One observation & a lucky load

Moderators: gds, bakerjw, renegade, bamachem

Post Reply
BJK
Silent Operator
Posts: 57
Joined: Thu Jun 18, 2020 8:30 am

One observation & a lucky load

Post by BJK » Wed Jul 22, 2020 5:12 pm

While I'm not at all new to handloading I'm absolutely new to the 300BLK so I'm amazed by this cartridge. I get it that it's not new to lots of you folks who have been with it for years.

I got enough 9mm ahead to where I could convert the loader over to 300BLK and set up the dies. I have a mess of load data but nothing exact for my components; what's new there? I have lots of Lil'Gun, WW296, and some A1680. The bullets I have are Rainier plated 180 FP & HP and they say to treat them as though they are lead. I had a few brass from recently fired S&B loads. I guessed and put the big powder bar in the loader, and I was hoping that it would meter a small enough amount of powder to keep me subsonic.

In looking over the data and not having the precise components to fit any of the listed loads I hedged my powder charge. One listed charge was pushing a 208gr jacketed bullet and used 8 some odd grains for a subsonic load. A supersonic load for a jacketed 180 used 16 some odd grains (? Don't quote me on that and for sure don't anyone load that!) . Then putting powder in the measure and gently screwing the bar down all the way I couldn't get it down to the 8 grain load. But OK, it's not a 208 grain bullet but 180, and also not jacketed, so more powder would be OK. I had plenty of wiggle room on the charge. I upped the charge a little bit to give myself some adjustment both ways and came up with 11.5 grains for a starting load. A COL of 1.195 fits the Lancer mags fine with a little room to spare. Gee, that's not much powder! Intellectually I knew this cartridge was going to just sip powder, but this is just silly frugal! It uses less powder than many of the handgun cartridges I load!

So I went out of the shop and fired it*, no chrono' set up, I just wanted to hear it go bang. It did indeed go bang. I didn't hear any sonic crack. The new build (10.3" barrel and Amtak can) locked open on the empty mag' and the carbine spring I put in it worked fine. The brass was found at the correct clock position telling me that I don't even need to play with buffer weight. Could I have been lucky enough to get a sub sonic load out of the gate? Setting up the chrono' is a bother so I'll probably just up the powder charge until I hear the crack then back it down, then work from there for accuracy. That's the plan anyway. I might chrono' the final load if I can work up an accurate one.

*No I don't live in Chicago where gunfire is common, but I live in a rural setting where gunfire is commonly heard, but unlike Chicago it's not normally accompanied by dead bodies. No one gives shooting any thought here and no one ducks for cover or checks for holes in their home. No one thinks anything of it if someone goes for a walk with a firearm either.

Off the wall question... Does anyone know of an online reloading program? Or can someone run my load to check pressure & velocity with their program? I know it's safe I'm just curious.

BulletFlight for Android
User avatar
dellet
Silent But Deadly
Posts: 6384
Joined: Fri Nov 30, 2012 1:25 pm

Re: One observation & a lucky load

Post by dellet » Thu Jul 23, 2020 9:32 am

Your probably in the ballpark, on the fast side. I use 1 grain per 100 fps as a rule of thumb for 1680 across the board for any bullet weight.

If using jacketed data, use a lighter bullet for reference. 168-175 for a 180.

As for judging going super by listening for the crack, you need a minimum of 50 yards without a suppressor and at least 10 with.

If you want to post data, bullet weight, seated depth, charge weight for a minimum of info I can run the numbers later. Case capacity in water weight would be helpful, but not necessary to get within 100 fps.
300 Blackout, not just for sub-sonics.

BJK
Silent Operator
Posts: 57
Joined: Thu Jun 18, 2020 8:30 am

Re: One observation & a lucky load

Post by BJK » Thu Jul 23, 2020 12:45 pm

Thanks.

S&B brass unknown water cap'
Rainier 180 plated (lead bullet load data)
11.5 g Lil Gun
WSR primer
COL 2.190 (got it wrong 2x. note to self: don't work from memory!) Near as I can figure the base is about even with the neck/shoulder junction
80°F

If you could tell me what load gives me subsonic I'd appreciate it. It's hard to tell, but forget yesterday, I think I lost the sonic crack at 9.0 grains and the gun wasn't locking back. It still functioned @ 10 grains, but again hard to tell, I think I was hearing the crack @ 10 grains.

As mentioned below I need to set up the chronograph. That's not happening today though.
Last edited by BJK on Thu Jul 23, 2020 2:37 pm, edited 2 times in total.

User avatar
plant.one
Silent But Deadly
Posts: 6690
Joined: Tue Jun 23, 2009 8:31 pm
Location: Oakland County, MI

Re: One observation & a lucky load

Post by plant.one » Thu Jul 23, 2020 12:55 pm

one thing to note about load testing with subs - not wise to do with your can on.

there's a possibility of stability issues with these long for caliber bullets typically used for subs in the blackout....

so what most of us do is work up our loads, get the FPS & accuracy we're searching for (using a chrono - this is one use where its probably important, if not critical to have one), then verify that they're punching nice round holes in card stock at 10 feet or so.

once you know you don't have a wobbly bullet then screw the can on and have fun



be a damn shame to have a baffle/endcap strike for the sake of being lazy.


HTH
Reloading info shared is based on experiences w/ my guns. Be safe and work up your loads from published data. Web data may not be accurate/safe.
This disclaimer will self destruct in 10 seconds.

BJK
Silent Operator
Posts: 57
Joined: Thu Jun 18, 2020 8:30 am

Re: One observation & a lucky load

Post by BJK » Thu Jul 23, 2020 1:52 pm

Thanks.

User avatar
rebel
Silent But Deadly
Posts: 7241
Joined: Mon Apr 22, 2013 2:01 pm
Location: Moonshine Country

Re: One observation & a lucky load

Post by rebel » Thu Jul 23, 2020 9:53 pm

# 1 test stability at 10 yards on a clean white target. No can
#2 Work down to subsonic using a chronograph. Your ear just ain't good enough. Can on.
#3 Have fun
You can't beat the mountain, pilgrim. Mountains got its own way.

BJK
Silent Operator
Posts: 57
Joined: Thu Jun 18, 2020 8:30 am

Re: One observation & a lucky load

Post by BJK » Thu Jul 23, 2020 10:37 pm

Well, you're absolutely correct, my ear isn't good enough. I gave up until I have time to set up the chrono'.

Post Reply