300win mag 215 berger help

I stopped measuring SD, ES and velocity a few years ago. It doesn't matter to me as long as it groups. I load up until I see pressure, then back off two grains. Test at 500 and 1000. Been lucky so far. The weird thing I do is pull the expander ball out of the sizing die to increase neck tension. Lastly, I only shoot 3 shot groups. Never saw the need for five shot groups.

My 300 Win Mag load development consisted of 15 shots. Started at 75 gr and worked up to 79 gr of H1000. No marks on case or hard bolt lift in my gun. I stopped there because I was right in line velocity wise like Broz. Running at 3000 fps. All 5 powder charges shot into basically the same point of impact. 30 thou off was were my gun liked the 215. Broz did help me with reamer specs.
Gun: 26" #3 BRUX 1-10
Borden action
Holland brake
Mcmillan Game scout
Jewel trigger
Using Nosler Brass with FED GM 215M
My friend built a gun using my reamer with the exact same results. We just load his lighter because his brass is heavier. But his velocity is also 3000 fps. Exact same barrel as me.

I switched to 4831sc on my wm. I run 74.5 gr over 210m's. I get 3050. The 215 should hit upper 29's pretty easy in a 26" tube. 15-20 thou off seems to work in most guns

I am running Berger 215s in a 25" Bartlien with a 1-9" twist on a GAP 300 WM rifle. I started off trying 0.010-0.040" off the lands with H1000 (74.0- 77.0gr), Norma brass and F215m primers. The results were slightly less than 1 MOA with unimpressive SD/ES. Then I tired a max magazine length COAL of 3.625" (-0.110") and the groups tightened up to 1/2-3/8 MOA. It appears the Berger 215s can tolerate jump well with certain barrels so I think this is worth adding to your testing. I believe Applied Ballistics factory 300WM Berger 215 ammo is 3.60" which must mean they believe it will work well in a range of rifles.

I continue to struggle with SD greater than 10fps with all combinations of H1000 that put me in the 2800-2900 fps range. I am not complaining about accuracy with H1000 and am using 76.2 grains, giving me 2845 fps, for hunting to moderate range. I started experimenting with RL26 which appears to be giving me better SD/ES at around 75.0 gr and again about 2840 fps. (While keeping the same accuracy with the 3.625 COAL)Interestingly, my SD/ES for both RL26 and H1000 climbed as I increased charge weights resulting in velocities much above 2850 fps.

ok well maybe I will seat some a little deeper and see if my results change. I have noticed the same thing with increasing sd/es as I increased charge and velocity. once I over 2950fps things got wild, so im happy with 2850-2900 as long as the groups are good. what kind of accuracy should I consider acceptable and just be happy with??

My 300 WM took about 40 rounds before they started to increase in Velocity. My 300wm sounded like yours! I tried every seating depth, and every grain of H1000 but my Remington 26" barrel just did not like H1000. Like you I found some .80" at 2950 fps but I was not happy with that. I tried IMR 7828ssc 70g at 2830 fps. I ended up at .222 MOA and shooting at 540 yards I was right under 3 inchs. My belief, but Im no pro reloader like some on here but, is that if you can do a bunch of loads over and over and it doesn't even get close to what you want, it will take another bunch of loads to even get somewhat close to what you want.
Once I switched over to IMR 7828ssc after 20 rounds fired I found a nice node and great groupings. Then work on that. I haven't seen or heard of a load as of yet (unless someone can chime in and tell us) that after all you can do and you end up with a 1" load and by changing primers, seating depth, .01 grain of powered, neck trimming, and then it turns into a 1/4 MOA.. Maybe they get it down to .80 if lucky a .60 but not drastically to a .25

What is considered good enough accuracy is pretty subjective, depending largely on your objectives. Brian Litz and his WEZ modelling concepts for probabilistic results might be good starting point for assessing your needs. For myself, when shooting a custom rifle with the potential for long range application, I want consistent 1/2 MOA or better with SD +/- 10 fps. When using my dad's old Model 70 30-06 for general purpose hunting, I am happy with 1 MOA and don't pay much attention to ES/SD.

I've recently been following Adam MacDonald's blog on line. (He is the auto-trickler inventor and a competitive shooter in Canada.) Adam has an interesting working theory that charge weight is the main driver for SD/ES and seating depth is the main driver for group size. My own experience tells me this is not always the case, but as he points out in his blog, it sure simplifies testing to use this theory for load development. In my case for 215 Bergers and my 300 WM, changing the seating depth gave me a dramatic improvement in group size once I backed off more than I had typically been trying. It was also interesting to note that I achieved very similar group sizes for both RL26 and H1000 when pushing similar muzzle velocities.

I agree with Zeke-BE in the respect that some of my most significant improvements in group size seem to be when I change an important variable. Unfortunately, determining that key variable for a particular rifle/ bullet seems to all too often be mostly a matter of chance in my load development. Most times, it seems to be incremental gains as Zeke-BE indicates and no real break through gains.

ok just an update here, the other day I decided to do another load work up to verify my max pressure because I have since turned all necks and did some extra brass prep since the last time I looked for max. well I started at 77.5gr h-1000 since I have recently worked with 77.0gr.
I loaded 5 rounds from 77.5gr-79.5gr and wen to the range just to find pressure. well at 79.5gr my bolt lift got real sticky and I had clear markings from the ejector on the case head. but what I did notice was that 77.5,78.0,78.5 all created a horizontal spread. kinda like you would see on a ladder test. by the way I was at 200yards. but I had no real pressure issue. could neck turning have helped with pressure? Well I went home and loaded 10 rounds at 78.0 and 78.5gr at a seating depth of .030 off the lands and raced back to the range. they both shot good but 78.5gr had better es with 10fps.
So I ran back home and loaded 10 more but this time I weight sorted the brass and picked 10pc that were within 1.0 grain of each other, I trickled each charge, I feel my ammo was good. so this morning I found myself back at the range. group 1 at 100yards was ok at just under an inch, the es was still 10 so I was impressed. after letting the barrel cool I shot a second group. to my surprise my sd/es were all under 10, I mean what has happened for such a change and the 3 shot group measure .4.
I am still blown away by that, really I am. so I went home loaded some more and went out tonight and shot at 500 yards. I took 2 3shot groups letting barrel cool for maybe 10 minute. All shot were fired at the same target. the first shot was about 2.5" high left followed by the next two within 3.25" from each other. On the second group all three shots formed a perfect 3.5" group grouping with the second and third shot from the first group.
if it weren't for that flyer in the first group that 6 shot group would've rocked!! I didn't thing I pulled that first shot but who knows now. the group measure just over 5'' with the flyer.
I really happy things are looking on the up, but I still want to load a few more and confirm, oh I for got to mention that the vertical dispersion not including the fler was right at 2.5". my velocity average is 2938fps. Is there anything else you guys can think of that may give me and edge continuing my accuracy with this load if the flyers persist. I do believe I will shop for new brass because after weighing all my ww brass I am shock at the difference in weight with some being upto 4 grains diff,
thanks guys for all your input over last few days, youe experiences have helped me so much

I'd say you are barking up the right tree. Once I sorted my brass and settled on a 1g total spread my SD went right down to 8 and has held consistently.

is nosler brass worth the money or should I just go the norma route and prep?

at this rate

bowkill02 said:

is nosler brass worth the money or should I just go the norma route and prep?

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I wont have much ww brass left after im done sorting it.

I'am having problems with my Nosler brass in 300 win-mag with the primer pockets enlarging.I'am shooting 208-A max with Retumbo powder and I have a really nice group and still under max powder in the book. can anyone help me with this problem ?

How many firings do you have with the brass?

bowkill02 said:

How many firings do you have with the brass?

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It starts around the 3rd firing and last time it happen I bought a new box of 50 and sure as heck the same thing happen on the 3rd time. After I shoot the brass I ultrasonic clean it then I clean the inside of the neck and spin the brass outside with a light steel wool and then trim to size then neck size and I have a rcbs triming station for the pocket cleaner and small wire brush then VLD inside and out of the neck and I always check my blow hole with a Lyman tool in side and out. I checked the pocket reamer it looks ok and I'am in the process of trying to find a new one just to see if that is the problem but I have also been using the same equipment on other hand loads that I have been making with the same Nosler brass in 2506 and been having no problems.I have some older Nosler brass that I have shot over 9 times and still no problem with that brass on primer pockets. I also have a friend that has the same problem, I always buy Lupua brass when I can but they don't make it for 300 win-mag. Hopefully you can help me this. THX Dana