LOADING THE 9MM 120 GR BEARTOOTH CAST BULLET
Bill McConnell 11-13-12
Most of my load development begins with the best bullets and gets watered down to the lower quality and less expensive ones with time. But this time was the opposite. I hunt with other cartridges and carry factory ammo (mostly anyway). Cast bullets were new in the 9mm since I only recently acquired a couple Storm Lake aftermarket barrels for my G17 and G26. The goal was just to produce good quality less expensive ammo with cast bullets in my 9mm Glock’s.
While the 9mm project was beginning, I was just wrapping up the 45 ACP project with the 225gr .452 Beartooth flat nose ball cast bullets. The results were so good that it seemed worth a couple boxes of the 9mm, 120gr flat nose ball bullet and some time testing them while finishing up on the practice loads.
All load development was done through my G17 with the factory length Storm Lake barrel. Except for the 4.5lb connector, the Glock is factory stock (with factory night sights). All brass is Starline and the same 20 pieces of brass were used throughout the test. Primers were CCI small pistol standard. The 9mm Beartooth bullets came sized to .356”. I use Lee dies including a Lee Factory Crimp die. Unlike lead bullet loads in most other cartridges, all lead bullets tested in 9mm never caused the cases to touch the carbide sizing feature of the Factory Crimp die. I seat my bullets into the case until cycling the action feels just like jacketed bullets. There is NO desire for the bullets to touch the lands and interfere with functioning of the gun. In my case these bullets are seated and Factory Crimped to 1.065”.
This brings us to powders. The original plan was to develop a +P load with this bullet. My objective was to load it to over 1,300 fps. Read on and you’ll see that I found something better. 2 powders were tried. Power Pistol and Longshot are my most used semi auto handgun powders. Let’s look at Longshot first. This Hodgon powder has a burn rate similar to Blue Dot but, in my opinion, only performs at its best with heavier bullets and higher pressures. Because Beartooth bullets are very compact for their weight, slick and slow to oburate, Longshot became quite a failure. Look at the raw data…
5.9gr gives MV of 1,168 fps and an ES of 23 fps
6.1gr gives MV or 1,196 fps and an ES of 26 fps
6.3gr gives MV of 1,190 fps and an ES of 42 fps
6.5gr gives MV of 1,221 fps and an ES of 44 fps
6.7gr gives MV or 1,260 fps and an ES of 72 fps
In 25 years of using chronographs I can’t recall a powder that gave ever increasing extreme spreads as the powder charge was increased. There was just not enough mass to push back against the powder charge to allow the Longshot to ignite properly. Frankly, I never expected it to work out but was compelled to try.
Now let’s move to more fertile ground. Power Pistol proved to be ideal for this bullet. Here is the raw data…
With Power Pistol
6.2gr gives MV of 1,185 fps and an ES of 51 fps
6.4gr gives MV of 1,216 fps and an ES of 35 fps
6.6gr gives MV of 1,233 fps and an ES of 51 fps
6.8gr gives MV of 1,250 fps and an ES of 23 fps
7.0gr gives MV of 1,292 fps and an ES of 41 fps
This is a lot better with Power Pistol. This is an easy to ignite powder. I stopped at 7.0gr of powder as I was getting over 100% load density. That is outside my comfort zone so the loading stopped. Now it was time to begin testing for accuracy. I selected the 2 loads with the lowest extreme spreads. That is the 6.4gr and 6.8gr of Power Pistol. Picture #1 shows the 50 yard group for the 120gr Beartooth bullet and 6.4gr of Power Pistol. Picture #2 shows the 50 yard group for the same bullet but 6.8gr of Power Pistol. As you can see, the difference in grouping is notable and significant. I fired 2 groups of 5 for each load and the attached pictures are accurate for the overall results.
Testing had to wait a few more weeks until I got out of the wheelchair (different range) but was able to try some loads at 100 yards just last week. You’ll recall I started this project with the intent of practice loads. The most accurate of them is a 147gr production cast bullet doing a bit over 1,100 fps. It is certainly a +P pressure load in my opinion. As you can see, it does very well (#3) at 100 yards. But take a look at #4. It’s the Beartooth 120gr 6.8gr of Power Point load. The group size is barely my heart beat in the sights. It is a lot more accurate than I am.
How about leading in the barrel? My Storm Lake barrels are not firelapped but have been broken in and polished with JB Bore Compound. This 120gr bullet at 1,250 fps does not lead the barrel at all save a bit of lead flashing.
So we are throwing a 120gr bullet out of a 4 ½” barrel at 1,250 fps. In shooting a Glock 17 there was no fear of a +P load but I still want some idea of the pressure being generated. Ruger to the rescue. I have an old SP-101 in 9mm that sticks cases on +P factory loads without fail. The degree of stick varies with the ammo and when reloading, varies with the amount of powder in the case. I always test against a clean cylinder and new brass. It is not perfect but it’s been an amazing constant for some time now (I’ve shot 9mm revolvers for some time). I fired this 120gr bullet with 6.8gr of Power Pistol out of the SP-101 and absolutely no stick of any sort. That strongly suggests less than +P pressures. So I have a lot of speed, target accuracy and normal pressures. Not bad.
One more thing. Have you wondered how this 120gr load does in shorter barrels? I did.
120gr Beartooth bullet and 6.8gr of Power Pistol
SP-101 with 2 ¼” = MV of 1,224 fps with an ES of 28 fps
Glock 26 with 3.4” SL barrel = MV of 1,185 fps and and ES of 25 fps
Not bad! Not bad at all. It’s the most accurate load I ever developed for a semi auto handgun…. And it’s powerful as well.