Diagnosing plunk test failure

Outlander has the right of it. You need to compare the shape of the ogive along the sides to a regular round nose bullet so that it matches the curves even though it ends up shorter overall. Does Campro have any data on suggestions for a range of length for this bullet?

My opinion is that the pinching you have there is excessive. The proper crimp for any round that is head spaced off the mouth of the casing is an amount which is basically a "no crimp" amount. With a slight error of pinching into the bullet being OK if that's what it takes to pass the plunk test. But I consider the amount you show there as far too much. And in fact part of your issue might even be that there's a resulting bulge in the casing behind the crimped area which is causing the issue. Seen that from the force needed for a strong crimp as well.
 
Wish I was home to meet and see the whole issue with my own eyes.
Not all bullets are the same even if they weigh the same. Shape matters big time.
If plunk test is ok then don't worry about rotation. Reload 5 rounds and go to the range. Shove them rounds in the magazine, rack the slide and see if it feeds. If so shoot the first. See if the shell was ejected and the next one went in the chamber. If so find the spent case and inspect it. If it looks normal and the second round is in the chamber fire the gun till the slide stays backwards. Then go home and inspect all casings and barrel. If everything looks fine then reload 50 rounds and repeat the test.
Just make sure your powder is at the minimum allowed at the first try.
Don't get to worried. It is a process of trial and as long you're not loading to wild pressure you are just fine.
 
09outlander said:
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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I happen to have a couple of Berry's Bullets 230 round nose handy. The bullet's length is 0.640 for one and 0.642 for the other. Call it 0.640 to make the math easier.

Also if it helps at one time I did up a batch of 500 cast bullet loads for .45acp using Bullet Barn's LRNFP. So sort of similar to the Campro flat nosed bullets if you stand back a ways and squint a little..... To get the sides of the ogive right the final OAL for these ended up being 1.20". A value for OAL that I suspect you'll be very close to with the Campro bullets when they fit correctly. These shot well for me and I've only got a few left over at this point. At the time the cast bullets were cheaper than the plated. But that switched around and now I can buy Berry's or Campro for cheaper than the locally cast lead bullets.
 
Bynming said:
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.
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If the bullets in your photos are plated that is way to much crimp. When I taper crimp it is to just streamline the case mouth and if I remember correctly the case mouth is only reduced .001 to .002 smaller in diameter. The case is to headspace on the case mouth and the bullet grip is controlled by sizing and the expander. Meaning the taper crimp should remove the case mouth belling and just streamline the case mouth.

My guess is your crimps are causing a bulge just below the crimp and the Lee Carbide crimp die will squeeze down the bulge.

And again the main culprit that causes this are cases not trimmed to the same length or over crimping.
 
BCRider said:
Outlander has the right of it. You need to compare the shape of the ogive along the sides to a regular round nose bullet so that it matches the curves even though it ends up shorter overall. Does Campro have any data on suggestions for a range of length for this bullet?

My opinion is that the pinching you have there is excessive. The proper crimp for any round that is head spaced off the mouth of the casing is an amount which is basically a "no crimp" amount. With a slight error of pinching into the bullet being OK if that's what it takes to pass the plunk test. But I consider the amount you show there as far too much. And in fact part of your issue might even be that there's a resulting bulge in the casing behind the crimped area which is causing the issue. Seen that from the force needed for a strong crimp as well.
Click to expand...
Campro lists the OAL to 1.25" on the data for this specific bullet, but I seem to need to go below 1.235" to avoid touching the rifling. They also list the "taper crimp" to 0.464 which is apparently too much as you can see from the dented bullets. Would you say that it's dangerous or can I shoot those loaded cartridges?

09outlander said:
You really only want to remove the bell you put in the case mouth to seat the bullet, not much more of a crimp is needed.
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That's what I'm looking to do now. It seems to work with a shorter OAL.

09outlander said:
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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I'll get myself some factory rounds then.

bigedp51 said:
If the bullets in your photos are plated that is way to much crimp. When I taper crimp it is to just streamline the case mouth and if I remember correctly the case mouth is only reduced .001 to .002 smaller in diameter. The case is to headspace on the case mouth and the bullet grip is controlled by sizing and the expander. Meaning the taper crimp should remove the case mouth belling and just streamline the case mouth.

My guess is your crimps are causing a bulge just below the crimp and the Lee Carbide crimp die will squeeze down the bulge.

And again the main culprit that causes this are cases not trimmed to the same length or over crimping.
Click to expand...
Alright thanks!
 
09outlander said:
My OAL when using these bullets is 1.164"
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Damn, good to know. Doesn't the bullet start tapering inside the case though? That's quite a bit shorter than what I've needed.

It looks like if I had just disregarded Campro's published data I would've been fine but I went and followed what they put on their website and it's just a mess that makes no sense.
 
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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.
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I too use a factory crimp die with the internals removed for 40 and 45 on my Dillon 650 final stage. Works great
 
Bynming said:
Damn, good to know. Doesn't the bullet start tapering inside the case though? That's quite a bit shorter than what I've needed.

It looks like if I had just disregarded Campro's published data I would've been fine but I went and followed what they put on their website and it's just a mess that makes no sense.
Click to expand...

No, if you were to measure a Campro round against a standard ball round the distance between the ogive and base of the bullet will be nearly the same, it's only the distance from the ogive to the tip that is different.
 
Bynming said:
Damn, good to know. Doesn't the bullet start tapering inside the case though? That's quite a bit shorter than what I've needed.

It looks like if I had just disregarded Campro's published data I would've been fine but I went and followed what they put on their website and it's just a mess that makes no sense.
Click to expand...

With any load data, the published OAL should not be taken too seriously; it can only be guaranteed to be correct for the same barrel and the exact same bullet used to develop the data. The key is to not get caught up in chasing a particular number for OAL. Whatever fits your gun is the correct OAL.

Some 1911 barrels, particularly GI ones, have a short rifling throat that may require some bullets to be seated surprisingly deep. This is commonly seen with semi-wadcutter bullets. It could be that this is the case for your gun.
 
tjhaile said:
With any load data, the published OAL should not be taken too seriously; it can only be guaranteed to be correct for the same barrel and the exact same bullet used to develop the data. The key is to not get caught up in chasing a particular number for OAL. Whatever fits your gun is the correct OAL.

Some 1911 barrels, particularly GI ones, have a short rifling throat that may require some bullets to be seated surprisingly deep. This is commonly seen with semi-wadcutter bullets. It could be that this is the case for your gun.
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Excellent, good to know. I found other load data that suggests that the powder charges I used are fine with 1.2 too so I just went all the way down to 1.2 and eliminated all issues. I don't know yet how many liberties I can take when it comes to derogating from published data so I guess being a bit shy that way may be causing me some grievances.
 
I have fallen down this rabbit hole as well, my question is if I am using cam pro projectiles and seat them at 1.250 as per their spec it passes the test ok but going by another reloading manual they say 1.20 and it also passes which one should I use or does it matter?
 
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