Diagnosing plunk test failure

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Bynming

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Hello guys,

I'm here again with a question because better safe than sorry. I've been quite successful reloading 9mm so I decided to give 45 ACP a shot, as I have a Norinco 1911 I'd like to feed. (Yay Norinco!)

I ran everything through the press, I use small pistol once fired brass, 4.2gr of HP38 (starting load) and Campro 230gr bullets. OAL is 1.25. Every cartridge "plunks" in the case gauge fine. I made 40 rounds, trusting the gauge because I'm lazy. When I drop it in the barrel, it doesn't rotate freely like it should. I tried an OAL of 1.235, thinking maybe I was getting some very shallow rifling engagement, but it hasn't fixed it. It seemed better but it could be in my head. Should I try shorter? Should I try the marker trick with the barrel? Anything else I should consider? Are they safe to shoot? They do sit below the lip of the barrel.

For additional info, my full length die is definitely adjusted fine, and my crimp is just enough to remove the bell of the case. It measures at 0.471, perhaps I need more?
 
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I'd think a little more crimp might solve the problem, or the profile of the bullet could be such that it is still just barely touching the rifling. Taking a marker to the end of the case and the shoulder of the bullet would be a good idea. Drop into the barrel and rotate the case a bit. This should show you where the friction is.

I just measured some of my reloads. I don't have any plated bullets loaded up, just Bullet Barn (which have a crimp groove) and Gold Dots, both 200 gr. They measure 0.468. These run fine in my STI Spartan and Ruger SR45.

:) Stuart
 
Seat the bullets a little deeper. If your rounds are going all the way in, but they're sticking a little, you're almost there for correct OAL.

.471" should be OK for crimp diameter; the SAAMI maximum is .473".
 
josquin said:
I'd think a little more crimp might solve the problem, or the profile of the bullet could be such that it is still just barely touching the rifling. Taking a marker to the end of the case and the shoulder of the bullet would be a good idea. Drop into the barrel and rotate the case a bit. This should show you where the friction is.

I just measured some of my reloads. I don't have any plated bullets loaded up, just Bullet Barn (which have a crimp groove) and Gold Dots, both 200 gr. They measure 0.468. These run fine in my STI Spartan and Ruger SR45.

:) Stuart
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Alright thanks I'll try that.
tjhaile said:
Seat the bullets a little deeper. If your rounds are going all the way in, but they're sticking a little, you're almost there for correct OAL.

.471" should be OK for crimp diameter; the SAAMI maximum is .473".
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I did try down to 1.235, which is much shorter than the SAAMI max of 1.275 for OAL, I figured that would be as short as it would be relevant to try? Can the chamber really be that short?

Moose_Master said:
Do ya size yer bullets? Also do ya crimp at all? I asked because some people don't like to crimp and some people never size.
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I don't size my bullets, I've never heard about sizing plated bullets. I do "crimp", but I only crimped enough to remove the bell so that the cartridge would fit in the gauge with no issue.
 
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I load over 25 different calibers. 45ACP is the one that caused problems. Similar to yours.

I doubt it is an OAL issue. It is either too much crimp, causing a little bulge; or not enough crimp, leaving a little bell.
 
Is true, didn't read the Campro part. I'd play with OAL and crimp a bit. If you think you exhausted all the option just call it a day and then tomorrow with fresh eyes and mind try it again. Sometimes it works like magic.
 
So here's what's new... I tinkered with it, I reduced OAL to 1.24 and increased crimp to 0.464. Just reducing OAL didn't work, and just increasing the crimp didn't work, I had to do both. 37 of the rounds pass the plunk test, one is iffy and fails to rotate but it seems to be due to a slight burr on the rim of the case that slightly catch on the lip of the barrel, and 2 mysteriously won't rotate easily and I can't explain why. I may do the marker test with those two but those irregular results are annoying, to say the least... I'll agree with Moose_Master and get back to it tomorrow, I'm getting a bit frustrated and that's not useful.

Nonetheless this is baffling to me. Especially since I had to push the bullet in AND crimp. Is it maybe a bad idea to push the bullet in a little bit further after crimping?

Still open to more suggestions and ideas, and would appreciate an explanation for why 37-38 cartridges started working after doing two separate operations and 2-3 didn't.
 
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Read the link below and the posts and drawings by "Wobbly" it applies to all pistols and uses the barrel as the case gauge. Get your length and check before and after you crimp looking for your case binding.
A Lee Carbide Factory Crimp Die has a carbide ring in the base and will remove any bulge at the case mouth. "BUT" this die does not work with oversized cast bullets and will resize the cast bullets to a smaller diameter.

How to determine Max OAL for a CZ Pistol
http://www.czfirearms.us/index.php?topic=34225.0

Lee Carbide Factory Crimp Die
http://leeprecision.com/reloading-dies/hand-gun-dies/lee-carbide-factory-crimp-die/

"A carbide sizer inside the Carbide Factory Crimp die post-sizes the cartridge while it is crimped so every round will positively chamber freely with factory like dependability."

How many times have you read in a forum that someone never trims his pistol brass. The Lee die above was made for them and longer crimped bulged cases.
 
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bigedp51 said:
Read the link below and the posts and drawings by "Wobbly" it applies to all pistols and uses the barrel as the case gauge. Get your length and check before and after you crimp looking for your case binding.
A Lee Carbide Factory Crimp Die has a carbide ring in the base and will remove any bulge at the case mouth. "BUT" this die does not work with oversized cast bullets and will resize the cast bullets to a smaller diameter.

How to determine Max OAL for a CZ Pistol
http://www.czfirearms.us/index.php?topic=34225.0

Lee Carbide Factory Crimp Die
http://leeprecision.com/reloading-dies/hand-gun-dies/lee-carbide-factory-crimp-die/

"A carbide sizer inside the Carbide Factory Crimp die post-sizes the cartridge while it is crimped so every round will positively chamber freely with factory like dependability."

How many times have you read in a forum that someone never trims his pistol brass. The Lee die above was made for them and longer crimped bulged cases.
Click to expand...

Do you think it would be beneficial for me to just stop using my dillon crimp die? I hear some people use both, but I don't have a free slot on my RL550B
 
I've had issues with some of my 45ACP rounds in the past where I'd get FTF every once in a while and it drove me nuts. Here's my suggestions.

Get a Lee Factory Crimp die as bigedp51 mentioned. You can go on the extreme side and also get a Lee Undersized sizing die.

Some bullets can be on the max tollerance side of the scale and/or some brass walls are a hair thicker than others so when the bullets are seated, the diameter could be a wee bit on the max end of the scale. The Lee Factory Crimp die will resize the full length of the finished ammo.

After adding those two dies, I've yet to have a feeding problem.

Bynming said:
Do you think it would be beneficial for me to just stop using my dillon crimp die? I hear some people use both, but I don't have a free slot on my RL550B
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I would. You won't need both. Just make sure you get the carbide factory crimp die. I believe they make a cheaper steel version.
 
Bynming said:
Do you think it would be beneficial for me to just stop using my dillon crimp die? I hear some people use both, but I don't have a free slot on my RL550B
Click to expand...

Because I had similar problems I seat and crimp in separate operations and this solved 95% of case bulge at the case mouth. This is on a single stage RCBS Rockchucker press and I have never used a progressive press in over 46 years of reloading. Meaning I know nothing about your press and its setup and it could be a press setup problem and not the dies.
 
Just for giggles and to aid in identifying if it's the bullet hitting the rifling or if it's the casing mouth being tight in the bore before it hits the shoulder why not crimp an empty casing by itself and see if that passes the plunk test?

It may be that your barrel was not reamed to the proper size due to worn tooling or some other cause.
 
BCRider said:
Just for giggles and to aid in identifying if it's the bullet hitting the rifling or if it's the casing mouth being tight in the bore before it hits the shoulder why not crimp an empty casing by itself and see if that passes the plunk test?

It may be that your barrel was not reamed to the proper size due to worn tooling or some other cause.
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I assume it would pass now that I've changed the crimp setting but i may try that out just to see if anything interesting happens
 
So I disassembled the problematic rounds and the bullets look like this. Is this normal? Does it indicate way too much crimp? If it's the crimping I'd find that really curious because when I crimp a freshly sized round, the measurement at the mouth essentially doesn't change.

Edit: looks like there's a .009" dent in the bullets, seems to indicate too much crimp... Right? This is what it took to get them to chamber but now it seems like I should worry about a pressure spike from that crimp. Then again my taper crimp numbers are in line with Campro's reloading data... So confused still. So right now, my 37 rounds chamber but I have a dent on the bullets. Brass thickness is .011, bullet is .451, it kind of follows that the location of my crimp on the bullet would measure at 0.442 with a 0.464 crimp.

Am I overthinking this? On one hand, the 0.464 crimp suggested by Campro seems excessive... on the other hand, it seems to be what I needed to get the rounds to chamber properly. Maybe my barrel's chamber is very small?

xUpvL1o.jpg
 
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09outlander said:
230 gr Campro bullet have a flat nose, you must reduce your COAL according, if you don't the ogive of the bullet will hit the lands.
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Not quite sure how to measure it then.

I'm getting conflicting messages though, other people are now telling me that I shouldn't worry about the rotation test and if it plunks in it's fine... 45 ACP is turning out to be quite annoying to reload :p
 
Left is a 230 gr Campro bullet, right is a factory 230 gr American Eagle ball round. As you can see the Campro bullet is shorter, the line is a rough representation of the ogive of both rounds. If you set the Campro bullet to the same OAL as a standard ball round you are going to jam the bullet into the lands.

rx5Fm5q.jpg
 
Pull a 230 gr bullet from a factory round, take it's length and subtract the length of the Campro round, take that number and subtract it from your OAL.
 
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