retumbo vs n570 in 300 rum testing

[Earnhardt]

ok...back on track with the OP's thread...
I started out using Retumbo in my 300 RUMs a while back
The main reason I changed to N570 initially was that, retumbo seemed to "spike" in pressure once you got to a certain threshold.
Don't get me wrong, I got great accuracy and consistent velocities with it, but when I got the upper end of the pressures, I'd have primers blowing out, and crazy bolt lift problems....
One load would be fine...bump the power load minimally...Retumbo spike....

N570 is probably the most "forgiving" high velocity power out there....(ok, Reloder 26 is amazing also...)
Accurate, consistant velocities, and extremely accurate... My 30" Bartlein/BugHole barreled 300 RUM, shoots solidly in the .2's...and at velocities I'm not going to mention here...

 

[jessej]

My 30" Bartlein/BugHole barreled 300 RUM, shoots solidly in the .2's...and at velocities I'm not going to mention here...

That's what I love about rums. Unmentionable velocities.

 

[Benchrest Braxton]

The main reason I changed to N570 initially was that, retumbo seemed to "spike" in pressure once you got to a certain threshold.
Don't get me wrong, I got great accuracy and consistent velocities with it, but when I got the upper end of the pressures, I'd have primers blowing out, and crazy bolt lift problems....
One load would be fine...bump the power load minimally...Retumbo spike....

N570 is probably the most "forgiving" high velocity power out there....(ok, Reloder 26 is amazing also...)
Accurate, consistant velocities, and extremely accurate... My 30" Bartlein/BugHole barreled 300 RUM, shoots solidly in the .2's...and at velocities I'm not going to mention here...

i mean, i shot a sub 1/2" group at 310 yards with 225 eld match going 3,300+ fps.

i could have probably pushed it to 3,400 fps if i wanted to….

 

[Earnhardt]

i mean, i shot a sub 1/2" group at 310 yards with 225 eld match going 3,300+ fps.

i could have probably pushed it to 3,400 fps if i wanted to….

yup...that's about right with your 34" barrel...

I'm using 215 Bergers and 245 Bergers

 

[Earnhardt]

That's what I love about rums. Unmentionable velocities.

Yup, stupid fast with N570!

 

[Benchrest Braxton]

yup...that's about right with your 34" barrel...

I'm using 215 Bergers and 245 Bergers

what are you getting with the 245's in your 30?

 

[Earnhardt]

what are you getting with the 245's in your 30?

30" Bartlein 1:9 twist…the node I'm on with the 245's is ~3090 fps with N570

 

[Mike Matteson]

From their web site:

VIHTAVUORI POWDERS WITH DECOPPERING AGENT ARE BETTER FOR BARRELS

All Vihtavuori reloading powders produced today have an added decoppering agent, also called anti-fouling agent. What does that mean for the reloader using Vihtavuori powders?

The decoppering agent reduces the amount of copper residue that forms within the rifle barrel when shooting. Less copper residue translates as a cleaner rifle barrel. For the reloading target shooter, this means muzzle velocities with less deviation and increased accuracy, especially when firing multiple groups.

I don't see anything on temp there.

 

[Mike Matteson]

I use H 4350, H4831SC, and H1000. I just did get Rumbo here the other day. M go to powder is H4350.
Here a couple of charts to look at. They don't have N570 in there, but there is others N powders. That leave me to believe that temp stability is in the same range.

 

[Earnhardt]

Have you ever used N570 before?

If not, go shoot a load with N570 in a temp range of 60-80 degrees…
Post what YOUR results ARE.
Not an assumption you extrapolated from something you read on the Internet…
It is NOT .97 fps/degree…

I'm just guessing here…are you an engineer, bean counter or "scientist"of some sort?

 

[Mike Matteson]

Have you ever used N570 before?

If not, go shoot a load with N570 in a temp range of 60-80 degrees…
Post what YOUR results ARE.
Not an assumption you extrapolated from something you read on the Internet…
It is NOT .97 fps/degree…

I'm just guessing here…are you an engineer, bean counter or "scientist"of some sort?

No! Highschool with some college, but very little. Retired at age 60. Self made person. Been reloading now for over 61 years. Started at age 14. I don't use N570. I have some N powders in 1# cans, but not much. I don't care what powders you use, just like to keep people informed if possible.
I hunt in weather from -25 to 110+ degrees. I use very little double base powders. Seen the problems that can develop with them with temp changes. Especially with hot loads.
It's to bad that more info isn't out there on how temp effect the powder. I watch for it all the time.
SD. Change in velocity of just 30fps variation of your bullet drop by about 8.5" @ 1000yds. A 50fps variation would change your bullet by as much as 14" @ 1000yds.
Now if you are shooting 500yds or less it doesn't make much different, but going beyond that the path can change greatly. Missing or wounding animal.
This is the last that will hear from me.

 

[Axl]

I don't see anything on temp there.

Was just showing fraz the decoppering agent

 

[jessej]

I've never put a grain of n570 in anything.
I'm having what great results with h1000 and 215s in a 26" bbl.

With that 215, what could be expected with n570 in that same bbl.