Chronographs

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  • Last Post 02 May 2010
JSH posted this 30 April 2010

Many of you guys use them?

I have had one for 20 years and don't use it near as much as I use too. This was when I was still chasing things with FLGC projectiles,

I quit using it near as much when I went to cast. I found if I crossed a few of the load books with CB loads and went in the direction of their “accuracy load” I was very happy and went on my way.

The last project I used it a lot on was a 357 mag load. Looking for excllent accuracy. The harder I pushed it the more it came around. I ended up with a 180 running at 1560 fps. I did get it to 1640, but things went down hill. Groups and numbers.

I spent a fair amount of time tinkering with this one summer. I had all of it on paper and it got wet, so I transfered it to my old computor, which crashed in an electric storm 3 years ago, lost it all.

So what all do you guys keep an eye on for an accuracy load. Just curious so as to maybe enlighten me.

jeff

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Duane Mellenbruch posted this 30 April 2010

I am primarily a handgun shooter, and may fall into a classification of “serious plinker".  I do not compete, although I have shot the NRA Hunters Pistol course.  I enjoy shooting the cast bullets rather than spending the money on Jacketed bullets.  I have a fair number of molds for many calibers of rifle and handgun.  I do not own and have never used a chronograph.  I do not feel particularly hampered by that fact either. 

I do not play with unusual powders or extremely heavy or light bullets so I pretty much stay with published data and am comfortable with that.  I have been enjoying this hobby since the 70's and only 5 or so years ago decided I could use a thermometer.  That is because I am now playing with antimony and blending it with lead as a home caster may need to do in the future as the supply of good WW dwindles to nothing.

Since I have no large bears or cougers in my back yard, I do not need to develop maximum charges for those handguns.  A bullet weight and velocity sufficient to nick a golf ball at 25 yards is about all I really need. 

When developing a load for a new gun or bullet, I will usually start near the bottom of the velocity chart and work up until I find an accuracy load as mentioned above.  I have also gone a little below the starting load if the bullet groupings suggest that might be worth while.  I let the gun tell me what it wants, I do not try to beat it into submission.  That just is not fun and if it is not fun, I really do not want to be involved in that project.  Perhaps my approach is too relaxed for some and they would prefer to test and ducument each and every primer, powder, seating depth, and alloy hardness.  I think that the Chrono might help to document those details, but do not think that it would actually show where the most accurate load is.  It would only show consistant velocity.  And it might be that the most consistant velocity is at the high end, where the alloy has failed and the groups are now a pattern.  

I would not turn down the opportunity to run a few of my loads across the screens, but I certainly would not weep and wail if the “numbers were not favorable to an accurate load". 

I think that it has already been noted that the jacketed bullets might benefit from the use of a chrono, but there are sufficient other variables with cast bullets that might be of more importance than just a consistant velocity.  Just an openion and certainly not intended to offend those that feel a Chrono is the very best investment they have ever made.  I spent my money on a lead hardness tester instead.  I can use that every day and set up time is seconds not minutes.    Duane Mellenbruch  Topeka, KS

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Ranch Dog posted this 30 April 2010

I'm a hunter, no plinking or any other endeavor, taking at least 25 to 35 big game animals a year. My interest is with max loads so a chrony is very important when settling in on a given load for any rifle. As I back off of a max load to improve accuracy, I might be better off shooting a near max load with another powder. FPS is very important to me.

I have an old F1 and a CED Millennium. Actual bullet BC is very important to me as well. That F1 spends a lot of time sitting in front of a target at 100 and 200 yards!

A product that has helped me sift through a lot of data to select a load to my liking is Tom Myer's (a cast bullet guy) http://www.tmtpages.com/>Precision Ballistics & Records software. It has the best http://www.tmtpages.com/analysis.htm>target analysis functions of any software I've used and I've used most of them!

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corerf posted this 30 April 2010

Velocity consistency, from shot to shot. That and max velocity at tightest group. But the groups for me are always tight (that is a relative statement) if the ES is low. Under 10fps, under 5 fps if I can do it is the target mark. With 5-10 fps ES in velocity, it's one hole in my pistols at 50 yds... and not one big hole. I feel I would be lost without the chrono as I can go back on the target and place most shots according to velocity, predicting where impact point WAS even if I didn't see it.

But the chrono only gets used at develpment, once it's accurate and I am happy, battery comes out and it goes to sleep.

I keep a hardbacked really old vintage notebook with each shot recorded. I don't trust PC's, and I build them for a living.

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gunarea posted this 30 April 2010

Well heck

   My particular situation puts me on the wire. While I am a killer of game animals, and other animals, hunting isn't what I do at all. Being in a wonderful piece of Florida, the opportunity to “harvest” something which comes within range happens often enough to satisfy my cravings. My wife is not so keen on some of the stuff I bring to the table. 

    I always use my old Saeco hardness tester as part of my normal smelting process.

   A NEF in 30-30 is good to 120 yds, which figures to just across the pond out the bedroom door. That load was worked up strictly for accuracy fifteen years ago, no chronograph. The Remington Kodiak chambered in 30-06 will get us a deer pretty much when wanted, again, no chrono will tell you when the firearm likes the cartridge. 

   IPSC loads all saw the Pact II, making major power factor at the lowest velocity. A much cheaper, Chrony was bought to test velocities further out when working on Hi-power 50 BMG rounds. Hunter pistol cartridges are checked for extreme spread and standard deviation. Plinking stuff is generally just something laying around.

   Lawnsteel has velocity limits that can, will and do put folks out of tournaments, matches and State games. I can take being bested by a good shooter, but I sure have a tuff time being beaten by stupidity.  Old Bullseye loads were used to start with. My Lawnsteel loads will be velocity compliant with a wide margin of respect. Tomorrow I will compete in Sunshine State games and I can guarantee my cartridges will pass the certification chrono tests. The velocity limit in large caliber is 850 fps. Tuesday I ran a 21 shot string over my Pact II and got an average velocity of 807 fps and SD of 4.2 fps. Now I guess it's up to me.

   Bottom line; All the tools have a use and a place where it is needed. We just have to be smart enough to figure out when and where. Myself personally, I'm still figuring. Gee, that was long winded opinion.

                                                                                                          Roy

Shoot often, Shoot well

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hunterspistol posted this 30 April 2010

     I have an F-1 that I bought on sale. The use that I have for it is too 'tone' down loads for use on ranges that limit target damage.  If you shoot Hunter's Pistol, you find that some range officials want loads to be shot softly at their targets, even though there are more accurate loads.

    Load development, I do in 1/10th grain increments until I get the best at 100 meters. Then I can load them back down to an acceptable level.

     Accuracy loads I keep track of by pinning the cutdown target to the wall.

Ron

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JSH posted this 02 May 2010

Interesting comments. I find topis of this sort interesting. Replies are from one end of the spectrum to the other. I need a good scolding as I have yet to use CB's for hunting anything bigger than tree rats. Used a marlin 357 with the little 120 truncated nose. Honestly I just have to much jacketed ammo loaded for specfic guns. However I have good intentions of solving that with the 45-70 SMLE Gibbs I ran across this winter. Not much done yet, but all of the loads I have tried thus far are promising on paper. I shoot 95% of all my CB's shooting IHMSA targets. Not all are with hanguns, some are with rifles using CB's, but still the steel critters. I wish I had started shooting iron sights before my eyes caused me fits. I really enjoy shooting field pistol. As to my speeds. I have run from top end to sub sonic, with less luck accuracy wise shooting the subs at distances beyond 100m. My favorite case to work with is the 30-20, 308 bore rather than .312. I have ran 85 grainers to 210, all with good accuracy at certain speeds and powder charges. The heavy for caliber CB's (180-210) caused me more problems than the 140-170's out to 200M. Even when the numbers were right. Yes I shoot a fair bit of surplus powder. That is one reason for the chrono for me. With a bit of work I have found it to follow one commercial powder or another, to a point.

You CB BR rifle shooters don't think that this is just a psitol thread. Jeff

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offhand35 posted this 02 May 2010

I have a Chrony F-1, and use it for everything from clocking 16ga 2.5” shot loads to 12ga slug to 22lr to handgun to 405Win, and recently for 338 Federal. I can't picture myself doing handloading and shooting cast bullets and slugs without it! Working up ballistics is 1/3 the fun for me!

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AzShooter posted this 02 May 2010

I shoot USPSA and ICORE matches which both have requirements for minimum and maximum loads.

I use the Chrono to develope the speed I need for each application and then play with .1 grain incriments to get the best accuracy.

I'm shooting iron sights on a S& W Model 29 8 38 inch barrel for Major calibre and need 670 fps with a 245 grain bullet. Easy to come by with my .44 Russian loads. For minor I chron to get a 200 grain bullet just over 600 fps.

In my S&W 586 I shoot .38 short Colt. I'm a gaimer. I use 160 grain molly bullets or my Lee 158 grains that I cast and need about 795 fps.

I'm always making sure the loads make the power factor I need and then the accuracy. Not asking for much, just groups off the bench that measure 1 to 1 1/2 inches.

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AzShooter posted this 02 May 2010

Delete double post

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cityboy posted this 02 May 2010

I have a Oehler model 35 and have used it a lot since I bought it in the late 80's.

Since only reduced loads are used, I like to check velocity data. If there  are large variations, it is likely that the pressure is not high enough to promote uniform burning or the load is position-sensitive.

Jim

 

 

 

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