300 Winchester Mag Loads

Pirate-69

Private
Minuteman
Jan 1, 2009
98
2
Greenville, NC
I have recently extracted a heavy-barreled 300 Win. Mag from the back of my gun safe that was barreled in 1996. I shot it about 50 times and it lost favor to the other toys. At the time I semi-retired it, I had settled on a load of 69.0 grains of IMR 4350 behind a 180 grain Sierra SBT (#2160)and it was doing what it was built to do. My best five shot group was 2.25" at 500 yards. It was a perfect morning, clear, cool and dead calm. The three manuals I owned at that time gave the following as loading ranges for a 180 grain bullet and IMR 4350:

Speer #7 1966 71-75 grains
Speer #12 1994 68-72 grains
Lyman #45 65-72.5 grains

It has been recently suggested that the 69.0 grains of IMR 4350 may by near max and I may want to consider something in the 67 grain range for a 180 grain bullet. My Hornady #5 does not have data for IMR4350 behind a 180 grain bullet. The nearest comparison is the 168 grain bullet and it lists the max at 69.8 grains.

I am curious as you other's loads for 180 grain and 168 grain bullets and IMR4350. I am not seeing any pressure indications with the 180 grainers but I do not want to spend the barrel any quicker than necessary. I just bought 1,000 rounds of the Nosler 168 grain HPBT CC to play with. Getting the bug again. It is a Douglas SS Premium Grade barrel and it was not cheap even in 1996 Is 69.0 grains considered hot for the 180 grain? What has happened to the suggested load ranges over the years?
 

Pirate-69

Private
Minuteman
Jan 1, 2009
98
2
Greenville, NC
Re: 300 Winchester Mag Loads

No one loading IMR 4350 behind 180 or 168 grainers in 300 WM? 69 gains is averaging 3048 fps out of a 25" barrel.
 

chain

Sergeant
Full Member
Minuteman
Jan 6, 2008
196
0
63
MI USA
Re: 300 Winchester Mag Loads

RL 22 for 180's 75.5 gr H-1000 for 200's 76.5 gr That is what I load.
 

Grumulkin

Sergeant
Full Member
Minuteman
Re: 300 Winchester Mag Loads

The 300 Win. Mag. is supposed to be loaded near max. If you have no signs of excess pressure and your accuracy is satisfactory there is no need to change your load.
 

TOP PREDATOR

Gunny Sergeant
Full Member
Minuteman
Jul 19, 2008
4,590
80
52
SCRANTON AREA PENNSYLVANIA
Re: 300 Winchester Mag Loads

i never used 168's, and 180's caused too much damage on game (blew the side out of one of my bears), but this is what i was using for 165 sst's

REMINGTON BRASS TRIMMED TO 2.615
L.R. MAG.PRIMER, MAX. OAL 3.34, SHELL HOLDER #4

165 GR. HORN. SST MOLY 3.34" OAL
4350 72 GRAINS 3025 FPS(MATCHED HORNADY FACTORY LOADS). THROUGH A 24" RUGER A LITTLE OVER 1" AT 100 YARDS, 2" AT 200, A LITTLE OVER MOA TO 500
 

mavrick10_2000

Private
Supporter
Full Member
Minuteman
Jan 8, 2009
372
2,650
Oklahoma
Re: 300 Winchester Mag Loads

Similar to you're original load.

Win Brass
Win LR Mag Primer
Nosler 180gr Partition PP
68.0 gr H4350
 

308isgreat

Sergeant
Full Member
Minuteman
Oct 1, 2008
274
0
Milton, FL
Re: 300 Winchester Mag Loads

78.0 grains of RX25 behind a 168 Barnes TSX is accurate and deadly out of my 300WM. Same load with 165 Sierra Gameking hollow points has dropped every deer where it stood.