Purpose of a chronograph in Bullseye Shooting

I was watching this video (out or curiosity, not because I'm looking to buy), and got to wondering if this type of device is something all (most?)  (many??) of you use in testing loads and deciding what to shoot?

Is something like this used by ordinary Bullseye shooters?

Also, in what ways might it be useful?  Is it to compare the speed of your ammunition with what the books and charts say it should be?

Last, is this used to compare the speed of your bullets with what has been identified as the "best" speed, so you vary the powder charge to adjust the speed?

I hope I'm not asking anything too silly here - I've never seen one of these in person.

Mike, many of us have them for various reasons.
I use an inexpensive Chrony brand to simply try and duplicate a factory load velocity.
Let's say I want to duplicate the Zero 185 GR jhp load.

I'd Chrono a handful to get the avg spd of the factory rounds and adjust my reloads according.

But, it's not a necessity, you can probably get the same results using established load data from the many Masters of the sport.

I can tell you this much and only since it’s based on my experiences and what little work I’ve done with a chronograph. When I was developing a hunting load for my rifle I used a chronograph because I was looking for a powder that had a consistent burn. I wanted the velocity from shot to shot to be as close together as possible. The idea is of course that consistency will bring accuracy. In the end the load I settled on was accurate off the bench and shot to shot velocities were fairly close together. 

For pistol - maybe specifically bullseye - I would imagine that people could check their loads to see if they’re close to the common or “recommended” target velocity. Truthfully in my opinion that’s not going to matter. Reason is, your gun may prefer something slightly faster or slightly slower than what’s considered “the sweet spot”. It’s a guess. So I wouldn’t say load with a velocity in mind. Load and test to find what shoots best. And once you’ve got it, maybe chrono it for information gathering to see where it falls. 

Just my thinking on it. Time for waffles!

I've used chronograph data to compare loads.  Lower powder charge loads have less velocity and higher have more, but the velocity (and subsequently kinetic energy) can't be determined without a chronograph.  Some have used the chronograph to adjust the powder charge between powder lots to get the same velocity.  The velocity value affects bullet impact location and the variation in velocity (for the most part) affects group size.

The difference between observed bullet impact adjustments and measured velocities is similar (IMO) to the difference between empirical and analytical data.  Both are useful and valid, but with velocities the numbers can be compared between lots of powder or changes in bullet weight, seating depth, or powder charge.  As mentioned, having the velocity aids in duplicating factory loads or checking the bullet velocity is within a range. While one may not be able to shoot Master levels scores, the ammunition can be loaded to those levels and a chronograph helps in quality control.

Chronograph:

(Noun)  A complicated device used to determine the velocity of a projectile.  Commonly used by shooters in an attempt to load X's to be fired in a <1.00 inch custom precision pistol rather than learning how to shoot 9's and 10's.  

I'm just joking, well a little.  Chrono's can have a place in the reloaders arsenal of equipment.  But groups on the target will be the ultimate goal (both from a rest and offhand).  

Have fun.

Cecil

The purpose of a chronograph in Bullseye, to me, is to determine velocity. I do that to determine if I’m in the velocity window desired. For 45 ACP that is approximately 700 to 800 fps. The next thing to determine is accuracy on target. For that a Ransom Rest is helpful but decent comparative results can be had shooting off a rest. But results on target overrule velocity.

I could very well be wrong, as I've been wrong once or twice in my lifetime, well maybe three times total, but no more. If a load is accurate in your pistol, functions as flawlessly as possible, and the bullet clears the cardboard backer, then who cares how fast or slow it's going? If that .45 projectile will hold the 10 ring at 50 yards, does it matter if it's velocity is 700 or 800 FPS?

A chronograph may reveal what a target may not. It may reveal what a Ranson Rest will not. Don't take my word for this, test it for yourself, but many loads based on powder chosen and velocity sweet spot, do in fact have a flaw. That flaw is powder position sensitivity and it can vary velocities by 50 or more fps.

Why isn't this noticed? From a Ranson Rest, each shot has the gun pulled back to common point, then gracefully lowered to firing position. This causes the powder to position itself in the case the same way each shot. A similar act is done during slow fire. Timed and Rapid are different. Drawing from a holster is different. I first discovered this potential problem shooting on a moving target from a holster. Even with known needed lead, often the first shot would be trailing. This was quite repeatable, so I did some testing.

Next time you chrono. Before each shot, raise gun and fire through chrono never permitting the muzzle to drop below horizontal before shooting. Gather data.

Next, have muzzle down, then raise to horizontal never permitting muzzle to above horizontal before shooting. Gather data.

Next if so inclined, alternate the rasied gun fire, then the low gun fire. Gather data.

Here is what you will find.

The all raised shots will have the highest average velocity and the lowest SD.
The all lowered shots will have the lowest average velocity and the SD will not be as low.
The alternating position will have the highest extreme spread in fps and the worst SD. 

So the chrono may reveal that your great load, shot out of a Ranson Rest, or SF, if done properly is quite good. However, if the velocity drops below that sweet spot when the gun is fired a different way, then the accuracy will drop off. Temperature sensitivity can also be identified with a chrono, which is another problem.

Wonder why Clays, VV310, WST have taken lead in some of the best choices, over BE, W231 and some of the others? Check out their density figures. Since they are less dense, they fill the case a tad more, thus reducing powder position sensitivity in the case. Some have chosen the route to just shoot hotter loads to get more accurate recipes. Hotter load, often means more powder in the case. More powder reduces powder position sensitivity variable. Seating the bullet a tad deeper helps too. Wonder why 200 gr LSWC shoot well at 50 yds? More bullet, seated deeper, fills the case with bullet instead of powder, which also reduces the variable.

Dont' take my word for it try it. You will be amazed at the variation. Or maybe you don't want to know. Otherwise keep in mind next time you go out. Raise gun exactly the same for each shot without exception. If you lower the gun, raise it again before shooting. Your result will improve, especially at the long line. Of course shooting a hotter load will help to, because we tend to load at the lowest velocity of the sweet spot range, rather than going a tad above that. Or use less dense powder, which fills case more for the short line.

Wouldn't it make sense to put a filler, like little pieces of tissue, on top of powder before seating bullet.
 Stan

chopper wrote:Wouldn't it make sense to put a filler, like little pieces of tissue, on top of powder before seating bullet.
 Stan

That idea has been substantially debunked. Powder still migrates in and around the filler.
Most times some form of oatmeal was used. If done carefully you could use a wad to hold powder in position. I guarantee no High Master or National Champion in Bullseye has ever considered or bothered with it.

(Not applicable to muzzleloader or black powder shooting)

james r chapman wrote:

chopper wrote:Wouldn't it make sense to put a filler, like little pieces of tissue, on top of powder before seating bullet.
 Stan

That idea has been substantially debunked. Powder still migrates in and around the filler.
Most times some form of oatmeal was used. If done carefully you could use a wad to hold powder in position. I guarantee no High Master or National Champion in Bullseye has ever considered or bothered with it.

(Not applicable to muzzleloader or black powder shooting)

Filler is not the proper answer in my opinion. Finding the proper burn rate powder, married to the best density which fills the case to desired level is what we want. Some older loading manuals used to display the percentage of case volume their recommended load was. BTW, not full by any means! Burn consistency is what we seek. I tried Trail Boss, the least dense powder I am aware of, it was not good. It has it's place, accuracy is not it. There are plenty of fast burning, low density (bulky) powders to play with. Alliant E3 has a density of .1489, Clays .1462, Red Dot .1413, Nitro 100 .1349, VV310 .1214, WST .1205 …...BE .1063. BTW, Trail Boss is .2172.

No surprise that Clays, VV310, Red Dot and WST are so successful. Take your charge weight, multiply by the density figure and you get volume of powder in C3. All very interesting. Then do Volume of cylinder calculation (Pi R squared) of your brass, using the height from bottom of inside case to bottom of bullet base. Subtract powder by volume from your case calculations and you'll find the percentage of available case volume you are filling. You will find that your pet load, likely fills a greater portion of the case than other loads which did not work as well. I am told Tight Group is one of the least powder position sensitive of the powders using lighter loads. I have done no testing with TG.

Powder position matters. The velocity range can be 40-60 fps variation in an otherwise 9-17 fps variation loads. BTW, you will see even greater velocity variation when using light loads in .38 spl, with exception of WC which by nature of seating, the case volume is used up. I have worked up very accurate loads in .38 Spl with 125 grain bullets using W231, WST, Clays, Alliant E3 and even WSF. All of these will yield a first shot low value of 50-70 fps from the avg of other shots when first shot is fired from holster without raising gun above horizontal. WSF can yield a low first shot value in excess of 100 fps slower than the avg of the other shots. 

Regarding the "better" shooters, they likely have a very consistent shot preparation sequence. which includes very consistent raising of the gun. They also, likely do not shoot marginal velocity loads. If they abort a shot, they likely re-engage the shot sequence with the raised gun again. These techniques, all contribute to uniform powder position in the case. On the short line, the velocity variation is likely quite insignificant, thus shot dispersion is likely insignificant, due to velocity variation.

I guarantee that I can make a chrono yield higher or lower fps avgs by simply altering how I start the shot sequence, then bring to horizontal. I have demonstrated this countless times to non-believers, with light loads. The hotter the load (less empty space in the case) the less of a problem it reveals. The volume in the case is filled by volume, not by weight. We weigh to be able to duplicate that found amount of volume which works for our load. Like I said, had it not been for first shots on a moving target from a holstered gun yielding consistent trailing shots, this would have never crossed my mind. "Position matters".

Allgoodhit wrote:......There are plenty of fast burning, low density (bulky) powders to play with. Alliant E3 has a density of .1489, Clays .1462, Red Dot .1413, Nitro 100 .1349, VV310 .1214, WST .1205 …...BE .1063. .........BTW, Trail Boss is .2172.No surprise that Clays, VV310, Red Dot and WST are so successful. Take your charge weight, multiply by the density figure and you get volume of powder in C3.....

In another forum, people were suggesting that a "bulkier" powder would be good for safety reasons - with Bullseye, looking into a case during reloading, the amount of powder is so small.  In that discussion, Trail Boss was suggested, as getting a double load is pretty much impossible.

Specifically from what you wrote, if Bullseye has a density of .1063 and E3 has a density of .1489, that means there will be half again as much powder (by volume) in the case.....    or twice as much with Trail Boss.

Are all/any of these suitable for Bullseye?  Seems like they would help with the problem you're discussing.  Hopefully they would meter properly from a powder dispenser.  I sort of doubt Trail boss would though, it would be like dispensing Cheerios.


It sounds like a chronograph could be a fascinating tool to work with!

Allgoodhits, thanks for sharing your experience and insight.  It has given me a few things to think about.

just sayin'

I did the powder position shots across the chronograph with a 38 revolver.  Tip before each shot, up to settle the powder back gave significantly higher velocity that tip down to settle the powder forward.  Doing no tipping (Not talking how I eat out) just shooting a normal sustained string gave a velocity in the middle of the forward and back tipped shots.  I do not have the numbers at hand.  But the results were very significant.  I think the powder was 231.  Considered very sensitive to position as I recall.

SAFETY : From a safety standpoint perhaps the bulkier powders may be considered "safer" since double charges would either be noticed as it is visibly much higher or over filling the case. Trail Boss as a PP quality powder just did not deliver accuracy compared to other known good powders such as WST, VV310, Clays, E3, BE and probably others.

METERING: I have heard others state that they have issues with Clays, E3 and some of the flake powders. As such they indicate weight variations which they find unacceptable. I am not sure why, but I don't have those problems on my Dillion powder measures. Something to consider is that the bigger concern is volume variation, not weight variation. We only use scales to repeat settings for previously determined amounts (volume) of powder which gave the results we found to our liking. Powder measures work on volume. not weight.

In my pursuit I was trying to reduce velocity variation with first shot from low ready, without the necessity to just make the load hotter, which may handicap the shooters results due to excess noise, recoil, muzzle flip. I found by using the bulkier powders which filled the case a tad more, I could still have a light to moderate load, and reduce that position variation to a more acceptable range. Previous standout powders were W231 and HP38 and BE. Now many have started using WST, VV310, VV320 and of course some of the old standby powders like Clays, 700X, Solo 1000 have always been good. They are also bulky compared to BE and W231. It is all fascinating to me, as is temperature sensitivity of powders, which can be another huge problem, depending on the game one is shooting and how close to run/not run threshold they have their equipment set up.

Allgoodhits wrote:........I found by using the bulkier powders which filled the case a tad more, I could still have a light to moderate load, and reduce that position variation to a more acceptable range.......

If the criteria were to include only "bulky" (reloading safety), accuracy (from an RCBS or Dillon type powder hopper), and accuracy (as you have described), along with a preference, not requirement, for "cleaner", what would your top two suggestions include?

mikemyers wrote:

Allgoodhits wrote:........I found by using the bulkier powders which filled the case a tad more, I could still have a light to moderate load, and reduce that position variation to a more acceptable range.......

If the criteria were to include only "bulky" (reloading safety), accuracy (from an RCBS or Dillon type powder hopper), and accuracy (as you have described), along with a preference, not requirement, for "cleaner", what would your top two suggestions include?

tite group? not sure how it meters though.

Clays

Thanks for the recommendation.  I couldn't find anything negative about Clays.  I will ask in the ammunition forum for load recommendations with Magnus bullets. It's now added to my MidwayUSA shopping cart.

Maybe in several months I might be asking for recommendations on a chronograph.  I doubt I need one, but it seems to me that it would be useful as a learning tool.

For the reasons listed up above, it does sound useful as a tool.  I have the feeling that it only starts to be useful at 50 yards, and the longer the range, the more useful it gets.  At 25 yards, based on what I was reading, it's not going to make much of a difference.  Maybe if I was more into load development, but for me load development has meant shooting Unique for 25 or so years, until I got the advice here to switch to Bullseye.  I go by the recommended load posted here, and never vary it.

Dies, and expander plugs matter since they affect bullet pull force. I switch between standard dies for jacketed loads, Hornady 454 Casull dies for hard lead and a Lee factory crimp converted to a resize-decap die for swaged like Star or Zero lead.  Same thing for exp plugs. Therefore, a chronograph can be handy to verify the effect.  Thanks for the info on powder position! Also handy to check factory loads or stuff from others that worked well for you. Std deviation is nice but not a true indication of precision. I use a Pact model 1 without the sky screens. Works even for shotgun provided that the sun isn't directly on the sensors. If so, l tip it at an angle. Also won't work under flourescent lights. Best regards

I wonder if those powder position observations are why my shots are often off-call in SF when I fire 2 shots in succession without lowering the gun (during winds, get the shots in during lulls). I am not raising the gun up from the bench and lowering it into the target in the exact way I do for every other SF shot, but recovering from recoil and taking the shot like sustained. That would explain why these shots often seem to be a couple inches off where I call them...

FWIW, I've had conversations with bullseye pistol shooters who describe using a 'filler' over Alliant Bullseye powder when reloading the .45.  I've never tried that, but they weren't kidding about the filler.  The purpose behind the filler is to keep the powder in place, regardless of round position or recoil effects.

I don't think a chrono is a need to have tool, but they are revealing and interesting at the same time. PP/BE is forgiving in that shooting takes place only at two distances, and all shootings commences from at least horizontal, and much of it commences after an elevated gun. This helps to distribute the powder in the case fairly consistently. Use one of the "classic" known good loads is likely fine. We need not reinvent a wheel. However sometimes an otherwise mysterious condition, can be explained through internal ballistics.

In action shooting which is most often commenced from holster, and since time is critical then one does "not" want to raise the gun any higher than the target, because why pass the target on the way up, only to have to come back down to it? This would be considered using unnecessary time. Often action pistol is done with a little hotter loads so the case is fill a bit more. As stated at the onset, the huge problem surfaced shooting moderate loads in .38 Spl with 125 gr bullets. The condition exists with 9mm, .38 Super & .45 ACP with fast powders/light loads. In this scenario fast burning powders work best for accuracy, but they leave a great deal of empty space in the case. That first shot from holster created the low fps first shot condition.

What to do? Don't worry about it, unless you are shooting loads so light that they are on the marginal low end of bullet stability, and low end of gun functioning. If you are already on the low end, then you can't afford an extreme spread  lower. Such a low extreme spread shot with an already low load may - Cause gun not to cycle properly, and/or produce a very low shot. In PP/BE we do have the luxury to raise the gun above horizontal, before all first shots, and in SF, for every shot.

I think the best insurance is three fold. Don't shoot marginal low powder charge loads, don't let the gun drop "below" horizontal, with out raising it again before the next shot and select one of the known good powders such as VV310, Clays, WST, E3 and a few others. If you shoot slightly hotter loads, then BE, W231 and others could be fine as well. I have not mentioned Tight Group, only because I do not have a great deal of experience with it, and have not bothered to research it's density.

Allgoodhits wrote: .........and select one of the known good powders such as VV310, Clays, WST, E3 and a few others. If you shoot slightly hotter loads, then BE, W231 and others could be fine as well.......

This discussion has been fascinating.  When I posted, I only was asking about a chronograph, but the things you guys are discussing goes way beyond that.

At the same time, anything I read on this forum is dissected and analyzed by me, and those things that apply directly to what I'm doing get more of my attention.  I'm using 2.8/2.7 grains of Bullseye over Magnus bullets for my Model 52 (recommended by Terry, and by posts in this forum), and in my mind I thought I was shooting a light load, certainly not a "hot" load.  Based on that one sentence I quoted, switching from Bullseye powder to Clays seems like a good idea.

(.....and I'm very aware that for now, I need to pay infinitely more attention to "the fundamentals" than I do to powder drift, or bullet speed, and I need dry fire and practice more than I need a chronograph....)


Sorry for any diversion.  What you guys are talking about is more important.