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Uncharted territory

Doublezranch

Doublezranch

Well-Known Member
Joined
Mar 24, 2011
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Location
Texas
Went to the range Saturday to continue testing with my 300 rum. I'm up to 103 grains of 33 with 230 targets and let me tell you, the more powder I feed her, the more accurate she gets. This gun truly eats powder and craps thunder!! She just hit another power node at 102.8 and I'm assuming she will plateau out being the most accurate load at the 103.6 range. I have loaded what I think will be my final ladder up to 104.5. I haven't seen anything close to a pressure sign yet and I'm not compressed either. This is very amazing too me. I haven't heard of anyone going this high on the ladder with this powder bullet combo. Thus turning this into uncharted territory. Case over all length is just shy of 4 inches (3.98) and barrel length is 27.5. I haven't ran her through a chrono yet but should be 3200+\-. Do you think the people at Alliant knew they would have this big of a spread in ranges? Some can only shoot 90+ grains and some can shoot 100+ grains. They have their hands full! Have any of you been this high with a charge in this combo? If so, I'd love to here your experiences.

Jayson
 
I know how you feel...Finding load data for my Ackleys is proving to really be trial & error, too. Good luck, and keep your powder dry.
 
I suppose I should run my rifle up to absolute max. also to see where she actually peaks, but my 225 hornady pills broke 3000 fps at 95 grains and the pressures are normal so I see no reason to go for broke. If you keep having luck at higher charges though I may just get goaded into working the load higher, though I doubt it really matters with the bc the 225-230 grain 30 cal. pills have.
I had a similar situation with 180's and I5010 with this rifle (300RUM) where I landed at a good load (right at 3320 fps with a 180) that was actually 6 or 7 grains below the real max. load for the combo; I never did chrono the absolute max. load... wish I had.

Keep in mind you will likely see a bit more pressure in hot weather even with the newer rl powders.

I load to mag length so I'm at 3.650" or so and that'll change top load a bit; I don't think my throat would tolerate a 4" cartridge, even with that pointy pill.
 
CogburnR said:
I have been considering a RSI Pressure Trace. I have a 270 Sherman that does not show much pressure but loosens primer pockets. I also have acquired a 300Rum recently along with Rl 33 and some 230 otm's.


https://www.shootingsoftware.com/pressure.htm
Click to expand...

I was using an earlier version of that with my old 7mmstw back in the mid 2000's. It worked well, but the gauge doesn't stay on the barrel very long (glued on), so get your ducks in a row and shoot your pressure stuff in an outing or two to make sure it's still secure on your barrel.
 
Before I got too exited I would reload the same case a few times and store them in my inside shirt pocket to check for temp issues.
I don't shoot the 300 but that brass doesn't last long hotroded in the 338 Edge.
 
That's the reason why I am excited. Shells were kept in a pocket against my body inside my jacket for no less than 10 minutes before lighting them off. The fact that they showed very good consistancy and accuracy suprised me. Should be very interesting to see where we go from here. Primers were awesome and pockets are still very solid. These have been reloaded 5 times and annealed once. Brass life will deminish, however if I can get 5-7 reloads out of them....that's a winner winner chicken dinner.
 
CogburnR said:
I have been considering a RSI Pressure Trace. I have a 270 Sherman that does not show much pressure but loosens primer pockets. I also have acquired a 300Rum recently along with Rl 33 and some 230 otm's.


https://www.shootingsoftware.com/pressure.htm
Click to expand...

I've been using a pressure trace this winter on a 6.5 Sherman and we tried some R33, the results were interesting, the pressure was still up there with Retumbo at the same velocity but the pressure signs on the case are far less with the R33. I think there are some loads with R33 that are significantly higher pressure than guys think.
 
bigngreen said:
I've been using a pressure trace this winter on a 6.5 Sherman and we tried some R33, the results were interesting, the pressure was still up there with Retumbo at the same velocity but the pressure signs on the case are far less with the R33. I think there are some loads with R33 that are significantly higher pressure than guys think.
Click to expand...
I think this is one powder where you have to use the velocity as a speed limit/ pressure estimation too. Most 300 rum loads with other slow burners are topping between 2900 and 3000 fps with 220-230 grain pills and 26" bbls.. Any more than 100 fps more is a red flag IMO.
I saw this with the 7 stw in the old win factory loading too; 75Kpsi loads weren't tough on the brass at all. They should have been eating it up.
rl25 was new at the time ( deja vu I guess) and I was seeing some good speeds for the exhibited pressures so I asked my bro in law to strap up his pressure trace to my rifle to do some checking. Turns out rl25 was able to equal 7828 with around 6Kpsi less pressure, but there really wasn't that much more speed on the table before that one (rl25) hit the wall too.
 
Lefty7mmstw said:
I think this is one powder where you have to use the velocity as a speed limit/ pressure estimation too. Most 300 rum loads with other slow burners are topping between 2900 and 3000 fps with 220-230 grain pills and 26" bbls.. Any more than 100 fps more is a red flag IMO.
I saw this with the 7 stw in the old win factory loading too; 75Kpsi loads weren't tough on the brass at all. They should have been eating it up.
rl25 was new at the time ( deja vu I guess) and I was seeing some good speeds for the exhibited pressures so I asked my bro in law to strap up his pressure trace to my rifle to do some checking. Turns out rl25 was able to equal 7828 with around 6Kpsi less pressure, but there really wasn't that much more speed on the table before that one (rl25) hit the wall too.
Click to expand...

I tend to agree after seeing traces back to back with different powders. The pressure ramps up slower with R33 and has a longer peak than Retumbo so I think you should see some gain but I'd like to check it on more chamber sizes, the 300 RUM really seems to be one that is seeing some big numbers with the R33 and under that big 230 Berger it's hard not to get warm fuzzy feeling :D
 
I most certainly agree with the warm and fuzzy feeling one gets when hitting the giggle switch with 104 grains of 33 and a 230 screaming down range. :D
 
Went back to the range to finalize my 300 rum load. Brought the chronograph with to see how fast we can get the 230 Berger going. Results where staggering to me. My ladder was 103.3 to 104.5 grains. I was suspecting that my most accurate load would be at 103.6 with my top being somewhere around the 104 mark.
My results showed my most accurate load was 103.3. Hole in a hole with my first 2 shots and then the pressure got to me and I pulled a bit on the third. I did run the ladder up to 104.3 where I had a major crater on the primer and hard bolt lift. The thing that spun me in a circle was that this load was very, very accurate. The three holes were touching. I found power nodes with 33 are not the drastic open groups in the middle of the nodes. There is only around .5 to .7 grains difference in nodes.
Now, the fun part. I chronographed every load and again, super surprised.

Results as follows:
103.3 - 3200
103.6 - 3210
103.9 - 3230
104.2 - 3250
104.5 - didn't shoot

My conclusion is that this powder is going to be a game changer for so many large bore and fence caliber rifles (wsm and saum). It will also be a headache for Alliant because everyone that has tested it has a different starting and ending point. Load data will be generic at best. The fact that you can fill the case with powder and not blow yourself up is amazing to me. I have been shooting 7828 ssc forever in my ultra mags with wonderful results. But never once could I fill the cases and get uncharted velocities without some sort of pressure sign big or small. I sure hope that whitetail I saw at 1350 last year pokes his head out of the trees again this year. I want him to say hello to my little friend!! :D
 
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