Cronograph accuracy question

[Surffshr]

I went to the range today and shot 208 a-max's for the first time in my 300wm. I kept everything constant except I used 3 different powders with 3 loads apiece using 220 grain bullet data from a Sierra manual. I shot 3, 5 shot strings of H1000, H4831SC, and RL 22 over a crony. Then I find hornandy load factory load data posted here just now...I assume what I found is correct, but what I recorded at the range is 100-120 fps faster than the published data.

My rifle has a 26" barrel and the data I found says it is a 25" barrel.

This got me to thinking about how to check a cronograph's accuracy. How would one do this?

 

[The Mechanic]

Re: Cronograph accuracy question

put a PVM 21 right behind it and verify yours is accurate.

 

[Surffshr]

Re: Cronograph accuracy question

I thought about checking with another...say I only have one cronograph because I only have one.

 

[BOLTRIPPER]

Re: Cronograph accuracy question

stick with what you brought and dance with it......what you should be looking for is trends.

it has been my experience that two eye vs.the oehler is not that far removed from one another.....so record and save your velocities and environmental's and generate some dope.....and confirm by shooting

 

[former naval person]

Re: Cronograph accuracy question

The Ripper is right. Shoot drops at distances past 100 yards (as 300 and 400 with a 100 yard zero) and confirm your chrono accuracy. JMHO

 

[BLAWTON]

Re: Cronograph accuracy question

The accuracy your looking for with chrono's is the shot by shot. The MV is not really important for load development until you do a drop chart on it. Even then its easy to just adjust it until your chart matches up with your real world data.

 

[ChadTRG42]

Re: Cronograph accuracy question

The chrono should be very close. You should be able to confirm your velocity when shooting at distance with actual drop data. It is not unusual to be faster than book data.

 

[Rhys]

Re: Cronograph accuracy question

I've consistently run about 150-250 faster than what hornady shows with most calibers that I run.