.380 load question

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jwrowland77

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Ok I was having an issue with the bench push test and I want to see if this sounds right. I think I have fixed it.

Using R-P case. After sizing the mouth it .3645. After flare the mouth is .3685 then after I seat and crimp the mouth is .3700.

With the measurements above, does it seem like I should be getting enough tension?

Earlier I was basically leaning on the cartridge against my bench and was getting setback. With the measurements above I was doing the push test from above with just my fingers basically until I got white knuckles and leaving a dent in my bench and there was no setback.

The reason I guess I'm a little over worried is because I am doing these for my parents and just want everything to be safe.

Also would I be safe in using this seat and crimp with Federal and Win cases?

Any and all help is appreciated.
 
What I would do is measure the COAL of a few rounds, then load them in the handgun mags to be used and chamber them each from the mag without firing. Measure the rounds again and see if the lengths are exactly the same as before.
 
LivewireBlanco said:
What I would do is measure the COAL of a few rounds, then load them in the handgun mags to be used and chamber them each from the mag without firing. Measure the rounds again and see if the lengths are exactly the same as before.
Click to expand...

I did that as well. Loaded the rounds into the mags and racked the slide pretty hard, and there was no setback by doing that.
 
.370" is WAY too much taper-crimp.

A factory loaded .380 ACP round will measure in the vicinity of .371 - .373".

Any more taper crimp then that will squish the bullet and make neck tension looser.

The hard brass case will spring back more then the soft copper jacket and softer lead core of the bullet. That makes the bullet looser in the case, rather then tighter.

rc
 
rcmodel said:
.370" is WAY too much taper-crimp.

A factory loaded .380 ACP round will measure in the vicinity of .371 - .373".

rc
Click to expand...

Question...am I not flaring enough? Because I'm flaring just enough to set bullet on top and it not fall off. I figured if after the flare, the mouth is still larger than it was after flaring, pretty much all I was doing is seating the bullet, since the mouth is larger.

I'm a little perplexed, to say the least.

Side note: I had seated a bullet with crimp backed off from where it is now and pretty much come up to same mouth measurements are seating of .370.
 
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RP brass is thinner so you will have a slightly smaller reading. If you can detect that the flare is still there you need to use the crimp die to remove it. Over flaring will give you less neck tension just as doing to much crimp.
 
Blue68f100 said:
RP brass is thinner so you will have a slightly smaller reading. If you can detect that the flare is still there you need to use the crimp die to remove it. Over flaring will give you less neck tension just as doing to much crimp.
Click to expand...

That's kind of what I was thinking. Right now, the only way you can tell I flared the brass is with the calipers. I figured with the mouth measuring smaller and the larger after the bullet is put in, then the bullet has to be stretching the brass a little and giving neck tension at same time.

Can I keep my setting for WIN and Federal headstamps? I'm OCD so I'll be checking those measurements as well.
 
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