RL33 vs N570 (temp sensitivity)

Hey Rich I have been using N 570 in my 6.5Sherman ,and its a real winner was out the other day only 1deg C out shot dead on at 600 yards shot rifle later on in day when it was +29 ,and same results dead on . I will verify again once weather gets colder out but for early season hunting I have no worries in temp swing so far.
65.5 GR with 140 Berger 50 tho off no pressure signs 3250ft/sec load shoots better that 1/2 MOA all day long .
Ramrod, what reamer and brass? I'm about ready to do a ladder with N-570.
 
Hey Rich,

N570 and RL33 are on different ends of the world when it comes to temp sensitivity. In testing 33 in quite a few applications, the 33 goes volatile super quick once any heat is introduced. Whether it's outside temp or chamber temp it gets squirly quick. I found that a very accurate load (within pressure limits) at 75-80 degrees outside temp was about 2 grains less than at 45-50 degrees outside temp in my 300 RUM. Winter shooting I could get 102.5 grains in the RUM and it was amazing. But shooting in the summer with 102.5 was catastrophic. I didn't see a positive change until I dropped the charge to 100.5 grains. 33 is good, but really tricky. I use N570 in the 338 Texan and in the 375 Zayne with unmatched accuracy, performance, and consistency. In fact the 375 Zayne shot a .184 group at 100 yards last weekend at 85 degrees with no pressure signs whatsoever. 120 grains of N570 and 395 Hammer. In my opinion both powders have their place, but both are on different spectrums when it comes to temp sensitivity.

All the best!! Jayson
 
Hey Rich,

N570 and RL33 are on different ends of the world when it comes to temp sensitivity. In testing 33 in quite a few applications, the 33 goes volatile super quick once any heat is introduced. Whether it's outside temp or chamber temp it gets squirly quick. I found that a very accurate load (within pressure limits) at 75-80 degrees outside temp was about 2 grains less than at 45-50 degrees outside temp in my 300 RUM. Winter shooting I could get 102.5 grains in the RUM and it was amazing. But shooting in the summer with 102.5 was catastrophic. I didn't see a positive change until I dropped the charge to 100.5 grains. 33 is good, but really tricky. I use N570 in the 338 Texan and in the 375 Zayne with unmatched accuracy, performance, and consistency. In fact the 375 Zayne shot a .184 group at 100 yards last weekend at 85 degrees with no pressure signs whatsoever. 120 grains of N570 and 395 Hammer. In my opinion both powders have their place, but both are on different spectrums when it comes to temp sensitivity.

All the best!! Jayson
Boy, that is even worse than I thought for RL22! I guess it is time I paid the hazard fees and ordered some........thx/Rich
 
Thank you all for the info! It just makes me want some N570 more than ever. I HAVE heard that it and RL33 are both hard on barrels compared to other powders, but have no personal experience......rich

Heat of Explosion numbers for like powders. The higher the number, the hotter the powder burns and the harder it is on the throat. If the throat is kept polished and shot strings kept low this should not be an issue with N570. Great powder in 7STW.

H1000 - 3630
Retumbo - 3710
RL33 - 3900
N570 - 3950
 
Heat of Explosion numbers for like powders. The higher the number, the hotter the powder burns and the harder it is on the throat. If the throat is kept polished and shot strings kept low this should not be an issue with N570. Great powder in 7STW.

H1000 - 3630
Retumbo - 3710
RL33 - 3900
N570 - 3950
Thanks, I have heard it is harder on throats! I have learned to use a few strokes on the throat with 0000 steel wool every couple hundred rounds to keep the roughness down. It seems to help as long as you don't get over zealous!......Rich
 
Depending on your coal, I run 79.5-80 with 3.750 that's equal to 3070. 78.5 is 3026. 76 would bellow 3k for sure. I would start higher. I didn't get pressure at 80 grains. Accuracy was best between 78.5 and 79.6
 
Picked up some n570 for the new 28nosler to try. Is 76g a safe start for the 195's?
The Berger Load data I received from them last year for the 28 Nosler has the starting load at 76.0gr with a velocity of 2822 and the Max at 79.8gr with a velocity of 2970. The COAL they listed is 3.499 in and used a 26" barrel.
 
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