goodgrouper
tryingtobeabettergrouper
How many active 100-300 yard fellow benchresters own chronographs? And for those who have them, how often do you use them?
Curious........
- Thread starter goodgrouper
- Start date
jackie schmidt
New member
Goodgrouper
Here are some examples when I pull out my Ohler 35P
When I develop a new round, such as my 30PPC. Going in, (after I have chosen a bullet), I have a pretty good idea at what realistic velocity I want to achieve. I will load up untill I hit that mark. (being careful to watch for any signs of trouble). I can then tune from there for accuracy.
With the 30PPC, I knew from my experience from other chamberings that a flat 3000 fps would be the top load window. I hit that, but finally settled in on about 2940, as the 3000 was a tad hot in the load window.
Also, while testing the two powders we had, (4227 and N120), the chrono is very handy to get the same velocity from each. This is valuable since one is on the fast side, while the other is on the slow side.
With the 6PPC, any time I switch to a new lot of powder, I shoot over the Chrono to hit the same velocity as the previous lot, then compare that powders weight by volume with the previous lot, and tune from there.
A good example is now. I am switching over from my last can of 03 133 to 07 133. Using my 35 P allows me to hit my target velocity, and compare the tuning characteristics of the 07 to the 03 lot. The first thing I found was that 30.4 grns gave the same velocity, but it takes less volume of the 07, by about .6 grn. That means it is a tad denser. The Chrono allows me to find things like this, and get on to the tuning.
I consider my 35P to be a very valuable tool........jackie
Here are some examples when I pull out my Ohler 35P
When I develop a new round, such as my 30PPC. Going in, (after I have chosen a bullet), I have a pretty good idea at what realistic velocity I want to achieve. I will load up untill I hit that mark. (being careful to watch for any signs of trouble). I can then tune from there for accuracy.
With the 30PPC, I knew from my experience from other chamberings that a flat 3000 fps would be the top load window. I hit that, but finally settled in on about 2940, as the 3000 was a tad hot in the load window.
Also, while testing the two powders we had, (4227 and N120), the chrono is very handy to get the same velocity from each. This is valuable since one is on the fast side, while the other is on the slow side.
With the 6PPC, any time I switch to a new lot of powder, I shoot over the Chrono to hit the same velocity as the previous lot, then compare that powders weight by volume with the previous lot, and tune from there.
A good example is now. I am switching over from my last can of 03 133 to 07 133. Using my 35 P allows me to hit my target velocity, and compare the tuning characteristics of the 07 to the 03 lot. The first thing I found was that 30.4 grns gave the same velocity, but it takes less volume of the 07, by about .6 grn. That means it is a tad denser. The Chrono allows me to find things like this, and get on to the tuning.
I consider my 35P to be a very valuable tool........jackie
T
trgtsnpr
Guest
Chronograph
I use mine everytime i work up a new load and whenever i open a new bottle of powder with a different lot # ive found it to be very helpful.
I use mine everytime i work up a new load and whenever i open a new bottle of powder with a different lot # ive found it to be very helpful.
T
Twud
Guest
Chrono
I use mine as a hunting tool. By knowing your velocity you can calculate the rounds' ballistic curve with ballistic software. It will also surprise you by measuring how far off the load is from the manuals.
It's also fun to know how fast your pushing them.
I use mine as a hunting tool. By knowing your velocity you can calculate the rounds' ballistic curve with ballistic software. It will also surprise you by measuring how far off the load is from the manuals.
It's also fun to know how fast your pushing them.
JerrySharrett
Senile Member
I have an Ohler Model 35. I probably use it at least each week. I am always using different powders and different bullets. Each load combination, I write down the data and accuracy results in a log book for that barrel.
I shoot 100/200 group and IBS 600 yard. Since there are not many 600 yard ranges in this area, I chrono a load that I have zeroed at 100 yards. Then I use QuickTARGET to calculate the click for a 600 yard zero. I am always on the paper at 600 and usually within 6" of zero from the QuickTARGET calculations.
I also shoot 2 different wildcat cartridges which are variants of the 6PPC. I have found there is no relationship to a particular velocity and its accuracy from one chambering to another. I have not shot a 6PPC in competition since about 2001 but I have 1:14 and 1:13.5 barrels chambered for the 6PPC. In no instance have I found a super accurate load in the 6PPC to be the same velocity as a super accurate load in my wildcats even though they are all within about 2.5 grains of the same case capacity.
Strangely, I have not found a relationship between extreme spread/standard deviation and accuracy in the 100/200 game.
What I am trying to explain is that a chronograph is very valuable to the experimenter but it is not a Gold Nugget to finding an accurate load considering the difference in bullet sources and difference in powders and powder lots, but it does have great utility in the accuracy game.
I shoot 100/200 group and IBS 600 yard. Since there are not many 600 yard ranges in this area, I chrono a load that I have zeroed at 100 yards. Then I use QuickTARGET to calculate the click for a 600 yard zero. I am always on the paper at 600 and usually within 6" of zero from the QuickTARGET calculations.
I also shoot 2 different wildcat cartridges which are variants of the 6PPC. I have found there is no relationship to a particular velocity and its accuracy from one chambering to another. I have not shot a 6PPC in competition since about 2001 but I have 1:14 and 1:13.5 barrels chambered for the 6PPC. In no instance have I found a super accurate load in the 6PPC to be the same velocity as a super accurate load in my wildcats even though they are all within about 2.5 grains of the same case capacity.
Strangely, I have not found a relationship between extreme spread/standard deviation and accuracy in the 100/200 game.
What I am trying to explain is that a chronograph is very valuable to the experimenter but it is not a Gold Nugget to finding an accurate load considering the difference in bullet sources and difference in powders and powder lots, but it does have great utility in the accuracy game.
C
caroby
Guest
SD usefulness
Strangely, I have not found a relationship between extreme spread/standard deviation and accuracy in the 100/200 game.
Yes, I too Jerry........
Matter of fact, 10-20 Deviation seems to be a """sweet""" range...?
Weird but true. Wind reading skills and SOLID bench technique is "where it's at"!
Some say that if you really jump your bullets (> .025) the SD will be tiny...
One the other hand, I have found suspect cases with outta place SD readings, typically a consistent 10+ FPS variable compaired to the rest.
cale
Strangely, I have not found a relationship between extreme spread/standard deviation and accuracy in the 100/200 game.
Yes, I too Jerry........
Matter of fact, 10-20 Deviation seems to be a """sweet""" range...?
Weird but true. Wind reading skills and SOLID bench technique is "where it's at"!
Some say that if you really jump your bullets (> .025) the SD will be tiny...
One the other hand, I have found suspect cases with outta place SD readings, typically a consistent 10+ FPS variable compaired to the rest.
cale
Dick Grosbier
Club Coordinator
I own an Oehler 35P and I use it less than once a year.
Jim Erickson
Member
I'm currently using a CED Chronograph...
after having two Oehler's and a ProTAc. The CED uses the same sensors as the Oehler and is an accurate, compact unit that is quick and easy to set up.
I use mine three-four times a year at diffent ranges, usually Phoenix (1700'), Springville (5000') and Raton (6700'). Using the same rifle, barrel and weighed load combination, you'd be surprised at the differences in velocity obtained. Also, The tune windows are always different...and Phoenix is always squirrelly!
Jim
after having two Oehler's and a ProTAc. The CED uses the same sensors as the Oehler and is an accurate, compact unit that is quick and easy to set up.
I use mine three-four times a year at diffent ranges, usually Phoenix (1700'), Springville (5000') and Raton (6700'). Using the same rifle, barrel and weighed load combination, you'd be surprised at the differences in velocity obtained. Also, The tune windows are always different...and Phoenix is always squirrelly!
Jim
goodgrouper
tryingtobeabettergrouper
Thanks for the replies thus far guys. Keep 'em coming.
Here's my take on it for anyone who gives a hoot. I own an Oehler 35 and use it constantly. But it is generally employed in the task of working up long range loads for hunting rifles, bench rifles, and ultra long range varmint rifles. I can't imagine doing any of that without the chrono. In fact, I've spent so much time learing how to do load development with a chrono and learning how to "read" the data, that I felt lost when I started into this short range benchrest shooting. You see, when I first started, I was told by many, many great shooters that you leave your chrono at home and tune your gun by group shape and size alone. While this may work for some guys that have decades of br experience under their belt, it certainly didn't work for me. Lord knows I tried, but without knowing the direct result of tinkering with components, how does one even know what he is affecting by changing any one thing?
So I decided to approach the 6ppc just like any other cartridge (which I still believe it is) and I tried to find the node windows indicated by group size as well as combustion efficiency. I think a lot of guys have this superstition they apply to the 6ppc like it some kind of mythical, holy entity that operates in another dimension or something. Well, it is certainly an efficient and accurate round, but it uses the same four components as any other round. Therefore, it has mappable and predictable characteristics too. But, for me, I think you need (or at least it helps) to chronograph the round to determine what is happening.
So whenever I get a new barrel, a new lot of powder, or want to experiment, the Oehler is being used. And I don't just try to find a certain velocity that worked in another barrel or something like that. I map out what each barrel wants and try to record what that is throughout different temperature swings and at different elevations and humidities. Because each barrel is so different, just loading up a charge that gives 3400 fps and expecting it to work in every barrel exactly the same is going to be disappointing.
What I'm looking for is the group size combined with standard deviation readings. Now, I know there are lots of articles on this and a lot of them reported that not always the smallest group had the lowest SD's. In fact, I seem to remember an experiment that Allie Euber did where he actually found a load that had zero deviation from shot to shot and it would only produce high .2" groups. But the loads that shot the smallest groups still had decent SD's. By decent, I mean in the teens or low 20's. But in my testing, perhaps I've been lucky. My smallest groups have usually had the smallest or second smallest SD's of the string. It could be a coincidence, but I doubt it.
Now I know we can get the SD down to single digits and if the barrel doesn't like the bullet or something just isn't jiving, we can still get horrible groups. But that is looking at two seperate things and trying to make them one. The low SD simply means that the combustion is at an efficient peak and that is the best it will get. Then if all other things are in harmony, the group will be small in size. It is a cooperation of the factors in the equation that give us the right sum.
So, with all that being said, then why do some loads that have SD's in the teens or twenties shoot better at 100 and 200 yards then the loads that shoot in the single digit SD's? In my testing, what I believe I have found is that those loads might shoot better that day (or even just that hour in some instances) but they don't hold up as long as the really low SD loads do. Or in other words, the low SD's are more forgiving of outside parameter changes. This could explain why sometimes we can drill zeros in the warm up match but then 25 minutes later, the same load can't hit the broadside of a proverbial barn. Or we can drill em on Saturday, but then Sunday cools off 5 more degrees and we are all scrambling to find out what's going on.
Unfortunately, setting up a chrono during a match to check all this is impractical. But, what's to stop us from setting one up on practice day? Or maybe we don't even need to set one up at all if we have already mapped out and recorded what we need to do for that temperature and humidity at that particular range.
I have been lucky enough thus far to have been able to chronograph and verify my loads a day or two before every match I have attended this past year and I know it has helped me. I have a good idea what I will have to do with my powder charge for the weekend just by watching the weather forecast and monitoring it as it goes. On Friday, I know I can just simply try 5 or 6 shots of a load or maybe two loads, see what one is working, and then enjoy the rest of the day instead of scrambling around burning up powder and depositing a box of bullets into the dirt before the match even begins. That reason alone would be worth it to me if the only price was the slight inconvenience of setting up a chrono.
Just my thoughts and experiences on the matter. They could be nothing but horrible hallucinations!
Here's my take on it for anyone who gives a hoot. I own an Oehler 35 and use it constantly. But it is generally employed in the task of working up long range loads for hunting rifles, bench rifles, and ultra long range varmint rifles. I can't imagine doing any of that without the chrono. In fact, I've spent so much time learing how to do load development with a chrono and learning how to "read" the data, that I felt lost when I started into this short range benchrest shooting. You see, when I first started, I was told by many, many great shooters that you leave your chrono at home and tune your gun by group shape and size alone. While this may work for some guys that have decades of br experience under their belt, it certainly didn't work for me. Lord knows I tried, but without knowing the direct result of tinkering with components, how does one even know what he is affecting by changing any one thing?
So I decided to approach the 6ppc just like any other cartridge (which I still believe it is) and I tried to find the node windows indicated by group size as well as combustion efficiency. I think a lot of guys have this superstition they apply to the 6ppc like it some kind of mythical, holy entity that operates in another dimension or something. Well, it is certainly an efficient and accurate round, but it uses the same four components as any other round. Therefore, it has mappable and predictable characteristics too. But, for me, I think you need (or at least it helps) to chronograph the round to determine what is happening.
So whenever I get a new barrel, a new lot of powder, or want to experiment, the Oehler is being used. And I don't just try to find a certain velocity that worked in another barrel or something like that. I map out what each barrel wants and try to record what that is throughout different temperature swings and at different elevations and humidities. Because each barrel is so different, just loading up a charge that gives 3400 fps and expecting it to work in every barrel exactly the same is going to be disappointing.
What I'm looking for is the group size combined with standard deviation readings. Now, I know there are lots of articles on this and a lot of them reported that not always the smallest group had the lowest SD's. In fact, I seem to remember an experiment that Allie Euber did where he actually found a load that had zero deviation from shot to shot and it would only produce high .2" groups. But the loads that shot the smallest groups still had decent SD's. By decent, I mean in the teens or low 20's. But in my testing, perhaps I've been lucky. My smallest groups have usually had the smallest or second smallest SD's of the string. It could be a coincidence, but I doubt it.
Now I know we can get the SD down to single digits and if the barrel doesn't like the bullet or something just isn't jiving, we can still get horrible groups. But that is looking at two seperate things and trying to make them one. The low SD simply means that the combustion is at an efficient peak and that is the best it will get. Then if all other things are in harmony, the group will be small in size. It is a cooperation of the factors in the equation that give us the right sum.
So, with all that being said, then why do some loads that have SD's in the teens or twenties shoot better at 100 and 200 yards then the loads that shoot in the single digit SD's? In my testing, what I believe I have found is that those loads might shoot better that day (or even just that hour in some instances) but they don't hold up as long as the really low SD loads do. Or in other words, the low SD's are more forgiving of outside parameter changes. This could explain why sometimes we can drill zeros in the warm up match but then 25 minutes later, the same load can't hit the broadside of a proverbial barn. Or we can drill em on Saturday, but then Sunday cools off 5 more degrees and we are all scrambling to find out what's going on.
Unfortunately, setting up a chrono during a match to check all this is impractical. But, what's to stop us from setting one up on practice day? Or maybe we don't even need to set one up at all if we have already mapped out and recorded what we need to do for that temperature and humidity at that particular range.
I have been lucky enough thus far to have been able to chronograph and verify my loads a day or two before every match I have attended this past year and I know it has helped me. I have a good idea what I will have to do with my powder charge for the weekend just by watching the weather forecast and monitoring it as it goes. On Friday, I know I can just simply try 5 or 6 shots of a load or maybe two loads, see what one is working, and then enjoy the rest of the day instead of scrambling around burning up powder and depositing a box of bullets into the dirt before the match even begins. That reason alone would be worth it to me if the only price was the slight inconvenience of setting up a chrono.
Just my thoughts and experiences on the matter. They could be nothing but horrible hallucinations!
Last edited:
goodgrouper
tryingtobeabettergrouper
Thanks Jim. I remember the day you set yours up at Hobble Creek. I was very impressed with the CED. And I really liked the readout screen and it's functions.
goodgrouper
tryingtobeabettergrouper
back to top
Butch Lambert
Active member
I have a 35P and got it out the first time this year since 9 years ago.
Butch
Butch
M
mike in co
Guest
i have a 35p....use it all the time, lots of guns, lots of load development.
mike in co
mike in co
Dusty Stevens
Hollow Point Dispenser
so if a load turns out to be a tad slower and have more deviation but shoots good would you chrono boys not shoot it? I see a need for it for hunting rifles and bows but for benchrest?... I'd rather shoot a group
I have a chronograph and have used it forever,for all the same reasons you guys have already pointed out. But when it comes to the PPC and match tuning I do not like shooting over or through anything ! Sky screens,Holes in a concrete wall designed to save the non shooting public from my errant shots( yeah right),Trap houses,100yd berms,another shooters junk piled up in front of the bench because he's too lazy to put it behind the firing line. Truth is I don't even like shooting over a line of rotating, wind deflecting cheap plastic daisy wheels on windflags. I like the information they give me but feel that they and surveyors ribbon whipping straight up in front of the target play a role in causing the very inacuracy that we are trying to prevent.Give me a solid bench,a nice level mowed lawn( Canastota),no shock wave deflecting awnings hanging over the bench,plenty of elbow room and a staggered left flag set up and I'm a happy shooter.
Joel
Joel
B
Boss Hoss 540
Guest
I get the 35p out about 5 or 6 times a year but that is over a weekend at the ranch usually so it really means more than that.