6 BRA 300 yard ladder

[kyotekiller25]

Took the 6 BRA out today for its first run at a pressure/velocity ladder test. Range was 300 yards, 30 degrees and no wind, from a bench. All the info is on the target. 26" BRUX 8 twist, .135" freebore, 4 thou neck tension.

I have an idea where I think I want to start, but I want to see what some of you guys think? Seems to be running a tad slower than a lot of guys I see with H4895 and taking a little more powder to get there. I believe I have room to go up from 31.2 as I had no sticky bolt, easy extraction, no ejector marks, and primers looked fine. However, I also don't feel like I want to push it to hard and be at the top node when our summers are 100-110 degrees. I also don't want to be at the low node either. Would prefer the middle node if there is such a thing.

Would love to hear your guys thoughts on where you would go from here!

 

[Matt_3479]

Normally I like to shoot 2-3 ladders in an outing to help outline group dispersion and thin out the heard to make to easier to read. The br’s shoot so well it’s sometimes hard to determine the best node especially in 1 ladder. With the little information gathered here I’d play with 30.3grs, 29.7, 30.7 to see how they shoot.

 

[kyotekiller25]

Normally I like to shoot 2-3 ladders in an outing to help outline group dispersion and thin out the heard to make to easier to read. The br’s shoot so well it’s sometimes hard to determine the best node especially in 1 ladder. With the little information gathered here I’d play with 30.3grs, 29.7, 30.7 to see how they shoot.

I'm only working with 12 pieces of brass at the moment, until I get them fired 5x or so before I'll put them in with the other 150 I have that are 5x fired. But that's exactly where I was thinking also! So that's good to know! Thank you.

I was thinking about starting around 30.7 at 2860fps, or 30.3 at 2815fps. My goal for this rifle was to be around 2850fps with 1/4 MOA 5 shot groups.

 

[kelbro]

Doesn't look like your velocity starts to flatten out until 31.0-31.2. I would keep going. Start back at 30.8 and work up a little more.

If you use GRT, you can plug your info in and see approx where it says the nodes are and where the pressure maxes out. It's not exact but pretty close.

 

[SpencerC87]

Not really enough information to go off of, but imo, I would load up a minimum of 10 shots each of 30.2, 30.5 and 30.8 to see what groups best

 

[Deputy819]

Hard to identify true vertical dispersion (as it relates to powder charge) at only 300 yards. Can you stretch it out to @ 500 yards or so?

 

[kyotekiller25]

Not really enough information to go off of, but imo, I would load up a minimum of 10 shots each of 30.2, 30.5 and 30.8 to see what groups best

Can you explain why you would try those charges?

 

[kyotekiller25]

Hard to identify true vertical dispersion (as it relates to powder charge) at only 300 yards. Can you stretch it out to @ 500 yards or so?

I can possibly get 500 yards. Just do the same charges and test?

 

[kyotekiller25]

Doesn't look like your velocity starts to flatten out until 31.0-31.2. I would keep going. Start back at 30.8 and work up a little more.

If you use GRT, you can plug your info in and see approx where it says the nodes are and where the pressure maxes out. It's not exact but pretty close.

Would I go up until 2950 or so? Around 31.8 maybe? I do not have GRT...Maybe someone here can plug all that in?

 

[Rick300]

I'm on barrel #4. If you go above 31 grains of H4895 you're going to be buying new brass in my experience. If this is a new barrel then it might speed up. I wouldn't chase velocity, it's telling you it likes 30.2 - 30.8 of powder. Also, a different bullet might get you more speed if that's what you're after

 

[kyotekiller25]

I'm on barrel #4. If you go above 31 grains of H4895 you're going to be buying new brass in my experience. If this is a new barrel then it might speed up. I wouldn't chase velocity, it's telling you it likes 30.2 - 30.8 of powder. Also, a different bullet might get you more speed if that's what you're after

This is not a new barrel it has around 1K-1200 rounds through it. I'm not so worries about velocity in this one, hence why I don't really care to explore the very top end node. I would be perfectly happy with around 2850fps as long as it shoots dots...

Can you explain why it likes 30.2-30.8g of powder even though they didn't really group close to each other? Meaning the split group on POI? Just trying to learn here.

My original thoughts were to try 30.3 and 30.7 split the middle between those sets of 2 shots each.

 

[Rick300]

From what I see, 30.2 - 30.4 OR 30.6 - 30.8 looks like 2 areas worth exploring, so yes 2 different groups. I was just taking a shortcut on typing

 

[Deputy819]

I can possibly get 500 yards. Just do the same charges and test?

That’s what I would do. I do ALL of my powder ladders at 500 yards. As long as your “shooting mechanics” are correct you’ll get a much clearer picture of the dispersion at that distance (and beyond) and be able to clearly identify what charge(s) correspond with the preferred node.
I can tell you that my 6 BRA shows its best CONSISTENT accuracy in the 2,860’s fps with the 108 Berger Extreme Hunter. I tried the “upper node” (low to mid 2900’s) and it just wasn’t consistent there. I chase consistent accuracy….not speed.

 

[kyotekiller25]

That’s what I would do. I do ALL of my powder ladders at 500 yards. As long as your “shooting mechanics” are correct you’ll get a much clearer picture of the dispersion at that distance (and beyond) and be able to clearly identify what charge(s) correspond with the preferred node.
I can tell you that my 6 BRA shows its best CONSISTENT accuracy in the 2,860’s fps with the 108 Berger Extreme Hunter. I tried the “upper node” (low to mid 2900’s) and it just wasn’t consistent there. I chase consistent accuracy….not speed.

Gotcha. My bench mechanics I would say are pretty dang good and consistent as thats how I shoot and prsctice 75% of the time. Have put thousands upon thousands of rounds downrange from a bench. It's also pretty hard to pull shots with an 8 oz trigger.

The charge area of 30.6-30.8 are pretty decent, and I was going to split that and go 30.7 which would put it right around that 2860 fps area. That's what I was going to concentrate around from the start anyway.

Probably just gonna load 10 @ 30.7 and see what it gives me for 2 seperate 5 shot groups at 100 yards. Collect the 10 shot data from the Garmin and go from there.

 

[Ccrider]

30.2-30.8 in a 6bra? Heresy!!!

Or, maybe where you will find a node. If it will not shoot somewhere in that range, neck tension, seating depth or just the wrong bullet/powder combination for that barrel.

If you are worried about speed, you should get a longer barrel. Much over 31gr and you are going to spend time making new brass.

 

[JFrank]

@kyotekiller25
It may be of interest that your powder lot number might be of a very slow nature, I have lots that run 31 gr around 2960 while a different lot is above 3000 fps with 31g
On the side there’s a date code as well as a pallet/ packaging number, would you care to share that number ?

 

[kyotekiller25]

30.2-30.8 in a 6bra? Heresy!!!

Or, maybe where you will find a node. If it will not shoot somewhere in that range, neck tension, seating depth or just the wrong bullet/powder combination for that barrel.

If you are worried about speed, you should get a longer barrel. Much over 31gr and you are going to spend time making new brass.

I'm not to worried it won't shoot this combo. It put a 10 shot FF group with 29g H4895/108 ELDM into .6xx"

I have not even begun load development yet. I will now start after this ladder test. Still have to fine tune my powder charge first, seating depth second, neck tension 3rd, and lastly a couple primer swaps. I figure another 4-5 trips to the range and only changing 1 thing at a time, I'll be pretty close to getting it as good as it will get with this combo.

Not worried about speed, anything from 28-2900 fps will do just fine for this rifle. It's just for LR steel and local matches out to 1K, and coyotes.

 

[kyotekiller25]

@kyotekiller25
It may be of interest that your powder lot number might be of a very slow nature, I have lots that run 31 gr around 2960 while a different lot is above 3000 fps with 31g
On the side there’s a date code as well as a pallet/ packaging number, would you care to share that number ?

These are the only numbers I see on this can, it's a sticker on the bottom. No other numbers anywhere on the side or jug itself like my other Hodgon canisters. It is an older can with the metal lid @ price of $17.95

I'm about to order an 8# jug of H4895 in the next week or two. I'll get a load figured out with this pound I have, so that way I'll know what velocity I need to be at with the new keg.

 

[Ccrider]

My goal for this rifle was to be around 2850fps with 1/4 MOA 5 shot groups.

This is why I mentioned speed. You say you had a “goal” for speed. 1/4 inch 5 shot groups at 100 should not be that hard if you get everything dialed in.

I have not even begun load development yet. I will now start after this ladder test.

Like many, I run and consider ladder test as load development.

30.2- 30.8 or so should put you in the middle node. 31.2- +++ will push you into the high node. Also, like one poster said, you seem to have a slower lot of H4895 for whatever that means to you. I would not worry about it and would focus on finding a good tune.

 

[SpencerC87]

Can you explain why you would try those charges?

Well, That range prints in the same area and at a velocity you are looking for. You should be able to find something relatively easily in that range that will work. You could look for good load at the lower charges, but, I always prefer the fullest case of powder reasonably possible.