Best 300 WSM powder?

Whelen B

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I'm helping a friend to get started reloading for his 300WSM rifles. He has a BAR semi and a X-bolt. He wants to reload ammo for both for hunting with 180gr loads. Your real world experience with reloading the 300WSM would be appreciated.

Any best all round powder choice suggestions?
Any specific tips for reloading for the BAR semi?

I load other calibres myself in both semis and bolts. But as yet have not reloaded for the 300WSM (just my 350 WSM wildcat).

Thanks.
 
I have not loaded 180gr but my powder favorite is MagPro. W760 and H414 have been very accurate and consistant for me. Good velocity and consistant groups just over 1" at 100 for a few years with all three powders. I have found my 300wsm is not at all picky about the powder used, and seems OK with any velocity, not just the max. I load 165's most of the time, but also found a 125gr NBT at near 3600 fps with H414 (going from memory here) that was VERY accurate, just not sure what to use it for.
 
For the semi-auto, a powder a bit on the fast side is recommanded, Win 760 is the one I would go with.
It gives me great results in my A-Bolt 300WSM too!
 
For the semi-auto, a powder a bit on the fast side is recommanded, Win 760 is the one I would go with.
I wondered about that burn rate issue in the semi. I myself lean towards compressed charges of slower powders. It can prevent bullet set back when the bullet hits the feed ramp. But I wondered how his semi would cycle with that. He already bought a pound of H414 which is essentially W760 I gather. So maybe we should begin with that.

Do you crimp or just rely on neck tension when loading for your semi? Without a compressed load this could be important. Do you factory crimp or get bullets with the canelure in the right place?
 
A lee factory crimp die is best for the semi-auto loads, I don't crimp loads for bolt actions. I've crimped bullets that don't have cannelure with that die. Don't overdo it, just a small dent on the case mouth is enough
Yep H-414 is almost identical, you should have good results with it.

Go with Magnum primers.
 
I've persnally tried Viht-550, RL19 (most accurate powder for 180 grainers in the Nosler and Barnes Manuals, respectively), H4350, IMR4350, and RL17 (not a full test - velocities were so high with RL17 - I lost my nerve even in the absence of over-pressure indicators).

IMR4350 was the most accurate (four of five 3-shot groups went sub-MOA - average for 5 groups was .87"). However each group had a noticably different POI (not ideal when using the OCW method of load development).

H4350 had no group that went sub-MOA (closest was 1.03"; largest group 1.54"), However, it pretty much had the same POI (very desirable when using the OCW method). I will plan on playing with bullet seating depth to see if I can tighten these up becasue as far a powders, it is more prefereable (virtually identically POI across a diverse load weights, and this powder is said to be less sensitive to temperature extremes).

All other powders averaged in the 1.5" - 2.0" range (i.e., nothing to write home about).

I surveyed the Nosler forum and 24hourcampfire sites. The most common "pet load" powders encountered on this sites for 180 grainers in a .300 WSM, in order of most to least common, were (1) H4350 (2) IMR4350, (3) IMR4831 (IM4831 was generally "better" than IMR4350 for 165 grainers).

In short my experience, and the research of others would suggest to start with these three powders.

BTW - Most powders tested with Barnes Bullets (MRX and TTSX 180 grainers).
 
I'm just starting with mine and am trying RL-19, RL-17 and H4350 because that is what I had on hand. I guess I should crony the RL-17 as I have already got a load that shoots around an 1" with 180 gr Accubonds and 66grs of RL-17. And another at around an 1" with 180 gr Accubonds and 68 grs of RL-19.
 
If trying RL17, and article in Handloader magazine recommends stopping if your velocities are 50 to 100 fps faster than velocities obtained using IMR4350 even if you do not get pressure signs.
 
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