.380 bullet push back

S

stephensackro

New member
I have been reloading .380 acp using Missouri Bullets 95 gr RN bullets (.3565 almost .357). Works very well. I recently bought some X-treme 100 gr RNFP platted bullets (.355). I always test a few completed bullets by measure the OAL then pounding the nose on a wood block several times then measuring again for push back. I seem to have push back when loading some of the platted bullets even when I use a very small flare on the case mouth. The platted bullets are a lot slicker than a regular bullet and they are smaller. Wonder why the platted bullets are made smaller? Any one else having problems?
 
I have reloaded a few of the Berrys Plated but I use the Lee FCD with probably a bit to much crimp.I haven't had any problems with these yet after about 250 so far.Are you crimping heavy enough.
 
I taper crimp in a separate step using the Lee factory crimp die. I crimp just enough to take the bell out of the case mount since Xtreme and Berry's recommend not cutting into the platting.
 
In my experience with .380 I don't worry as much about bullet setback as with other rounds. Especially because it's plated I don't do an excessive taper crimp on mine. I'm more concerned about initial C.O.L. So they feed properly.

BTW, most of my range fodder is Xtreme's 100gr RNFP.

But I also don't pound the rounds to check them. Just a simple push on the edge of the reloading table is suffice for this round.
 
I use the Lee FCD on 380 and have never had an issue with setback. Not a huge fan of the FCDs in general, but it does seem to work well for me with 380.

I usually use Rainier 100 gr plated.
 
whose dies are you using? If the expander plug is labeled, what is it labeled for?

Have you tried this test with an actual jacketed bullet? measured the extremes?Measured the expander plug?

The simplest solution is to just buy bullets that work and not use the ones that don't work. Set them on the shelf and try them later.

The other solution is to have the plug carefully measured, and make sure that it is right, then see if you can get a smaller one from the maker or a dealer.
 
I wouldn't rap a bullet on a block of wood to test for neck tension. If I were concerned, I would load a magazine. Fire the first round, eject the second and check for bullet set back. Hand cycling doesn't always tell you haw your gun acts/reacts when fired.

Here's another "plated bullet problem". I don't recommend plated bullets for really new reloaders as too many "problems" arise (New reloaders question load data, crimp, velocities, etc., on every reloading forum I attend). Experienced reloaders have no trouble discerning loads or crimping plated bullets, just new reloaders get confused by a lack of easily found information...
 
Are you using a Lee sizing die? I had problems with setback in .380 and realized my Lee sizing die was not sizing the brass enough to the point I did not have to flare my cases to start my bullets. I contacted Lee and they told me that there is known issues with their standard .380 sizing die and "certain brands of brass" and recommended I get their "undersized" sizing die. For the most part the problem was with all types of brass, even the better stuff like Winchester and Federal. The undersized die solved the problem, but the one die alone cost as much again as the standard 4 piece carbide set.
 
somebody answer this for me. I've got a migraine and i'm not in the mood to go dig around in my bench and do the measuring and experimenting.

If one chooses to not expand the entire length of the .380 brass, could you use a .357 plug to flare it by just touching on the case mouth?

The dies expand the whole casing before flaring, so you can't flare a .380 and still retain a heavier friction fit by leaving the body unexpanded. The usual expanding die has at least a small taper at the front end to guide it into the casing.

Could he use a .357, setting it up so that it only contacts for a few hundredths of an inch, so that it barely flares the front end by about 2/100? It would allow the opening to accept a bullet of that diameter, while leaving the body of the case at the actual sized diameter.

After working with extreme bullets myself, I didn't like them and will try to use them up in my 9mm. The dinky little charges in a .380 might be best served with a hollow based bullet that can obturate a bit.
 
I use RCBS carbide dies and a Lee Factory Taper crimp die in a seperate step. Bullet set back is a concern for me since the case volume for a .380 is small and setback can increase pressures significantly. Also on a .380, there is just not much bullet in the case for the case neck tension to hold the bullet. I have been reloading since the 70's but this is the first time I have tried copper platted bullets in a .380.
 
Have more concern with bullet pull on .380, with jacketed bullets. Especially with winchester flat points.
 
Preventing setback is a function of proper case resizing, and case tension, and not the crimp. Seating the bullet usually creates a visible "bulge" where the bullet forces the case to expand as it's pushed in. If your bullet seats all the way in without expanding the case a little bit, either your resizing die is not adjusted for the case to go all the way in, its not sizing small enough for the thickness of brass you are using, or the bullet is undersize.

Jacketed bullets are not made smaller, but cast bullets are often made larger. .380 is a special situation though in that some models won't chamber with .356" bullets, so sometimes cast bullets made specifically for .380 are sized at .355" same as jacketed.
 
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