300 winmag help


New Member
Mar 6, 2004
interior BC
New member here.I am load developing for my new Tikka T3 hunter.So far I have 120 bullets through the rifle.80 winchester 150grPP for break in and brass collection.I have 40 handloads through it too.Hornady 180gr BTSP with IMR 4831 from 69gr to 72.6gr, win brass and fed 215 primers.The barrel is 1 in 11 twist.The accuracy with the 150gr factory loads were good to great,a couple of 5 shot groups at 1".Two bullets touching in a group was normal.Accuracy with the 180gr has been sporadic at best.I have one four shot group at 71.5 gr that measueres 1.4",and one four shot group at 72.6gr that measures 1.2".I am not the most seasoned loader but I do take my time measure each powder load,neck size my brass, do all I can for accurate consistent loads.I just read in an old post here that the barrel twist suggests lighter bullets.I was trying the 180gr for more stability in the wind at long ranges.I hunt muleys in open country{ why I bought a 300winmag}.I will be trying the hornady 165grBTSP next and if I try more bullets I will be useing either the Nosler BT, Sierra MK or Amax.You guys sure have amazing accurate and lethal results from the Baltips,SMK,and Amax bullets.I have IMR 4831,4350.Fed 210m,215and WinLR primers here.I also have new and fireformed brass all winchester.Any load formulas to try or accuracy tips would be appreciated.I hope to make my new iron a honest 800 yd rifle.

[ 04-01-2004: Message edited by: Canadian Buck ]
72 grains of H4831, in Winchester brass, with 200 grain Sierra Match King, and magnum primer.

Capable of 1/2 MOA accuracy in a good rifle.
Have had good luck with Hornady 180 SPBT in my T-3. Only difference is I'm using Win. primers, Win. brass and RL-22. Have found you have to pace yourself as barrel heats up fairly easy. Keep us updated.
I shoot 2 then wait 5 mins then shoot 2 more for the group.Win large rifle or large rifle mag primers?

[ 04-02-2004: Message edited by: Canadian Buck ]
Just Large Rifle Primers, haven't needed Mag primers yet, and it does get a bit chilly here in Sask. during hunting season. Of your two powders try 4350 and one of your 165 grain bullets, IMR-4350 and 165 Nosler ballistic tips used to shoot one ragged hole out of my old 300, haven't tried that in this one yet but a lot of people have had good luck with this combo. If you use this combo for mulies let them get a little farther away
For hunting accuracy try the 165gr Nosler Ballistic tips with 79gr H-4831, 3430fps.(not great for shorter ranges at high velocity).
For more controlled expansion try the Barnes 168gr triple shocks with I-4831 can't remember the grains of powder on that one don't have my book here, at 3390fps, these will expand out to 1700 or 1800 fps. (make sure you seat them well off the lands).
I get 1 hole groups with both of these in my .300 win mag. (26" barrel)and very consistent velocity readings on my chronograph.
I shoot a 300 win mag model 70 with a 26 inch barrel. My magic load is 75 grains of RL-22, 180 grain SST seated touching the lands. I also use Norma brass with a FED 215 match primer.
The 300 Win mag shooting 190 gr Matchkings at 2900-2950 has been a winning combo for many years.To get your best accuracy you need to find your sweetspots and tune from there.Load each round 0.6 grains more than the previous round and load enough rounds to cover the entire powder charge range.Go to 200 or 300 yards and place a target up backwards so its all white.Place a small aiming point in the middle of your target and carefully shoot all your shots while watching the chronograph and keeping track of each hit.What you will see on the target is each shot going up the target then several shots all close together,this is your node or sweetspot.Your chronograph will show the velocity the same way,it will be going up then several will be close together.If you get two clusters go to the highest cluster and starting at the middle shoot 5 shot groups.What you will see is that best accuracy is generally on the upper half of the cluster.If your 4 shots in the cluster were 74,74.6,75.2,75.8 start at about 75 grains and go up slowly shooting groups,when best accuracy is achieved vary your seating depth and shoot groups again.
This three shot group shot at 100 yards measures .221" and was shot with Berger 210 VLD's moving at 2814 fps. The charge was 68 grains of IMR 4831 loaded into Remington Brass with Federal 215 primers. The barrel was a Shilen SS 1:10" twist connected to a Remington Model 700 action. I was pretty happy with this group until "Froggy" (Sniper's hide Forum) split that group size in half shooting his Accuracy International .308. In any regard, there are .300 WM's out there that do shoot better than this!
Oh and by the way, a new 1000 yard world record was set by "Bill Schrader" who shot a Five shot group that measured 1.473" using Berger's 210 VLD's.

[ 04-07-2004: Message edited by: W ]

[ 04-07-2004: Message edited by: W ]

[ 04-07-2004: Message edited by: W ]
My Sako 75 .300 Win mag, will shoot up to 200gr. bullets OK. Better if you stay at or under 180gr.
1:11 twist barrel as well...sakofan...
Senior Sendero and Brown Dog the 11 twist barrel will handle 200 gr bullets without any problems.My 11 twist barrel shoots 216 Clinch River bullets without any problems at all.
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