Help on spread!!

[Ralo79]

Hello guys, need some info on getting my velocity spread down. My setup is a trainer rifle isa savage 11, criterion match chambered in .223 7 twist, .090 freebore, shooting 77 gr Sierra MK at 2840. My PB was today with a 4 shot group at 300 yds measuring .417”. My problem is it had almost 100 FPS velocity spread! I would like to get this down to at least 20 FPS. I don’t want to change my load because it is consistently shooting around the .5” . What are my options, leave it or finds new node?.

 

[rwj]

If you’re consistently shooting .5” groups at 300 yards I wouldn’t change anything!

 

[1mil]

I am rather surprised that you did not see more vertical spread on that group at 300 yards with thar ES. Would 5 more groups all be that small? If so, I'd leave well enough alone.

 

[Ralo79]

I am rather surprised that you did not see more vertical spread on that group at 300 yards with thar ES. Would 5 more groups all be that small? If so, I'd leave well enough alone.

I will test more tomorrow but all groups today were .75 and under, this being the best,

 

[L.Sherm]

Are you sure your chrono is right?

 

[kwarw123]

This is why I don't own nor want a crono. Your pretty well dialed in there IMO.
Assuming that your powder weight is absolutely perfect the other variable would be the internal volume in the brass.
I would be very pleased if I where you. Great shooting as well.

 

[Ralo79]

Are you sure your chrono is right?

Yes, I use it for everything I do, it’s always been reliable!

 

[Ralo79]

This is why I don't own nor want a crono. Your pretty well dialed in there IMO.
Assuming that your powder weight is absolutely perfect the other variable would be the internal volume in the brass.
I would be very pleased if I where you. Great shooting as well.

Using LC brass , Rem 7 1/2 BR primers, thank you for the comment!,

 

[DShortt]

If you’re consistently shooting .5” groups at 300 yards I wouldn’t change anything!

It ain't broke. Nothing to fix.

Unless it was dead-calm, that little bit of horizontal was probably the wind.

You didn't mention any wind speed/direction. What were the wind conditions?

 

[Ralo79]

It ain't broke. Nothing to fix.

Unless it was dead-calm, that little bit of horizontal was probably the wind.

You didn't mention any wind speed/direction. What were the wind conditions?

Slight right to left from about 45degree

 

[DShortt]

Slight right to left from about 45degree

That's probably your answer unless you were compensating for it.

 

[Ralo79]

Checked my input from my ballistic app during testing, it showed 4 mph from about 45 degree. However my lane is cut through the woods so probably around 2-3 mph

 

[DShortt]

Checked my input from my ballistic app during testing, it showed 4 mph from about 45 degree. However my lane is cut through the woods so probably around 2-3 mph

It took me a long time to accept that the wind played more of a factor than I thought it did.

It doesn't take much at all to move a 77 grain .223 at 300 yards.

Wind is never constant, though sometimes it's worse than others.

Anyway, don't 'throw the baby out with the bath water'. You've obviously got more going right than going wrong. I don't think a load change is the best choice.

 

[Ralo79]

It took me a long time to accept that the wind played more of a factor than I thought it did.

It doesn't take much at all to move a 77 grain .223 at 300 yards.

Wind is never constant, though sometimes it's worse than others.

Anyway, don't 'throw the baby out with the bath water'. You've obviously got more going right than going wrong. I don't think a load change is the best choice.

Thank you!, as I said I really don’t want to move anything, it’s shooting it’s best right now. And yes I can testify on the wind, I shoot from one hill side to another hill and the wind can be totally different direction in the bottom of hollow!

 

[L.Sherm]

Yes, I use it for everything I do, it’s always been reliable!

Well if the chrono is right goes to show you chrono numbers don't mean much.
Some people put way to much stock in numbers.
Trying a different primer would be easy enough like a 450 or BR4 if you have them

 

[Krogen]

I am rather surprised that you did not see more vertical spread on that group at 300 yards with thar ES. Would 5 more groups all be that small? If so, I'd leave well enough alone.

I ran QuickTarget with the Sierra 77 gr Matchking at 2840 fps +/- 50 fps. The predicted vertical dispersion between 2790 fps and 2890 fps was 1.3" at 300 yds. As so many other folks say, the target is what matters. Chronographs, ballistic programs etc. can fool us. Of course, I use both, but I keep my salt shaker nearby.

 

[doctorh]

I would play with neck tension. Different in neck tension of 1--2 thousand could cause 50+ fps. Or greater. Lighter neck tension may work for you.

 

[Ralo79]

I ran QuickTarget with the Sierra 77 gr Matchking at 2840 fps +/- 50 fps. The predicted vertical dispersion between 2790 fps and 2890 fps was 1.3" at 300 yds. As so many other folks say, the target is what matters. Chronographs, ballistic programs etc. can fool us. Of course, I use both, but I keep my salt shaker nearby.

Thanks for the input!! I did load another text using Starline brass with same primer. The starline case capacity was around 2 gr less than the LC. Results were much better on velocities, although higher with same 23.2 gr . My 5 shot avg was 2870 withs a 19 fps spread and an SD of 6. Am pleased with this!

 

[Ralo79]

I would play with neck tension. Different in neck tension of 1--2 thousand could cause 50+ fps. Or greater. Lighter neck tension may work for you.

Thanks doc, I usually try to stay around the
.0015–.002 tension . I think my problem was my LC brass. It was range pickup and didn’t separate for yr produced. I don’t know if they vary that much or not!! I don’t know know they weight different, so they must be different volume.