300 Win Mag Tests

Skeeter22

Beginner
Mar 24, 2016
12
0
Well, here is the deal on my tests with the 300 Win Mag Rem 700 Sendero. Factory ammo did not shoot well in the rifle, so I got into reloading. I like Nosler bullets, so I started with Nosler Load Data.

(1) 70 Grains of IMR4831 pushed a 168 grain NBT 2880. Much slower than the load data.

(2) 68 Grains of IMR4350 pushed the same bullet 2900, again, much slower than the load data.

(4) Even max load of IMR4350 with a 180 grain NBT pushed was 100fps below the load data.

(4) H1000 was much slower on the 180- grain NBT as well.

None of them shot all that great. The best one was the IMR4350 at max load with the 180 grain NBT. At the time, the only primers I could find were CCI250's. After doing some reading and research, the CCI250's, apparently, are not as "hot" as other brand primers. So, I finally found some Winchester WLRM's.

I know I shouldn't change but on thing at a time, but I switched primers and bullets: (1) to the WLRM's, and (2) to the AccuBond 165's. I tested IMR4350 at 71 grains, and it shot 1". I made a ladder of IMR4831 starting at 73 grains. 73 grains did not do well. 73.5 grains had three bullets touching in the center of a 1" circle and probably .75 or a little less. I put the rifle up after that because it was getting warm outside (longer for the rifle to cool off), and I will test the 74 grains of IMR4831 later. I also have 79 grains of H1000 to test in the 180 NBT's again as well. I don't have speeds with the WLRM primers yet. I used my buddies chronograph the weekend before last to test speeds. I'll have me a chrono soon though. I can't accurately compensate for bullet drop if I am guessing from the load data. The chrono will tell me for sure.

I doubt it had much to do with changing bullets from the NBT's to the Accubonds. I suspect the WLRM's do a better job in my rifle than the CCI250's. Everything tightened up when I switched primers.

What are your thoughts?
 
180 grain bullets 76 gr RL22 or H4831. 300 mags usually like full bore loads. Fed 215 or win mag caps
 
Changing primers can really make a huge difference in accuracy that's for sure. Sounds like you have a shooter with 4831 if you end up with a speed you're happy with. If not, trying increasing the charge while watching for signs of pressure along the way. RL22 has always been a winner for me in a 300wm when speed and accuracy are the objective. YMMV.
 
OU812":2ugu9g5e said:
Changing primers can really make a huge difference in accuracy that's for sure. Sounds like you have a shooter with 4831 if you end up with a speed you're happy with. If not, trying increasing the charge while watching for signs of pressure along the way. RL22 has always been a winner for me in a 300wm when speed and accuracy are the objective. YMMV.


Just like you, I don't really see the point of having a big magnum rifle if it is not running over 3000fps accurately because I get 2800 out of the same bullet with almost half the powder out of my 308. My Redding Competition die says not to use it on compression loads. That is one of the reasons I have not tried RL-22...also, it has not been easy to find in my area as well.
 
Try 75.0 grs RL22 and a Federal GM215M primer. This load shoots well under MOA for me in 3 different rifles.

JD338
 
JD338":3b9zm5md said:
Try 75.0 grs RL22 and a Federal GM215M primer. This load shoots well under MOA for me in 3 different rifles.

JD338


Trust me!!!!!!!!!! I would love to get my hands on some Federal GM215's. There is not a single one anywhere in the whole nation. I even e-mailed federal. They said we will be lucky to see any rifle primers by July.
 
I never found RL-22 to be a compressed load with the seating depth used with 180gr bullets.
 
OU812":1ajekkrm said:
I never found RL-22 to be a compressed load with the seating depth used with 180gr bullets.


Yeap. You are correct. I was looking at the 165 grain loading data. 165's are compressed--all of them. It don't makes sense though. 75 grains is compressed for a 165 but 75 grains is not compressed with the 180 with a longer bullet and deeper seating depth. Hmmm.


http://www.nosler.com/nosler-load-data/ ... er-magnum/
 
As Fotis already stated, 300 WM's like full loads. I am using H-4350 at 70+, grains with the 180 gr, Sierra BT or PT.
 
180 gr npt or nab with 75.4 grans of 4831sc or 78 gr of 4831sc and a 165 npt boom dead.
 
Something seems wrong with your gun barrel or your powder measure or your chronograph. That 168g bullet should be in the 3100+ fps range. RL-22 with a 180 g AccuBond has been well over 3050 fps in several guns and over 3100 fps in mine.
Do you have another chronograph to shoot through?
 
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