What one bullet is most accurate in a .300 Win Mag?

[FLChinook]

I know there are more discussions about this bullet being better or that bullet being better than most of us have had hot breakfasts. But I'm having an accuracy issue with my new Weatherby Accumark in .300 Win Mag. I've tried mostly Berger bullets, 168 and 185 gr., and now find that since Weatherby's have such a large freebore, the Bergers may not be suited to the gun.

If I don't care about killing game and only want to test the accuracy of this gun, which one bullet should I try? Surely, it will be a hollow point; possibly one from Sierra's MatchKing range? What say ye???

[big al hunter]

Sorry Chinook only your rifle knows what bullet will shoot best. If the bullets you already tried were hollow point, try boat tail soft point. Then try soft point or fmj. I do wish you luck in your search. Maybe someone else has a load that will perform in your rifle, but you wont know for sure until you pull the trigger.

[FLChinook]

You are right, of course. But I'm only getting 2" groups from a bench rest and want to try another bullet that at least has a chance of doing better.

[srfisher3]

It's possible that you're using a bullet that is a little to light for your gun. Do you know what twist the rifling of your barrel is? Try something a bit heavier and see what you get.

[Saskhunter]

Try some Ballistic Tips. They often shoot well.

[FLChinook]

Do you know what twist the rifling of your barrel is?

I haven't measured the twist but the spec is 10".

Try some Ballistic Tips. They often shoot well.

Even Nosler acknowledges that hollow points are the most accurate bullet type and that BTs are a less expensive way to deal with a bullet tip than to do a hollow point. However, for hunting, I suspect hollow points would be less successful

[Art Eatman]

"What one bullet is most accurate in a .300 Win Mag?"

The one which gives the tightest groups.

(Sorry. It's just a character defect. )

I've always had tight groups from Sierras in my 1:10 '06 sporter. Always sub-MOA. Sometimes down around 1/2 MOA. That's through some 4,000 rounds over a bunch of years.

[B.L.E.]

I think the Weatherby Magnum calibers have a specified freebore in the chamber dimensions. That doesn't necessarily mean that Weatherby uses freebore in rifles built for Winchester Magnum ammo.

You could experiment with seating the bullets out a little more, though you may have to use it as a single shot if the overall length doesn't fit in the magazine.

[FLChinook]

I've always had tight groups from Sierras in my 1:10 '06 sporter

Is there a specific Sierra you can proffer? Thanks

[kraigwy]

I've tried mostly Berger bullets, 168 and 185 gr., and now find that since Weatherby's have such a large freebore, the Bergers may not be suited to the gun.

That certainly narrow the range of Berger Bullets. I think you might take advantage of that freebore by trying Berger's 230 grn bullets. They have two, the 230 Gr Hybird (BC G1 .743, G7 380) and the 230 Gr Hybird OTM Tactical (BC G1 .719 G7 .368).

I use to think I could do no better then the 200 Gr SMK in my 300 WM Model 70 1000 yard gun, but I've been working with Berger's 190 VLD and its showing promise in my gun.

Of course all guns are different.

[FLChinook]

I think you might take advantage of that freebore by trying Berger's 230 grn bullets.

Yikes, my shoulder is hurting at just the thought of that big bullet

There seem to be so many factors to consider. A longer bullet may reach my grooves sooner but a longer bullet is harder to stabilize. And recoil will be greater for a 230 gr. vs. a 165 gr. I'm not a complete wuss when it comes to recoil but I did once sell a .338 WM when it was putting my already-depleted rotator cuffs into jeopardy..

I'd like to find a circa 165 gr. bullet that works...

Now that I consider it, my Berger 168s did badly when my scope was bad. It was only the 185s that I tested with the re-conditioned Swarovski (and did not do well). I could go back and recheck the 165s. But if the 185s did not do well, what are the chances for the 168s?

[Lloyd Smale]

if i told you id have to kill you

[FLChinook]

if i told you id have to kill you

Aha, so you REALLY don't know....

[kraigwy]

Yikes, my shoulder is hurting at just the thought of that big bullet

I cheated, I put a Badger Ord FTE muzzle brake on my 300 WM, it's about like shooting a light weight 234.

[FLChinook]

Did that muzzle break give a big increase in "bang", I.e., did you find shooters at adjacent benches pick up their stuff and move further away from you..?

[kraigwy]

Not as bad as you think.

But to be honest, I shoot on my own private range.

[hooligan1]

Listen to the captain, try heavier bullets..... circa 200 grn or larger.

[buckhorn_cortez]

The most accurate bullet I found for my magnum 30 caliber (30-338) is the Sierra 190 grain match HPBT. Not much of a hunting round, but it is accurate.

[Art Eatman]

In the Sierra line, I have used 150-grain soft-points, both flat-base and boat-tail. 165-grains, HPBT. 180-grain, SPBT.

All gave sub-MOA groups, regularly. Reliably.

I mostly used the 150s in my deer hunting. I made one bad hit on a buck and lost him via a setting sun in the scope at 4X. I hit one running buck a bit far back and needed a finishing shot. Otherwise, it was bang/whop/flop on a tad over twenty bucks. Some exit wounds; sometimes none. But if they go flop, what difference does it make?

Ranges from 25 to 450 yards, but mostly around 100 to 200 yards.

Another couple of dozen bucks with my .243, using the Sierra 85-grain HPBT, which is also a tack-driving load.

[jdillon]

I shoot Berger 155 gr. VLD's out of my 300 WM with excellent results. When I am having a good day, it will group under .5 MOA. Bergers are very sensitive to seating depth and you may want to try different seating depths before giving up. Most people recommend having the bullet in contact with the lands but this is always not possible especially with lighter bullets. They also can perform effectively with a bit of jump and there is an excellent article on Berger's website explaining how to do so. You may want to try their hybrid bullets which are reported not to be as sensitive to seating depth. Also you may want to experiment with different powders since and may have an impact as well. I tried several different powders in my rifle and settled on IMR 4350. Only adjust one variable at a time otherwise you will have difficulty ascertaining which variable provides the best results.

[warbirdlover]

I think the Weatherby Magnum calibers have a specified freebore in the chamber dimensions. That doesn't necessarily mean that Weatherby uses freebore in rifles built for Winchester Magnum ammo.

You could experiment with seating the bullets out a little more, though you may have to use it as a single shot if the overall length doesn't fit in the magazine.

B.L.E.

I was going to say this same thing. The long freebore is for the higher pressures from the .300 Weatherby Mag vs. the .300 Win Mag. They would be making a giant mistake if they put that freebore on the Win Mag.

Just for the "heck" of it try a box of factory ammo. And 150 gr. should shoot fine in a .300 Win Mag.

[Lloyd Smale]

[QUOTE][Quote:
if i told you id have to kill you

Aha, so you REALLY don't know.... /QUOTE]

nope because ive never seen two differnt guns in the same caliber like exactly the same load best. Not that it couldnt happen but i wouldnt wager any of my money on it. How do you find out. You buy and shoot everything you can find until that majic load somehow appears.

[warbirdlover]

I got lucky. My Ruger 77 MkII all-weather .300 Win shoots any factory ammo (and bullet weight) to the same hole and groups with anything I run through it. I quit handloading when I couldn't beat it with my own loads. I'm talking sub-MOA with anything. That's why I kept the rifle for over 20 years. It's one in a million.

[mapsjanhere]

Have you measured the length of your chamber with those bullets? Bergers like to be set close to the lands or touching. My method of measuring uses two wooden dowels, one to press the bullet against or into the lands, the other used from the muzzle to measure the distance. Then use the muzzle dowel to measure the length of the empty barrel and chamber - the difference gives you your best OAL for Bergers.
I like the 210gr in 30, but they are making rather long cartridges when set to the right distance. They might not fit into the magazine in your gun.

[Bart B.]

Note that a 1:10 twist in a 300 Winny Maggie will spin bullets lighter than 200 grains much too fast for best accuracy. As 97% of all bullets are unbalanced to some tiny amount, it's enough that spinning them too fast creates enough centrifugal force to make 'em jump off the bore axis when they exit.

Which is why 1:12 twists were (and still are) popular for 30 caliber cartridges of that size with heavy bullets for long range matches. I've shot 180 HPMK's from my .300 Win Mag's 1:13 twist with excellent accuracy through 1000 yards.

So, for best accuracy with a 1:10 twist in one, I suggest a 220-gr. Sierra HPMK. But it'll only work well accuracy wise if the barrel's groove diameter is smaller than those bullets; they're typically about .3082". Lots of 30 caliber factory sporter barrels have larger groove diameters (Winchester was nororious for that and may still be). If the groove diameter's bigger than that, then I'd try to find some fatter bullets to use.

The 1:10 twist for so many 30 caliber magnum barrels came about when Winchester built their first Model 70's in .300 H&H Mag. They used the same twist as the .30-06 had, but even Harry Pope (famous barrel maker a century ago) said that was way too fast for best accuracy. Roy Weatherby used that twist for his .300 Wby. Mag. 'cause both he and his customers felt if the H&H version's twist was good enough, then so would his be. But Winchester and arsenal engineers were smart enough to make the 7.62 NATO's and .308 Win's twist 1:12 for 150-gr. to 200-gr. bullets leaving slower than the .30-06 shot them. They were more accurate with that slower twist.

Whatever bullet you choose to test, shoot enough shots per test group to be meaningful. At least 15 and 20 is better. Judge accuracy by the largest group for a given load as that's what you can count on all the time. Rarely does anybody shoot a group the size of the smallest one shot with a given load.