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Elkins45
I am trying to work up a good cast load for a suppressed 10″ 300 blackout. So far, so good but now I want to add a bit of a twist: I would really like to be able to shoot a bullet around 200 grains with a plain base. I just ordered a 311365 PB and have high hopes. I’m mostly starting this thread as a place to report results as I get them.
My best shooting so far has been with the RCBS 200 grain silhouette sized .310 WQWW and any old lube seems to work just fine. If I can get similar results without using a gas check I will be very happy.
Now for the next issue: my silencer is user serviceable and after 100 rounds it is so full of gunk it is really amazing. Given the low performance demand on the lube of a subsonic bullet I don’t think I need a really sophisticated lube to get good accuracy. What I would like to find is a low residue lube to minimize the gunk that accumulates in the silencer. I experimented with a soy mix today but haven’t had a chance to clean it yet. The next experiment will go in the opposite direction with a carnauba heavy mix that might not fling off inside the can so badly.
Experimenting is fun! My new mold should be here tomorrow so maybe I can cast some over the weekend.
Elkins45-
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ericstevens
At that velocity level, 45-45-10 should work just fine. If you’re not familiar with it, its 45% liquid alox, 45% Johnson Paste wax, and 10% mineral spirits. You can make it yourself by heating the JPW to liquify and drive off the solvents, remove from heat, add in the liquid alox, and then the mineral spirits. The resultant lube is thinner and less tacky than liquid alox, and dries more quickly. While I have used this by swirling around in a plastic bowl, you might want to just dip the driving band portion and stand them on waxed paper to dry.
IIRC, there is a vendor on ebay that sells it, and is/was a vendor over at castboolits.
adamsutherland
Yep tumble lubing is the way to go.
45-45-10 or just ordinary xlox should work, White Label Lubes sell both.
The trick is to just go for a light, thin overall covering. The boolits should just have a light golden hue to them, don’t worry about trying to fill lube grooves.
I shoot about 200 rounds a week from my 310 Cadet at around 1000 fps and the bore is clean. The boolit I use is smooth sided with lube grooves at all.
My first test was fairly successful. I cast some 311365 from quenched COWW, sized them .310 and lubed some with 666+1 and some with Fryxell’s MolyGraph/beeswax. The powder I used was AL-8 and I loaded half at 7.2 grains and half at 7.5. I only had the chance to shoot 25 of each, but groups were about equal with either lube or powder charge. I didn’t chrono them but to my ear they weren’t supersonic. Function was 100% with my pistol length gas tube suppressed.
More testing is needed, including tumble lubing, but results thus far are encouraging.
FYI- just in case there’s somebody else out there with a jug of AL-8 who wonders how fast 7.5 grains of it will move a 200 grain bullet from a 10″ suppressed 300 Blackout the answer is right at 1100 FPS.
When my only jug of it runs out I think I’m going to try 800-X as a replacement. It’s the worst metering powder I have never used but those big square sheets of AL-8 come in a close second. It can’t be a concidence they are so close together on the burn rate chart. I guess they are the upper end of how big a ‘flake’ of powder can be before it start to become an extruded kernel.
SwedeNelson
ericstevens
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