.300 Win Mag question

[gpspowell]

I have a question re: a hunting load but first a bit of background:
I'm shooting a Classic Remington 700 .300 Win Mag beautifully redone by APA. Broughton 1:11 barrel, Jewel trigger, blueprinted, bedded, no brake. The chamber is nicely tight, brass growing only .003 on firing. Using load data from before the rebuild, and available components I loaded a "practice" round and fell into an awesome antelope/deer load. Hornady case, 150g Nosler AB, 76.0g A3100, Win mag primer, OAL=3.426, jumping .047 to the lands, 3260fps! This load is shooting consistent 1/2 minute at 500 yds. off the bipod.

So here's the question: I want a moose/elk load using 200g Nosler Partitions. As A3100 is no longer manufactured I've decided on H4831. Working up I'm at 74.0g, muzzle velocity=2910fps, no pressure signs at all. This load is already above max for all my books except Lyman which max is 74.0g. As I tweak for accuracy (already good) what opinions are there regarding increasing speed if accuracy goes that way? I know some old data for 4831 was greater than 74g.
This load is using Remington brass & Win LRM primers

 

[Lefty7mmstw]

What is your barrel length??? My browning 300 win(26" w. brake) usually eats 165 hornady with rl22, but in another life, it ate 180 hornadies with imr7828. It made 3100 fps with those. Modern h4831 isn't what the old surp. stuff was. I had a lefty rem in 300 win that really liked the paper can h4831(3150 fps) my uncle gave me, but when I tried to duplicate the load with modern powder, the best I could come up with was 3000 fps with barely moa accuracy(the mil-surp was more like 1/2 to 3/4).
I would say to try rl22 or rl25, and if you want to stay single base(shiver) 7828 or h1000. I've had good luck with all but rl25 with 180's in the 300 win, and I haven't tried rl25 because I use it in my 7stw and 300 ultra.
The horses mouth(hodgdon 26) goes to 76 grains, and the newer yearly manual(2012) goes to anywhere from 73 to 76.3 depending on whether you are using the 180 e-tip, the 180 speer mag tip, or the 175 sierra.
Also, your twist isn't 1:10, it is 1:11, so you will develop slightly less pressure than a 1:10 twist. Give her a couple of grains, but if you want over 3K, go to rl 22 or 7828/ h1000.

 

[gpspowell]

What is your barrel length???

Barrel is a 24" (actually 23 1/2"). I'm actually not so concerned with trying to increase the speed so much as to find an accuracy node near where I am now, without getting dangerous if that node happens to be a bit hotter than 2910fps. Thanks for your reply.

 

[Lefty7mmstw]

Barrel is a 24" (actually 23 1/2"). I'm actually not so concerned with trying to increase the speed so much as to find an accuracy node near where I am now, without getting dangerous if that node happens to be a bit hotter than 2910fps. Thanks for your reply.

A 24" barrel in 300 win should net 3K to 3100 fps with accuracy if it isn't a slow barrel. You have just gotta play with it. I'd go to a bit slower powder too.

 

[jsthntn247]

Try H1000 in the neighborhood of 76-79 grains. You should find a sweetspot and speed somewhere in there. My gun likes 79 grains with the 190 Bergers at 2980fps and 81 grains with the 180 sst's at 3075.

 

[Lefty7mmstw]

I have a question re: a hunting load but first a bit of background:
I'm shooting a Classic Remington 700 .300 Win Mag beautifully redone by APA. Broughton 1:11 barrel, Jewel trigger, blueprinted, bedded, no brake. The chamber is nicely tight, brass growing only .003 on firing. Using load data from before the rebuild, and available components I loaded a "practice" round and fell into an awesome antelope/deer load. Hornady case, 150g Nosler AB, 76.0g A3100, Win mag primer, OAL=3.426, jumping .047 to the lands, 3260fps! This load is shooting consistent 1/2 minute at 500 yds. off the bipod.

So here's the question: I want a moose/elk load using 200g Nosler Partitions. As A3100 is no longer manufactured I've decided on H4831. Working up I'm at 74.0g, muzzle velocity=2910fps, no pressure signs at all. This load is already above max for all my books except Lyman which max is 74.0g.

Sorry man, I miss - read and thought you had gone from 150 to 180 grains. A 200 grain needs to go with Retumbo or rl25 to get past 2900 or so in a 300 win. Even then, you won't get past 3K by much. If you need more than that, you're gonna have to re-chamber to the ultra, and then you'll barely get 3100 to 3200 fps.
I currently use 71.5 gr rl22 in my browning to push a 200 sierra to 2920 fps. It has some head-room, but not a lot.

 

[Lefty7mmstw]

A 24" barrel in 300 win should net 3K to 3100 fps with accuracy if it isn't a slow barrel. You have just gotta play with it. I'd go to a bit slower powder too.

Again, I misread and meant on a 180-190. We've had 9 300 wins between my brother, father, and I. All seemed to top out at 3150 with a 180. and most liked 3100 or less. The ones that have used 200 grain pills have gone from 2920(my current one) to my brother's #1 that would do 3100 with retumbo and heavy compression. That was a fast barrel and routinely walked my browning by 50-100 fps.

 

[Lefty7mmstw]

Try H1000 in the neighborhood of 76-79 grains. You should find a sweetspot and speed somewhere in there. My gun likes 79 grains with the 190 Bergers at 2980fps and 81 grains with the 180 sst's at 3075.

+1 on the h1000
you'll hit 2900 to 3K with h1000 and a 200.
I don't know if you could get enough retumbo under the partition to get it up to speed. My brother was using 200 speer and once fired brass and it barely fit. The load was out of the speer #11 manual if I'm not mistaken. Retumbo is slow enough in the 300win that you could simply start with h1000 charge weight and work up to speed.

Another thought, just shoot it with 4831, as you have said the accuracy is good and you are over 2900.

 

[gpspowell]

Thanks guys for the replies. I went out this morning to try to finish up the experiments. 74.0g of 4831 averaged 2898 (cooler this morning) and 74.5 was 2939 for 4-shot groups. An interesting correlation within the groups to bullet shape: I measure the length of my loads to the lands, not to the bullet tip and I've noticed that Partitions are a bit inconsistent in shape at times so I usually note the differences when I load (just for the sake of anal curiosity). In the 74.0g loads there were three that ended up at the same OAL and one .020 longer. this group was a touching cloverleaf of three with one flyer making the group = 1" exactly. The 74.5 loads OAL were: two at 3.376" and two at 3.396". This group was two separate figure-8 holes, making the group 9/16". The faster load also shot 1/4" higher and 1 3/4" to the right of the slower. At 75.0g the average speed went up to 2970fps but accuracy blew out with a scattered group of 2". It looks like the hunting load will be the 74.5g at 2939fps. Now if I can find a northern Saskatchewan moose in September to try it out on.

No pressure signs on any of these loads except the 75.0g loads which were beginning to show a bit of mild primer flattening