Loading for 300 Win Mag

[undeg01]

After stepping away from this project for a while, I tried another load this afternoon, and it got the results I was looking for. 70 grs IMR4350 and 180 gr Accubond crimped at the cannelure got a 3 shot cloverleaf at 100 yards.
I’m still planning to try 71 and 72 grs just to see what happens, but it appears I was either pushing too hard or the inconsistent neck tension was causing my accuracy issues.
View attachment 210373

That’s a hot load!

 

[Cowbaby]

I just checked my Nosler book and your right at the max @70gr IMR 4350 and 180gr and if that shoots good no problems you got it perfect, at least for hunting purposes, a load shooting good towards max. 71 and 72 and your in uncharted territory unless you have some old data. If you must, work up super careful from there.I would not press it if its shooting like that, No need.

I knew you would find it as my rifle being bone stock hunter contour isn't half the rifle your barrel is. If it makes you feel any better I have yet to find a 165gr bullet load that suited me either. I have nail driver loads for 180 and 150gr and 125 SPs. I am beginning to think my rifle just isn't that fond of boat tails. Maybe something to do with the bearing surfaces. Sad part is a have a ton of quality 165 BTs and can't find a SP 165 right now to even test my hypothesis. I guess I will have to be satisfied with what I have until such time.

 

[retrieverman]

That’s a hot load!

A friend of a friend who’s a PH/guide in Africa told me his pet load is 72 grs of 4350 with 180 gr bullets. The guy is a serious shooter and reloader, and he’s been using that load for years in various rifles with no issues.

 

[Cowbaby]

I am sure he has. I have an old Lyman book that goes a little higher than todays lawyer pruf loads. It stops at 72.5 for just generic 180. The paper that comes with Lee dies lists 71.5
And I am not saying I have not done this myself. I was just quoting the Nosler book and website data.
Its just now days I generally use the data for whatever brand of bullet I am using. You should still be ok just watch your ease of bolt lift, signs of case bulge, ejector marks and flattened or leaker primers as you step up to the 72. Just caution is all I am saying when your going hot.

 

[Okie4570]

I usually determine what is hot and what is not. My first edition manuals from decades ago that were my dad's is what I still use the majority of the time over my new ones. I rarely seat my bullets the recommended bullet depths, therefore more case capacity. It's all variable, I've yet to ever blow a primer or have a sticky bolt loading over max loads for any cartridge. My only loading issues have come from subsonic loads trying to keep noise at a minimum. I had one bullet that failed to leave the barrel, it hissed at me when I lifted to bolt lol.

 

[Kev1Doggy]

I had a load for Elk with a 180g Speer Grand Slam that was a proven killer! Most of my cases would wear out after 4 reloads!

 

[retrieverman]

Hot or not, 70 grains of IMR4350 is the sweet spot for this rifle. I loaded up 4 more rounds to see if the last grouping was just a fluke but evidently not.
I’m also crimping every shell to ensure consistent case neck pressure.

 

[retrieverman]

I had a load for Elk with a 180g Speer Grand Slam that was a proven killer! Most of my cases would wear out after 4 reloads!

The friend of a friend who’s a PH/guide in Africa swears by 180 gr Hornady Interlocks which are a similar bullet for 300 WM. I have used Grand Slams in some 270 Win loads and really like them.

 

[Cowbaby]

Nice Chootin. Only problem is those cattle are going to find there feed ration tommorrow a little on the extra crunchy side,. HA. And yes, those Interlocks are called the poor man's partition.

My pet 150gr load is with 4350 but I never would have guessed it would work for heavier 180loads. I have to switch to 4831 or Rl 22 for the heavier stuff.
But I never argue with success.

I tried again yesterday with Hunter powder in the 300 and moved down to 150gr. Thought I found a scorcher on my first shot at 75gr as it dead centered my target dot and knocked it off. Second shot almost through the same hole and knocked it off again. But I only had two as I squashed the shoulder on the 3rd load making it because like a dummy I screwed the die in 3/4 more like a crimp die. I was kinda glad as I was getting kinda tired having to walk 100yrs every time to put my dang dot back on.

I had 5or6 hotter ones that went all over the map 1-1/4-1-1/2 so I did not reach anything conclusive. I don't think it will ever work for anything in this case really, just not enough case fill. But I am going to try the 75grain load again with more rounds next time. Just begging it to work until the powders come back for my smaller stuff.

On the plus side I found some darlin off the wall 30/30 loads dinkin around. with 4320 and LVR. Was shooting about an inch with open sights at about 65 yd. To bad 4320 ins now going to be discontinued. figures.

 

[retrieverman]

Nice Chootin. Only problem is those cattle are going to find there feed ration tommorrow a little on the extra crunchy side,. HA. And yes, those Interlocks are called the poor man's partition.

My pet 150gr load is with 4350 but I never would have guessed it would work for heavier 180loads. I have to switch to 4831 or Rl 22 for the heavier stuff.
But I never argue with success.

I tried again yesterday with Hunter powder in the 300 and moved down to 150gr. Thought I found a scorcher on my first shot at 75gr as it dead centered my target dot and knocked it off. Second shot almost through the same hole and knocked it off again. But I only had two as I squashed the shoulder on the 3rd load making it because like a dummy I screwed the die in 3/4 more like a crimp die. I was kinda glad as I was getting kinda tired having to walk 100yrs every time to put my dang dot back on.

I had 5or6 hotter ones that went all over the map 1-1/4-1-1/2 so I did not reach anything conclusive. I don't think it will ever work for anything in this case really, just not enough case fill. But I am going to try the 75grain load again with more rounds next time. Just begging it to work until the powders come back for my smaller stuff.

On the plus side I found some darlin off the wall 30/30 loads dinkin around. with 4320 and LVR. Was shooting about an inch with open sights at about 65 yd. To bad 4320 ins now going to be discontinued. figures.

View attachment 211129

It was entirely too hot to be shooting today, but I really wanted to try this load again and am glad I did. I bought this barrel used from a “friend”, but he’s been known to pass off problematic guns to others without disclosing the problem. I was kind of afraid this was one of them but evidently not.
Being kind of a cheapskate, I save all my feed sacks and pizza boxes to use as targets, and I keep spray paint on hand anyway.

I may try shooting out to 200 tomorrow if the mirage isn’t too bad.