Case Prep, Velocities and Point of Impact

[JimSC]

A couple of years back I experimented with annealing, various neck lubes, and checking concentricity but saw little if any improvement in my match scores so I stopped and began doing minimal prep work. At the time my scores were in the upper 180's and low 190's. Over the past couple of years the scores began inching upward mostly due to thousands of .22 LR shot in the name of wind reading. However every match those 3 or 4 shots in the 9 ring or that WTF one out in the 8 rng has had me plateaued for the past couple of months.

So last week I prepped 40 Lapua Rem 260 cases for my practice rifle. These cases got mixed up in the move, some less than 10 firings others approaching 20 firings. I cleaned them, checked primer pockets, trimmed to length and at that point put ten aside. The other 30 cases got annealed on a Anealeeze, and necks dipped in Imperial graphite lube. All 40 had the powder measured on my A&D to exact weight readout or within the scales accuracy tolerance. The 30 annealed and lubed cases were then checked for runout and corrected as necessary to be within .001 runout.

At the range I ste up my target at 300 and set up my spotting scope and chronograph. After five sighters to warm up the barrel I shot a 10 round group at the left hand dot. Between shots I verified the POI and made notes. I repeated on the right hand dot with the ten that had been minimally prepped again noting point of impact. Since the range was going to be hot for a while I improvised on a third group, using the sighter dot and two other dots for aim and shot ten more but without breaking my cheek weld.

attachment 1 is the target, attachment 2 is a spreadsheet noting velocity, point of impact relative to the point of aim, and velocity relative to the average velocity. The numbers make very little sense to me and the only thing I have learned that the best way to eliminate flyers is getting real anal on my case prep including annealing after every firing, lower SD's produce smaller groups, and keep that head down between shots.

Just thought some may have further insights on the velocity differences and point of impact

 

[CharlieNC]

First that is an extremely high degree of velocity variability, and probably too much for ladder load tuning to compensate for. Is this typical? How did you optimize the load? Given many potential variables and trying to identify the general culprit, how did this shoot with virgin brass? I'm not familiar with that bullet or powder so I cannot comment regarding the suitability of the components and load.

 

[JimSC]

yeah it is

First that is an extremely high degree of velocity variability, and probably too much for ladder load tuning to compensate for. Is this typical? How did you optimize the load? Given many potential variables and trying to identify the general culprit, how did this shoot with virgin brass? I'm not familiar with that bullet or powder so I cannot comment regarding the suitability of the components and load.

yeah it is. Long story on that barrel and powder. It's a Shilen prefit on a Savage 12. I had it on the rifle a couple of years ago but after shooting it for about 700 rounds I got the wanna for a 6CM . I recently burned the 6CM out and put this barrel back on for a practice rifle. Looked at my old load tests and found pic 1. I had 500 140 gn Barnes match burners I had picked up on sale so I loaded 50 of them at touch and took them with a seating die to the range and shot pic 2. Then seated 15 more @ .030 off and did a chrono test and shot 10 at a 600 F class target I had in the truck in pic 3. Nine of the ten shot pretty good and I had one flyer I circled iin the lower right.

I have been having good targets in general lately with my 6 BR except for the odd flyer so the target in the OP was a case prep test to see if going back to annealing and neck lubing would help eliminate those flyers. Obviously it did but I agree but with those chrono numbers the entire groups should be in the toilet. I have 50 more loaded now that will be shot at 600 or 800 when the weather decides to cooperate. Rain and 10 -15 mph winds for the last few days.

What blew me away was higher velocity rounds hitting lower than POA and lower velocity rounds hitting higher than POA and rounds loaded the exact same way when picked randomly from the storage box having radically different SD and ES numbers when shot in the same conditions

 

[CharlieNC]

Faster rounds hitting lower means you are way off of the charge node, probably too high. Back off 3% as starting point to run a ladder, focusing on vertical poi. I bet you will find the node at about 1.5% lighter.

 

[JimSC]

Faster rounds hitting lower means you are way off of the charge node, probably too high. Back off 3% as starting point to run a ladder, focusing on vertical poi. I bet you will find the node at about 1.5% lighter.

thanks for the input. Personally I am theorizing the velocity vs POI thing is due to barrel harmonics, I am just looking for possible alternate theories.

Problem is now I am wondering if SD and ES really matter that much. On the 300 target the lower ES/SD resulted in a smaller group size but even the middle group had the numbers are higher than what I would like to see. The other thing I was concerned with is why the drastic difference in the numbers between the far left group and the middle one. Those 20 cartridges were loaded as exactly the same as I can manage with case prep, powder charge, and seating depth. Some have said shoulder pressure and hold have no effect on velocity consistency but I have to wonder. I am not afraid to reevaluate what I think I know as I experiment with various techniques and make changes as needed.

Two months ago I would have given several reasons all backed up by science on why annealing has no effect on accuracy. Now after doing some experimenting on my own I am rethinking my loading practices. I figure to eat a lot of crow on that subject so I stocked up on hot sauce

My main concern at the moment I am is to eliminate the odd flyers. If annealing, neck lube, and checking the concentricity keeps the annoying flyers like the one on the 800 target under control then I will not touch this load except for adjusting the base to ogive as needed. Velocity stats be damned, it what prints on target that matters. The 300 yard target seems to indicate the flyer problem may be under control. If I keep getting .6 and .7 MOA 10 round groups with minimal numbers of flyers out to 800/1000 then to heck with velocity numbers other than an average for scope come ups

 

[CharlieNC]

Yes, higher velocity striking lower is due to barrel harmonics. Clearly there is also a charge weight region where higher velocity strikes higher, as generally expected. BUT in between there is also a transition zone where a similar difference in velocities strike at the same point, which is the basis for my suggestion to conduct the charge ladder. You only need to shoot one per load at 300yd to see this clearly. And getting on this node will help with flyers too.

 

[JimSC]

of course the differences in point of impact could be as simple as the guy pulling the trigger may not have a perfect of a technique as he likes to think

looks like I will be able do a test at 600 tomorrow to see if the the flyer issue is gone and how it groups

 

[RegionRat]

@JimSC Maybe there is a little to the technique issue since there is a contrast to your groups just based on your hold, but even that points to a sensitivity that is because you are out of tune or there may be an ignition issue.

The case prep methods that deal with annealing, lube, neck tension, etc., are all intended to minimize variations with internal ballistics, but unless you are tuned in a capable rig, none of your data above is statistically significant. In other words, with those samples, there is no evidence there is any real difference between the prep and no-prep for velocity. So I agree with CharlieNC that we would have to debug the tune issue and get your SD down around 15 or less to make progress with being able to see case prep as an independent variable.

Even if we can't debug or critique your shooting technique, the chronograph numbers and your loading methods should be good enough to where we can find out why the SD/ES stats are so high. 300 yards is good enough for now, but these numbers will take you out of the running before you go much farther.

Is the trigger, bolt, firing pin known to be good to go? Scope the bbl lately to make sure it wasn't fouled?

 

[JimSC]

@JimSC

Is the trigger, bolt, firing pin known to be good to go? Scope the bbl lately to make sure it wasn't fouled?

Barrels get a thorough and scoping after every match with never more than 100 rounds between cleanings. I had suspected a copper problem at first also but I scoped the barrel and found very little throat erosion, no carbon ring and a just a tad of copper down at the muzzle end. My next step was re evaluating my case prep. The firing pin spring is a possibility, I will order two new ones this week. It's been at least a year since I replaced them so it is time.

The Savage's have gotten me from low 180's to mid 190's in the 2 years I have been shooting matches so they have served the purpose. Last match I shot with the 260 was at 600 and I averaged 97.3 % even with the flyer problem. I did a bit better with the 6BR the last couple of matches but I still have that 1 shot per match going out into the 8 ring and a couple of borderline 9's just outside the 10 ring . Decent but not outstanding X counts

I will be buying a new custom build this spring. I just need to get my flyers under control for the next couple of months until I will have a better rifle. I think the extra case prep will solve the flyer issue, I will know by next week.

Anyway main reason I made this thread was I remember a while back one of the better known shooters on here posted a pic of one of his 1000 yard targets. It was one of electronic targets that logged the shot #, POI and velocity. His score was either 199 or 200 near as I can remember but his numbers were like that 300 target. At the time I wondered how such crap velocity #'s shot so well. He theorized that the barrel harmonics evened the velocity swings out, I am starting to think he had a good point.

On the technique. Like I keep saying, the middle and left groups on that 300 target were shot with ammo that was loaded at the same time in the same manner in cases that prepped in the same way, randomly pulled from the storage box. Yet a 60 - 80 % reduction in ES and SD. It had to be a difference in shoulder pressure, that's all I can think of at least.

 

[ShootDots]

I have an observation and a question. I noticed you stated in your post that you check for run out and THEN CORRECT. Does that mean you are using that Hornady "run-out / correct" tool? If it is, you just found your problem.

 

[JimSC]

I have an observation and a question. I noticed you stated in your post that you check for run out and THEN CORRECT. Does that mean you are using that Hornady "run-out / correct" tool? If it is, you just found your problem.

actually it seems to have been part of the correction of the problem. 20 shots in less than 1 MOA @ 300 centered is a 200 score in F class shooting. Letting it sit on the shelf unused seems to have been the problem

 

[ShootDots]

actually it seems to have been part of the correction of the problem. 20 shots in less than 1 MOA @ 300 centered is a 200 score in F class shooting. Letting it sit on the shelf unused seems to have been the problem

That may be so>>>I will take your word for it. I used that tool and it only caused my groups to open up and give me an inordinate amount of "where did that come from" flyers. I have spoken to two other people who have used that tool with terrible results. Neither of those gents were competitors, but they do know how to load and shoot.. That's why I said that I thought that that tool was the issue.

 

[JimSC]

That may be so>>>I will take your word for it. I used that tool and it only caused my groups to open up and give me an inordinate amount of "where did that come from" flyers. I have spoken to two other people who have used that tool with terrible results. Neither of those gents were competitors, but they do know how to load and shoot.. That's why I said that I thought that that tool was the issue.

here is a OnTarget composite of the two groups that were shot when the cases were annealed on a Annealeeze , lubed with Imperial graphite, and tweaked into alignment on the Hornady. Notice the distinct lack of flyers. I would take take this any day in a 300 yard match and if I could manage to do it three times in a row would probably place first

 

[ShootDots]

Hey, if it works, use it. Just keep an eye on it. But I am glad that it does work for you.. Annealing is always great.

here is a OnTarget composite of the two groups that were shot when the cases were annealed on a Annealeeze , lubed with Imperial graphite, and tweaked into alignment on the Hornady. Notice the distinct lack of flyers. I would take take this any day in a 300 yard match and if I could manage to do it three times in a row would probably place first

 

[Bc'z]

Question
Have you changed lots on any of your components?
Why are you trying to correct run out versus solving the problem of why your getting run out?

 

[JimSC]

Question
Have you changed lots on any of your components?
Why are you trying to correct run out versus solving the problem of why your getting run out?

On the 6 BR no change in components. On the .260 Rem changed from Nosler/ Sierras 140's to Barnes Match Burners and redid the seating test. Temps have dropped 40 degrees since any load development except for a seating test on the .260 when I changed bullets on the .260.

I would not say I have much of a runout issue. Any runout is pretty mild, maybe 15% of the rounds have between .001 and .002. I am just tweaking everything to less than .001 just because I can. No idea if what runout I had was causing flyers but I am making checking it a part of my routine again, like the neck lube. I can say for certain neither is hurting the groups but would not swear on a Bible that either is helping.

Shot 13 rounds from the 6BR this morning @600. Odd number was to shoot the leftovers from my last match alongside 15 rounds loaded yesterday so I shot 5 sighters and emptied the box. Shooting conditions was 55 F, very sunny, 5 mph wind, medium to heavy mirage. About a half MOA width and height. No flyers at all. Nice round group about three to four inches in diameter

Shot 20 rounds from the .260 and the 19 of the 20 rounds was a tad less than a MOA vertical but had about a MOA and a quarter Horizontal the one flyer was called, my fault totally. The horizontal was not flyers and was pretty evenly distributed. Might be that the seating depth could stand a bit of tweaking or could have been the mirage. It was pretty bad with a bit of left to right flow

Bottom line is it seems I have cured my flyer issues. ES and SD numbers aside. I was real happy with the 6BR's numbers and will tweak the .260's load/seating a bit. I have plenty LRP's and 4831 and 4350 to use for practice with a few K of assorted weights and brands of 6.5 bullets. No use burning up my Varget and 105's for practice/fun shooting

Once again the only reason for the thread was I just thought it was interesting how screwy those chrono numbers were compared to how well they grouped

 

[JFrank]

Do you get those huge fps variances on the br?

 

[JimSC]

Do you get those huge fps variances on the br?

I have no clue what the numbers are now. Last time I chronoed it was just after barrel break in. Barrel now has over 1K and temps are 40F cooler. The barrel had less than 100 rounds down it when these were shot. Later on a 300 yard test had 29.6 grouping the best and that is what I have been shooting ever since. Average speed must be pretty close to the same however, it is what I use in Strelock for scope adjustments and it is always within a MOA or so even when going from 100 to 800