300RUM Long Range Reloading

[AdamL]

I am currently trying new hand loads that can reach out to 1,000 yards accurately from a cold bore, one to two shots from my 300RUM. I am currently running the 180gr. Nosler Accubond with the IMR 4350 powder. I am using 80.3 grains of powder and the overall length of the round is 3.550". This past weekend I shot a 5 round group. Three rounds landed .115" apart but the last two made the group grow to just under .5", (operator error). This load is great when the barrel is very hot. When the barrel is at room temp, the group is about an inch. At about 3125 feet per second, it is fast but I want it faster and with a tight cold bore 3 round group. I tried RL25 with 95.3 grains of powder and the group with right at .375 inches with one flyer. The next day I shot the same three round group and it grew to about a 2" group. The weather was warmer on the second day and I read that the RL25 is temperature sensitive. I was going to try the IMR 7828 and or the H1000 next. Does anyone have any information on what I could use or do to get that group tighter? I seat the bullet at the max casing dimension, test for pressure, once pressure is achieved I play with the bullet depth. Any help would be greatly appreciated.

Thanks.

 

[gahunter12]

I load 300RUM with H1000 under a 200gr Accubond. IMR7828, and Retumbo worked well, but H1000 seemed to be my best powder in major temp swings. The 300RUM works well with 180-210gr Bullets, but really shines with the 200gr pills. My load for my Rem700 300RUM is 92.0gr of H1000 under 200gr Accubonds loaded .015" off the lands. The Accubonds seem to like a little jump. Its not the fastest load out there, but I really like the 200gr bullet.

 

[AdamL]

Sounds great, I will try both powders in the near future and give an update on how it performs!

 

[Bart B.]

I would shoot no less than 15-shot groups testing ammo for long range. IMR4350 or IMR4831 should be a good powder but IMR7828 might be better.

Whatcha using to measure pressure?

Hope you're full length sizing those cases; that's best for that cartridge, or brand new cases should also do as well.

Use the largest groups shot as a measure of accuracy or precision. That's what you can count on all the time with a given load. Smallest groups happen seldom and are about impossible to duplicate.

Are you seating bullets shallower every hundred rounds or so? The rifling erodes forward about .001" for every 15 to 20 shots increasing bullet jump if that's kept the same for the life of the barrel.

 

[AdamL]

I was going to do a five shot group so the barrel has a chance to get a bit hotter than the three shot group. My long range purpose is for hunting so a hot barrel in my opinion will not likely happen. When resizing the cases, I do use the full case die. I was told to use just the neck sizing die but chose not to. As for seating the rounds deeper even hundred or so, I have not heard of that but could give it a try beings I have approx. 400+ rounds through it.

 

[DeadEye9]

Try this load if you are into IMR powder for .300 RUM.
80.5gr 4350
Nosler 180gr E-tip
Win Brass/Win LR Mag primer
3.550" starting length, work up or down depending on what YOUR action likes. For me this has been a superb load. I've also had great success with 180 Nosler partitions at 80.7gr 4350. I now use a Savage 110 in .338 Lap Mag as my 1000yd tool, but I've used the RUM quite a bit beforehand with the aforementioned loads.
If your looking for max velocity, I would try either MAGPRO or ReTumbo. Both of those yeild max velocities for the .300 RUM in my experience.

 

[AdamL]

Try this load if you are into IMR powder for .300 RUM.
80.5gr 4350
Nosler 180gr E-tip
Win Brass/Win LR Mag primer
3.550" starting length, work up or down depending on what YOUR action likes. For me this has been a superb load. I've also had great success with 180 Nosler partitions at 80.7gr 4350. I now use a Savage 110 in .338 Lap Mag as my 1000yd tool, but I've used the RUM quite a bit beforehand with the aforementioned loads.
If your looking for max velocity, I would try either MAGPRO or ReTumbo. Both of those yeild max velocities for the .300 RUM in my experience.

The load that I have is exactly the same except I have 80.3 grains and use federal 215 primers. I will research MAGPRO as well. Thanks for the help.

 

[Captcurt]

I have not had a lot of experience with the 300 RUM, but I did get one to shoot Sub-MOA with Retumbo. I was shooting 165gr though. I would have to look in my manual, but I believe that it was 100 grains and Max was 103. They sizzled.

 

[farmerboy78]

With that weight bullet and speed you're already getting, if you have accuracy, why do you need any more velocity for 1000? That will be way more than enough. My 6.5-06 shooting a 140 is only going 2870ish and is still supersonic beyond 1000.

 

[Captcurt]

With that weight bullet and speed you're already getting, if you have accuracy, why do you need any more velocity for 1000? That will be way more than enough. My 6.5-06 shooting a 140 is only going 2870ish and is still supersonic beyond 1000.

Your 6.5 is a lot less punishing than the RUM. I put over 40 rounds thru a Rem 700 from the bench and it wasn't any fun. I don't know if I would want to shoot a match with one. My Creedmoor is pleasant.

 

[GooseGestapo]

From my experience you've pretty much maxed out the potential for the Accubond.
Two suggestions:

For the accuracy you're seeking, go with the 200, or 220gr MatchKing. You'll likely get better on-game performance from the Nosler ABLR. It's claimed by Nosler to have an expansion threshold of 1300fps vs 1800for the 180AB.
The new Hornady ELD-X bear looking at, too.
Secondly, stick with extruded powders.
I've gotten top velocity with Retumbo, but IMR7828, RL25, RL22, and H4831 have given best accuracy. Might be worth trying the new RL26. Supposed to be more heat insensitive version of RL25.

I would use 3-shot groups max, also. For long range hunting, it's the first one that counts. You'll wear out your barrel tweaking your loads. Don't over think it.
I'd bet what you're actually seeing is your actual aggregate accuracy like BartB intimated.

I won't go into the ethical concerns of long range hunting.
This is the high road, so as I see you are newcomer, be cautious what you post.