SHERMAN LONG ACTION SHOOTERS

[elkaholic]

I am making a couple of recommendations for the folks shooting the 270 based line of Shermans. I am finding that the RWS brass is working VERY well. It has a little less capacity but is so tough that you can reach higher velocities safely without loosening the primer pockets as easily as any other brass available. I still like the Norma, but RWS is better. Make sure you get 270 and not 280 as the neck wall is too thin on the 280.
Also, if you can get it, N570 powder from Vihtavouri gives great accuracy and velocity as well as low es and good temp stability.......Rich

 

[benchracer]

I am making a couple of recommendations for the folks shooting the 270 based line of Shermans. I am finding that the RWS brass is working VERY well. It has a little less capacity but is so tough that you can reach higher velocities safely without loosening the primer pockets as easily as any other brass available. I still like the Norma, but RWS is better. Make sure you get 270 and not 280 as the neck wall is too thin on the 280.
Also, if you can get it, N570 powder from Vihtavouri gives great accuracy and velocity as well as low es and good temp stability.......Rich

This is good information. I can remember you telling me about the neck wall thickness problems, but couldn't remember for sure if that was with 270 or 280. Now I have something to use for reference! Planning to order some RWS 270 brass in the near future for my 338 Sherman.

 

[dok7mm]

Rich, in my 6.5 Sherman, the Norma 280 brass was thicker. Had to turn it to .0145" for .004" clearance. All three lots were .015-.017", thin to thick sides of neck. Could be lot variation, but they came from 3 different sources. This is in the .297" neck with .235 freebore.

 

[elkaholic]

Rich, in my 6.5 Sherman, the Norma 280 brass was thicker. Had to turn it to .0145" for .004" clearance. All three lots were .015-.017", thin to thick sides of neck. Could be lot variation, but they came from 3 different sources. This is in the .297" neck with .235 freebore.

But the RWS is thicker on the 270 than the .280 brass and just about right for no turn.

 

[dok7mm]

You're right on the RWS, I remember you telling me that a couple months back. That's what I get for not reading it correctly.

 

[elkaholic]

That's ok, I think we are the same age

 

[couesaddict]

Rich, have you read what Shawn Carlock has stated about n570 and throat erosion in his 338 Terminator? Claiming half the life out of it vs RL33. Wondering if anyone has enough rounds down the pipe and maybe access to a borescope to notice any difference in a Sherman yet with this powder. I didn't have the greatest luck with it but I was maxing out on capacity before any pressure due to not having a drop tube. Considered getting one and trying one more time but I'd like a bit more insight before I go that route. RL26 is working very well in my 270 Sherman with 170's so maybe I'll just wait a bit before any more experimenting. Thanks

 

[elkaholic]

I have heard that before about the Edge. I don't know what to think as I have heard other theories too.........Rich

 

[SHRTSHTR]

I believe N570 is hard on throats, especially wildcat throated barrels. I know of several rifles giving up the ghost 400 rounds and lower myself included. Many well known people on this forum and others feel it is design not powder.
I am running N570 in my 6.5ss. My barrel is Nitrided. Only time will tell!

Ray

 

[CA48]

I have been curious about n570 and throat life as well now because I was thinking of switching back to it in my 6.5SS. Shawn may be experiencing this because he is running right around 100 grs of powder and a stepped throat will erode faster in general. N570 is a high energy double based powder. From my understanding they add nitroglycerol to double based powders to create a higher flame temperature which creates more velocity without increasing pressures excessively. So running over 100 grs in a 338 lap imp with a stepped throat I can see why the throats went so quick. I remember a forum member on here some time ago, from Norway I think. He was running n570 in his 338 lap with 300 gr scenars and had about 4000 rounds on his barrel and was still grouping less than half moa. So maybe n570 only accelerates throat erosion to the extremes when ran in overbore cartridges?

 

[BEEMAN]

Where are you guys getting the RWS brass? Did a search for it but can't locate it anywhere in Canada.

I have not shot my Sherman very much lately. Hopefully this winter I can develop a load with the 147 ELD-M.

I have only used N570. My gun has shot the 140 Berger very well at 3339 fps out of a 28" Hart. It also shot all the 6.5 cal Matrix very good.

 

[elkaholic]

I have been curious about n570 and throat life as well now because I was thinking of switching back to it in my 6.5SS. Shawn may be experiencing this because he is running right around 100 grs of powder and a stepped throat will erode faster in general. N570 is a high energy double based powder. From my understanding they add nitroglycerol to double based powders to create a higher flame temperature which creates more velocity without increasing pressures excessively. So running over 100 grs in a 338 lap imp with a stepped throat I can see why the throats went so quick. I remember a forum member on here some time ago, from Norway I think. He was running n570 in his 338 lap with 300 gr scenars and had about 4000 rounds on his barrel and was still grouping less than half moa. So maybe n570 only accelerates throat erosion to the extremes when ran in overbore cartridges?

Huntington dies is the only place I know of. They have always had it in stock..........Rich

 

[CA48]

I think you meant to quote Beeman there Rich. But I went ahead and checked and they had rws 270 brass in stock

 

[elkaholic]

Ya, I did! Thanks for checking on the brass. Be sure to get 270 and not 280 folks.....Rich