300 Win Mag Load Development Help Needed

Ddwarren

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Joined
Dec 1, 2007
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Location
Helena, MT
Hey guys,
Need a little help. I am trying to dial in a handload for my 300 Win Mag. I am shooting a Rem 700 Sundero with 26" barrell. I have been flailing with some Barnes TTSX 180 grain rounds. I got info to load them extremely long (OAL of 3.5) I have messed around and cannot make them work. I am getting ready to try some old standbyes, ie the Sierra HPBT 180 gr. I would love to use H1000 since it is my choice for my 338 edge. Keeping one powder for both would be great. I am using CCI 250 Mag Primers (Same as Edge for reasons above). Any help would be great!!
Thanks
Dev
 
I probably won't be much help here, as I've never reloaded any of the Barnes bullets...but, all that I've read about them is that they like quite a bit of jump before they hit the lands. How far off the lands are you seating the bullets? I've read as much as 0.050" before they started getting any accuracy out of them.

Good luck!
 
I am shooting a Rem 700 XCR long range tactical with a 26" barrel. Don't know how similiar it would be to the sendero, but I would think they would be close.

I am currently shooting 150 grain Sierra BT gamekings ( I have some 180's ordered but they haven't come yet). I got some promising results shooting
80 grains of H1000. My brass is winchester with a winchester WLR primer. My COAL is mesured with a stoney point bullet comparator and is 2.860" which in my rifle is jumping .050". For some reason this is what my rifle likes with these bullets. Last weekend I shot a 3 shot group at 200 yards that measured 0.977", pretty good for a factory rifle.
 
Dev,
I have not tried the TTSX in any of my rifles yet, but have had good luck with the 100gn TSX in .257 cal and 140gn in .284 cal.
That said, in my .300WM, I tried the 180gn NBT with RL22/9.5M & BR2 primers and never could get accuracy under .6". Then I tried them with H4350/9.5M and @ 69.0gn I got .370" and 3094fps (avg). This load shot good for me at 650yds. I let my son, three nephews and brother-in-law shoot it at that distance. Only my son had previous shooting experience that far, but the nephews and B-I-L are hooked! They all could consistently ring the 12X18" gong I made and boy were they'a grinning!
I tried the 190gn SMK with RL25 and WLRM (and 9.5M) primers but the best I got was a .5" (once) and couldn't duplicate it.
Then I tried the 180gn SMK with RL22/9.5M OAL:2.8950" and @ 75.5gn's I'm getting an average velocity of 3133fps and accuracy is running in the .3's.
Still got more testing to do (180NBT/w RL25 & 190SMK/w RL22 and others) but will share this info if you like.
Oh, I did try some 165gn NBT's I had on hand the day after I bought the rifle. I used H4350/9.5M OAL: 2.8925". I tried 71/72/73gns and accuracy and velocity ran; .585" @ 3244fps (71.0gn), .4175" @ 3269fps (72.0gn) and .6340"@3296fps (73.0gn).
Hope all this helps and encourages you to keep trying. The .300WinMag is an awesome cartridge and capable of very good accuracy. JohnnyK.
 
seat the bullets .50 from rifling. change primer then try a different powder. i had better luck with imr 4350, rl 22 than h1000 in my gun. my gun actually liked the 168s better than 180s.
 
I load for 9 different guns in 300 win mag and in all cases the TTSX's shoot well seated .050" off the lands but you should be using RL22 and Fed215 primers. H1000 shoots good but not as good as the RL22 or even RL25. But you definitely should move to the Fed215's (if you can find them).
 
My load was 72 grains R22, 210 Berger, Gm215m. seated to touch rifling

This produced sub .5moa and 3013 fps out of my Sendero. It was flat awesome.
 
70.4 gr rl-22, 190 smk, fed mag match primer, c.o.a.l. 3.660 this shoots 1.125 group @200 yds out of my ecipse
 
Thanks guys. I am now doing some shopping to find some different components to load up with. I will keep you informed as I get the different load combinations together and some shots on paper.

How many shots do you take when trying a load. Lets say I am going to try 5 different combinations. Typically, I will load 9 rounds of each combination. I will then shoot 3 let it cool 10 minutes, shoot 3 let it cool 10, shoot 3 let it cool 10, then do a quick barrell clean. Then I will repeat with the next combination, so on and so forth. Is this a good concept? Any better ideas?

Thanks
Dev
 
I would work one powder bullet combo at a time. I have had good success choosing the bullet I want to use, then an appropriate powder.

I start with the bullets just touching the rifling.
I load 3 each in .5 grain increments.
You should clearly see the accuracy nodes on both the target and the chrono.
If I go through a few grain spread without seeing what I want I'll seat the bullet deeper and repeat the process.
If this doesn't work, swith components.
 
if your group size dont improve to your expectations try changing you seating depth a few thousandslightbulb
 
I load for 9 different guns in 300 win mag and in all cases the TTSX's shoot well seated .050" off the lands but you should be using RL22 and Fed215 primers. H1000 shoots good but not as good as the RL22 or even RL25. But you definitely should move to the Fed215's (if you can find them).

I thought "Woods" was shooting my Encore with a 300wm by his comment! That's the same combination my rifle likes best.

Barnes requires you to shoot the TTSX .030 to .070 off the lands but recommends starting at .050. and "grit" hit the nail on the head. Don't put to many variables it to the mix all at once. You also have to keep in mind that the closer to the lands you are the high the pressure cup is, "keep track of your velocity's" so you know when your reaching un-safe limits.

Honestly, I have found in some rifle / bullet combinations that the highest velocity isn't always the most accurate. Not only that, you may want to lower the grain of the bullet a tad to like the 168's. They shoot better in my WM than the 180's do. Realisticly most "not all" 30 caliber rifles perform best at that grainage. Just look at the .308 Winchester. Don't be affraid to slow it down a bit, you may be surprised by the out come. I know I was. One other powder that works good in my WM with the TTSX is IMR4831 but RL-22 has a more consistant performance shot to shot.

My work-ups consist of 5 shot strings in 5 grain increments. I run 1 powder with 3 different bullets, 1 case brand and 1 primer to start. All information is then run threw a ballistic program. Next I change up the primer only. Than the case. Next I take the best of the best and mess around with the seating depth in 3 shot strings. If I am still not satisfied with the results I move on to another powder choice and start over.

If I am using new cases I fire form then twice before I get serious and pay close attention to case prep, headspacing, & runout. No more than .002 runout. Headspacing no more than .002 but look for .001 anymore than that your working the brass more than needed and your running in the danger zone. To much HS can be very dangerous and hurts accuracy so be carefull!


Good choice with the Barnes if you take your time working up a good load. Best performing bullet on game out there bar none! Because they do retain nearly 100% of mass upon impact you don't need to run the heavier grain bullets like you need to with other bullets!

WRG
 
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