First failure

[GeoDudeFlorida]

I use the .5 dipper and have noticed same basic volume thing.

That’s why I say give-or-take a tenth or two. I have a “4.9gr of Bullseye” dipper. It’s a modified 0.5CC and I can change my angle of pull to get a higher or lower load pretty easily. Practice.

But I do still weigh each throw, just as a double check. And to test my eye/hand every once in a while. I’m not bothered by +/- 0.1gr of Bullseye. I can’t shoot the difference between 4.8 and 5.0gr and my chronograph can’t tell one from the other either. I keep trying to fool the little bugger but it just won’t play along.

 

[CQB45ACP]

That’s why I say give-or-take a tenth or two. I have a “4.9gr of Bullseye” dipper. It’s a modified 0.5CC and I can change my angle of pull to get a higher or lower load pretty easily. Practice.

But I do still weigh each throw, just as a double check. And to test my eye/hand every once in a while. I’m not bothered by +/- 0.1gr of Bullseye. I can’t shoot the difference between 4.8 and 5.0gr and my chronograph can’t tell one from the other either. I keep trying to fool the little bugger but it just won’t play along.

Yes I knew what you were saying. I've convinced myself I can feel a difference of one or two tenths, but am not about to test myself. That'd take all the fun out of it.

 

[Russ57]

Just how much setback does it take to get into the dangerous range?

The one that blew up on me was a 165 Valiant LSWC, 4.5 grains of Bullseye.

 

[CQB45ACP]

Hey OP, what bullets are those?

Here are 230gr RN .452" x .6415" long, seated at 1.260" OAL (some look shorter, they're not. All exactly 1.260")

No crimp. Zero. Zip.

Edit: expanded with Redding M-type standard sized for 45acp.

Tried to get good pictures of bulge like you did but this is best I can get.

 

[CQB45ACP]

Measure outside diameter of sized brass, before & after seating a bullet. The OD needs to get larger by a minimum of .002" after seating.
Maybe try a Lee Undersized Carbide sizing die?

Neck tensions, mixed brass-

Trying to decipher your chart...the neck tension is the seat or taper crimp measurement minus expanded measurement, correct?

Are you then saying the larger that value, the greater the force required to push back the bullet as shown in first column as # of pounds of force? How'd you measure the pounds of force?

Im probably making this more difficult than necessary, sorry.

 

[emb]

Good article and discussion. I had an issue with some 9mm Luger lead rounds that I loaded not chambering. I was not able to figure it out and couldn't find anything on taper crimping that really helped. I knew the answer had to be in there somehow but lacked the knowledge to figure it out. So, I just pulled the bullets on that lot and went back to using the FMJs I used previously. That solved the issue but without any real understanding on my part. I did not know that it was possible to fire out of battery. Fortunately, mine just jammed. Always something to learn. Thank you.

 

[lightman]

I am glad that you were not injured!

I agree with the others, a heavier crimp is not the answer. The fix will be in the sizing die. I didn't see if you said what sizing die you are using. I load a lot of mixed brass and have had zero issues with bullet set-back using either Dillon or RCBS dies. I did have a problem with a set of Herter's dies. (they are long gone) One of your pictures shows RP headstamp and RP is known to be thinner.

 

[243winxb]

Trying to decipher your chart

Seat minus expanded = neck tension. .472" - .4698" = .0022"

The (#) pounds to move the bullet were recorded using a bath room scale. Made a wood lever to slowly apply pressure to the bullet nose. The highest pounds will be right before the bullet starts moving into the case.

The Winchester brass never allowed the bullet to move at 100 pounds, i gave up.

 

[CQB45ACP]

Seat minus expanded = neck tension. .472" - .4698" = .0022"

The (#) pounds to move the bullet were recorded using a bath room scale. Made a wood lever to slowly apply pressure to the bullet nose. The highest pounds will be right before the bullet starts moving into the case.

The Winchester brass never allowed the bullet to move at 100 pounds, i gave up.

Thanks

You’ll never be able to sell that on Etsy or eBay so can’t you have someone 3D print it? I’m almost serious.

 

[CQB45ACP]

Anyone know the pounds of pressure exerted on a 45acp round being chambered?

Thinking of set back vis a vis @243winxb ’s chart/test

 

[GeoDudeFlorida]

Just how much setback does it take to get into the dangerous range?

The one that blew up on me was a 165 Valiant LSWC, 4.5 grains of Bullseye.

Are the ones you’re using from before they switched to the bevel base?

I stopped using BB SWC in .45ACP after a few I ordered for samples failed the push test. They slide right down while flat based bullets hang tight.