RFI: 19" 300 WM Data

SkyScrapin

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Sifting through the mountains of 300WM data, most are loading H4831sc or H1000 paired with longer barrels. My barrel is 19" from recoil lug to muzzle, 10 twist, and it will be shot with a suppressor 100% of the time. What I'm looking for is a powder that will have the most complete burn in the barrel (to avoid powder burn continuation through the suppressor).

Looking to launch either 185g Juggs or 215g Hybrids. I have the following powders on hand, though none of them seem ideal at 19": H4350, H1000, Retumbo. If I had QuickLOAD, this would be a lot easier, but I'm on a MacBook and it's only windows compatible.

Anyone have similar use case as myself? What powder and charge did you land on?
 

Vargmat

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No idea on powder type, but 19" is very short for a win mag. Whats the reasoning behind the setup?
Im running a 26" barrel currently, and the next one will be 28"...
 

strow

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I have two Broughton 1:9 twist cut to 20" with an Ultra 7 attached the vast majority of the time. I have only tried one bullet/powder combo and have no real reason to try anything else so my data is limited. Load dev for both barrels never had a load shoot over 1/2-5/8moa. I worked up the powder charge to a velocity I was happy with an left it. The rifle is a Win M70 classic switch barrel that Accuracy Speaks built for me. It is my one and only hunting rifle.

Berger 215, Norma brass, F215, and 77.0gr of H1000. MV is 2820 with the can on. SD's are single digit. The second (newer) barrel runs a couple grains less and ~50fps slower.

I have taken a mess of cow elk, Coues, mule deer, coyotes, and ferals and the combo never stops impressing me. Ranges from less than 50yd to 635yd. I have thought about trying RL26, H4831sc, and the 190AB and 185 Juggernauts...but with the way the 215 kills stuff I don't know why I would bother. If there is a better killing bullet for the 300WM case than the 215 Berger...I would like to see someone with the gut piles to prove it.

Hope this helps!
 

SkyScrapin

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Whats the reasoning behind the setup?
This is an ultra light hunting rig specifically built for back country packability. Compact. Light. Maneuverable. 26" without a suppressor is stupid where I hunt; let alone adding 9" of suppressor.
 

Vargmat

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This is an ultra light hunting rig specifically built for back country packability. Compact. Light. Maneuverable. 26" without a suppressor is stupid where I hunt; let alone adding 9" of suppressor.
I see. Not a rifle I would put together, but we are free to pick...
 

strow

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People have asked me the same about my set up. I wanted 30/06 or better performance with heavy for caliber bullets, in a suppressed package that was still reasonably sized. The external and terminal ballistics have turned out to be everything I had hopped for.

I may pay a bit more for brass with a bit less barrel life but it makes up for it quickly in filled tags and down ranger performance. I think most of the "poor effificancy" concerns are penny wise and dollar silly when you factor in the total hunt expense. It isn't perfect...but it has been boringly reliable on game.
 

knuckleballz

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I am running h1000, berger 215, out of my falkor 20 inch proof 10 twist ar with 9 inch suppressor and am happy with the ballistics at 2820fps
 

SkyScrapin

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I am running h1000, berger 215, out of my falkor 20 inch proof 10 twist ar with 9 inch suppressor and am happy with the ballistics at 2820fps
What powder charge for reference?

I loaded my fire forming loads steps from 75g to 77.1g of H1000 and 215g Berger’s.
 

smoooth1

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Personally, I've noticed that 77.0gr H-1000 is awesome in heavy Federal brass and that with the lighter, more spacious, Norma brass, I need 78.0 or 78.2gr H-1000 to maintain the same POI. This is in an old 26", 1-10" Bartlein, but everywhere I have looked 77.0gr H-1000 is the load for 208 AMAX / ELD, 210 Berger VLD, and usually 215 Berger Hybrids.

You said your barrel is 19" from the recoil lug, but barrel length is legally measured to include the tenon / chamber as well, which makes your barrel closer to 20"+, depending on recoil lug thickness.

I've been wanting to have a 22" 300WM built for some time and am wanting to get an 1-8" or 1-9" twist. Adding 9" of suppressor drastically changes the entire system, especially in a hunting situation.

Best of luck to you!
 

SkyScrapin

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@smoooth1 its 20” including tenon.

I was out fireforming brass in my chamber, mostly testing for pressure. Working up to 77g, I started seeing crazy flat primers around 76.2g with 215 hybrids. Didn’t even shoot my last 3 loads... went back and fired some lower 75g charges that an hour before showed absolutely perfect primers and no ejector marks - now they’re flattened primers. Temp started at 38F and dropped to 34F. It wasn’t a heat related pressure spike. Powder was measure on a Prometheus scale, and being an electronic triple beam setup, it doesn’t drift.

I’m wondering if my barrel fouled out with H1000. If it did, I’ve never seen a barrel foul this quickly. Bartlein 10 twist barrel with a AAC MK13-SD. Thinking I need to clean this poor SOB and try again.

Launched some 185g Juggs at 2740fps at 77.1g H1000. The ES was terrible though.

Being a hunting rifle, I’m only searching for moderate velocity and preferably with the 215 hybrid. I can work with 2640fps, but I’m going to get 100-150 rounds on the barrel to see if it will speed up at all.

Rifle pic:
8C1C3DC2-B4C9-48E6-A904-FA93175F8B5E.jpeg

Forgot my front bag. The Spotter45 case worked in a pinch.
 
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smoooth1

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Very nice rifle and set up you have there @SkyScrapin!

Every barrel is different, some more than others. I've been running 77.0gr H-1000 with the 208 Amax and Berger 210 VLD, have not tried 215's yet, but will soon. This is with Federal brass and a barrel with 1000+ round count (guessing, bought it used).

What brass are you using?