I'm working up another load with Barnes TTSX 180 gn for my .300 Win Mag.
RL 22 around 73.5 - 74 gns looks promising at this stage for a little over 3000 fps ( over Barnes book max but no pressure issues ). I am aware of comments re temp. sensitivity / inconsistency with RL 22 and want to ask what powder would be the next best option for similar accuracy potential, pressure and velocity. I know Alliant has in recent years released a series of newer propellants so maybe one of these ?
Are any of the newer IMR propellants just the berries for .300 WM ?
I can get almost identical performance from identical charges of H4831 but this powder is slightly bulkier and at performance level the charges need to be compressed a bit which my Redding Competition Seater doesn't like so I'll put this aside for now.
Earlier I tried RL19, IMR 4831 and IMR 4350 but these were not doing anything special.
Appreciate thoughts, suggestions from any 300WM fans out there. Thanks.

Grant,

I had great luck with H4831 with my 300 WSM but ran into the same problem with it being to bulky for max loads. Then I discovered the H4831 SC (short cut) and H4831 ssc (super short cut). The much shorter kernels of the SC and SSC powders let me get more powder in the case with less compression.

I don't know how available they are there in NZ but it's all I buy for my 7 Mag and 300 WSM.

Thanks Frank,
We have H4831sc here ( AR2213sc ). Not sure about a ssc version. I use it for the 180 gn Hornady SST which is a brilliant load. Excess compression only occurs due to the TTSX 180 gn length. Possibly a lower charge with faster powder might work but I would like to stay in the burn rate range of RL22 or H4831 as pressures still run under max it seems. I'm sure somebody here will have had success with something.

I would try H1000 over H4831 any day of the week.
Currently I use either H1000 or Retumbo in my own 300WM.
I also use RE25 quite successfully with 180gr Accubonds.

Cheers.

I poured the RL22 out. It always gave me both poor and very inconstant results.

I had loaded the RL22 for other rifles with those poor results. When I decided to load ( finally ) for my 300 Weatherby Mag I loaded it up with 7828SSC and Boom it was shooting great.

So you might look in to it for your Win Mag.

FWIW the RL25 was a better powder for me. But it is all replaced by the 7828, my existing tight fisted supply of Win 780, and the Norma MRP.

I've owned a 300 Win mag since the early 70's and always found IMR 7828 to be a great powder with various 180 gr bullets. Recently I tried a new bullet, the 175 Barnes LRX with a newer powder, RL-26. I worked up ta a max load (76.5grs ) in my 24" barrel BSA. Accuracy was .7 MOA and the vel an astounding 3220 ft/sec. At first I thought my chrony was off, but no it wasn't. I checked it with a known load. All was good. If your looking for something new give it a try. Might be worthwhile.

I , much like thousands of other Reloaders, have had great results from Reloader 22 out of my model 70 .300 win mag.
But I have had better consistency from the newer R23 with 180gr bullets. The R26 is my preference with 200gr. pills.
I get 3/8" groups at the hundred consistently with these powders and A-max 168gr., 180 Accubond, and 200ELD-X bullets.
I think the seating depth coupled with a good burn rate powder is the most important over bullet choice for accuracy and velocity.
Obviously a good bullet is key to performance on game or targets of various types, as needed.

RL22 wasn't the answer as I had hoped.
I persevered with H4831 despite my misgiving over powder compression and got some semi acceptable results.
The comments re RL26 interested me so I bought some and worked up some starter loads which looked really good. Then progressed to trial loads and found a very good load at 77.50 gns so called it good there.
I will also do as 416RH suggests and try some H1000 ( AR2217 ) as well since I have this on hand.
Appreciate all the help. Thanks guys.

My gunsmith once told me the following ... "In the 300 Win Mag, use any 4350 powder at 72 grains with a 180 grain bullet for about 3100 fps. If that load doesn't shoot, we need to work on your rifle." At the time, I was trying Ramshot Magnum, IMR 7828, RL 22 and 25, etc. with various results, but not consistent.

I'm currently using the Barnes LRX 175 gr bullet with 72.5 grains of IMR 4350. My previous load was using the 180 gr TSX with 72 grains of IMR 4350. Absolutely fantastic accuracy out of both loads and two different rifles. So much so, I've quit looking for another 300 Win Mag load.

Good luck and I wouldn't give up on the IMR 4350, just yet.

In my Rem Sendero 300 win mag I had great results with 81 grains of H1000 using a rem 9.5m primer. What I found was that the 180 TXX requires a long jump into the rifling. I used a .060 at 2993 fps. This load would consistently group within an inch at 200 yards. Another great hunting load is using the Nosler 180 NPPP at 81.5 grains with a .010 jump. My Sendero has a rather long lead. As these are rather warm loads, I would work up in steps but I have found that all of my 300 wm's love H1000.

The bullet is more than likely your problem.
Barnes cam bea finicky bullet, just like any all copper bullet.
Their new bullets are a big step forward, but it wont do anything a partition won't do.
If it wont shoot with 4831 , or RL 22, it aint gonna.
With ALL 300 Winchesters. I have always said that if 74-77 grains of 4831, and 180 Sierra Pro Hunter won't shoot, then the rifle won't shoot.
Compression is normal, not a problem. You should also try the Short cut version.
I have shot 60yr old 4831, along with 30yr old, along with Short cut. I get more velocity out of the old Military, but accuracy was the same for all.
If you think that 4831 is compressed, what do you think 81 grains of H1000 is gonna do.
As a side note, the 180 Pro Hunter, and the Nosler Partition shoot to the same POI. So practice with one, hunt with either.

Personally my powders of choice are H4831, Rl22, IMR 7828, If I have not found a load that wont shoot with those, out it goes.

Graybird, Seismic, LeeC,
All good food for thought, thankyou.
As I mentioned I think I've found a great recipe in RL26 paired with Barnes TTSX 180 gn. It's not that some of the other powders I've tried were so terrible, and I guess I strive for certain standards with hunting loads, but so far RL26 seems to be something of a standout with this bullet.
I think my rifle setup imposes some constraints. It's not a specialty long range rig, just a standard Tikka T3X Lite action mated to a NZ made True Flite barrel, 1:10 twist. I couldn't get the original Tikka barrel ( very long throated, 1:11 ) to shoot so installed the shorter throated True Flite and saw immediate improvement. This helped greatly against the restriction to COAL imposed by the short Tikka magazine, and I want to cycle rounds from the mag. Absolute max COAL is just under 86 mm ( 3.38 inch ) so the long Barnes TTSX 180 gn is invading quite a bit of case capacity. I'm not liking it but am getting my head around working with somewhat compressed charges for this rifle. If my experiences to date with Barnes TTSX bullets holds true it's that they give accuracy at the higher speeds with charges that are at max or close to. And yes, ensuring the Barnes jump to the lands makes a difference to accuracy. Due to the variable nature of component availability in NZ I need to find at least one more load than the two I have so far, ( Hornady 180 SST / H4831 sc, Barnes TTSX 180 gn / RL26 ). For sure it will be with one of those favourite powders you guys like. The fun is in working through the bulk to find the gold.
Thanks again to all.

I will just repeat, if you really want to know how well the rifle shoots, try the Pro Hunters.
Then work to see how close you can come with the Barnes.
180 Pro Hunters, and 180 Partitions are all I use. I also Have only used Federal 215M's.
Nothing else.
I never use Boattails to figure out a rifles accuracy, only flatbase, then I will turn to a boattail, to see how well it stacks up to a flatbase.
I persoanlly do not shoot boattails at all, in anything. Too many variables. Not all boattails are the same.
I would even bet you that the Pro Hunters would work with all your powders.
That is if the shooter,and rifle are capable.
Once you get the baseline of what your rifle is capable of, then you can wander off into different bullets, powders, etc.

LeeC,
Thankyou.
To be crystal clear, the ProHunter you recommend is the Sierra... correct ??
Yep, Federal 215M primers...I swear by those.
Rifle / Shooter capability ( LOL )...well, I do my best. Some days I am happier than others but generally I can show some sort of result.

Yes Sierra.
And the answer is yes, I also hunt with them, never had a failure
I have shot thousands of 300win, or 300 Weatherby. It is 99% of what I have shot since I was 16yrs old. from Antelope to Elk. Its what I use.
Even I know when to stop, or when I begin to flinch. The groups will invariably get weird quick. The first 20 shots are the most important, even mortals begin to flinch, even if you don't realize it.
If you don't believe me, make a dummy cartridge, have someone else load the rifle, so you are not sure where the dummy is. When the dummy comes up, you won't know it but you will find out if you have a flinch.

It happens to all of us