Help pick my load

[robtattoo]

6.5x55 Tikka, Norma brass, Winchester LR primers & IMR 7828SSC. 143 ELDx loaded to .0010 from the lands.

48.4, 48.6, 48.8 or 49?

Working up a new load for my rifle & these are the groups I'm getting really promising results. I'm 99% sure i should pick something bang-slap in the middle (48.7) & call it good.
49gr is absolutely the maximum so going higher isn't an option.
I'm seeing zero pressure signs on any of these loads but they're all over published loads. No tough extractions, no heavy web stretch, no extractor or swipe marks. But i really don't want our need to go hotter.

I haven't run them over a chrono yet, because I don't want to get too hung up on velocity. I'll test them once I pick a load. From previous experience, I'd guess around 2790 up to 2840fps

 

[nhyrum]

I'd go with 48.4. between 48.2,48.4, and 48.6 there's almost no poi(point of impact) shift. The middle node gives you the most margin for error. That's likely a velocity plateau, but it's impossible to tell without a Chrono

Sent from my SM-S918U using Tapatalk

 

[Billogna]

48.5 and run it!!

 

[SDHNTR]

If you have to do it this way…. 48.4-48.8 are all the same group. So split the difference at 48.6. Confirm with a 10-20 shot group.

But I also question the validity without bigger shot count groups, chrono data, es and Sd.

 

[EVO6]

Agreed, split the difference and do another string of shots

 

[Vern400]

Standard deviation and extreme spread and velocity will only start showing up at 200 or 300 yards. Chances are theyre similar. Without a chronograph all you can do is maybe shoot 400 yards and see if you get vertical stringing from Big velocity spreads. I have seen some loads to shoot good at 100 yards that fall apart at 300. But with the level of technology you're running go with the mid-range powder charge and shoot a couple more groups and make sure your results are real.

 

[eaglemountainman]

I would shoot a 10 round group each, of 48.4 and 48.6. Whichever did best would be my charge weight. Then, I would see if I could shrink the group further by tweaking seating depth.

 

[bmart2622]

Man Im just not sure that the average guy is going to be able to shoot well enough to discern a difference between a 0.2 gr difference in powder charge

 

[CCooper]

Am I the only one that likes 49?

 

[Billogna]

Am I the only one that likes 49?

49 looks to me like it's starting to show the signs of a coming pressure spike (looks like a double group to my eye). And as OP mentioned before it the absolute MAX - no where to go or allowance for temp swings or cooking one in the chamber....

 

[CCooper]

I see minimal vertical. I look at it and see the high right shot could have been shooter error and otherwise best group of the bunch. Albeit I'm constantly concerned with velocity and like to step on the throttle. It's funny how we all do things and look at things a little differently. I always appreciate these threads and responses for that reason.

 

[kevlar88]

Am I the only one that likes 49?

I'm liking it as well especially if its not showing pressure like Rob already mentioned. Seat .0025 and .0045 off the lands and see if she'll really sing for you.

EDIT: keep in mind seating deeper will increase pressure so keep an eye on that if you think you are already approaching the top end.

 

[kevlar88]

I see minimal vertical. I look at it and see the high right shot could have been shooter error and otherwise best group of the bunch. Albeit I'm constantly concerned with velocity and like to step on the throttle. It's funny how we all do things and look at things a little differently. I always appreciate these threads and responses for that reason.

I push my reloads pretty hard as well, one of the main benefits of reloading in my opinion. If you want to reload an '06 to 308 performance or not get the max out of it in a combination of velocity and accuracy what's the point?

 

[bmart2622]

More jump is going to equal less velocity

 

[doverpack12]

I like 48.6 or 48.5.

If velocity is where you think that is a good performance window for the bullet.
Still a little messy at 100 ish yards and really nice performance for a long ways past that

 

[Dos XX]

48.5 if chosen from that data only.

49 has a lower poi, unless the shooter caused it.

I'm also a fan of testing on and around the velocity flat spot on the chrono.

 

[Billogna]

48.5 if chosen from that data only.

49 has a lower poi, unless the shooter caused it.

I'm also a fan of testing on and around the velocity flat spot on the chrono.

Lower POI not likely caused by the shooter based on previous groups. More likely barrel harmonics throwing shots slightly lower. Also a sign of increased velocity/pressure.

 

[Mack84]

48.5

 

[Slugz]

Regardless what ya go with nice job and kudos in taking the time to make the most accurate weapon you can!!

 

[Cahunter805]

48.5 or 48.6 and shoot some 5-10 shot groups at further distance and see how they shoot.