Testing my recently acquired Brownng BDA 380
http://imageshack.us/g/1/9934904/Having acquired an early Browning BDA 380 (figure 1) manufactured in 1979, I was interested in seeing how it would perform with hand loads similar to my Buffalo factory ammunition. In my reloading cabinet there was Ramshot TrueBlue, Hodgdon TiteGroup, and Winchester AutoComp powder; Ranch Dog 100 grain cast flat nose bullets (0.356 diam.) from Carolina Cast; Starline brass and Winchester small pistol primers.
I could not find any recipes on the Ramshot web site for this particular bullet. I called Ramshot and received a very nice reply that for this bullet powder charges from 3.4 to 4.1 grains were a usable range. The seating depth would be critical for pressure on the 380 ACP and lower seating depths would require a corresponding reduction in charge. One reference in my loading manual suggested seating a bullet 0.020 deeper can cause the chamber pressure to rise from 3,000 to 4,500 psi compared to 1,000 for the .38 Special.
First step was to weigh (in grains) each case: (Mean 47.1, sigma 0.206, N=100). Second step was to weigh (in grains) each bullet: (Mean 100.6, sigma 0.816). Third step was to measure length (inches) of each bullet: (Mean 0.418, sigma 0.001). Fourth step was to measure diameter (inches) of each bullet: (Mean 0.356, sigma 0.0002). These statistics are extremely good for such a small bullet. The bullet weight deviation is less than the accepted 1% in rifle shooting, bullet length will not increase/decrease seating depths substantially and extremely consistent bullet diameter with virtually no variation.
The case head method was used to obtain the seating depth which requires a resized case to be dropped in the barrel and then noting the gap to the barrel hood (figure 2). A bullet is then seated incrementally until the gap on the hood is matched (figure 3). One case at a mean case weight was selected to obtain the barrel hood gap and a cast bullet with a mean weight and length value was used to obtain the seating depth. I then measured it and found 0.9011 overall column length. Figure 4 shows the COL along with a single bullet indicating the seating is just above the lube rings which is consistent for loading cast type bullets.
I set the taper crimp at 0.373 which is what the SAMMI cartridge drawing indicates and set it up on my crimping die.
Testing with TrueBlue started at 3.5 and incremented by 0.1 to 4.0 grains looking for functionality, accuracy and indications of excessive pressure. For TiteGroup 2.7 to 2.9 and for AutoComp 3.8 to 4.0 – please note that I have triple checked these numbers but before trying check with Hodgdon and Ramshot for assurance.
All testing was done at 15 yards which is the maximum distance used in CHL license testing in my state. A sand bag rest was used for stability. The Browning had no load malfunctions and the best accuracy was 2.9 grains TiteGroup producing a 1.7250 center to center group at 15 yards (figure 5). TrueBlue at 3.9 grains provided a 2.7 inch group while AutoComp and other charges did not produce any groups of interest.
One problem encountered was that TrueBlue and TiteGroup powders are very dense and require very low charge weights. My Lee deluxe powder measure with either standard disks or the auto disk would not throw consistent small loads. I ended up buying a used Lyman Ideal #55 Powder measure; ordered the small drop tube, 7/8 x 14 adapter and adapter lock ring and mounted it on my Lee expander die with the Lee riser attached. This worked fine and was able to obtain consistent charges.
Trigger pull was moderate and smooth in double action mode. In single action the pull is much less and with some creep before firing.