Chrono help

[notalib]

I am finally doing rifle ammo after about a year of pistol reloading. One of the things I think (Read new guy opinion here..) I need is a good chrono.

I have looked around and see prices that vary so much (F1 for $80 all the way up to OMG) I dont want to step up to a purchase without some advise.

I want one with a stand (I think several of the ones you have to find a stand after the purchase....I think).

I think () I want Infrared screens (It seems like a hassle to wait for the sun and not be able to use indoors.... comments .. I know it jumps the price??).

I think (repeat laugh!!) I want the smarts to be separate from the screens.. (ie a cable of some sort). A missed placed shot and you could be out big bucks... once again.. comments.. this is a new guy talking..

Also, tips on setup, how do you make sure you dont leave a hole in it, or the muzzle blast is so high that it takes one out...

Or.. best of all... a good book that is a "chrono for dummies"....

Tnx

 

[rep308]

I use a cheap shooting chrony and yes it only works outdoors. I have a pen and notebook and calculator for all the math stuff. Yes I did shoot my shooting chrony and mailed it back to get repaired.

It's 12 years old and working fine.

 

[bpm990d]

I am finally doing rifle ammo after about a year of pistol reloading. One of the things I think (Read new guy opinion here..) I need is a good chrono.

They can be useful, but I'm not sure that they are really necessary for someone without a specific need to know the exact velocity they are getting.

If your going to be doing competition shooting at long range or hunting at longish ranges then they can be useful to get velocity data so you can calculate drops. Some people use them to calculate standard deviations for loads (with the thought that low SD=Good Load), but I've seen loads that are not all that impressive over the chronograph shoot just fine at long ranges.

I got by without one for years.

B

EDIT: A lot of pistol shooters have them for figuring out power factors for pistol ammo.

 

[Gammon]

They can be useful, but I'm not sure that they are really necessary for someone without a specific need to know the exact velocity they are getting.

If your going to be doing competition shooting at long range or hunting at longish ranges then they can be useful to get velocity data so you can calculate drops. Some people use them to calculate standard deviations for loads (with the thought that low SD=Good Load), but I've seen loads that are not all that impressive over the chronograph shoot just fine at long ranges.

I got by without one for years.

B

EDIT: A lot of pistol shooters have them for figuring out power factors for pistol ammo.

Sorry, but I disagree BIG TIME. If you are loading your own ammo you need a chrono, otherwise you have no idea what you are doing. The manuals can give you an estimate of what your reloads will do, but only testing the ammo in your gun will give you accurate data.

 

[Gammon]

I am finally doing rifle ammo after about a year of pistol reloading. One of the things I think (Read new guy opinion here..) I need is a good chrono.

I have looked around and see prices that vary so much (F1 for $80 all the way up to OMG) I dont want to step up to a purchase without some advise.

I want one with a stand (I think several of the ones you have to find a stand after the purchase....I think).

I think () I want Infrared screens (It seems like a hassle to wait for the sun and not be able to use indoors.... comments .. I know it jumps the price??).

I think (repeat laugh!!) I want the smarts to be separate from the screens.. (ie a cable of some sort). A missed placed shot and you could be out big bucks... once again.. comments.. this is a new guy talking..

Also, tips on setup, how do you make sure you dont leave a hole in it, or the muzzle blast is so high that it takes one out...

Or.. best of all... a good book that is a "chrono for dummies"....

Tnx

I bought a Competition Electronics chrono over 20 years ago and it is still going strong. It is the down range type of chrono that is basically a sealed unit. All you have to buy is a camera type tripod to support it. This chrono only gives you the average velocity of the rounds fired; nothing else.

I have been tempted to buy a more expensive chrono with "all the bells and whistles" but this 20 year old machine works too well to replace. The major disadvantage is that this chrono won't work indoors. To be honest, this hasn't really been a problem as I do most of my testing outdoors.

I paid $175 for this chrono over 20 years ago and couldn't be happier with it. You can buy the same model today for about $95. At this point I have to put a plug in for Competition Electronics. I have one of their timers that died on me after about six or seven years of use. I returned it to them and recieved a rebuilt timer for $35, including shipping. I had the same problem with a PACT timer and was told "What do you expect, its seven years old?" They refused to even open the timer up and look at it unless I agreed to pay an hourly fee. All they wanted to do was sell me another timer. PACT customer support is the pits. Competition Electronics is a much better outfit to deal with.

 

[notalib]

tnx.. I have a CE timer myself and like it... I'll look into their chronys

 

[Timberwolf]

Sorry, but I disagree BIG TIME. If you are loading your own ammo you need a chrono, otherwise you have no idea what you are doing. The manuals can give you an estimate of what your reloads will do, but only testing the ammo in your gun will give you accurate data.

+2 on whey Gammon said.

I have a Pact Professional which I like. Does all of the calculations I need.

Other's have stated about the poor service from Pact BUT my experience with it has been exemplary.

Last year was a very bad year between me and my Pact. I took out skyscreen housings, the IR elecrtonics the uprights, all with a pistol and not with the .308 nor the .338LM. All to the tune of $200. When I called Pact they were laughing at me.



CAN THEY DO THAT?

Anyway the Shooting Chrony will do what you want.

I wouldn't say thank you for a CED M2. AFAIC they are junk.

 

[bpm990d]

Sorry, but I disagree BIG TIME. If you are loading your own ammo you need a chrono, otherwise you have no idea what you are doing. The manuals can give you an estimate of what your reloads will do, but only testing the ammo in your gun will give you accurate data.

How do you think people got by before chronographs were reasonably priced and available to the general public? Did the people shooting back then have no idea what they were doing? Of course not, they relied on other things besides velocity measurement to gather information about their loads.

For example:

accuracy
case head expansion
functioning
recoil
extraction force
primer condition
case cleanliness
barrel headspace and throating
bore and groove diameter
case capacity
bullet bearing surface
resizing force

While I agree that a chronograph will provide lots of information about the velocity of the bullet, but what does that tell you about the above? In some situations you can have very high chamber pressures with relatively low velocity. If you simply look to a chronograph with out paying attention to the above where will you end up? All these things give you much better information about the internal ballistics that are happening than a chronograph alone gives you. In fact if you look at the Military Specifications for ammunition testing, they have a great number of visual inspections of fired cases that are required for lot acceptance. Of course they also rely on velocity measurements, but there are a number of failures that are found by visual inspection, that can result in lot rejection.

Beyond the chronograph you can get a strain gauge system (like an Oehler M43) to measure time pressure curves in the chamber. However even the strain gauge systems only provide a relative measure of pressure because they need to be calibrated with known ammunition and so on and so forth to get a true measurement of chamber pressure.

What a chronograph does allow you to do is to predict what the exterior ballistics of your projectile will be without actual firing tests. Quite useful for hunting applications where you are shooting at unknown distances and need to calculate a point blank range or come ups. Some bullets also only preform reliably within certain velocity windows. It's also very useful in some competitive events like 1000 yard shooting where you need to calculate come ups or make a determination if your ammunition will still be supersonic and stable at the target. In some cases you may absolutely need a chronograph, because you may not be able to get to a range to conduct a test firing.

However if you are not in need of precise velocity measurements, you can still reload fantastic and safe rifle ammunition by examining all the data points I mentioned above. I would suggest that it's done all the time. When I talk to guys at rifle matches, I can probably count the number that have chronographs on one hand. Those shooters are shooting accurately all the way out to 600 yards and in some cases beyond that with nothing more than the information they obtain by reading a good manual like the Sierra 5th Ed., looking at the results on target and evaluating all the information the rifle and cartridge provide. Like I said, I got by pretty well without one for a number of years.

Is it a useful investment? I think so. I wouldn't trade my Oehler M35 since they don't make them any more, but I would not put it into the category of a requirement for loading rifle ammunition unless you really need to know the precise velocity of your projectiles.

Respectfully,

B

 

[gerrycaruso]

I've been using a cheap Pro Chrono for years and have managed to not shoot any holes in it. You're shooting from so close that it would be difficult to flinch a shot into the chronograph, unless you shoot like my friend Kevin who flinches so bad he looks like he's having a siezure. If you're still concerned.put a steel plate in front of it.

 

[Gammon]

How do you think people got by before chronographs were reasonably priced and available to the general public? Did the people shooting back then have no idea what they were doing? Of course not, they relied on other things besides velocity measurement to gather information about their loads.

For example:

accuracy
case head expansion
functioning
recoil
extraction force
primer condition
case cleanliness
barrel headspace and throating
bore and groove diameter
case capacity
bullet bearing surface
resizing force

While I agree that a chronograph will provide lots of information about the velocity of the bullet, but what does that tell you about the above? In some situations you can have very high chamber pressures with relatively low velocity. If you simply look to a chronograph with out paying attention to the above where will you end up? All these things give you much better information about the internal ballistics that are happening than a chronograph alone gives you. In fact if you look at the Military Specifications for ammunition testing, they have a great number of visual inspections of fired cases that are required for lot acceptance. Of course they also rely on velocity measurements, but there are a number of failures that are found by visual inspection, that can result in lot rejection.

Beyond the chronograph you can get a strain gauge system (like an Oehler M43) to measure time pressure curves in the chamber. However even the strain gauge systems only provide a relative measure of pressure because they need to be calibrated with known ammunition and so on and so forth to get a true measurement of chamber pressure.

What a chronograph does allow you to do is to predict what the exterior ballistics of your projectile will be without actual firing tests. Quite useful for hunting applications where you are shooting at unknown distances and need to calculate a point blank range or come ups. Some bullets also only preform reliably within certain velocity windows. It's also very useful in some competitive events like 1000 yard shooting where you need to calculate come ups or make a determination if your ammunition will still be supersonic and stable at the target. In some cases you may absolutely need a chronograph, because you may not be able to get to a range to conduct a test firing.

However if you are not in need of precise velocity measurements, you can still reload fantastic and safe rifle ammunition by examining all the data points I mentioned above. I would suggest that it's done all the time. When I talk to guys at rifle matches, I can probably count the number that have chronographs on one hand. Those shooters are shooting accurately all the way out to 600 yards and in some cases beyond that with nothing more than the information they obtain by reading a good manual like the Sierra 5th Ed., looking at the results on target and evaluating all the information the rifle and cartridge provide. Like I said, I got by pretty well without one for a number of years.

Is it a useful investment? I think so. I wouldn't trade my Oehler M35 since they don't make them any more, but I would not put it into the category of a requirement for loading rifle ammunition unless you really need to know the precise velocity of your projectiles.

Respectfully,

B

I never suggested that the chrono was the only critrerion for ammo testing, just probably the best. Of course you should pay attention to the other criteria mentioned. The velocity data provided by a chrono can be a wealth of information, if you know how to interpret it.

Reloaders got along without chronos for years. That doesn't mean they are not an invaluable source of information. We got along for quite a while without the wheel, but I have no desire to return to those idyllic times.

 

[Timberwolf]

A chrono is just another tool in the arsenal of safe reloading.

The numbers are more of a guideline than anything but when used in conjunuction of the other tests tha bpm990d stated, the info becomes more valuable.