My 6.5 Sherman rifle and load development thread

Got my rifle back! Had a problem with the barrel so another one was supplied for me and will be doing a short break in procedure and then do some load development for it. Also put a smaller break on it. The other one was M1 Abramsish. Still gonna use the 143 ELDX until the 155 Gr Berger comes out. Will keep you posted on the load development results. Weighs in at 11.5 lbs with everything in the pic below.
SWEET!! That thing has long range written all over it!.........Rich
 
Reading the great results with RL-26 made me pick up 2 lbs of it the other day. I had high hopes for the 142 ABLR and Retumbo, but results were not nearly as great as I had with the 140 Accubond and 7828 SSC.

I've got an elk hunt starting in a few weeks - new plan is to try RL-26 along with the 140 VLD and 140 Amax.
 
Rl-26 and the 140 VLD was the ticket in my 6.5 Sherman. All groups tested were 3/4 MOA or less with 60.5 gr creating a nice clover leaf at 100 yards. I'll be throwing some of these over the magneto speed to get a velocity on them.
 
Depending on your barrel, that charge should easily get you 3150 if not 3200.....Rich

Rich,
You were spot on! Average velocity of 60.5 gr was 3167. Tried out 61.5 as well and average was 3226. With only a 60 fps difference and slightly better groupings, 60.5 will be the charge I run with.

Looking forward to filling some WY tags over the next two weeks with the 6.5 Sherman!
 
Well I was able to get out today finally and do some shooting. I had a problem with the first barrel that was on this rifle but that got taken care of rather fast!

I went out a couple of weeks ago and did some load testing with H1000 and the 143 ELDX. I just couldn't get the kind of accuracy that I was expecting out of this rifle with those bullets. I did get a 1.3" group at 300 yards with 62.5 Gr but the pressure was just too high and would trash my brass so that was a no go.

So today I went out with H1000 and the 140 Gr Bergers. I loaded up 60-62 Gr of H1000 with the 140 Gr Berger seated .010 off the rifling. The results with the Berger bullets was much better than with the ELDX.

All of the loads were sub-MOA but 60 and 60.5 Gr were sub-half MOA. 60 Gr produces a 1.2" group and 60.5 Gr produced a .972" group at 300 yards. I am going to play with the seating depth of theses two loads and maybe alter the powder charge by .1 Gr to see if it tightens up any but I am more than pleased with these two groups.

60 Gr 1.2" At 300 yards
4B5D9D2F-8C78-4D00-91DB-058613F88879.jpeg


60.5 Gr .972" At 300 yards
BB4E898B-3F92-4DFD-BE88-BB76F86F9AE8.jpeg
 
The 155's will be nice I'm sure. I plan on trying the 147 ELD-M in my Sherman next.
 
I had planned to run a 400 yd ladder test today, with R-26 and N-570 w/140 HVLDs, but between a horrible mirage and a failing battery pack on my LabRadar, it turned into a velocity/pressure test. I had to switch to the MagnetoSpeed and that played havoc with my ladders.

It was 20* cooler than when I first tried R-26 & I had smears and sticky bolt @ 59.0 gr and 3,040 fps. Today, I ran it to 61.0 gr. @ 3,160 fps and no pressure signs on brass or bolt. I still have a bit more room, so I'll try to see where max is. I do believe the the R-26 gets wild at 85* and hotter.

Thanks to BEEMAN and ramrod79 for their data on N-570 and the Berger 140. I also ran that load up to 65.0 gr @ 3,158 with no pressure signs. This load also needs more testing & will find my max pressure. This was 6th firing on turned Norma 280 brass.

I need to establish that the seating depth ( I used the .015" jump of my Retumbo loads w/140) is correct with these powders. This is from a 26" Bartlein 5r, 3B contour @ 1550 ASL, 70*, 29% humidity, 28.55 station pressure, wind variable 2-6 mph.

FYI, my current accuracy load w/63.9 gr Retumbo 5 shot average is 3,139 fps, sd-3.3, ed-8.0 and usually will shoot 1/4 moa @ 400 yd.This load was worked up @ 90*, but handles temp range very well. I have to drive 1 hour to 1000 yd range and will do that when I decide loads to take.

Korhil78, Thanks for the use of your thread.
 
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