Chronograph Technique Tactics Procedures

[RedHawk357Mag]

Tried searching for the info on how to make use of this little critter called a Chronograph, and it has remained elusive. I get the jist of setting it up and what it does but not quite certain what I am looking for exactly. For instance I have decided to develop a 357 Mag load for two of my revolvers. The bullet is each Match and Magnum Missouri 158 gr LSWCBB. New Winchester brass. Powder is TiteGroup. Pwdr wt is 3.8, 4.0, 4.3, 4.5, 4.8, 5.0, 5.3, 5.5, 5.8, 6.0. I will switch to the Magnum bullet with the 4.8-6.0 gr wt loads. Planning on making 10 rnds per pwdr charge. Will check for pressure signs on all cartridges as well as look for leading in the gun. The test gun will be a Ruger RedHawk 357 Mag with reamed cylinder throats. Provided this will be successful I will rinse lather and repeat for the other revolver, a S&W 686-4. I plan on measuring CTC groups for each load. But what is mystifying me is this Chronograph data. SD ES and whatever other little abbreviations this wonder box can spit out or I can get MS Excel to tally for me. So what data do I use to develop "the load" for this RedHawk? And yes I did find the post where one person wrote "it is not uncommon for normally happy reloaders to develop ulcers shortly after purchasing a Chronograph" Thanks any insight offered

 

[MCMXI]

But what is mystifying me is this Chronograph data. SD ES and whatever other little abbreviations this wonder box can spit out or I can get MS Excel to tally for me. So what data do I use to develop "the load" for this RedHawk?

You can enter all of your velocities into Excel and use that program to generate as much information as you need ... that's what I do. Generally, chronographs process the measured velocities to give the following:

HI = High > highest velocity
LO = Low > lowest velocity
ES = Extreme spread > difference between fastest and slowest velocity
AVG = Average > average velocity
SD = Standard deviation > how much your velocities deviate from the average

Ideally, you want the ES and SD values to be as low as possible but the average depends on what you want out of the load. Some folks load to achieve a specific average velocity, most likely because they're after a specific bullet energy range for hunting or some other application. Others load for accuracy and just want to know what the average velocity of the most accurate load is. Some are after a combination of both. For handgun loads, I would think that most folks are after consistency so ES and SD are more important to them than average velocity assuming that the AVG is acceptable. Chronographing rifle loads is a little more involved in terms of the objectives and variables.

As for your loads, what are YOUR objectives? Are you trying to find the most accurate load, fine tune your loads for consistency, achieve a certain velocity without leading, are you concerned about recoil, excessive pressure, are your loads within published "safe" ranges? Hodgdon lists a load range of 4.5 to 5.0 grains of Tightgroup for the 158gr LSWC with a maximum velocity of 1108 fps at 24,900 CUP so your starting load seems to be on the low side at 3.8 grains particularly since you have a Redhawk. The SAAMI maximum pressure rating for the .357 Magnum is 35,000 psi which is about 34,895 CUP if you use the conversion formula here but the Speer #11 manual lists the SAAMI working pressure as 46,000 CUP. All of the loads in Lyman's 49th edition are under 45,000 CUP with the majority being under 42,000 CUP.

Basically, if you load within published limits, chronograph data can help you improve your loading techniques, loads, and/or components to reduce ES and SD values. This can become an obsession all by itself which can bring both pleasure and pain. If you're pushing the envelope and developing loads outside published limits, a chronograph can help to give you some idea as to how far over the line you are.

 

[RedHawk357Mag]

Sir I appreciate your informative reply. That is exactly the info that I was seeking. The 3.8 gr start load you mentioned is the start load the LaserCast Co sent me when I requested load data from them for 357 and 44 mag bullets. It is also the published max for 38 Special in the 2009 Hodgdon's Annual Reloading Manual. What I am seeking are the best conceivable loads for two calibers, 357 Mag and 44 Mag. I have several choices of powders and clearly realize that no one powder is going to get it for me. I am wondering if there is one that will come close, and what I must give up to have "close". Since I am a middle range guy I am looking at powders on the lower side of power i.e. TiteGroup and Universal. So the plan is to work through the ranges of loads for these two calibers to find a load that works the best. Best meaning anything that could be considered a plus. Accuracy is the top of the list as well longevity of the life of the gun, almost would have to say these two things are probably equal in my book. If those two items get meet everything else can be worked on. Again I really appreciate the excellent answer you have provided have a great day.

 

[41 Mag]

As 1858, so put into detail, my main uses are looking for velocities which are somewhere in the ball park with published data, or when working up loads to closely duplicate factory ballistics.

Your need, at present, will revolve more around keeping the velocity in the ballpark of the cast bullet range which reduces possibilities of leading. I can however say, that I have not seen much if any leading from the Oregon Trail offerings. I note your using others but should they not work to your satisfaction the OT are ones to keep in mind.

Have fun, the chrono will help give you much more control over your loads, but as mentioned can result in a bit more head banging in the process.

One other powder you ight try if the selected ones don't work out for you is Win.- 231. It has a good record of many accurate cast bullet loads.

 

[Walkalong]

"it is not uncommon for normally happy reloaders to develop ulcers shortly after purchasing a Chronograph"

I am quite sure of that..... It will tell you the truth, and not what some manual says or what you guessed it to be.

Nice low ES & SD numbers are good to try for, and critical for really longe range stuff, but for handguns at 100 yards and in, reasonable numbers are just fine as long as it is accurate.

This can become an obsession all by itself which can bring both pleasure and pain.

One other powder you ight try if the selected ones don't work out for you is Win.- 231. It has a good record of many accurate cast bullet loads.

Agreed

 

[MCMXI]

What I am seeking are the best conceivable loads for two calibers

... to find a load that works the best. Best meaning anything that could be considered a plus. Accuracy is the top of the list as well longevity of the life of the gun, almost would have to say these two things are probably equal in my book

Longevity won't be an issue for the Redhawk and given that you are a "middle range guy" it shouldn't be an issue for the 686 either. So basically you're after the most accurate load for each that is in the middle of the velocity range. It's good that you have a specific objective and you may even find that you want to increase the velocities a little as you chase the most accurate load since ES and SD often decrease with an increase in the charge. At some point you'll start to give up accuracy due to recoil so this is the "breaking point" for you.

I would second the choice of W231 and add H110 to the list ... particularly for magnum loads. Also, I've found that magnum primers (from CCI for example) result in an average velocity increase of about 100 fps compared to WLP primers which claim to be for standard and magnum loads.

my main uses are looking for velocities which are somewhere in the ball park with published data, or when working up loads to closely duplicate factory ballistics.

Excellent point about duplicating factory loads. Without a chronograph you'd just be guessing. I also agree with the comment about Oregon Trail bullets. I shoot their Laser-Cast bullets in 250gr and 300gr out of a Redhawk and Marlin and I don't have any leading issues at 1500 fps with H110.

Nice low ES & SD numbers are good to try for, and critical for really longe range stuff, but for handguns at 100 yards and in, reasonable numbers are just fine as long as it is accurate.

I would agree with Walkalong to an extent. I shoot pistol loads at 25 yards but some of my loads (the .45 Colt for example) get shot out of a 4" Redhawk (at 25 yards) and a 20" Marlin (100 to 150 yards). I've noticed that the ES and SD numbers are a lot lower for the same load fired out of the Marlin compared to the Redhawk. This may be due to the difficulty in shooting the bullet over the same spot on the chronograph firing the Redhawk offhand (more error) or it could be due to the time of the bullet in the barrel and the subsequent pressure vs time plot. Either way, a reduction in ES and SD out of the Ruger will improve accuracy out of the Marlin, but as Walkalong says, as long as the numbers are reasonable then that's good enough. It's up to you to decide what's reasonable.

 

[RedHawk357Mag]

Thanks for the heads up about the 231 I bought a lb of it as well as it's twin HP38 a week or so ago when I was driving through Duncan OK. Going to figure out the ins and outs of this TiteGroup and Universal first. Appreciate the info about the primers as well.
On leading...I had much more issues with leading loading powder puff 44 Mags with Unique and LaserCasts than loading a warmer load with the same powder and bullet. Now to be fair it was neither powder or bullet issues as much as some really tight throats on that S&W DX Classic had. Sent the cylinder off to cylindersmith and the problem never showed itself again. granted I don't recall exactly what my load was that bathed the bore in liquid lead.
When the chronograph arrives and weather clears a bit going to hang a definition on the word "Reasonable" Appreciate the help all.

 

[Walkalong]

I've noticed that the ES and SD numbers are a lot lower for the same load fired out of the Marlin compared to the Redhawk.

Better burn in the long barrel is my guess.

I shoot at 100 yards quite a bit with pistols. If your ES is pretty large it gets difficult to make hits because the drop is erratic.

I was shooting clay pigeons with my Trailside at 100 yards the other day. The drop on the Fed bulk ammo wasn't too erratic, but not great. The Trailside has a different Red Dot on it now.

 

[MCMXI]

Better burn in the long barrel is my guess.

Walkalong, I think you're probably right on that one. Cool pistol by the way ... I had to Google it since I've never heard of the Trailside.


RedHawk357Mag, one tip for you for when you get a chronograph. It really needs to be level when you're using it. I found this out the hard way a couple of weeks ago. In my ignorance and stupidity, I thought the chronograph had to be level so that both sensors are parallel to the path of the bullet but it hadn't occurred to me that it's also so that the skinny sun shades are directly over the sensors. I was getting erratic data during my last session with a bunch of Err1 and Err2 messages. I had leveled it side to side but not front to back. Once I properly leveled the chronograph I had no problems.

 

[Walkalong]

Cool pistol by the way ...

They can be found reasonable. If you like shooting .22's, you won't regret picking one up.