[BUGUDY]

I started reloading last year with some success. I wonder when I am working up a load if I am getting the fps from the load I should be{ according to the chart.} I am thinking more about calculating bullet drop.

[bullseye308]

I am starting to use one. It is very helpful if you are trying to duplicate a factory load for example, or you want to figure drop over a distance. It can also be a good indicator of when you are approaching dangerous pressure. It is also fun trying not to hit it. :cool:



As a side note, buy a wooden dowel the same diameter as the steel rods and pre-cut it to length just in case you hit one. That way you won't have to pack up and go home before you are done. Not that it ever happened to me....:rolleyes:

[The Bushmaster]

Well a chronograph will help you determine if you are under, matching or exceeding factory fps. However...Most of the time you will not match listed or factory fps because you were not using the same barrel as the original fps readings were taken from. But, you will be close. I have some reloads that are under listed fps, some that match listed fps and some that exceed listed fps. The most important thing is whether they are accurate or not from your gun over a given distance...

And if you pay attention you will not shoot your chronograph. If you are shooting a rifle with a scope over the sensors. Allow for the highth of the scope over the barrel. I've been using my Pact 1 with the same parts for the last 20 years and haven't hit it yet...

[Walkalong]

They are not necessary, but they are fun, and like The Bushmaster said, it's the only way to know if you are matching facory velocities.

[bullseye308]

It is also a good way to know how consistant your loads are. Stuff like ES and SD can help you fine tune a load.

ES extreme spread
SD standard deviation

[USSR]

It is also a good way to know how consistant your loads are. Stuff like ES and SD can help you fine tune a load.

+1.

Don

[glockgod]

I think everyone who handloads ammo should have one! The Chrony models are almost within everyones price range.

[Smokey Joe]

Bugudy--As has been pointed out, a chronograph is not necessary for reloading, but is very helpful. The Shooting Chrony models are nice. I got a steal of a deal on the Gamma model, so I bought it, thinking "What do I want with all those bells & whistles??"

Let me tell ya, having the machine do all the math, and print up the results right there on the range, and having the readout on the bench rather than out by the sensors (therefore less to replace when--not if--you shoot the sensor unit) is (Tony the Tiger voice) Grrrr-EAT!!! (/Tony the Tiger voice)

Nice for other shooters @ the range, too. They come over, see what I'm doing, and want their loads chrono'd, and I can hand them a slip of paper with the results. Good for maintaining a positive balance of favors (like a positive balance of trade for nations.)

Agree w/Bullseye 308--As a side note, buy a wooden dowel the same diameter as the steel rods and pre-cut it to length just in case you hit one. That way you won't have to pack up and go home before you are done. Not that it ever happened to me....But I'll go him one better--And Mr. Shooting Chrony recommends this also--Get wood dowels and replace ALL the steel rods holding up the shaders, BEFORE you shoot one of the steel rods. Less potential damage to the chronograph base that way. I carry extra dowels in my "chronograph kit," a fishing tackle box where the Chrony fits, plus the printer, all the rolled-up wires, extra batteries, extra printer paper, etc, etc, etc. As a side benefit of using this kit, I don't have to fold up the Chrony when putting it away.

Bottom line: A chronograph is nice to have. Helps in developing loads and other uses. Shooting Chrony's are nice but I would not denigrate any other brand.

[Galil5.56]

After using one for 15 years, the thought of not having one is unimaginable, and right up their with not having an analog dial caliper.

As far as which one to buy, if you are still shopping I had a good first basic Chrony F1, and then a total POS Chrony F1 Master. Now using a ProChrono Digital, and it's actually enjoyable again to gather data. If they (Competition Electronics) would offer an IR remote unit for the ProChrono Digital, it would be unbeatable IMO for a non IR sensored chronograph.

[R.W.Dale]

A chronograph is an invaluable reloading tool and is the ONLY reliable and widely avalible method to determine the pressure of your loads

[The Bushmaster]

Krochus...Read...It is one of the many indicators for determining pressure. Surely not the determining factor...All a chronograph does is tell you how fast your bullets are traveling. You must, using other data and the chronograph, determine if you might be over pressure.

[Ky Larry]

Am I doing something wrong? I load all my reloads according to published data. I start at the recomended min. load and work up in half grain increments. I watch for pressure signs on every fired case. When I find the load that gives me the best accuracy, I tinker with it (C.O.L; different brand primer,etc.). If my loads are within the published data, why should I care what the velocity is? If I can't hit anything with a certain load, I don't care how close it is to matching factory loads. I thougt we reloaded to make better ammo than what we can buy. Not trying to start an argument, just curious why I need a chronograph. Please educate me. Thanks.

[XD-40 Shooter]

I use a chrony because I really enjoy clocking my reloads and seeing what the extreme spreads are, its fun. I bought the basic shooting chrony for $85 at Sportsmans Warehouse, I like it.:)

[The Bushmaster]

Ky Larry...You will get no argument from me as you are correct in your statement. Your method will not let you down. As stated before. A chronograph is an unnecessary tool to aid in cartridge development.

[bullseye308]

A chrono just gives you more info to better understand your loads. It is not necessary, most of us that have one loaded just fine for years without one and got by. There is a lot of info they provide if it is something you want to know, but if you are satisfied just loading something that is accurate and don't need all the other info, there is nothing wrong with that either. It has it's place for some and for others it is just an unnecessary toy. I'm an info junkie and I use mine. :D

[R.W.Dale]

Krochus...Read...It is one of the many indicators for determining pressure. Surely not the determining factor...All a chronograph does is tell you how fast your bullets are traveling. You must, using other data and the chronograph, determine if you might be over pressure.

The chrony and reloading manual are the only hard numbers you have in determining safe max loads. Looking at primers and case head expansion are about as an accurate indicator of pressure as throwing a handful of chicken bones on the floor. You're simply fooling yourself if you think you've determined ANYTHING from the condition of a fired case short of a full on rupture or a primer falling out.

I don't care how close it is to matching factory loads. I thougt we reloaded to make better ammo than what we can buy. Not trying to start an argument, just curious why I need a chronograph. Please educate me. Thanks.

Because sometimes you'll end up with loads that while under max will chronograph faster than the published data indicates for a given or shorter barrel length. That is a HUGE indicator that you should STOP right there and reevaluate.

A chrony also helps greatly in those all too frequent situations where different manuals give wildly differing max loads.

Lastly a chrony will improve your shooting prowess because once your velocity is known ballistic data all of the sudden can apply to your rifles. Without a chrony at the range and a laser rangefinder in the field I couldn't have made this shot.
http://thehighroad.org/showthread.php?t=405210&highlight=bloodied

[qajaq59]

They're really nice if you have the place to use them. However, if you hold up the line to set it up on a busy day at the range, you can get unpopular real quick.

[RonC133]

A couple of observations. I use a Chrony Beta.

1. Be sure to allow enough distance between muzzle and face of the chronograph. I melted the faceplate from burning powder impact from placing too close to the muzzle of a rifle. (Replacements were inexpensive and readily available from mfg. Now I use the plexiglas covers in case I have another senior moment.)

2. I find it real helpful in load development, especially when trying to duplicate hot factory ammo for magnum pistol. I found it not so easy to duplicate Federal performance in 41 magnum, for example. The Fed factory is pretty hot. (In addition, you don't have to worry about what barrel and conditions was used for load book data. You can calibrate against factory in your own gun.)

3. I have always heard you can load better than factory. I have found that you can TAILOR your ammo to your guns for improved accuracy, but beating most reputable factory ammo for consistency can be a challenge. The biggies, Rem, Win, Fed, etc. do a pretty good job and are generally amazingly consistent. (That is, in terms of standard deviation and extreme spread.)

[The Bushmaster]

Well Krochus...I refer back to post 11 and 14...I have made longer shots without having the information of a chronograph with my Browning .30-06 and hand loads. Yes. Having a chronograph is nice when you are working at the higher end of the powder charge, but the lawyers have pretty much illiminated any real over charge fears for those without a chronograph even at those levels. It is not often that I use the data from my chronograph to determine over pressure. I usually note other indicators long before I note anything from my chronograph. Such as pierced, sooty or cratered primers. Sticky extraction, damaged rims from extractors. Excessively ballooned cases, or large number of split cases in a set that has few reloadings.

Will I be without my trusty 20 year old Pact Mod 1 when working up new reloads? No....Like Bullseye308 said. I, too, am a bit of a data freak.

[243winxb]

For long range 600+ yards, knowing your ES extreme spread &
SD standard deviation is importent. Other wise its just a new toy. The first chronograph i shot over had wire running through a piece of cardboard. When the bullet broke the wire the timer started, the 2nd one stopped the timer. Then the new sky screens came out, great new invention.:) I did not learn anything from it. What is on the target is what counts. The guy i sold the chronograph to killed the sky screen with the first shot. :p

[.38 Special]

A chronograph is a fun and useful toy for many of us, for many of the reasons already mentioned above. I have one and use it regularly, and if I lost it I'd buy another.

Ky Larry cuts through the BS though. It is absolutely possible to work up loads according to the manual, observe for "traditional" signs of excessive pressure -- which are very unlikely to occur if using modern materials and adhering to the manual -- and end up with an accurate, deadly load. And the best way to "calculate" long range trajectory --no matter how fancy your gadgetry -- is to actually shoot the gun and load at long range.

So yes, chronographs are fun and informative, and no, chronographs aren't at all necessary.

HTH!

[Wilburt]

Havn't heard anyonemention this reason: I don't have one but I am getting one b/c i'm trying to work up loads for IDPA. No one around here I know has one so....:D

[USSR]

You're simply fooling yourself if you think you've determined ANYTHING from the condition of a fired case short of a full on rupture or a primer falling out.

Respectfully disagree with you, krochus. Brass at high pressure goes thru a series of events prior to the primer coming out and case failure. Aside from primer condition (which is unreliable), there is: brass flow into the extractor hole, which leaves a shiny mark on the headstamp; and gas cutting around the perimeter of the primer. Also, you will generally experience heavy bolt lift prior to the primers coming out, to say nothing about case failure. The truth is, the more indicators you use (chrony, brass condition, etc.), the better indication of high pressure you have available to you.

Don

[.38 Special]

Problem with that, as per the last time we went around on this subject, is that brass varies, as do chambers. You can have soft brass that shows traditional pressure signs with safe loads, and hard brass that resists flowing even at extreme pressures. Same goes for primers -- most of us have seen Federal handgun primers, for instance, flattening and cratering even with light target loads. Additionally, a rough chamber or an oversize firing pin hole can create pressure signs, while a tightly fitted target gun with a polished chamber will gracefully extract 85,000 PSI loads with nary a peep.

There's nothing wrong with looking at traditional pressure signs and using them as part of the experience. Pretending that these rough guesses are truly dependable predictors of pressure, though, is a mistake IMO. The only thing the handloader can take to the bank -- assuming he has not invested in genuine pressure testing equipment -- is that velocity = pressure and vice-versa. If your load is getting 300 fps more than the hottest load in the hottest manual, you can bet you've got too much pressure regardless of what your primers look like.

[USSR]

You can have soft brass that shows traditional pressure signs with safe loads, and hard brass that resists flowing even at extreme pressures.

Sorry, but if you have soft brass and it is showing pressure signs, then going beyond that (even if a reloading manual shows higher charge weights) is too much pressure for the components being used in that particular rifle. And hard brass DOES NOT resist flowing at high (but not extreme) pressure. I don't think you can find brass much harder than Lake City Match, and it will flow in the extractor hole when the upper (but not extreme) range of pressure is reached.

Don

[.38 Special]

How do you know that to be true?

[USSR]

How do you know that to be true?

Personal experience in six years of load development for F Class Competition.

Don

[243winxb]

http://www.handloads.com/misc/saami.htm Seems a little on the proof load side of pressure???? :confused:

[Smokey Joe]

Bushmaster--Your comment,but the lawyers have pretty much illiminated any real over charge fears made me think of lawyers being forced to sit all day in 15th century monkish cells, painting pretty decorations in hand-lettered books. Mrs. Smokey Joe asked what was so funny and I showed her. She added that the hand-lettered books should be reloading manuals.

I'll be grinning about that all day! :D

[dagger dog]

Just another tool, a reloader can't have too many tools! Another step in the quest for the perfect load for ole Betsy.

How could a red blooded brass polishing, lead slinging, primer popping reloader not want another tool? Especially one that uses batterys and is computer driven?

If you're not drooling in your powder somethings wrong with ya:eek:

[The Bushmaster]

Glad I was able to get a laugh out of ya, Smokey Joe...:D

[.38 Special]

Personal experience in six years of load development for F Class Competition.

So you had a bunch of different brands of brass tested for hardness, then loaded them up with various charge weights and, using laboratory grade instrumentation, determined that the softer brass was incapable of handling standard pressure loads and that harder brass doesn't resist flow? And you repeated these tests in a variety of rifles to see the effects of chamber and bolt face tolerances?

FWIW, after having read a great number of your posts, I think you are one of the most knowledgeable handloaders here. It's just that you occasionally make "absolute" statements that seem essentially impossible to prove, and I think you place too much trust in certain kinds of reloading dogma. There are just far too many variables in the game to allow simple rules of thumb to be dependable.

[.38 Special]

Seems a little on the proof load side of pressure????

Exactly the point. I once worked up a .30-06 load in Lapua brass -- which is the hardest brass I have ever worked with, including Lake City -- without a chrono. As a firm believer in the bolt lift/primer appearance/case head inspection dogma, I kept adding powder until I saw pressure signs. I then backed down a grain so that the pressure signs went away, and called it done. A month later I fired some of those loads across a friend's Chrony and discovered they were significantly faster than they should have been. And years later I referred to my notes on the load and, using the "load from a disk" software, determined that that particular load was probably developing something like 80,000 psi. Without any pressure signs, other than several hundred extra fps.

John Barsness -- who IMO is one of the most knowledgeable gunwriters out there -- wrote up a nearly identical experience, although he had his ammo sent to a pressure testing lab where it was determined that it was making 85,000 psi -- again with no pressure signs whatsoever.

Taken as a whole, this all made me seriously reconsider what I thought I knew about handloading.

[SlamFire1]

I use a chronograph when developing loads. I regularly compare to factory velocities fired in the same weapon. And regardless of components, I get nervous when my bullets exceed factory velocities.

There ain't no free lunch. When things are going faster it is because pressures are higher. And pressures in smokeless powders don't increase linearly, they increase exponentially.

I use what tools I have.

And sometimes, even Chicken Bones.

Roll dem Bones! :D

[USSR]

FWIW, after having read a great number of your posts, I think you are one of the most knowledgeable handloaders here. It's just that you occasionally make "absolute" statements that seem essentially impossible to prove, and I think you place too much trust in certain kinds of reloading dogma. There are just far too many variables in the game to allow simple rules of thumb to be dependable.

.38 Special,

I'm a bit confused by what you're saying. You choose to disregard brass condition as a variable, and that is fine. I think I am the one who is saying I don't just rely on a single variable, but rather on a host of different variables (chronograph data, brass condition, interior ballistics software, reloading manuals, firsthand knowledge, etc.) to determine safe/unsafe pressure levels. Yet you freely admit to "adding powder until I saw pressure signs" and only "later I fired some of those loads across a friend's Chrony and discovered they were significantly faster than they should have been" and later yet using interior ballistics software "determined that that particular load was probably developing something like 80,000 psi". I don't work that way. All my load development work involves pressure levels that are within SAAMI specs, except for the 6.5x55SE, which is deliberately downloaded in the U.S. due to the possibility that someone might be shooting a single bolt lug Norwegian Krag. Since my F Class Match Rifle uses a very strong M70 action, developing modern 60k loads for it is not unwarranted. Yes, the Lapua .30-06 brass is excellent brass with a similar case capacity to LC M72 Match brass, and in my experience, loads are interchangeable between them.

So you had a bunch of different brands of brass tested for hardness, then loaded them up with various charge weights and, using laboratory grade instrumentation, determined that the softer brass was incapable of handling standard pressure loads and that harder brass doesn't resist flow? And you repeated these tests in a variety of rifles to see the effects of chamber and bolt face tolerances?

First, I am not concerned about a brass hardness "number" generated by laboratory instrumentation. Nor am I concerned about how any of the loads I develop react in a variety of rifles. My only concern is that I develop an accurate load at an optimal velocity at a reasonable pressure level in my rifle. If I give out an optimal load that I am using in my rifle, it always comes with the caveat "start lower and work up towards it, while looking for pressure signs".

Don (the chicken bone reader)

[.38 Special]

I freely admit to doing stupid things before I knew better. And I admit to them in the hope that it will illustrate why guessing pressure via brass condition is essentially worthless. Estimating pressure using velocity, manuals, and brass condition is a lot like predicting the weather by using a thermometer, barometer, and crystal ball.

As for keeping your load development within SAAMI specs, the whole point is that you don't know that, at least not with brass condition as your tool. Again, this is what my story about being young and stupid was meant to illustrate. If you'd asked me I would have told you my load was within spec because I "knew" -- via brass condition -- that it was. And going by your thread about how you develop loads, I'd bet a significant sum that your hottest loads are way over SAAMI limits.

[.38 Special]

One last try:

My only concern is that I develop an accurate load at an optimal velocity at a reasonable pressure level in my rifle.

Fair enough. Let's say you work up a load in your particular rifle. The first sign of pressure is a bit of flow into the ejector. You back down the powder charge by a few percent and see no pressure signs. Let's say, just for argument, that this load develops 55,000 psi, well within the SAAMI specs for the round. A friend of yours borrows a handful of those cartridges and discovers that, in his rifle, the brass flows into the ejector. Did the pressure change? Is it now more than 10,000 psi higher? Of course not. It's simply fired in a rifle with larger extractor clearances. Let's lay up the same load in a case with identical dimensions but much harder brass. Pressure's still the same, but now the brass flow has disappeared. Is the load now "safe" where the other one was "unsafe"? How about if we bump up the powder charge and get another 15,000 psi, still without pressure signs? Is this load safe? How about if we put it into softer brass and immediately see all sorts of scary pressure signs?

And that's the essential problem with brass condition as a "tool" for pressure estimation: dozens of variables and no control. It's guesswork.

[USSR]

And going by your thread about how you develop loads, I'd bet a significant sum that your hottest loads are way over SAAMI limits.

Well, .38 Special, you're entitled to your opinion. But QuickLoad interior ballistics software and all the guys on the F Class firing line with me using similar loads think otherwise, and I'm inclined to believe them.

Don

[.38 Special]

I don't recollect anything about Quickload in your thread about load development. I remember almost total reliance upon brass condition. Perhaps my memory is faulty.

I certainly don't have any real argument with folks who want to use brass condition as one "tool" in their arsenal, but again, "Quickload+velocity+brass condition=accurate pressure estimation" reads pretty much the same as "thermometer+barometer+tea leaves=accurate weather estimation".

[R.W.Dale]

pressure signs related to brass brass condition indicates one of two variables.

ONE characteristics of the individual chamber causing th brass to take on these indicators.


TWO a load that's already several thousand PSI over pressure

Let me cite an overly simplistic example:

30-06 is rated for 60K PSI, whilst 270win is rated for 65K on pretty much the exact same piece of brass. Now if 270 doesn't show traditional pressure signs that means in a rifle with a similar chamber 30-06 will be at least 5000psi overpressure with no traditional indicators whatsoever. So why would you expect to see high pressure indications on a piece of 06 brass magically appear once that arbitrary 60,000psi threshold is crossed?

What happens with the above reasoning applied to a cartridge like 7mm mauser and it's 51k PSI rating? Same piece of brass as 270 just slightly shorter


at the other end of the spectrum I had a ww231 load for a 200grn SWC in 45acp that was supposed to go about 800fps. I shot several of these and was happy with this load till I shot a string over my chrony that showed velocities so low that I was afraid the bullet might stick in the bore.


Well Krochus...I refer back to post 11 and 14...I have made longer shots without having the information of a chronograph with my Browning .30-06 and hand loads.

were any of these shots made very far outside the point blank range for 30-06?

but the lawyers have pretty much illiminated any real over charge fears for those without a chronograph even at those levels

This is one of the most foolhardy statements I've ever read related to handloading, The grumpy old man loading for 50yrs lawyer conspiracy I've shot several loads from hodgon's online data beat the numbers given by a great deal requiring a reduction from max. Saying that you don't have to worry about pressure with modern data because of some stupid lawyer superstition is well.....stupid

[1858]

There ain't no free lunch. When things are going faster it is because pressures are higher. And pressures in smokeless powders don't increase linearly, they increase exponentially.

Hmmm ... I was just shooting some .45-70 handloads today so referring to Lyman's Reloading Handbook 49th Edition, the load range for .45-70 for 1886 Winchester and 1895 Marlin using VihtaVuori N130 and a 405 grain Remington JSP is as follows:

43.5 grains > 1556 fps > 19,300 CUP
48.5 grains > 1744 fps > 26,900 CUP

So for the given range, an equation for pressure (CUPS) as a function of powder (grains) could be:

y= 1,520x - 46,820 (for 43.5 <= X <= 48.5)

... and an equation for velocity (fps) as a function of powder (grains) could be:

y= 37.6x - 79.6 (for 43.5 <= X <= 48.5)

So in the range given in the reloading manual, the increase in pressure and velocity are most likely LINEAR functions of powder charge (grains). Now I won't pretend to know what the relationship is at powder quantities significantly below 43.5 grains. However, at 48.5 grains the case is just about full so there's no point worrying about the relationship on the high side. The case pressure is affected by the amount of free space in the case and that is apparent from the reduction in powder when using a larger (heavier) bullet. Take the following min/max loads for the .45-70 and N130 powder:

292 gr bullet, 51.5 to 57.5 grains of N130
330 gr bullet, 48.0 to 54.0 grains of N130
405 gr bullet, 43.0 to 48.0 grains of N130

This is a stoichiometry issue I'd guess where the extra free air in the case needs extra powder ... but that's just a guess.

As for the chronograph, I currently don't have one and don't feel that I need one since I'm not pushing the envelope with my loads. I simply use the OCW method using reliable data from Lyman, Sierra, Speer, Alliant, Hodgdon etc and find the loads that work best in my firearms while staying within the guidelines. If I were pushing the envelope with loads above and beyond the ones listed in reloading manuals, I'd probably want/need a chronograph.

:)

[Galil5.56]

I consider my chronograph a de-liar, a lot to lot cross check, and a definitive way to see what my firearms prefer... I looked over some results when I was developing an FBI style 158 grain LSWC HP .38 Special +P loads about 15 years ago, and a chronograph came in real handy. Even at max charges, one propellant gave an avg of 610 fps, although listed at 885 fps. Even with match accuracy, if I had trusted but not verified this load with my "toy", would I have been well served in a SD situation, as was the intent of this ammo?

By testing other propellants I have been able to get almost listed velocities, and now know that the bullets are traveling at a velocity I want and expect, and can test this in any weather condition to again verify, and adapt as needed... I have seen this many times; i.e. seen what changes a primer can make, bullet hardness, temp... Needed, nope... real nice to have, and as long as I pull a reloading handle I'll use one, yep.

[xsquidgator]

I consider my chronograph a de-liar, a lot to lot cross check, and a definitive way to see what my firearms prefer... I looked over some results when I was developing an FBI style 158 grain LSWC HP .38 Special +P loads about 15 years ago, and a chronograph came in real handy. Even at max charges, one propellant gave an avg of 610 fps, although listed at 885 fps. Even with match accuracy, if I had trusted but not verified this load with my "toy", would I have been well served in a SD situation, as was the intent of this ammo?

By testing other propellants I have been able to get almost listed velocities, and now know that the bullets are traveling at a velocity I want and expect, and can test this in any weather condition to again verify, and adapt as needed... I have seen this many times; i.e. seen what changes a primer can make, bullet hardness, temp... Needed, nope... real nice to have, and as long as I pull a reloading handle I'll use one, yep.

I agree with all that. One other thing that I like about a chrony is that it puts numbers on your observations. I've read several reloading manuals and look for pressure signs when I'm working up loads. But I'm worried about some of those being kind of subtle. A chronograph is hard data and I feel a lot better about having that.

For instance, just this weekend I was trying to figure out if I really need to use magnum small rifle primers with my 30 Carbine W296 loads. The Speer book recommends them, but do you *really* need them? Without the chrono I wouldn't have known. The regular SR primer loads felt the same and seemed as accurate as the magnum SR loads. But, with the chrony I was able to get a hard measurement of bullet speed and see that in this case, the magnum primers don't make any difference.

[The Bushmaster]

"But the lawyers have pretty much illiminated any real over charge fears..."

I'm really glad everyone is getting such a kick out of that statement. I don't usually get that much mileage out what I say these days.:D

If you compare Lyman's 48th or 49th Edition with Sierra's Vth edition. Then compare both with some of the 1960's load data manuals you might just better understand what I was elluding to.

[USSR]

If you compare Lyman's 48th or 49th Edition with Sierra's Vth edition. Then compare both with some of the 1960's load data manuals you might just better understand what I was elluding to.

LOL, no way in he!! you can get anywhere's near a max load using Sierra's load data.:D

Don

[1858]

So now you chronograph guys have got me thinking. I have a Marlin XLR in .45-70 and a Marlin Guide Gun also in .45-70. The XLR has a 24" barrel whereas the Guide Gun has an 18.5" barrel. The theory is that the muzzle velocity (for the same load) would be slower out of the Guide Gun compared to the XLR ... maybe by as much as 200 fps ... due to the shorter barrel. So let's say I load some rounds to the maximum listed in the Lyman manual i.e. ...

48.5 grains > 1744 fps > 26,900 CUP

... and chronograph them out of the XLR at the given 1744 fps. I now shoot them in the Guide Gun and get 1544 fps. Does that mean that I can increase the charge for the Guide Gun until I reach the same velocity? It would seem to me that I'd have two completely different animals in that if I could measure pressure vs. time and plot them for the two barrels, even though the velocities are the same, the plots might look very different. I might also find that the peak pressure is very different.

:)

[The Bushmaster]

I can, but only in a very few of my handguns and then with very careful work up. I usually end up somewhere between Lyman and Sierra for hot loads...And those are loaded for hunting only. All my rifle stuff is loaded to below Lyman's maximum powder charges.

If you remember USSR. I weigh every powder charge I drop.

1858...NO

[Oddbod]

I guess whether or not you think using a chrono is worthwhile comes down to what you expect out of your ammunition.

If extreme & repeatable accuracy is your goal, then using one might well be considered essential, whereas working up loads for <300yd hunting or plinking doesn't really demand such precision.

I use one & keep all the recorded data in my load book.
It has saved time when using powder from a new lot #, as it means I waste less powder & bullets on confirming that it produces the same performance as the old one.

[R.W.Dale]

If you compare Lyman's 48th or 49th Edition with Sierra's Vth edition. Then compare both with some of the 1960's load data manuals you might just better understand what I was elluding to.

The reduction is due to many of the old loads having unsafe pressure spikes that the antiquated copper crusher measurement system would never have shown. I'll go so far as to say that in this day and age you shouldn't be even using load data that isn't pressure tested in PSI

It's not that new loads are too weak it rather than many old loads were way too hot.
the 28.0grn AA1680 load for 7.62x39mm comes to mind that's found on the old speer manual

But it's not because of some lawyer superstition believed by the same group who thinks the government has the plans for he 100mpg carberator.


... and chronograph them out of the XLR at the given 1744 fps. I now shoot them in the Guide Gun and get 1544 fps. Does that mean that I can increase the charge for the Guide Gun until I reach the same velocity?

no no and no

To get a shorter barrel to be as fast as a long one chambere pressures would have to be significantly ramped up

[Papa smurf]

I use a cronograph mainly to check for a difference from shot to shot.

[243winxb]

deleted

[USSR]

If you remember USSR. I weigh every powder charge I drop.

Bushmaster,

I was supporting what you were saying.

So now you chronograph guys have got me thinking. I have a Marlin XLR in .45-70 and a Marlin Guide Gun also in .45-70. The XLR has a 24" barrel whereas the Guide Gun has an 18.5" barrel. The theory is that the muzzle velocity (for the same load) would be slower out of the Guide Gun compared to the XLR ... maybe by as much as 200 fps ... due to the shorter barrel.

1858,

Each barrel/chamber is an entirely different circumstance. I've got two .30-06 match rifles, both with 26" barrels. With the exact same load, one does 2950fps, while the other does 2875fps. So, extrapolating an expected velocity based on barrel length can be misleading. Regardless of what velocity is listed in a reloading manual, there is no substitute for a chronograph.

So let's say I load some rounds to the maximum listed in the Lyman manual i.e. ...

48.5 grains > 1744 fps > 26,900 CUP

... and chronograph them out of the XLR at the given 1744 fps. I now shoot them in the Guide Gun and get 1544 fps. Does that mean that I can increase the charge for the Guide Gun until I reach the same velocity?

Short answer, Nope.

Don

[~z]

Sure you can load without one but the data gained from it is...insert grand word here.

I do a lot of long range shooting/hunting. I use the chronograph to develop drop charts and verify my drop data on the range. Without the chronograph I would be spending a lot more $ on components to verify my data. My Ohler paid for itself years ago.
~z

[1858]

Regardless of what velocity is listed in a reloading manual, there is no substitute for a chronograph.

I think I need one of those then.

Don, thanks for your informative post. Now I'm thinking that since I seat the bullets in my rifle loads 0.020" to 0.040" off the lands (typically 0.020"), which usually results in a longer COL than listed in reloading manuals, there's a very good chance that the reduction in pressure results in a reduction in velocity. This is something that I won't be able to discern without the aid of a chronograph.

OK guys, so what's the BEST one out there, and for good measure, what are the 2nd and 3rd place models?

:)

[1858]

Don, what's the long answer? ;) I REALLY would like to know ... I'm not lazy about this stuff and will certainly be doing a lot of research before I buy and use a chronograph but I'd really like to get your thoughts on the matter.

Thanks.
:)

[Walkalong]

If you are developing consistent target loads and want to get the most velocity possible within safe limits, a chrono is invaluable.

In Benchrest we would push the limits pretty hard. We used brass proven to hold up well, Lapua, neck turned to the nearest .0001 and fireformed to fit a tight necked chamber as close as humanly possible. We partially sized the necks and barely touched the body while bumping the shoulder back .001 or less. Loads we used would be very unsafe in regular chambers with average brass. We would prep 15 to 20 brass and use them for quite a while, loading repeatedly during matches.

The Highpower folks use a lot of cases loaded in advance. They don't worry about brass quite as much, but do prep it carefully. They do worry about ES & SD a lot more I have been told, because of the distances they shoot vs Benchrest.

A chrono is the only way of getting that info. :)

Correct me if I got anything wrong Don. ;)

Sometimes taking advise here from someone like Don who knows what he is doing is like your physics class in school. Some things you just accept the answer because you know the teacher knows what they are talking about. You don't need to know exactly why sometimes, just how to do it so you get the problem right. :cool:

[~z]

So far as "best" I'd vote Ohler 35P, now good luck finding one, I aint getting rid of mine!
~z

[USSR]

Walkalong,

Don't ask me about loading for benchrest, that's your forte.;)

Don, what's the long answer? I REALLY would like to know ... I'm not lazy about this stuff and will certainly be doing a lot of research before I buy and use a chronograph but I'd really like to get your thoughts on the matter.

Using the same make of powder (and just adding more) in a barrel nearly 6 inches shorter and expecting to reach the same velocity as the longer barrel, is a losing proposition. In rare cases it can be done when the long barrel is a factory barrel and the short barrel is a custom barrel. I would suggest you run loads from both rifles over a chronograph and see what you get. If you feel you need more velocity from the short barrel, then try a different make of powder (usually with a slightly faster burn rate).

Don