Extreme spread has me pulling my hair out.

[woods]

You might try a seating depth test, especially with the Berger

I did a test with a 6.5 rem mag, 130 gr SSII's and RL17 and the results were

Distance off lands / Average fps / Extreme spread / Standard Deviation

.015" / 3209 fps / 31 fps / 11.67 fps
.030" / 3200 fps / 32 fps / 11.70 fps
.045" / 3186 fps / 23 fps / 9.80 fps
.060" / 3176 fps / 8 fps / 4 fps
.075" / 3170 fps / 27 fps / 11.4 fps
.090" / 3156 fps / 52 fps / 31.7 fps

I think Berger even has a seating depth test they recommend and it is posted around here somewhere. Results were sometimes Bergers like being way off the lands

But my point is you might find a sweet spot that is much further off than your .020"

BTW I have the Pro Chrono and have no problem with it

 

[Mikecr]

Hello Woods. Was 60thou off also the most accurate in seating, or did it not turn out that way?

 

[woods]

Hey Mike

.060" was a little better than most

.030" off was about the same

Scirrocco's are not really an accuracy bullet, more a performance on game choice

 

[HARPERC]

It's no shortcut to validate data, or discuss tolerances of equipment. The chrony could give dead on numbers, and not reflect what the targets indicate. Or like you circled back to is it being set up correctly.

Ultimately we aren't testing chronograph's, but the entire system, and it always has to be proven, or not.

I read an interview years ago with one of the chronograph manufactures, when asked what were some of the things he'd learned from making/selling chronographs. He answered "nobody ever returns a chronograph for reading too fast".

We tend to like our equipment to tell us what we want to hear.

 

[SidecarFlip]

Interesting thread. You have the same issue my friend (that I hunt with ocassionally) had. His rifle would not group for (pardon the word) ****.

I believe you need to take a look inside your barrel with a borescope and have a good look at whats accumulating inside. His tube was extremely copper fouled even though he's a religious cleaner. Took some serious Sweets and serious scrubbing to remove the fouling.

All is well now.

Have a look-see.

 

[cowboy]

I felt I had researched it and the competition electronics procrono was supposed to be a good one. Brad

Any chance you could get your hands on a couple more chrony's? Set them up back to back to back.

I've sent mine back to factory at least twice and had it re-calibrated over the years.

Bottom line is I never take a chrony's reading as final gospel - do what Broz said and shoot it at 600 yds or beyond and let the vertical tell you what is going on. And if you do shoot at 600+ In conjunction with your chrony, keep track of each impact on target and you'll know if your chrony readings make any sense.

 

[RangerBrad]

I don't have another chrony to test aginst. I do sort bullets by weight and have on occasion done the same with brass. Ive tried retumbo and and h4350 with like results. My barrel is 24" Most all groups out to 600 range in the .5 moa. I ain't relly got a place handy to shoot any further than that. All shots are made over the chrony at a taped 15' Brad

 

[HARPERC]

I don't have another chrony to test aginst.

Do you want one?

I have one in the basement not getting used. I've been undecided about using for downrange testinggun) or donating it to one of the fund raisers.

This threads taken an interesting turn. Win, lose, or draw the results will make good discussion. PM me an address, I'll mail it to you, you make a donation locally to who, and what you choose.

The only condition post what you learn. Beats hair pulling.

 

[Kennibear]

RangerBrad

Lots of help from your buddies. My order of the universe:

1) Scrub your bore. Fouling can cause more problems than a floor covered with shattered glass.

2) Change powders. Guns are like women, they all go bang but that's all they have in common. IMR 4350 delivers SD's (not ES) in the 20fps range in my '06 and son's 300WinMag. Cannot get IMR 4350 to shoot under SD= 50fps in my Savage 375 Ruger. WW760 delivers an SD of 9fps (!!!) in the 375 Ruger. Go figure.

3) Neck size only. Sometimes a generous chamber can play havoc with a load and neck sizing will give you more consistency. We use the Lee collet neck sizer. Minimum working of the neck and absolutely no lube required, no scratches even.

4) SD is more important than ES. One shot can bump your ES off the page but shot to shot variables are way more important. Everybody telling you to look @ groups are right. Very low SD"s give you a small group and the long range groups point that out.
I have two chronographs a CED MII and a Chrony Beta Master. Set up w/ the Chrony tilted into the center of the MII (1' spacing vs. 2') the MII reads 3009fps Vs. the Chrony @ 2995fps. Shot to shot varies the same amount. 14fps difference from two different manufacturers is pretty dam good. It's not your chronograph.

 

[cowboy]

My barrel is 24" Most all groups out to 600 range in the .5 moa. I ain't relly got a place handy to shoot any further than that. All shots are made over the chrony at a taped 15' Brad

If you're shooting .5 MOA at 600 yds and your chrony is telling you that your ES sucks I would say you've got a chrony that is not being truthful. Any time I've got .5 MOA at 600 yds I say that I'm good to go for hunting purposes.

Sounds to me like you know what you're doing and have taken the proper reloading steps and your chrony isn't giving you that final warm and fuzzy feeling. I wouldn't waste any more barrel life in trying to get your chrony to read something that makes you feel good.

 

[RangerBrad]

Thank's fellas for all the good advice and HARPERC for the offer of your chrony tghough I doubt I'm worthy. Sorry about being tardy keeping up with the thread but been busy as our deer season starts tommorow. Went out and shot 4 rounds today through same chrony and got in order of shot 2917, 2923, 2911, 2936 average 2922fps. A far cry from the first spread but also 2 shots less. I am getting good groups out to 600yds which is about the max effective range of the caliber (on large game)anyway. HARPERC I'll send you a PM if your still interested and will be sure to post results. Brad

P.S. these speeds seem far less than what I would of expected from this round.

 

[HARPERC]

Absolutely, I work a bunch this weekend. It might be mid-week, but I'll send it. It should be interesting.

 

[HARPERC]

Brad, I got a little behind, but it went out today. I'm looking forward to seeing how you use it.

No worries about worthy, just an average guy on my end trying to learn a bit. Besides gives me a reason to upgrade

 

[RangerBrad]

HARPERC, I'll be looking for it and will give yal a comparison up date as quick as I can. It'll be interesting to see how the 2 compare. Brad