380 LRN load question

[Sefuller5741]

I am loading Acme 95 grain LRN bullets in 380, using Hodgdon HP-38. In a rare twist of fate, there is actual load data for my specific bullet available on the Hodgdon site! As a relatively new reloader, I have read and heard many times that there should be one caliber inside the case, however that would be an impossibility with these bullets. In general, my experience with the Acme bullets in 9 and 45 is they do like to be seated on the deep side, but even deep I am nowhere close to a bullet diameter. I loaded some rounds with a COL of .970 and 3.4 grains of powder and they ran pretty well, I had one that needed a nudge on the back of the slide to chamber fully. I loaded a batch last night at .944 COL since this is closer to the rim on the bullet and still well within the SAAMI specs for 380 COL. I went down to 3.1 grains, but then got nervous since Hodgdon specifies .970. Trying to balance the Hodgdon data with SAAMI specs, and the adage about seating a bullet diameter has me a little confused.

--
Scott

 

[griff383]

You should be fine with the reduced COAL and reduced charge to start your testing. When you seat a bullet deeper you increase pressure with all else being equal. Lowering the charge and working back up is the best way to ensure you find a safe load.

 

[murf]

does the .970" col load pass the "plunk" test? you also want to get as much grip on the bullet and still have the bullet show a bit of its full diameter shank. the .944" bullet looks good for that just so long as it feeds and functions well in your gun.

luck,

murf

 

[Crazy Horse]

Good morning,

I've reloaded 380 using ACME LRN bullets. I utilized the .970 COL with you listed without issue. I however, used CFE pistol.

When you look at SAMMI, it stated the max COL as .984 and the min COL as .910. While I did not deviate with the 380, I have in the past when loading for other cartridges. This was due to using 9mm COL published by a manufacturer caused the bullet to jam. What I did was perform the plunk test. I incrementally seated the bullet deeper and performed the plunk test until it passed the plunk test. I then verified the COL and ensured that the COL was not less than the SAAMI published min COL.

You didn't indicate having any issues using the published COL of .970? If there were no issues, I would keep it at .970. I would only adjust to the lower COL if the reload was not cycling and causing the firearm to jam.

I will add that the COL you listed of .940 is still greater than the published SAAMI minimum of .910 COL, but based on the manufacturer, they indicated that the min OAL they tested the bullet with was .970. So that is what they published.

For me, using ACME 125 LRN bullets caused issues using the published min OAL. At that time (now they list ACME 125gr LRN, which is great), they didn't have load data for that type of bullet at the time and only had 1.120 as a min COL. to get the bullet to cycle correctly I incrementally seated the bullet lower until it passed the plunk test. When the reload finally passed the plunk test, I was at 1.080. As you can see 1.080 is lower than 1.120, however the min COL listed in the SAAMI site (2015 data) of 1.000. So while the COL I used was lower at 1.080 vs the published COL listed by the powder manufacturer, it was NOT lower than the minimum COL published by SAAMI.

Since then, all my 9mm reloads have functioned without error.

As always if you find you are having cycling issues using the ACME bullets, proceed with caution and cross verify with other published data (whatever you may have, loaddata, Alliant, Speer, etc. the more the better). And do not exceed SAAMI mins/max loads.

CH

 

[NMexJim]

In our earlier discussion, I said I would "check" the OAL and that one caliber depth was recommended. I should have added, "if possible". I've loaded a lot of .380 90 grain cast just about where your case on the left shows. Basically, I'm trying to get all the bullet I can into the case. As long as they sit tight, no problem. Wadcutters, for instance, have no or very little bullet showing out of the case, but there's a lot of bullet in the case.

Now, you said you had specific bullet data from the manufacturer. By all means, use that as a start.

Increased internal pressure comes from two main reasons. Being seated into the lands and therefore eliminating bullet jump without making due powder allowance. And, being seated too short and getting a compressed load. It's good to note your powder volume (otherwise known as powder density), and just make sure you're not jamming the bullet down into the powder. Light compressed loads can be ok, but it's wise to follow a book or work slowly into these.

The issue with aftermarket bullets, as I've said, is that there is normally no data available. You're lucky in that they have given you some data. It's really all about working into your load. Start low, work high. play with seating depth, and get a good grip on the bullet.