9mm vs 380 auto

[Argonnakid]

Ok, so there is a host of info saying that powders, primers, and some bullet weights are interchangable between the two. My question is, would you use a 9mm 115gr HP bullet in a 380auto case? Everything I read says the two should be sized to .356" and the O.A.L. is the largest difference that I can see. Am i missing something here,,Or does it just make too much sense with the prices of reloading materials starting to go up that I could use the same bullet for my 9mm and 380auto loads. I ask this because I'm having a hard time finding 380 bullets locally

 

[Road Rat]

removed post.

 

[H Richard]

I beg to differ. The .380 uses a 90 to 95 gr bullet, and if you seat a 115 gr 9mm bullet the the correct OAL the case capacity has been decreased, which in turn has increased pressure. While it can be done, careful adjustment of the load is critical. The bullet diameters are the same, but the weight and OAL are not.

 

[steamloco76]

The 9MM Luger and the .380 ACP do have the the same bore diameter and use .355/.356 in bullets. However, the 115 grain .355/.356 diameter bullets are not suitable for use in the short 9mm "kurtz" AKA .380 ACP case. Overall length with the 115 grain will be too long unless the projectile is seated deep in the .380 case. More than likely this deep seating will cause a compressed powder charge and increase in chamber pressure.

You need .355/.356 bullets in the 88 to 100 grain range made for the lower velocities the little .380 ACP generates in comparison to the 9MM Luger.
Search the on-line component suppliers and you will find correct bullets. Your local gun store is unlikely to stock the bullets you need, as the .380 ACP isn't a particularly popular cartridge among reloaders due too the small cases and bullets involved.

 

[MMA10mm]

You sure can use 9mm and 380 bullets interchangeably, but there are trade-offs.

As pointed out, heavier 9mm bullets will need to be seated carefully. Certain ones, like FMJ-RN, might need to be seated so low the ogive goes into the case mouth preventing a proper crimp. FMJ-TCs will work better in this regard. Regardless, it will seat deeper, so take the advice above, and be prepared to load your powder charges down.

I've loaded 122gr lead RN bullets in 380, but there are a lot of variables to keep track of - basically everything mentioned above, but with even tighter tolerences.

JHP bullets generally are shorter in their out-of-case dimension, so a 9mm 115gr JHP-TC will usually fit, but don't expect it to expand. It will drill a .356" hole through the target...

Another way to go is to load 100gr 380 bullets in 9mm. Again, won't be perfect, as the screaming-fast loads will over-expand (blow up) if you use expanding bullets, and if you use FMJs, they're typically blunt-nosed (better for the 380), so they'll work better in 9mms which are forgiving of the shorter OAL loads.

So, bottom line is that both ways work, but neither is ideal, with their own difficulties.

 

[Argonnakid]

No difference. The same 115 gr bullet could be used in both.

However, I do not find any .380 115 gr ammo listed for sale...mostly 95 gr and a few 100, 102.

The 115 gr bullets just might be too heavy for the short .380.

I have the same issue, finding weights other than those you listed. But back to the 115gr. , if you have a copy, look at Nosler reloading guide #6 pages 652 and 655. It lists a 115gr JHP and only a JHP for both. Lyman 49th for the 380acp has information for a 120gr( a cast) and a 115gr. JHP as does the 2nd LEE 'Modern Reloading'. I'm not trying to correct you, just pointing out the published information. And this why I asked the question in the O.P. .

 

[Aticus]

I just checked several of my loading books and did find loads for the 380 for 115 gr. bullets. So they can be used.

Now my question, why? What would you gain? The velocities are really low and the powder charges are miniscule. Would it be worth it?

 

[Argonnakid]

I can buy locally pounds and pounds of 115 JHP cheap, trying to be more cost effective with my reloading. Same bullet for two different calibers would help.

 

[125JHP]

I've done it with 115 XTP and some Berry's RN but he results weren't all that great and the velocity wasn't there to get the expansion needed so the project was shelved. About 100gr is as heavy as you'll get to work with any reliability IMO.

 

[blujax01]

I can buy locally pounds and pounds of 115 JHP cheap, trying to be more cost effective with my reloading. Same bullet for two different calibers would help.

Just an idea: $78/1000 with free shipping.
380 Caliber plated pistol bullets

 

[growr]

Just because you CAN doesn't mean that you SHOULD or that it is a good idea...........

Randy

 

[PDL]

I don't know if you'd care to use lead or not. I've used the MBC 95 gr. for reloading .380. Anyway, here are two decent sources for lead.

Missouri Bullet Company

.380 Caliber Bullets Available

 

[Jellybean]

Short answer, yes.
You will want to be careful to watch the OAL if you are using data for a bullet other than the one you buy. You might even try loading them to maximum length and adjust back if needed.

Load up a few trial rounds first and make sure they will fit in your firearm. If so, load up a small batch and test for function, then if all goes well have at it.

I don't think they'd expand at that distance, but they will be slightly better than a FMJRN.

 

[longranger]

I have read all of the responses and think if you want to shoot 115gr bullets in .380 you are pushing the cartridge and maybe the gun to it's upper limits with poor performance(probably why not commercially available).Going up one cartridge size is a better idea.If you want 9mm performance,get a 9mm.

 

[Argonnakid]

I have read all of the responses and think if you want to shoot 115gr bullets in .380 you are pushing the cartridge and maybe the gun to it's upper limits with poor performance(probably why not commercially available).Going up one cartridge size is a better idea.If you want 9mm performance,get a 9mm.

I have several 9mm chambered handguns and one .380, enjoy all, but the PK380 is my daily carry. And no, not thinking of using reloads as defense rounds. Am looking to increase my options as far as loads I can build for practice, from a expense view

 

[125JHP]

The fastest 115 XTP that I loaded was 825 fps and had an OAL of .973". I don't think the XTP will expand at that slow velocity and as a ball proxy it probably wouldn't get good penetration either. Factory FMJ is typically 900~950 fps.
Now, I did get the 102 JHP Golden Sabre up to 1020 fps which is a little bit better.

 

[Rule3]

As Pecos Bill stated what is there to gain? IMO the 115 is just too much bullet for the 380, that's why you do not see a lot of commercial ammo loaded with it.

The velocity will be dismal so what's the point?

Stick with the 95, 102 or less. You are not going to save any money by buying only one kind of bullet. By the right bullet for what ever caliber and you will shoot them anyway.

 

[Rule3]

Just an idea: $78/1000 with free shipping.
380 Caliber plated pistol bullets

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

As posted go the above web site order some 380 and 9mm. You do not even need to get 1000. Just spend over $50

Buy 250 of each or 500, whatever you want and they are delivered to you door.

 

[blujax01]

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

As posted go the above web site order some 380 and 9mm. You do not even need to get 1000. Just spend over $50

Buy 250 of each or 500, whatever you want and they are delivered to you door.

You mean I don't have to buy 1000 at a time?
Don't tell my wife!

 

[Rule3]

You mean I don't have to buy 1000 at a time?
Don't tell my wife!

Yes, you need to, but not the OP!