"Plunk-Test" .45acp Pt.2

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Blazerbowe

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So....

I started the last "Plunk Test" thread:
http://www.thehighroad.org/showthread.php?t=691028&highlight=plunk

Quick Update: I took a few of these to the range over the weekend. All of them flew fine. Only 3 out of 100 had trouble chambering. So, all in all, very pleased. Thx for everyone's input.

New Question: With that success, however, comes some failure. I came home tonight with plans to load another batch of .45acp. Up until this point, I've been using my own once-fired brass. I ran out of that with my last batch so I stopped by the store and picked up a new bag of Federal .45acp brass.

My press is still set up from my last run. So I ran a single round through the press. After seating/crimping, I measured... checked... and attempted the plunk test. This round wasn't even close to "plunking." Only seats about 2/3's of the way down.

A finished round of once-fired brass, which I still have from my last batch, plunks perfectly. This brand new round however, nada. It's shiny new Federal Brass, CCI primer, Hornady XTP 185gr bullet, seated to an OAL of 1.200. Exactly the same as my others minus the new brass. I did 3 rounds, and they are all the same.

Visually, the only thing different is I can see a very defined edge in the brass where the bottom of the bullet sits. Crystal clear. It's not as evident in other rounds so it might just be that it's easier to see in the new shiny case. ?????? Or the Federal brass is a lot thinner? Idk.

Thoughts on this one? This is the first batch of "new" brass that I've ever bought. Am I missing something? Very frustrated. Thx for any input......
 
The bulge would seem to say, thicker brass. Try more taper crimp. The trim length will also effect taper crimp. Some longer than others. No need to trim any 45acp that i ever had. But if over maximum, maybe trim.
 
Look inside an empty case and see if there is a visable ring or ridge inside where a bullet base would normally be.

I know Federal is doing it with .380 ACP now to stop bullet set-back during feeding.
It's possible they started doing it with .45 ACP now too?

If that is the case, the only cure will be seating long enough the bullet base stops just short of the ridge or ring.

And that will work just fine.


PS: Seat your 185 XTP at 1.230" and try it. That's what Hornady says.

1.200" might be too short and getting into the case web taper.

rc
 
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Thx RC..... looked. No visible ridge or anything. Just smooth and shiny. I'm at a loss.

I did set one at the Hornady recommended OAL of 1.225..... with the same result.

(I figured with brand new brass, everything would be WAY smoother. Um... nope.)

:confused:
 
O.K>

Did you size the new brass, or just load it like it came??

Try sizing it first.

And try seating it 1.230" instead of 1.200" like I posted.

rc
 
I am re-sizing the new brass.

I just went in and did 3 rounds at 1.230. Not really any different (from a plunk perspective). The biggest issue with loading them this long however (which I submitted in a previous thread) is that those rounds won't chamber.

Using my Kahr .45, I load 3 rounds into the magazine. When I rack the slide to chamber the first round, the slide will not go all the way forward. And it takes a lot of force to rack the slide back and eject that round. However, moving the OAL on these rounds up to 1.200, fixed that issue and allows them to chamber. That same issue is still there and hasn't gone away.

At the range this weekend, I didn't use my Kahr but instead my 1911. I know the OAL of 1.200 is lower than the one published by Hornady.... but I can't get them to chamber any larger than that.

I've attached a couple pics.
 

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I know some won't want this mentioned, but do you have by any chance a <gulp>

Lee Factory Crimp Die available?

If you do, try using it and see if the plunk test works.
 
On one of the new rounds, use your thumb and try deliberately to press the bullet into the case. If it moves, you may be dealing with a slightly thicker brass. I can't justify this, but it's an easy test. If the bullet moves, re-adjust your crimp to accommodate the new brass.
 
I'm starting to think my knowledge of taper crimps (or lack thereof) may be part of what is hanging me up.

Focusing on 9mm during my first few months of re-loading (and not using much taper crimp, if any at all) I found myself doing very well. I have 3-4 sets of load data, all successful, for 9mm. When I switched over to .45, I've noticed myself having a lot of hangups (all of which I didn't experience loading 9mm).

Anyhoo.... I'm completely open to that fact that:

A) I may need to accept that fact that I'm not taper-crimping correctly.

And...

B) My Hornady die set (which includes a combo Seating/Crimp die in the last stage) may not be the best choice.... according to what alot of y'all say.

If that indeed is what's causing my hangup, I'm open to getting a separate TC die. I have an open spot for it... that's currently occupied with just a COP die.
 
Otto...

Let this be my first new lesson in the topic of taper crimp. How exactly to you measure just the crimp? Am I measuring just the edge of the case mouth, once the bullet is seated?
 
On one of the new rounds, use your thumb and try deliberately to press the bullet into the case. If it moves, you may be dealing with a slightly thicker brass. I can't justify this, but it's an easy test. If the bullet moves, re-adjust your crimp to accommodate the new brass.
Click to expand...

I have a hard time following this. Crimp will not make the bullet tighter in the neck and thus prevent it from being pushed in; only sufficient neck tension from proper sizing can do that.

How exactly to you measure just the crimp? Am I measuring just the edge of the case mouth, once the bullet is seated?
Click to expand...

Yes, the taper crimp should be measured as close to the case mouth as possible with the bullet seated. What is the diameter of the bullets you are using? If you have a fat bullet, say .452", and thick-walled brass, say .008", it may be hard to get the case mouth down to .469" without overcrimping, which can deform or even deplate bullets.

Also, if your barrel has a tight chamber, a bullet with a fat ogive can contact the lands and cause plunk test failure even at the recommended seating depth and with a proper taper crimp.
 
The tounds in your pics are not crimped. they still have a slight bell at the case mouth. The very edge of the case mouth should be less than .472". .469" is prolly overdoing it. Take your loaded round, back out the seater plug, and screw the seater die body in until it crimps the case mouth down to .471". Then while the round is in the foe still, screw the seater plug down tight against the billet nose. That will be the correct setting.
 
I load all of my .45 ACP to 1.200 with the 185 gr XTP. I run them through a Colt 1911 and a Kimber 1911 with no problems.

One thing you might check would be a dirty chamber. My Kimber UCC II is real finicky about using dirty burning powder (tight chamber). Make sure your not getting carbon fouling in the chamber.
 
I think 918v has nailed it.

I used to use the Lee 4-die pistol sets, and have recently swapped out to the Hornady 3-die sets with taper crimp/seating dies. It's a little more complex to adjust, but it sounds like you're not crimping enough.
 
When I have rounds that have seated slightly crooked I see a more pronounced bulge like in your pix and but it's only on one side. These will not plunk or will catch the rim in the edge of the Wilson case gauge. These are set aside for plinking or for the top round in the mag for timed/rapid fire matches because some if them have trouble going all the way to battery.

I get about 15% of cast lead rounds that do this. Fewer with jacketed.

Verify that the crimp is gone first though as mentioned above.

J.
 
They do appear to be seated crooked.

The light 185 bullet doesn't have a long enough shank to straighten itself up in the case.

Try chamfering the case mouth slightly.
Try belling a little more.
Try seating them half depth, then rotating the round 180 degress in the shell holder and finish seating.

It may also be caused by a spec of tumbler media or something stuck inside the shell holder rim and preventing the case from perfectly centering under the die.

rc
 
Your post, #10, leads me to believe that you are seating crimping in the same step. Try seating the bullets and then re-adjust the die for a taper crimp, just enough to remove any flare in the case mouth.

Bottom line the chamber is a hole and the cartridge is a peg. For the peg to go into the hole it has to be smaller than the hole. Your peg (cartridge) won't go in the hole (chamber) because somewhere it's bigger than the hole. Measure the finished cartridge. "Smoke", or use a black magic marker on the bullet to see if it's hitting the rifling...
 
So I just got off the phone with Hornady.... to pick their brain a little. I learned a couple things...

1. My die set is an older set and my seating/crimp die is not a taper crimp die. Which is kinda what I thought. He did say that many people use this die just fine, but it's a little more finicky and takes a little more work to get right. He suggested, like many of you, that if I continue to have trouble... picking up a separate crimp die might be good option. But did give me some suggestions on crimping.

2. He also suggested, with new brass, chamfering the case mouth slightly as new brass may have burrs and whatnot. (Maybe I was talking with rcmodel on the phone???? :)

I really wanna get my die set figured out. I don't wanna just go buy a separate crimp die. (Especially since my last batch of once-fired brass seemed to work fine.) So I think I'm gonna continue tinkering. RC.... I'll try your suggestions next. If push comes to shove, and my head & sheet-rock cant take any more banging, I may break down and get a separate crimp die.

As always, thx for everyone's interest and suggestions.
 
Try belling less, that way you will end up with less bell in your loaded round. I bell only enough to seat the bullet without crunching the case.
 
beatledog7 said:
I have a hard time following this. Crimp will not make the bullet tighter in the neck and thus prevent it from being pushed in; only sufficient neck tension from proper sizing can do that.



Yes, the taper crimp should be measured as close to the case mouth as possible with the bullet seated. What is the diameter of the bullets you are using? If you have a fat bullet, say .452", and thick-walled brass, say .008", it may be hard to get the case mouth down to .469" without overcrimping, which can deform or even deplate bullets.

Also, if your barrel has a tight chamber, a bullet with a fat ogive can contact the lands and cause plunk test failure even at the recommended seating depth and with a proper taper crimp.
Click to expand...
Help me with this one Beatledog. I have experienced this exact issue. Very first batch of .40s I did. Wouldn't pass plunk test and just holding a finish bullet, I "accidently" shortend it a tad. Said to myself "woops"!

Lowered the crimp die just a smidge... plunk test passed and slug was much tighter in the case, hence my statement. Would love to learn more on this especially if my impression is wrong here.

Machine here is 550B

Ex
 
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