380 neck tension problems...

[Reefinmike]

per my tags on boxed up ammo its been almost a year since ive loaded 380. I sat down tonight to load up some plated bullets for the first time. I had been loading using 102gr cast bullets over 2.7gr hp38 for some plinkin ammo that wont hurt bad out of a 10 ounce gun.

Bullets are extreme 100gr rnfp .355" bullets. I measured a sampling when I first got them, they checked out but my caliper batteries have since died. First issue I ran across was that the amount of flair the lee autodisk measure applied to fully charge the disk was atrocious...

I started loading some with the largely flared out cases. slowly seating them trying to find the max for my TCP... well, chamber on that gun is pretty loose combined with the light rifling in the barrel, I couldnt seat the bullet above max so I backed the oal down to what looked "normal" compared to some factory flat point and rnfp ammo. crimp was just enough to take out the flair in the cases... each and every one failed the push test

Then I used some cases with just a slight bell, just enough to sit the bullet in. varying lengths, same result. Then used cases with no bell in the mouth. bullets seated easily yet still failed the push test :banghead:

I cranked up the crimp- same result. I really cranked up the crimp... to what appears as a moderate/heavy roll crimp? (do lee 3 die 380 die sets have a roll crimp rather than a taper crimp?) This helped but about half of em still failed the push test.

the shellplate on my press just barely kisses the sizing die. cases have always resized just fine.


Im lost. Ive had good luck loading lead. not sure why im having trouble with these plated bullets. They are a bit small but I might just say screw it and work up some 38spl loads with them... or melt em down and cast some bullets.

 

[Jesse Heywood]

Are you able to seat without the expander? Don't know what dies you have, but one possibility is to use an expander with a smaller diameter.

 

[Reefinmike]

yes, im able to seat with zero flair on the case... straight from the sizing die to the seating die

Im using a lee 3 die 380 set. it appears the crimp that comes with this is a roll crimp... which shouldnt matter, just need to take any belling out.

 

[ReloaderFred]

Look for some current Federal or Blazer .380 brass. It has a built in shoulder inside the case to prevent bullet setback. As long as your bullet pretty closely matches the factory bullet, this will cure the setback problem.

The cast bullets are normally .356" and the jacketed bullets are usually .355". This can make a difference, especially if the brass has thin walls, and your die's diameter is at the outside parameter for the caliber.

Hope this helps.

Fred

 

[Reefinmike]

fred- Is that a thing? I am aware of the ammoland 9mm brass and have accidentally picked it up looking for 380. The range I go to weekly is very busy and has a good 2 inches of brass in front of the firing line to pick from. Ive yet to run across any fed or blazer with stepped cases. I found real tula brass of all common auto pistol calibers at my range months before I saw people posting online about them... I try to stay current with my brasses lol.

For what its worth, I pulled 75 odd 380's I had picked up from the range weighed and sorted them before loading several months back. the fmj bullets from winchester, remington s&b, tula etc loaded fine with good neck tension. the plated federals and blazer bullets had the same neck tension problems... I attributed it to the heavy crimp the factories applied that left a slight indentation in the plating... maybe im just having trouble with all plated bullets.

 

[hovercat]

>380 headspaces on the case mouth, you do not want a roll crimp. The 380 case has a taper inside the case. The taper can vary between manufacturers, you may need to sort headstamps for the new bullets.
You can try running the loaded rounds back into the sizing die, just about 0.10" past where you feel resistance.

 

[joneb]

One could have a custom resizing die made.
I have two expander plugs for some cartridges.

 

[Muddydogs]

Seat the bullets deeper. Its not all about OAL as different bullets have different nose profiles some of which could be .01" difference which you are not going to see with your eye but could mean the difference between fully cambering or not.

The dies should be putting a taper crimp on the case but once you cranked up the crimp it probably looks like a roll crimp.

 

[243winxb]

im able to seat with zero flair on the case... straight from the sizing die to the seating die. The sizing die is not doing its job, leaving the inside diameter of the neck to large.

Im using a lee 3 die 380 set. it appears the crimp that comes with this is a roll crimp... which shouldnt matter, just need to take any belling out. Lee"s die is said to taper first, then turn into a roll crimp. From there website. I do not use Lee.

 

[beatledog7]

It is often possible to seat bullets in the case with no flare/expansion/belling of the case mouth. It depends on the bullet's base configuration more than its diameter. Chamfering the inner surface of the neck helps as well.

When you seat the bullet without flaring, you get two advantages: 1) there is no chance of over-flaring and negating the neck tension that you gained in the sizing step, and 2) there is zero need to taper "crimp" (flatten out the flare) because the flare was never there in the first place.

 

[243winxb]

It is often possible to seat bullets in the case with no flare/expansion/belling of the case mouth.

Using a soft lead copper plated bullet as an expander, is not a good idea.IMO.

 

[beatledog7]

If the case mouth shaves the bullet, then a little flare is called for.

But no matter whether there is flare or not, the shank of the bullet does in fact expand the case neck as it is seated. If it didn't, you'd get no neck tension at all.

 

[2 Horse]

Stop using you seating die for crimping. Get the Lee Factory Crimp die and all your problems will disappear. I run a 4 hole turret and use them on everything I load. 380, 9mm, 357 Sig, 357, 44 and 223

 

[gamestalker]

Crimping AL rimless cartridges does not provide, or increase neck tension. The purpose of taper crimping is to remove the bell used for seating purposes only. Increasing the taper crimp will decrease neck tension.

As to your problem, either your sizing die isn't doing it's job, bullets are smaller than thought or should be, bullets are getting shaved during seating, brass is worn out, or all of the above, in my opinion.

Without a functioning caliper it will be difficult to accurately diagnose the cause. Personally, I wouldn't eye ball the OAL for a rimless cartridge. A tested & worked up charge at a specified OAL, can suddenly produce excessive pressures when seated deeper than what it was originally tested at. If it were me, I would either pick up some batteries, and, or, buy a HF $10 caliper to use when your batteries die.

GS

 

[NeuseRvrRat]

is it remington brass?

 

[Skinnedknuckles]

"the amount of flair the lee autodisk measure applied to fully charge the disk was atrocious".

Most likely, you need to readjust the seating die to reduce the amount of flair by raising the die. I've had this problem with my 9mm dies when I rushed the set up.

If that does not work, you can remove the neck expander plug and polish it with some very fine emery, but I wouldn't do that until you got your calipers working to make sure you don't get it too small. You may just have some copper build up or you may need to reduce the diameter so the resulting neck expansion results in the neck tension you want.

The crimp in all Lee autoloader dies is a taper crimp.