Experience hand loading 380?

[aasbra]

I have gathered some components to hand load for my CZ 83 in 380 auto, and did a couple of ladders with HP-38 and AA#2 using RMR 95 grain FMJ projectiles, and WSP primers, mixed brass, .990" OAL.  Using published loads from both powder manufacturers for the ladders, I was surprised to find the velocity measured via the chronograph was higher than I expected for the AA#2 loads.  For this powder, both the Lee and AA data suggests a starting load of 3.3 gr. and a max of 3.7, whereas the Lyman manual suggests 1.9 gr. to start and 2.9 gr. max.  This is a large variance between the two sources for such a small volume charge of powder.

Using the AA published range of 3.3-3.7, I was getting velocities of about 990fps on the starting load, and up to 1060fps on the max load, vs. published velocities of 822fps for the starting load, and 934fps for the max load.  I was really surprised that even the AA starting load produced velocity above the published maximum load's velocity.  For comparison, the HP-38 starting load of 2.9 gr. returned about 810fps, and the 3.2 gr. max load achieved 924 fps.  The AA#2 loads definitely felt snappier.  All rounds with both powder cycled and functioned fine.

Does anyone have experience loading 380 with AA#2?  Thoughts on the variance in published charge weights between sources?  Was considering stepping down the charge weight of the AA#2 a bit to see if I could back the velocity down to align with the published velocities.

[Wobbly]

Suggestions & questions....

• How close was the chrono to the muzzle? You may have been reading some of the blast.
• Light is critical to detecting the bullet. What were your light conditions & what bullet?
• You cannot compare manuals. Name one as your Primary and go with it. Secondary manuals are great to have... when the Primary doesn't have data.
• You must remember that data is gathered in a locked breach test gun with a longer barrel, and nothing remotely similar to a blow-back operated pistol.
• In the end, variations from the data is why we buy a chrono and test in our own gun. As they say, "Your mileage may vary."

[aasbra]

Thanks Wobbly, in response to your questions:

How close was the chrono to the muzzle? You may have been reading some of the blast.

I was using a LabRadar, placed about 6" next to the muzzle, same position with both powders tested for this application, and as I typically do when using this device for measuring handgun velocities

Light is critical to detecting the bullet. What were your light conditions & what bullet?

It was fairly sunny, but shooting from covered bench.  Bullet was RMR 95 grain FMJ

You cannot compare manuals. Name one as your Primary and go with it. Secondary manuals are great to have... when the Primary doesn't have data.

You must remember that data is gathered in a locked breach test gun with a longer barrel, and nothing remotely similar to a blow-back operated pistol.

Understood, on both points

In the end, variations from the data is why we buy a chrono and test in our own gun. As they say, "Your mileage may vary."

[skin]

 A few things for your 380. You're right about load data being all over the place. First on the load data. Are barrels the same length? Makes a difference. Same bullet in load data? Same case? All can make a huge difference.
 Velocity = pressure. You have a strong pistol which is good. Another pistol may not handle the pressures very well. If your barrel is close to the same as in the load data, I would say that you are going over the pressure limit of the 380.
 I have a ppk and a lab radar too. I chose the velocity I wanted with the powder I was shooting and adjusted accordingly. I try to use the same brass and not mix any for top end loads. I'll back off some for mixed brass that I use for plinking. There isn't much room in that tiny case. Little changes make a big difference. Use a good scale and measure carefully. Hope this helps.

[Wobbly]

Use of a LabRadar eliminates light conditions, but brings in other concerns.

[Wobbly]

In my 32ACP, the faster powders did better. The slowest powders to do anything good were in the W231 / N320 range. But for me, AA #2 and N310 resulted in the best performances. I am now toying with Nobel Sport Ba10, which is also in that speed range.

Tell us what you're seeing.

[aasbra]

The ES and SD data was definitely much tighter on the AA#2 than on the Hp38 loads, so I was hoping to go with that powder.  Plus, I have several lbs of it and don’t have as many applications to use it vs. the HP38.  Accuracy has hard to say, as I was testing at 25 yards that day (trying out my 97B for the first time after getting the CGW barrel bushing done).  I’m not that great of a shot, especially with the 380.  The 97 doesn’t disappoint, though!

I called Hodgdon (I guess they own Accurate powder now) to ask about the velocity my chrono was displaying and get their input on the published loads.  The rep I talked with recommended going with the minimum load of AA#2, as it was functioning fine if there weren’t any concerning signs noted.  So I loaded up some more at the minimum load to further evaluate when I get a chance.