190 gr Sub-x subsonic and supersonic loads

[300PreSub]

I am new to this forum but not new to the 300 blackout. My question is centered around the Hornady 190 gr Sub-x.

I recently purchased a 10.5" upper and wanted to run subsonic with it, supressed so I picked up a couple of boxes of the hornady sub-x. To my surprise, at 80 yards it shot a .75 group. The barrel only had 10 shots thru the barrel using 220 Remington subsonic before this so I was very pleased.

Ended up purchasing 500 of these projectiles for reloading. My plans for this 10.5 inch is hog hunting and plinking subsonic with supersonic being for more longer range hunting, possibly deer, who knows.

In looking at powders, I purchased Accurate 1680 since it seems to good reviews and cycles even at subsonic levels.

I need to put a plan together for a ladder test for both Subsonic and Supersonic. Being new to 300 blk loading I figured I would get some direction from the experts.

This is what I was thinking for my 10 shot ladder test using 1680;
Subsonic starting at 10.2grs @ .2 gr increments, ending at 12 grains. This should get me within the ballpark of my goal which is 1100 ft per second.
Supersonic starting at 16 grs and ending at 19.15 grains in .35 increments. Very concerned with this but will approach it with caution.

I have been reloading for sometime now but still have concerns due to lack of knowledge around the 300 blk reloading.

Please provide feedback and any recommendations you may have that will help me get a good start on this adventure.

[rebel]

Do you have a chronograph? If not it's just guess work as unsuppressed subs are loud as 45 acp. Get a chrony, then work DOWN to subsonic. It's the direct opposite of supers where you work up. Otherwise you could be beating stuck bullets out of your barrel. Also when you get what you think is a reliable sub load, check stability at 20 yards on a clean target. Baffle strikes suck.

[300PreSub]

I do have a chrono and will use it.

Good point, work down, that is important. Thanks

Any feedback on grains of powder.

I also have a 16" 300 I will be using for the supersonic builds if the 10.5 will not work. I figured if this projectile will expand at 1000 fps, then it should do good at 1500 fps.

[rebel]

Just to save components, start at 11 gr of 1680 and work down. I am playing it safe here but you may learn something on the way down.
Pick a coal that doesn't compress or jam ( no experience with this new offering ) and stick with it on the way down. Adjust seating slightly to tune and get the accuracy you desire.

[dellet]

How did you come up with your numbers for supers?

And what COL are you planning on using?

[DaedalusX]

By the look of Quickload, at 2.23 COAL I would start at 17.0 A1680 and wouldn't go any higher than 18.5. Past 18 you're compressing the load and it's pretty hot. Even then you'd be way better off with the 150 Gold dot 300blk for energy, ballistic and expansion - and it's quite accurate as well. Just because it can expand at 1000 FPS doesn't necessarily means it's the most optimal choice.

[300PreSub]

Thanks for all of the feedback and suggestions....

Regarding coal, my current plan is to duplicate hornady factory, 2.068 with the subsonic. With the supersonic, I just received my 190 Sub-x last night but do plan on seeing where they touch the lands as well as see what max grains of powder is relative to seating depth. Compression will play a role in my decisions of powder charge I will include in my ladder. I have a lot of reloading experience with the 6.5 Grendel. It is very finicky and requires a lot of precision and paying attention to detail so hopefully I can leverage that experience to have a safe and rewarding 300 blk expericence.

What got me interested in running this projectile supersonic was a youtube video of a guy shooting the 190 sub-x out of a 308 into gel and it looked very impressive. I figured why not try it at blk speeds. My goal is 1700 fps, but I would be just as happy at 1500 if that is all I can get. As we know running this projectile supersonic is a new adventure. There is no load data available yet but I thought i would take look at it and see what I find.

I came up with my supersonic ladder load based on loads for 180 to 208 gr projectiles. With the ladder approach, using 1680 which seems to be very forgiving regarding pressure, I will approach it with caution. May never see 19 grs, may even not see 18 but I wanted to include it instead of wishing I would have later. My main supersonic goal is the see what kind of velocities I can obtain with the 190 gr and 1680 combo and see what kind of projectile expansion we can get a higher than subsonic speeds.

I think there is potential here for a very good combination.

[bearcatrp]

I emailed Hornady about shooting the 190 subs supersonic. Was told not advisable until they do some testing. Would not elaborate any further.

[dellet]

Your thought process is sound, there are a couple of cartridge/bullet issues to consider.

Overall length will be limited to about 2.160-2.170", depending on your brass and chamber. Make sure you find that length.

At 2.170" you will start compressing powder around 16.5 to 17 grains, probably a grain less at factory length. That in itself is not a big deal, 1680 behaves very well compressed and is predictable. The bullet is the question mark. It's a hollow point designed to expand under low pressure. You might actually deform the jacket or start expansion, before you see a mark on the bullet from the seating stem. Push it to 1500 FPS (1.5 x design velocity) with a compromised jacket and it may come apart. I would not shoot it suppressed until you know.

It may perform too well at higher speeds, expand too much, too fast, and have too little penetration. Jacket separation is common, expanding solids like Lehigh shear the petals. Finding the high end of working velocity is more important than highest actual velocity.

Load data is available from both Sierra and Hornady for 190 grain bullets, so you don't need to feel like your off in the weeds somewhere. 16 is a reasonable place to start depending on length you choose, 19 is probably wishful thinking with this particular bullet/powder because of it's shape.

Keep in mind that you will probably be spinning this bullet 30% faster than the guy with the 308 at the same velocity, that is a lot more stress on the bullet jacket.

1500 FPS no problem, 1700, depends on the above factors. I know I can get the bullet out the barrel that fast, just don't know if it will make it all the way to the target.

Look forward to to your results and experiences, be safe.

[300PreSub]

Dellet, I believe you are right on;

I didn't reference it earlier because I wasn't sure of the numbers but Hornady 9th edition has a 190 Interlock with 1680 starting at 12.9 grains (1200 fps) with max charge at 17.8 at 1650 fps. It takes about 1.1 grains of powder per 100 fps increase in velocity so that would put it at ~18.4 grains needed for 1700 FPS which may not be worth the risk. Hornady is very conservative however.

I am going to change the supersonic ladder to 17.8 max with .3 grain increments. That would put my starting load at 15.1.

I also measure my 10.5 chamber using the 190 gr sub-x.
Max COAL is 2.166 with a OTB 1.665.
Hornady factory COAL is 2.068 with OTB 1.566, this is about 99 thousands jump which give me a little wiggle room for the supersonic seating depth.

Take a look at the utube video of the guy who reloaded the 190 sub into a 308. He suggested 2400 fps and did shoot a 1.27 MOA group. This projectile should be very safe at supersonic blackout velocities.