I’ve used my standard 27 gr CFE powder load under a 125 gr pill in temperatures ranging from a high of 60° to a low of about -10 so far and haven’t noticed any appreciable differences in pressure or point of impact From my three rifles.. It was -30 the other morning and I thought about going out to shoot But just couldn’t bring myself to do it lol.

I was reviewing some burn rate charts and I know to take them with a grain of salt but....Accurate LT-30 falls in between 1680 and CFEBLK. I was wondering if anyone has cautiously tried it to see how it did? It would be nice to have another option for powder.

Could you share what 125gr projectile you're referring to?
Depending on what bullet it is 27gr can be middle of the road or an upper limit load.

I'm concerned because I recall the math on some burn rates gets logarithmic on pressure regarding temp increases.
As an example [recollection] the pressure increase in a 30f change from 70-100f is greater than a pressure increase from the same 30 degree swing in temps 0-30f.

Only slightly more scientific than Greycard, but I did this test for temp

Same load/lot of ammo
10rds out of the freezer
10rds that had been out in the sun on a steel plate during a hot TX Aug day

Less than 20fps difference in velocity and I didn't notice any difference in pressure signs

I tried LT-30 and it didn't work for top velocity for some reason, I'll have to see if I can find my notes on it. I'm thinking it was too bulky and I ran out of powder space like 4227 and N120. The only upper I've blow up was with 11FS which acts like H110/296 safe/safe/boom!!!

This is still my assessment of powder options:

CFEBLK: Best overall for 125-150gr
A1680: Decent with 125-150gr, but you can only get about 90% of the velocity of CFEBLK and it has a lot of muzzle blast
SBR SOCOM: Excellent for 95-110gr

None of these have worked for me due to various reasons:
H110/296
N110
N120
11FS
LT30
H4227/IMR4227
A5744
A2200
Lilgun
300MP
Norma 200

Great info - Thanks

It’s awesome info and Bill’s been very forthcoming on the data for this round. I hate CFE BLK s much as the next guy but I’m also smart enough to pay attention. It meters pretty well through a Harrells precision powder dropper but still makes a mess. I still check every drop on a scale. If someone ever figures out a powder that doesn’t have the consistency and mess of sugar I’ll be one of the first to switch... but look at Bill’s list, it’s not looking good

Never had an issue with CFEBLK metering through a Dillon powder measure on 550, 750 or 1050 machines and it really meters well with the rotary measure on a MK7 Revolution machine. I'm curious what issues your having Judd?

The mess...it’s 100% about the mess. It’s so fine it ends up everywhere. The dropper leaks it, the auto trickler 3.0 leaks it...the mess and my OCD condition almost makes it unbearable but it shoots well and seems to be the best option so I’ll continue to use it.

Powder Valley has CFE BLK in stock as of right now.

Thank Goodness! I got 2lb! Man, I just got back from the range with my 2 builds and 200rds of W296 Loads. No BOOMS! To speak of, but as Bill stated it will not run the gun and is also teetering on the edge of Serious trouble. I had 3 or 4 primers get popped out. My thinking was adjustable gas block and Taccom3Gun ultralight buffer and spring.. pretty near the bottom of gas flow I could get brass ejection but even wide open could never get it to pick up the next cartridge or lock back on empty. Now I have a plethora of W296 to sell/trade for SmallRifleMagnum Primers and more appropriate powders

I will have to look over all of the numbers but they really seemed decent on the SD, ES, Velocity, and man of man is this an accurate cartridge! One ragged hole groups @ the 60yd bay during sight in and chrono work and then some 7/8" groups @ the 100yd with M80 147gr pulldowns (I didn't even weight sort those ones!) Quickloads numbers were dead nuts spot on for my loads, that program sometimes amazes me how close it can be if you put in as accurate info as you can.

Thank you again Bill, I'm very excited about this cartridge and the potential for target shooting accuracy and a light and handy all around hunting cartridge for GA. I should've really heeded the words of W296/H110 not being a suitable choice.. I just happen to get a Good deal on 32lbs 3lbs of CFE BLK should keep me busy playing with all of my bullets now.

I was fortunate enough to come across 10# of CFE blk recently. I love the stuff my Lyman brass smith powder measurer throws crazy accurate charges and doesn’t leak it at all. It’s so so precise I don’t even weigh my tiny .17 hornet CFE blk loads.

cfeblk does make a mess when you spill it, but i don't fill the case up to the top anymore

One of my good customers shot this 390# hog on our ranch Saturday with a 150SST from 70yds DRT

That's a good pig!

nice pig. of course mine was bigger, but that one will still make a trophy skull mount.

Hey guys . I’m new to the 300 ham’r and want to start reloading . I have cfe blk , and Speer tnt 125 gr . The 18” tactical hunter barrel . One of my main questions is do you crimp ? And what would be a good start with charges ? And also where do I start with off the lands ? Thanks

I'm real new to the cartridge as well.. But from my understanding you can't cram enough CFE BLK under a 125gr TNT to cause much harm and you won't get anywhere near the lands @ mag length 2.26".. I've got both haven't started on them yet though. I'm sure someone can give you a starting load. Welcome to the forum of all things HAM'R! I'd suggest reading every single page and take some notes. Lots of great folks with a plethora of info.

I load mine to fit the magazine, they don’t seem to touch the lands in my 3 rifles. My favorite load for all three on my ham’r s is 27gr of CFE blk under a 125tnt bullet. Very accurate but close to the listed max load. Get on hogdons site, look up the load data and work up a load from the starting load.

Do you crimp ? I’m just curious if I need to or not . Thanks

Mr. Wilson recommended the Redding 300 Blackout taper crimp Die to me. I have been using it with fantastic results for all of my loads.

The only die set I’ve been able to find is the rcbs set that Wilson sales . Are you putting a lite or heavy crimp ?

I crimp for a shiny taper ring at the neck of the case.

Thank you for the advice . I’m hoping to start working up loads next week .