300 Blackout loads?

[NightShade]

From what I have read the lake city brass has a little thicker casewall. One post said something about one brass being able to fit up to almost 5 grains more powder in a commercial 223 that was converted vs lake city. Would have to search around to find it but I will not be running real hot loads anyway since most of what I handload will be for fun anyway. I know that a lot of people posted about the "x-treme" bullets copper plated 150 grain 308 bullets being pushed over 2000 FPS (in a 308) without any issues even though they are rated for no more than 1500fps. At 10 cents per bullet they will be great for a plinking round and a lot of people are begging X-treme to make a 220 or 240 grain bullet.

 

[beastep]

I've reloaded in converted LC and several others as well as a lot of factory blackout brass and I really havent noticed any difference in pressure signs or POI differences. But I havent compared them over a chrono so there still may be truth to that.

 

[NightShade]

Alrighty, got me some 150 grain Sierra Gamekings to play with a little. Loaded them up with 15, 15.3, 15.6 and 16 grains of H110 with some cci450's. I do have to say that Hodgdon has something wrong with their minimum overall length on the 150 grain loads. I found the Sierra information and it showed 2.105 so I went with 2.125 for a little headroom. Hodgdon was showing 2.235 with Hornady InterBond bullets and I don't know the length difference but very little was being seated into the case at their OAL

Once the barrel comes in and I get a few more parts together I will actually be able to test them out but they look pretty good so far.

 

[NikatKimber]

Tested some Hornady 225gr HPBT bullets with 1680 this week. Ran 10.0,10.2,10.4 grain charges. All functioned and were subsonic to the ear. Was sick and was getting worse so I didn't finish the run up to 11.0 grains. Need to drag the chrono out next time. I was just glad it cycled well. I have an adjustable gas block in it, so once I find the maximum subsonic load I want to run, I can tune it back.

 

[lkothe]

I bought what I thought was new brass (I'm going to check vendor) and started to load it. Lip on case was kinda ragged.................... question, is NEW brass ready to go or do you run yours thru the sizing die typically?
I went ahead and cleaned up the lip inside and out, resized them and tossed em back in the tumbler for a few hours just because.......all clean and shiny, ready for 125's and 1680!

 

[Mad Professor]

I bought what I thought was new brass (I'm going to check vendor) and started to load it. Lip on case was kinda ragged.................... question, is NEW brass ready to go or do you run yours thru the sizing die typically?
I went ahead and cleaned up the lip inside and out, resized them and tossed em back in the tumbler for a few hours just because.......all clean and shiny, ready for 125's and 1680!

Resize it and check for length. Remove all unknowns to your reloading process when you can. More so as you are developing loads.

I suggest saving that 1680 for subsonic heavy bullets. Find some H110 or W296 for your 125s.

 

[DRC458]

I bought what I thought was new brass (I'm going to check vendor) and started to load it. Lip on case was kinda ragged.................... question, is NEW brass ready to go or do you run yours thru the sizing die typically?
I went ahead and cleaned up the lip inside and out, resized them and tossed em back in the tumbler for a few hours just because.......all clean and shiny, ready for 125's and 1680!

Depends on the brass. Most brands I will have to trim, but I don't normally size them. Some manufacturers, I think Nosler and Norma at least, claim their brass is ready to load. I have found that to be true with Nosler for sure. I always measure them, regardless of brand, but I have never had to trim new Nosler brass.

 

[beastep]

I always resize everything. I run a progressive and it isnt any harder to add that step.

 

[lkothe]

Resize it and check for length. Remove all unknowns to your reloading process when you can. More so as you are developing loads.

I suggest saving that 1680 for subsonic heavy bullets. Find some H110 or W296 for your 125s.

Why? Difference of?

 

[Mad Professor]

Why? Difference of?

There is a difference between a powder load pushing a 208-240 grain projectile at ~1000 fps vs a load pushing a 110-125 grain projectile at ~2100 fps.

While there were many wildcat predecessors to the 300 AAC Blackout cartridge (whisper, 300 fireball, 300-221). Robert Silvers did quite a bit of research in developing the round to work with the AR gas system in many different load groups in developing the 300 AAC Blackout. A1680 was chosen for the subsonic loads because it fills the case better at those loads while still producing enough gas to cycle the load. It is awesome for these rounds. While there is limited success with some other powders, A1680 is the preferred powder. The supersonic rounds were developed around H110/W296. At one time there were suggested loads on AAC website. I'm not sure is they are still there. LiLGun was a secondary choice.

1) Powders are not entirely universal. They will have a place where they work best. When possible, you want to pick powder that is working optimum during your intended use. A 6 oz gunsmith hammer, a 16oz carpenters hammer, and a 2lb sledge hammer, may all get the same job done. But, if possible, you want to pick the best one for that particular job. A1680 is the one for Subs. H110 hits the sweet spot at with higher pressures and lighter projectiles.

2) When loading A1680 to toward recommended loads using a 125 bullet it gets compressed pretty quickly. One of my data books show a MAX of 18.5 reaching a velocity of 1925 fps while another goes to 21.5 grains getting 2126 fps. H110 EASILY makes 2000 fps and there are published loads closing in on 2300 fps. ED and SD start to rise quickly with powders when they get to max. Also ambient temps can really come into play.

3) H110 (or W296 which is the exact same powder) can be found locally for under $19-20lb. A1680 can be found locally, but in my experience at a premium pushing $30lb. I last ordered it from Powder Valley and it is currently $22lb there, + hazmat and shipping.

4) H110/W296 is more readily available. I spent 6-7 months looking for A1680 last year but could easily find H110.



Do what you choose, but you can make much quicker progress by using the experiences of others that have been down the same path.