My 6.5 Sherman rifle and load development thread

Went out today and shot the loads that I loaded up yesterday. All shots were from 300 yards out and was testing for seating depth and three shots were fired.

1. .010 off lands yielded a 3.7" group
2. .020 off yielded a 2.4" group
3. .030 off yielded a 3.4" group
4. .040 off yielded a 2.7" group

Hopefully, I can take the seating depth of .020 and load different powder charge weights with it and get sub 1/2 to 1/2 MOA out of it.

Opinions would be good on this. Do you think that I should go test the same powder charge and seat the bullet deeper than .040? Or try .015 and .025 to see if anything around .020 off the lands is better before I just go with .020 and do different powder charges with it?
 
I agree on the neck tension. I am going to order a .290 and .291 bushing today. I don't think .001 neck tension is enough. I also saw where rich was using .020 jump as well.

And thanks Rhian for keeping close track of this and giving me help. I have been reloading for a while but never had a wildcat or fireformed brass or anything if this sort. So all the help is much appreciated.
 
You may also find accuracy will increase with a stiffer charge. 59 is not a heavy load in this cartridge and RL26 seems to like a little pressure. You might try .005" off the lands as well..........Rich
 
I will try .005 as well and see how it goes. Not too worried. I am sure that the different powder charges will tighten that grip up as well. The .290 and .291 bushings are ordered. I will be leaving on my archery elk hunt tomorrow probably so I will have to shelve this for a couple of weeks. It's a fun process though.
 
Had some time this morning so I went out to test the .020 off the lands with different powder charges. I had already started at 60 gr if RL26. So these loads went from 61-63 gr of RL26. The results are quite surprising and distinct.

All groups were shot at 300 yards.

Components:
Norma 280 brass fireformed to 6.5 Sherman
CCI BR2 primers
Hornady 143 gr ELD-X
RL26

1. 61gr shot a 3" group

2. 61.5gr shot a 4.7" group (no idea what happened there! But I was getting worried!)

3. 62gr shot a 3.3" group

4. 62.5gr shot a 2.4" group

5. 63gr shot a 1.1" group with .3" of vertical which was nice to see!

Here is a pic of the 63gr load group (holes highlighted in blue marker):
image.jpg


I then shot the 60gr of RL26 at .005 off the lands to see if it liked that seating depth. And it shot a 1.064" group at 300 yards right off the bat! So I am gonna load up some different charge weights for that seating depth and try it. I am also going to try a seating depth test with the bullet right on the lands and see how it does.

I don't know if anyone else is getting this kind of results but what it is telling me so far is that RL26 has some very sharp and short accuracy nodes. It will go from MOA or above straight down to sub half MOA with very little notice. So far it seems to like the higher pressure loads and it seems to go from low pressure to high pressure very fast so work up with this powder. I talked with Rhian very briefly about it as well. So don't get discouraged with the powder. You are gonna have to play with it. I have worked with H1000 quite a bit in other rifles and that powder is very constant unlike this powder. I may try some load development with H1000 as well.

I will keep updating on RL26 as I keep fine tuning it. Once I get it fine tuned, I will slap the magneto speed on there and see what we have. I am very interested to see if this accuracy is repeatable with the 63gr at .020 off and extremely interested to see if .005 off has even more potential and is repeatable.
 
And a pic of the (1.064") 60gr load .005 off the lands (gonna play with it and see if I can't get that vertical dispersion to go away)
View attachment 64685

That is consistent with what I have found! Likes higher pressure (good thing) for velocity, and .005" off the lands shot very well. I suspect you will be mid 3200's with the 63 grain load............Rich:D
 
Rich, have you shot any ELD-X right on the lands? If so, how did they do? I was starting to get worried about this powder bullet combo (RL26 and eld-x). Never seen a powder shoot like this before and then all of the sudden...BOOM! There you are below half MOA.

I believe my barrel is a little slower than yours. With 60 gr of RL26, you were getting around 3080 fps with the 150 matrix if I am not mistaken. With 60 gr and the 143 eld-x, I am getting between 3020 and 3030 fps. 63 gr should put me between 3150-3200 for sure which is what I was shooting for. I started to see slight slight signs of pressure at 63 so I don't want to over do it. I guess I will have to live with 1/3 MOA :D. Hopefully that accuracy is repeatable!

Very impressed with the cartridge thus far.
 
Every barrel is different, even with the same brand and twist, so I am not surprised at the difference. You can probably load a little heavier charge than me.
As far as right at the lands goes; I have not seen many rifles shoot well there. plus or minus.005", on the other hand, can shoot very well..........Rich
 
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