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Cronograph's ??

 
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  #29  
Old 03-17-2013, 09:54 AM
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Re: Cronograph's ??

Quote:
Originally Posted by phorwath View Post
Ouch. Oweeee.

Poor FEENIX. Poor, poor soul. More than three hours of stewing and brewing, and that's your best shot?
Been 10 hours since your last Post so here, let me hep ya along; go ahead and type "Did not." Then I type "Did so."


Are you the "post watch-er"?

Sorry it took me that long, my friend and I helped a rancher friend thin down the gophers! After a quick break when I got home, I took my dog for a hike then to the dog park for some quality time with my 4-legged buddy.

Yes, I am poor but not my soul ... I am not the one that belittle people if it does not meet your self imposed standard.
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  #30  
Old 03-17-2013, 10:54 AM
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Re: Cronograph's ??

Original Poster
Quote:
I dont want to spend a lot of $$ ..............What is your experiance with Cronograph's .....are they accurate and consistent, what problems have you had.
It would be nice to know what my exact velocity is.....................

Thanks
Quote:
Originally Posted by Engineering101 View Post
There are 3 chronos I would consider owning. Ohler 35, CED Millenium II and CE ProChrono Digital – the best value by far being the last one though the IR sky screens that are optional for the CED Millenium II are nice if you like to keep shooting as it is getting dark. I don’t like anything hanging on the gun barrel as the added weight will shift point of impact and “tune” accuracy to make it better or worse.

My best chrono trick - use a boresite laser to align it. Point your rifle at the target and insert a boresite laser. Put clear plastic targets in each sky screen that are marked with a grid. When the laser hits the grid in both screens in the same place it is aligned. Do this and it will be aligned in both the pitch and yaw axis and will read as accurate as it can. Don’t do this and it usually will be misaligned which will cause it to read low in proportion to the misalignment. Also, measure the distance from muzzle to the center of the chrono. I always put mine at 4 yards. After shooting, correct velocities back to the muzzle using bullet BC and you ballistics program.
For alignment I do almost exactly what Engineering 101 states above. I have a permanent shooting bench with a mount for the chrono that is 20 feet exactly in front of the bench set in concrete. On the stand pipe for the chrono I installed a adjustment mechanism so I can adjust up and down and side to side. I have two center marks on the plastic inserts and after the rifle is set in the bags on the bench and on target I simply look back at the rifle through the inserts and align the chrono dead nuts with the muzzle so the bullet passes through the center of the chrono perfectly. I used a laser boresite when building the mount to get it located properly but now only sight back to align.

The chrono is a CED M 2. I don't know how accurate it is but sense setting everything up I have taken the velocity numbers ran them in Exbal and put the bullet on the paper at my 800 yard target many many times. Once that is done I know the velocity is somewhat close then I can fool with the BC and velocity to prove the load.

So yeah I think a chrono is a good investment and set up properly it will do as designed. Exact velocities I doubt it but gets you in the ball game and speeds up the process.
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  #31  
Old 03-17-2013, 11:25 AM
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Re: Cronograph's ??

Quote:
Originally Posted by Greg Duerr View Post
I dont want to spend a lot of $$ ..............What is your experiance with Cronograph's .....are they accurate and consistent, what problems have you had.
It would be nice to know what my exact velocity is.....................

Thanks
You might want to monitor this thread too >>> Chronograph suggestions....
__________________

I voted for my "FREEDOM", "GUNS", and "MONEY" - keep the change - UNK.



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  #32  
Old 03-17-2013, 11:32 AM
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Re: Cronograph's ??

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Originally Posted by kcebcj View Post
Original Poster

So yeah I think a chrono is a good investment and set up properly it will do as designed. Exact velocities I doubt it but gets you in the ball game and speeds up the process.
Amen to that!
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  #33  
Old 03-17-2013, 12:02 PM
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Re: Cronograph's ??

at one time I had two steel rods that would clamp onto the chrongraph's nounting plate (light bar). Each one had a small round ball threaded onto the end. Simple and crude but it worked for aligning the chronograph. Later on I used the same method I use for bucking in a laser, and this actually took longer to do than the older method. The idea of printing out a grid setup on clear acetate (you need a laser printer) sounds like a much easier idea todo. I like for the bore center to be about 6" above the cells during travel as the bullet will climb as it travels thru the chronograph, and not down. At the range I drove gutter spikes into the ground out front of the bench. (I think I have five of them out there now on five different lanes. This makes the distance thing easier to measure as your already there. I carry to torpedo levels with me in the box, and this makes things go much quicker.

I rarely get a no read on a shot (maybe six or eight total as long as I've had the unit). My ES is more often very tight (often around seven to eight). The idea of using a laser bore sighter is probably as good of an idea as I've heard over the years.

I have an idea on how to find out if said chronograph is accurate (it it will read low enough) using one of the few constants that never changes. But have not tried it out, let alone took the time to figure the correct velocity before checking it out.
gary
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  #34  
Old 03-17-2013, 12:39 PM
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Re: Cronograph's ??

Gary,

I know you and I had this discussion before ... once your idea is materialized, can you make it affordable for poor guys like.

Ed
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I voted for my "FREEDOM", "GUNS", and "MONEY" - keep the change - UNK.



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"Leadership Rule #2: Don't be an @zzhole." - Maj Gen Burton Field.
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  #35  
Old 03-17-2013, 01:18 PM
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Re: Cronograph's ??

Quote:
Originally Posted by FEENIX View Post
Gary,

I know you and I had this discussion before ... once your idea is materialized, can you make it affordable for poor guys like.

Ed
I think the total cost would be well under ten dollars! And zero if you had access to some junk parts in an auto repair shop. I have to dig out one of my physics books to figure the actual velocity, but the rest is kinda easy.
gary
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