300 rum load development

[Walleye Steve]

97 grs H-1000 was my load in a 700. 3150 FPS with 180 accubonds was very accurate

 

[combatcurt]

97 grs H-1000 was my load in a 700. 3150 FPS with 180 accubonds was very accurate

I shoot 82 grains of h4350 with 180 accubond at 3180. Super accurate

 

[meatyrem]

97 grs H-1000 was my load in a 700. 3150 FPS with 180 accubonds was very accurate

Mine with H1000 I had stopped at 96gr with 180 Scirocco II and came around the ballpark of 3208. I know the two different brands of bullets aren't the same but kind of similar. If I do not get better groups out of the rest of the H-1000 loads I'll be switching to RE-25 and the scirocco II and see how that comes out. I have to try the 190 ABLR out of my other 300 RUM when I can get around to getting back to the bench. Thinking of starting out with retumbo

 

[lancetkenyon]

Don't do RL25 if you hunt/shoot in greatly varying temperatures. RL25 is quite temperature sensitive. RL26 is much better until you hit 85°F. RL33 would probably do very well in the .300RUM too with heavies like the 210/215/230.

 

[tbrice23]

Played with RL33 today. Had really good small groups at 200 yards with 200gr Accubonds.
At the highest two charges my ES was 3 and 2 for four shots each! The SD was Zero!

Never reached pressure signs so tomorrow I am upping the charge, I'm only going to be at about 97% capacity.

 

[Wedgy]

I got more velocity with RL33 than Retumbo but have stability issues at temps similar to RL26, above ~85F, and RL33 was very dirty as far as carbon fouling, much more than Retumbo. Both were very accurate.
Really great to see so much interest in the RUM now that the brass shortage of the past is gone. I have an 8 twist barrel waiting for a build that I'll have to dig out...Hammer 227 grain in mind.

 

[greatwhitehntr]

I have a question for the guys loading 180's what is the point?
The only thing I can come up with is lazzer like trajectories?
I am being serious I would like to understand.

 

[Gcan]

I shot my first rounds of hand loads this weekend for my 300 Rum. I loaded the following:

Nosler brass (first 5 new brass, others 1x fired)

215 M primers
Imr 8133 (88.5 to 91 grains)
Berger 230
Neck size only

The 89.5 and 91 loads had primer cratering bad. All shots had ejector marks and slight crater. I'm thinking my headspace is too tight that could cause this? My brass is pretty tight when chambering. All my factory ammo shows ejector marks also. I was hoping to get more velocity since I have 29" barrel.

On separate note, which do you think I should start next steps of load development? Also, if I full length size could I get more velocity and lower pressure?

Thanks,

DoubleG

I shoot a lot of 300Rum. My go to load for Surgeon 28" is 90 grains H1000. 210 Smk. Honest 1/4 moa gun. I use several primers as it is not primer sensitive. rem 9-1/2- CCI 250 3195 fps. Nosler brass always. No pressure or extractor marks at all. Load SMK touching lands. Use same load for 215 BERGER. .005" into lands.

 

[Gcan]

I have a question for the guys loading 180's what is the point?
The only thing I can come up with is lazzer like trajectories?
I am being serious I would like to understand.

I used to shoot the BT 180s for game. At 3200 plus. They are devastating on chest/lung shots on large to medium animals at out to 750 yards. Like hitting them with car. Great terminal performance. Enormous hydrostatic shock. Would not shoot large game much past that distance. 200grain or heavier fan for everything now.

 

[Slickrick0999]

I shoot a lot of 300Rum. My go to load for Surgeon 28" is 90 grains H1000. 210 Smk. Honest 1/4 moa gun. I use several primers as it is not primer sensitive. rem 9-1/2- CCI 250 3195 fps. Nosler brass always. No pressure or extractor marks at all. Load SMK touching lands. Use same load for 215 BERGER. .005" into lands.

What is your velocity with the 215 & 90gr of you don't mind me asking?

 

[combatcurt]

I have a question for the guys loading 180's what is the point?
The only thing I can come up with is lazzer like trajectories?
I am being serious I would like to understand.

Here is part of the reason. This was 780 yards and he went 30 yards. I've seen a LOT of elk taken with a 180 accubond and the RUM makes it fast.

 

[meatyrem]

Don't do RL25 if you hunt/shoot in greatly varying temperatures. RL25 is quite temperature sensitive. RL26 is much better until you hit 85°F. RL33 would probably do very well in the .300RUM too with heavies like the 210/215/230.

I don't see myself doing anything in temps above 75 so that wouldn't be a problem there. (I'm hot blooded) also what can you tell me about RL 26 it's too new to me and haven't researched it much.

 

[meatyrem]

I have a question for the guys loading 180's what is the point?
The only thing I can come up with is lazzer like trajectories?
I am being serious I would like to understand.

I get what you're saying about the 180's and I think they'll do just fine. What I can't understand is why use anything under the 180's. My limit is nothing under 180's or I'll just use something different

 

[lancetkenyon]

I don't see myself doing anything in temps above 75 so that wouldn't be a problem there. (I'm hot blooded) also what can you tell me about RL 26 it's too new to me and haven't researched it much.

Much more temp stable than RL25. Also, cleaner burning from what I have found. Speeds are similar and burn rate is close.

RL25 and RL22, to me, showed about 1.5-2fps swing per every 1* of temp change. RL26 & RL23 do not show that at all. RL26 does seem to spike over 85* in my personal experience. So my antelope rifle uses a different load for those hunts when temps range from 50-90*+.