Accuracy Woes

[dellet]

..., how far off from the nearest bad load are they? ...

How bad can bad get? It can get pretty darn bad.

In my 8.3" BA I mostly found OAL critical to reliability. Note also the loads I gave you will run fine in a GI mag. Pretty near every bullet that's fed out of a magazine needs to "jump" to get to the lands. I'm sure the manufacturer's liability carrier insists. So I mostly use OAL in 300 Blk to fine tune for reliability and velocity.

I spent a lot of time trying to get the 125 TNT to work. As a concept, they're cheap and look fragile in a good kind of way. I have a bunch. But they were never quite accurate enough to make me smile. Ok for fodder I suppose. 

The best 125gr TNT load I came up with was 18gr H110 @ 2.100" using Tula 556, Rem 7 1/2,  Win, Rem 6 1/2 and Fed 205M, in that order. CCI 41's didn't make the top 5. No CCI primer did. Standard deviations always seemed too high. (I actually track MAD instead of SD because "sum of the squares" and all, tend to pull the number toward the fliers. For me MAD is closer to what I expect to get.) Anyway, when I go to that trouble, it's a lost cause.

Now those other loads I gave you are awesome in my gun. They say the good barrels will shoot any bullet well, the budget barrels just take more work. That's not to say a budget barrel can't be good, there is just a higher chance it'll take more work. I own 3 BA barrels and they have a place. I don't spend $300 or $400 on every barrel.

Wish I knew who "they" always are.

So, OAl is important... just how important?

I am compressing CFE BLK for 150gr Gold Dot loads with some pretty good velocities (~1850fps out of an 8.3" barrel).

Even with identical processed brass there are some differences in bullets and powder settling which causes slight variations in both COAL and CBTO (cartridge base to ogive). How how crazy should I get with this, meaning what tolerances are "good enough" for 100 yard shooting? Should I be adjusting the seating die for each cartridge, or just set it once and leave it for the whole batch? Should I be looking at COAL or BTO? Are these variations small enough that they don't really matter? I would normally just shoot and check the results but I don't have enough bullets right now to perform extended testing. I will post velocity results for the below 20 bullets next time I have a chance to get out.

Load 1, 21.0gr CFE BLK, 10rd, (~1625 fps from previous testing)
COAL CBTO
2.103 1.521 min
2.140 1.532 max
0.037 0.011 ES
2.112 1.527 avg
0.011 0.004 StDev

Load 2, 24.0gr CFE BLK, 10rd, (~1850 fps from previous testing)
COAL CBTO
2.242 1.662 min
2.253 1.671 max
0.011 0.009 ES
2.249 1.666 avg
0.004 0.003 StDev

Is 0.037" variation in COAL or 0.011" in CBTO important?

Time for a trip to the woodshed and a harsh look at the basics.

CTBO has absolutely no meaning unless you have sorted the bullets base to ogive. If you start with no point of reference, everything else is meaningless.

Either throw that powder in the garbage can, or put it on the back of the shelf until you hone your loading skills some. All it will do is frustrate you.

Meticulously shaping the outside of the brass has little to do with what really counts for the most basic and important fundamental of case capacity. If you do not have matching headstamps and or volume, you are wasting your time with everything else you do. You’re setting your expectations too high.

If you are going to compress the loads, you have to have a very consistent powder drop into the case. A slow, even, high drop works best. No less than 6”. The powder has to settle and stack evenly. Inconsistent compression is 10X worse for accuracy than inconsistent seating depth, it just happens to be that you can have one without the other.

Likewise your seating of the bullet needs to be slow and consistent otherwise you will trap air and pound powder down in some loads and not in others.

Not sure why you would be working loads with a 15% difference in powder charge weight, unless you are just establishing min/max, but your loads should be varied by no more than 2%. .3 grains is my standard for this cartridge until I want to fine tune. I am looking for about 25 fps change in velocity when looking for an accuracy node.

Don’t chase velocity, nobody cares how fast you can miss a target.

You best load will rare be your fist, maybe not even in the first 10.

[45r]

My 8.3 inch BA barrel is the least accurate of any I've worked with.It only does around 2 inches at 50 yards while my 9 inch BA barrel shoots 1 inch with noe 230 Hp's powder coated.It shoots 110 vmax or varmeddon bullets OK using H-110 or 300-mp.I only shoot it suppressed.
Without the can supers not much fun.Subs too inaccurate to be interesting.Maybe the 8.3 barrels are ones to avoid.

[Odysseus]

I think one or both of the following possibilities are the cause of your troubles:

First, Dellet hit the nail on the head about your handloads. Brass can have a huge impact on accuracy -and through other mechanisms than velocity. Variations in neck wall thickness, neck tension, non-uniformity, chamfer, volume, etc. can all have an adverse effect on accuracy while still allowing for low ES and SD. You never mentioned what brass you were using; whether it was mixed headstamp, converted 5.56, if all pieces of brass had the same number of firings on them, or what brass prep you did. I once individually weighed and sorted 2000 Zero 185 JHPs for my 45 acp by tenths of a grain in order to remove every last possible variable. How far are you willing to go to figure this out? With your low ES and SD, the weights are probably consistent, so maybe sort by ogive.

Second, and based on my own barrel search, the most likely possibility, is that your first and second barrel are BOTH junk. Yes, yes, I know. 1 MOA guarantee and all that. A few months ago, I was about to buy the exact barrel you have now. I did a google search for reviews. I found lots of happy BA customers until about 2019. After that, there were tons of negative reviews -guys having to get a replacement barrel cause their first barrel wouldn't shoot under 3 moa, only to get a second, or in one case, a third barrel that didn't do any better. General consensus on several sites seems to be that BA's quality control took a nose dive in late 2018 or early 2019 and you are going to be hard pressed to get a decent barrel from them, guarantee or not. After reading all that, I decided to spend a little more and bought a custom barrel from Craddock Precision. If you want accuracy, my suggestion is see if you can get your money back from BA and buy a decent barrel. Craddock Precision offers a barrel cut from Rock Creek or Shilen blanks for $250 -pretty hard to beat.