270 Sherman Build completed!!!

[elkaholic]

Got out and did a little pressure test this morning with 170 bergers and then formed the rest of my brass.
RL-26
61- 2932
62- 3017
63- 3059
64- 3107 primer a little flat
65- 3194 flatter primer but good extraction

N-570
63- 2788
64- 2862
65- 2914
66- 2958
67- 3022 no pressure signs

Looks like it'll settle in comfortably pressure wise around 3050fps. I don't use hbn and honestly don't know that I want to add a step to my processes. Seems pretty quick to me as is. I believe the smith used the same throating reamer as Idaho trecker's. It's LONG!

Thats smokin'! You MIGHT get even higher velocity with N570 if you can get enough in the case? Looks like you would need between 70-71 grains......Rich
I would get some longer brass though. You are probably jumping the bullet over a bit of empty neck!

 

[couesaddict]

Yeah I checked the hottest load and the brass only grew .001 in length so I don't think they'll ever get there in their life span. 67.5 fills halfway up the neck. It pushed the bullets back out .001 so we'll see how it goes for some groups but I like the fill of 26 a little better.

 

[elkaholic]

ok, it sounds like 570 is out. RL26 has been pretty tough to beat in just about all of my cartridges anyway......Rich

 

[Idaho Trecker]

Those are some good speeds for sure. I was having pressure issues with both my 270 Sherman and SS recently but i think its from going away from hbn. I thourpighly cleaned the bore of each rifle but it seems like it took 20+ rounds to settle and get pressure back to normal. I had backed my SS load clear down to 57.7 grains to get under pressure and only 2837 fps. Now that I have more rounds through it the pressure dropped more and the neck/shoulder are filthy with piwder residue. Now I believe I can work back up to my 62 grain load with both. I'm considering a brake on my Sherman now since it's not setup as a pack/carry rifle anyway. How do you like yours?

 

[couesaddict]

That was a typo, it's pushing the bullets back out .010 not .001 with compressed 570. I have the hybrid brake from extreme hardcore gear and it barely kicks at all. Super easy to spot hits and no soreness after a lot of shooting. It is very loud though and throws a fair amount of concussion towards bystanders. My 300 rum is a little worse but not by much

 

[couesaddict]

63.5 RL-26 gave me 3105 with an es of 8. Pushing 90* out and pressure looks ok. Group toughed two and one about 3/4 left but I had the magneto on so I'll do a little seating depth work without it and see how it does. Pretty impressed with this little round so far

 

[couesaddict]

Coming in pretty nice. Here's 170 bergers around 3100 fps. Showing slight pressure signs but it's 95 degrees out and that's about the warmest I'll ever shoot at.

 

[couesaddict]

What are you guys seeing for temp stability with rl 26? So far I've been between 70-90* and I'm seeing right at 1fps/degree. Scanned through the thread on it but they seemed to be all over the place. Is this normal for this case size or it it just more drastic in these warmer temps?

 

[elkaholic]

I have not noticed that much swing, in fact, it has been pretty good in my rifles. I don't really have solid numbers though........Rich

 

[couesaddict]

Gonna go ahead and revive this one. My wife was the first to break in this 270 Sherman with her first muley buck. Now I've got to see if I can top it with my tag!

 

[elkaholic]

Congrats! Have any pics?......Rich

 

[couesaddict]

Congrats! Have any pics?......Rich

Trying to get them to load. Gonna have to figure out how to resize them. Went 157-1/2" gross

 

[couesaddict]

 

[elkaholic]

Very nice! It has pretty good mass.......Rich