Load development without a chrono worth it?

Gear Head

Gear Head

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I put together a new rifle in December and just got around to loading some 69 and 77 gr smk's to test in it. My only issue is that I don't have a chrono. Is it worth it to just go shoot groups with these to see what groups but not be able to see speed, SD, ES? It is my understanding that sometimes a small SD and ES are just as if not more important than group size. I will add that I am new to rifle load development and these with be my first test rounds. Basically I don't want to waste a bunch of bullets if I should be waiting to shoot them over a chrono.
 
I would just go shoot them and check my groups. I chrono pistol for PF, and rifle sometimes for boredom.

I don't get to shoot at extended ranges here so not terribly concerned with it. You could probably find someone that'll let you borrow their chrono, but then you'll probably have to buy one and not even get to keep it, so may as well by one now.

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Not searching for pure speed so I agree with that accuracy over velocity. But, I do need velocity for my ballistics app. I have been planning on buying a magnetospeed but I've spent a good bit on 2 rifle builds so I'm trying to hold off for a bit but I really want to go shoot one of the rifles I built.

I will also mention that this is a long range ar build that I plan to try to take to 1000yds.
 
Accuracy first in this case. You need accurate chronological data if you are shooting out 600+ yards so that your ballistics calculations are accurate, but inside of that at the speeds of .223, go for grouping all the way. If you want to play mid to long range with it, out to 800 you will need to chronograph and look for muzzle velocity nodes where ES and SD tighten up. the longer the range, the more likely that velocity variation can cause you to miss a target.

Also out past 600 it pays to chronograph different lots of powder and bullets also.
 
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Charlie R said:
Accuracy first in this case. You need accurate chronological data if you are shooting out 600+ yards so that your ballistics calculations are accurate, but inside of that at the speeds of .223, go for grouping all the way. If you want to play mid to long range with it, out to 800 you will need to chronograph and look for muzzle velocity nodes where ES and SD tighten up. the longer the range, the more likely that velocity variation can cause you to miss a target.

Also out past 600 it pays to chronograph different lots of powder and bullets also.
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As mentioned above, long range is my goal. That's my concern with shooting these without a chrono and not be able to gather ES and SD data from all of my charges. Basically, if I shoot these for groups and choose my charge based on that alone when it comes time to stretch things out I would really need to load all the charges up again to collect ES and SD and choose a charge based on that along with group size.

Just to spark some convo since I'm new to this, if you shot a 1" group with low SD and ES and a 1/2" group with higher ES and SD which would you choose?
 
Didn't notice you were in Winston. I have a Pro Chrono and I'm usually down to go shoot.

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Beef15 said:
Didn't notice you were in Winston. I have a Pro Chrono and I'm usually down to go shoot.

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You work tomorrow? Have a place to shoot 100yds? I normally shoot out to 400 at my uncle's place but I'm not sure he'd be too keen on my bringing a stranger over (no offence).
 
Gear Head said:
.

Just to spark some convo since I'm new to this, if you shot a 1" group with low SD and ES and a 1/2" group with higher ES and SD which would you choose?
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The problem with using group size alone is that you have several factors that go into your groups.

- temperature, barometric pressure, humidity, etc. on a given day
- your ability to be exactly consistent with trigger pull, cheek weld, position, grip pressure, rifle cant, stock pressure, load on your rest/bipod on every shot
- wind
- fatigue

Yes, accuracy is the ultimate goal, and you'll get pretty darn close just by shooting groups, but SD, ES and muzzle velocity are empirical data that shouldn't be overlooked.

If you are going to shoot for groups, do this.

Say you have 5 loads of 5 rounds each to test, then set up a target with 5 aiming points. I use a large sheet of butcher paper and 1" stickers. Label the stickers for each load.

Take a shot from load 1 at target 1.
Take a shot from load 2 at target 2.
And so on.
After you shoot the first 5 shots, let the barrel cool.

Start your next string with a shot from load 2 at target 2. And so on.

This will even out the fatigue factor....you won't be firing all steady well aimed shots with load 1 and rushing to get home for all of load 5.

It will also let 1 shot from each load be from a cold bore (clean too if you like).
 
Gear Head said:
You work tomorrow? Have a place to shoot 100yds? I normally shoot out to 400 at my uncle's place but I'm not sure he'd be too keen on my bringing a stranger over (no offence).
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Not offended.
Not working. Unfortunately my little range is only Fri-Sun.

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Tim said:
The problem with using group size alone is that you have several factors that go into your groups.

- temperature, barometric pressure, humidity, etc. on a given day
- your ability to be exactly consistent with trigger pull, cheek weld, position, grip pressure, rifle cant, stock pressure, load on your rest/bipod on every shot
- wind
- fatigue

Yes, accuracy is the ultimate goal, and you'll get pretty darn close just by shooting groups, but SD, ES and muzzle velocity are empirical data that shouldn't be overlooked.

If you are going to shoot for groups, do this.

Say you have 5 loads of 5 rounds each to test, then set up a target with 5 aiming points. I use a large sheet of butcher paper and 1" stickers. Label the stickers for each load.

Take a shot from load 1 at target 1.
Take a shot from load 2 at target 2.
And so on.
After you shoot the first 5 shots, let the barrel cool.

Start your next string with a shot from load 2 at target 2. And so on.

This will even out the fatigue factor....you won't be firing all steady well aimed shots with load 1 and rushing to get home for all of load 5.

It will also let 1 shot from each load be from a cold bore (clean too if you like).
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I know I said I'm new to this but I've been doing a lot of reading and it seems you place as much emphasis on the empirical data as most other things I've read which is why I was asking if I should even waste the bullets if I don't have a chrono to shoot them over.

I've heard of people shooting round robin style to spread margin of error across all loads but I can't wrap my head around how it accomplishes that. I understand your point with fatigue though.

I've also heard of people shooting for groups with their magnification dialed back some so that you don't see every little movement but I haven't tried that yet. With my CZ I have always shot groups at 25 and 50 yds on 24x lol.
 
the great thing about figuring out load development is all of the shooting you get to do while you figure out what is truth and what is myth in the world according to you. Everyone ends up with their own variations of the method. I used to put it ALL on muzzle velocity, then I started looking at groups and found some inconsistencies that I could not explain, so next I played with the seating depth at both of the muzzle velocity nodes that I had found and saw that I could tighten up the groups that way. That is now how I do it.

Oh, and I forgot, very important, I also have to have an Egg McMuffin for breakfast on the way to shooting my ladder, chew Bubblicious Bubble gum while I am shooting it, and I won't shoot it if there are any shooters to right of me on the range.

I have not tried groups at other charge weights to see if I can get better groups at muzzle velocities with large ES & SD, so I cannot say definitively that I have the most accurate load for my rifles, but I do have one with which I am satisfied - for now, or until I win the Lottery and devote myself to load development full time and have the money to spend on what I would otherwise consider wasteful.

What is the lottery up to now anyway? This may be the week!
 
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Another accuracy over velocity. Besides you'll just shoot your chrono at some point. Gotta by my third sometime :)

CD
 
Ditto for OCW. I have a chrono, but I'm using it mainly for subsonics. The round-robin method is meant to ensure each group has the fatigue taken out- but also barrel heat. Surprisingly, differences in your groups will be very apparent. I'm still trying to get my head around how much a little change in powder makes for changes in accuracy, but empirically, it's there. The groups grow and shrink and change with POI. If you dont' want to do round-robin, prepare to spend all day with your groups doing the same process of cleaning, taking some sighting/fouling shots, then your groups, wait for the barrel to cool. It's not necessary.

There is an alternate view of building loads only using a chrono (looking for 'nodes' in speed), but I call BS on that. I think that method is only successful when it intersects with a OCW node. The original method was the 'ladder' method, but it takes a long time, and shooter consistency is a much bigger factor (groups of 1).
 
I use the chrono when velocity data are important or useful:

- Determine velocity of my final load for drop calcs.
- work up a subsonic load
- double check results vs published manuals
- verify power factor
- diagnose problems

And yeah, two is one, one is none. Mine already survived a 44 cal slug from a rifle and it's held together with tape, but still works :)
 
Not to hijack thread, but what chrono do you guys recommend? I was looking at magnetospeed sport but not sure I want to spend the money on it.


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I looked at the OCW method and understand the principal but I'm lost on the method. I read through it but not following very well. It seems he's only testing near max charge weights?
 
Gear Head said:
I looked at the OCW method and understand the principal but I'm lost on the method. I read through it but not following very well. It seems he's only testing near max charge weights?
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Yes, sorta. The basis for a starting load for OCW is 10% less than max, because usually near max is where a load performs best. You can probably do the same thing getting the difference between max/min and dividing it among the 5 loads you're going to test, but OCW has you concentrate on the upper ones. I have a spreadsheet which calculates and creates a form for you if you want to check it out.
 
Conraq said:
Not to hijack thread, but what chrono do you guys recommend? I was looking at magnetospeed sport but not sure I want to spend the money on it.


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I sold a "Shooting Chrony" traditional style and picked up a magnetospeed. I like the Magnetospeed a lot better....but I'm not sure if I like it $250 better. If you shoot on your own range mostly, where you can call a cease-fire and deal with setup whenever you want, then I'd say stick with a traditional style. If you shoot public/managed ranges where you need to wait for someone else to call it cold, I'd go with magneto.
 
Sas quatch said:
Yes, sorta. The basis for a starting load for OCW is 10% less than max, because usually near max is where a load performs best. You can probably do the same thing getting the difference between max/min and dividing it among the 5 loads you're going to test, but OCW has you concentrate on the upper ones. I have a spreadsheet which calculates and creates a form for you if you want to check it out.
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Yes please, I'll pm you my email.
 
Assuming from the parameters above that you are shooting a .223, and in consideration of the effects of wind and resistance against such a small bullet over long distance - I think that velocity becomes more important up front if the whole purpose of the rifle build and load development regime is at long range. If you are going to be hand loading .223 specifically for 700-1000 application, then I think shooting 100 yard groups without gathering velocity is gonna prove to be an inefficient use of reloading time/components - nothing wrong with it if you are learning/enjoying the practice, just inefficient. However, if you are planning to use the rifle over the entire range of 100-1000, and the 800-1000 range is more for occasional capability than sole usage, then there is a lot of utility in finding a good 50 - 500 yard load without regard to velocity.

That being said, if the rifle is .223, you have plenty of barrel life to play with, so do whatever makes you happy. However, if you were shooting a 6.5 or 6mm barrel burner, then I would think the barrel wear and associated inefficiency of shooting initial load development without a chrono would be a dealbreaker.

Just my opinion, for what it is worth.
 
East of Here said:
Assuming from the parameters above that you are shooting a .223, and in consideration of the effects of wind and resistance against such a small bullet over long distance - I think that velocity becomes more important up front if the whole purpose of the rifle build and load development regime is at long range. If you are going to be hand loading .223 specifically for 700-1000 application, then I think shooting 100 yard groups without gathering velocity is gonna prove to be an inefficient use of reloading time/components - nothing wrong with it if you are learning/enjoying the practice, just inefficient. However, if you are planning to use the rifle over the entire range of 100-1000, and the 800-1000 range is more for occasional capability than sole usage, then there is a lot of utility in finding a good 50 - 500 yard load without regard to velocity.

That being said, if the rifle is .223, you have plenty of barrel life to play with, so do whatever makes you happy. However, if you were shooting a 6.5 or 6mm barrel burner, then I would think the barrel wear and associated inefficiency of shooting initial load development without a chrono would be a dealbreaker.

Just my opinion, for what it is worth.
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Nail on the head pretty much.

I fired the first shots in it today and the good news is it didn't blow up. The bad news is that I couldn't get the bolt to lock back regardless of gas block setting so I think I may have a misaligned gas block. No idea how to troubleshoot that so I'll be spending some time on google this evening.
 
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Gear Head said:
I fired the first shots in it today and the good news is it didn't blow up. The bad news is that I couldn't get the bolt to lock back regardless of gas block setting so I think I may have a misaligned gas block. No idea how to troubleshoot that so I'll be spending some time on google this evening.
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How heavy of a buffer are you using? When I first put together my Grendel, I used a heavy buffer thinking it would further reduce recoil. However, it did not cycle correctly and I ended up swapping it out for a lighter one. It now functions flawlessly. Considering your rounds may be on the lighter end of the spectrum, it may be that the buffer is too heavy or the spring is too stiff.
 
East of Here said:
How heavy of a buffer are you using? When I first put together my Grendel, I used a heavy buffer thinking it would further reduce recoil. However, it did not cycle correctly and I ended up swapping it out for a lighter one. It now functions flawlessly. Considering your rounds may be on the lighter end of the spectrum, it may be that the buffer is too heavy or the spring is too stiff.
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Honestly I'm not sure, I just ordered a rifle buffer and tube kit and I don't remember it being marked. I'll go double check it.

I was shooting factory PMC 62gr 556 to test function and set the gas block.
 
Gear Head said:
Honestly I'm not sure, I just ordered a rifle buffer and tube kit and I don't remember it being marked. I'll go double check it.

I was shooting factory PMC 62gr 556 to test function and set the gas block.
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I would certainly check that before going back and messing with the gas block. If you rule the buffer and spring out as causes or contributors, then you can move on to the more complicated fixes.
 
East of Here said:
I would certainly check that before going back and messing with the gas block. If you rule the buffer and spring out as causes or contributors, then you can move on to the more complicated fixes.
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No markings on the buffer. I tried to weigh it but it's too heavy for my digital powder scale.
 
I’ve been shooting .223 and .308 pretty successfully without a chrono since I started loading in 2011. I want one but I have other priorities right now

I am able to see how well my loads perform out to 300yds after getting solid 100yd results and if things go to crap
 
Gear Head said:
No markings on the buffer. I tried to weigh it but it's too heavy for my digital powder scale.
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If you have a kitchen scale, that will work. Otherwise, if you have another buffer lying around, compare or swap.
 
East of Here said:
If you have a kitchen scale, that will work. Otherwise, if you have another buffer lying around, compare or swap.
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I'm going to swap to a known good lower to at least rule out gas. I only have 1 rifle buffer, my other is carbine so I can't really swap buffers. Wont be able to get it out again till the weekend unfortunately.
 
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