling has been just removed by the taper crimp die. 

 

So the recommended diameter is .470 to .471".   Great, that's what i'll adjust to. Thanks for the help.

[Steve RA]

You can run a straight edge up the portion of the case that encloses the bullet and tell whether the belling has been removed.

[mont1120]

I can tell you what overcrimping does for ya, makes a nice huge hole in the target since the bullet is hitting it sideways...................

[Harpo]

There are several methods I've heard for deciding on/setting the crimp, and you can use whatever method you like.

I've heard of people:

Gradually closing the bell until it'll just "plunk" --that is, drop freely into the barrel, and some people spin it too--.

Adding the diameter of the bullet to twice the thickness of the case wall(and some people subtract 0.001" from that number). An example, just using the numbers found here(because I don't have my notes or any brass nearby) would be:   0.452" + (2 x 0.09") = 0.470"

Gradually closing the bell until it leaves a slight impression in a bullet(you have to pull the bullet to check), then adjusting to have a little less crimp.

 

My method, using plated and coated bullets with range brass, is to use the formula(I think I'm in the camp of subtracting 0.001", but don't quote me on that) to get approximately where you want it, then pull a few to make sure I'm not leaving a dent.

I do it this way simply because there's enough variance that I could go crazy chasing the "perfect crimp", instead of just accepting that not every round will be within 0.001" of what I'm aiming for.

[njl]

I've never seen .45acp as thin as 0.009".  If I'm loading .452 plated or coated bullets, crimp is only to about .473" or the bullets get a crimp ring.

[HHjr]

On 1/13/2019 at 11:22 AM, Steve RA said:

Basically, you just want to straighten the case walls.  Crimps are for revolver rounds where the bullet has a crimping groove.

This pretty much ... plus a little......Stop trying to chase a crimp taper number of .xxx.    Please!   Set your stand alone crimp die so it just burnishes the case edge and Stop!!! You can see it as you rotate the round....... Everyone’s measurement will be different on how They hold their caliper.... please no numbers needed!

 

H

[Glockster1]

On 1/13/2019 at 7:55 AM, SteelCityShooter said:

I'm going to help a friend set up his new Dillon XL 650 for .45ACP.  I have one myself but only use it for 9 mm and .38 Special so I'd appreciate some advice for setting up his crimp die. What OD of the  loaded rounds' case mouth am I looking for?  

 

I always crimp just enough that the crimped case mouth is only around .0005 smaller than the O.D measurement .070 below that.

[HHjr]

55 minutes ago, Glockster1 said:

 

I always crimp just enough that the crimped case mouth is only around .0005 smaller than the O.D measurement .070 below that.

Really ..... measuring to .0005 accurately consistently....?......  I just humbly say please stop.    But say you can That’s cool but not necessary for this purpose 

 

H

[Glockster1]

14 hours ago, HHjr said:

Really ..... measuring to .0005 accurately consistently....?......  I just humbly say please stop.    But say you can That’s cool but not necessary for this purpose 

 

H

 

Yes. It's an accurate measurement as long as you're using the same brass head-stamp and your brass is length trimmed all the same. But if you're just using mixed head-stamps, or brass that's been fired 6 or more times, then just get it close to that. i doesn't have to be exact, but that's what I do and mine are all within around a .0003 tolerance. I got used to doing that from all the bench rest rifle rounds I load.

[Absocold]

Case wall at .4732 and the crimped area at .4730 is specified.

 

However, unless you're doing 50+ yard bullseye competitions it's not super critical and calipers are not required. As long as the round chambers easily and you have the tiniest bit of crimp, all good. Under crimping will cause feeding issues and may cause bullet setback during feeding. Over crimping will cause poor accuracy and increase chamber pressure. Your gun will tell you what it likes.

[HHjr]

Non of these crimp numbers listed matter Unless you take the time to separate your brass as mentioned and can repeat the measuring location on the cases to a microscopic level .....and this for The Average reloader is just not even required. The probability of holding accuracy to One Tenthou is pretty lofty 

 

Set your separate crimp die to slightly turn in and burnish the case mouth .... that’s it Done

 

And I’m done.... go For It Lady and gentlemen reloaders.   Cheers!

 

H

[K-Texas]

.45 ACP case neck thickness varies, and probably has for longer than the other auto-pistol cartridges. I've definitely seen brass as thin as .009". So I agree with several points like HHjr mentioned, you're probably wasting your time to set Taper Crimp with one particular case if you load mixed headstamp brass.

 

I also agree that if you're using a single brand of cases, or if they are all the same thickness, Thickness x 2 + bullet dia. will give you the finished dia. after the flare is removed, with a straight case wall resulting.

 

Then there's the matter of cast/coated/plated at .452" vs jacketed at .451. With the larger dia. bullets you're already getting an extra .001" of interference fit between the bullet and case-neck. Some choose not to use any Taper Crimp, and simply removing flare is not taper crimping until you turn the case-mouth into the bullet.

 

For JHPs - I don't load FMJ - I use the simple formula mentioned and subtract .002" to get .002" of Taper Crimp, but I do segregate cases, and that's not quite as hard as it sounds. After a few times of sorting you'll learn which brands are thin, thick, or in-between. I like the in-between for JHPs, but thin cases get loaded with coated bullets due to the larger dia. of the bullet.

 

When I see mention of over-crimping, it makes me wonder how that is defined by that individual. To over-crimp to the point that the case-mouth doesn't headspace properly would be worse than extreme, and a review of the process is in order. .002" of taper crimp is plenty for jacketed bullets, and .003" is not so much to adversely affect accuracy. For you guys that also load for revolvers with JHPs that have cannelures, you probably don't think twice about roll crimping into it. So with a proper taper crimp on a jacketed .451" bullet, all you're really doing is creating a mini-cannelure. Taper crimp dies, however, are not all the same, and I like the REDDING stand alone taper crimp dies, myself. Rather than having a slight single-angle drilled into it, it has 2. The first being the longer one that's not quite as acute as typical TC dies, then there's a second angle higher up in the die that works directly on the case-mouth itself, which you can feel when you set up the die.

 

 

Edited March 5, 2020 by K-Texas