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<blockquote data-quote="Pdvdh" data-source="post: 394129" data-attributes="member: 4191">Copied and pasted from Oehler&#039;s web site.&nbsp; Some interesting reading here:<a href="http://www.oehler-research.com/specs.html" target="_blank">Oehler Research, Inc.--Ballistic Explorer</a>&quot;ACCURACYThe expected error on any one shot depends on both velocity and screen spacing. Typical errors are shown in the table. The table assumes good light conditions, dark bullets, exact screen spacing, and shooting through the center of the Skyscreen III window. Actual errors under your shooting conditions will be reliably indicated by the PROOF CHANNEL.&nbsp;_ _ _ _ _ _ 1 FT&nbsp; &nbsp; _2 FT&nbsp; &nbsp; _4 FT&nbsp; &nbsp; 8 FT1000 FPS_ 5 fps&nbsp; &nbsp; _3 fps&nbsp; &nbsp; 1 fps&nbsp; &nbsp; 1 fps2000 FPS&nbsp; &nbsp; 10 fps&nbsp; &nbsp; _5 fps&nbsp; &nbsp; 3 fps&nbsp; &nbsp; 2 fps3000 FPS&nbsp; &nbsp; 16 fps&nbsp; &nbsp; _8 fps&nbsp; &nbsp; 4 fps&nbsp; &nbsp; 2 fps4000 FPS&nbsp; &nbsp; 21 fps&nbsp; &nbsp; 10 fps&nbsp; &nbsp; 5 fps&nbsp; &nbsp; 3 fpsYou will typically see the above errors as differences between the primary and proof channels of a Model 35P as you shoot under &quot;normal&quot; conditions. Note: It&#039;s easy to claim fantastic accuracy with a chronograph measuring only one velocity. Who checks the claims? You know your accuracy only with the PROOF CHANNEL, or by using two chronographs on each shot. We know our chronographs are more accurate and more reliable, so we invite you to check each shot.&quot;These single digit deltas in the &quot;differences in velocity&quot; are similar to what I see when my dual chronographs are healthy, and hitting on all cylinders.&nbsp; I can&#039;t even count how many times I&#039;ve read Posts pooh-poohing the validity of chronograph data for establishing MV.&nbsp; Many Posts have taken the slant that a fellow is better off using measured down range drops to establish MV or BC.&nbsp; Time to get a decent chronograph if your&#039;s functions like a Mattel Jack-In-The-Box.&nbsp; If measuring drops gets the job done for the shooting scenarios a guy encounters, then that&#039;s certainly good enough for those uses.&nbsp; But trying to guesstimate MV or BC from down range drops is the equivalent of trying to pin the tail on the donkey - blindfolded, compared to establishing MVs with a dual set of quality chronographs.&nbsp; Using one chronograph is the equivalent of blind faith.&nbsp; Having two running in tandem provides some evidence the velocity data is &quot;good&quot; data.&nbsp; The 2nd proof channel recorded velocity on the 35P, or a second velocity value from a separate chronograph run in tandem, is the QA/QC needed to provide confidence the data meets a standard of quality suitable for use in your ballistics programs.</blockquote>

[QUOTE="Pdvdh, post: 394129, member: 4191"] Copied and pasted from Oehler's web site. Some interesting reading here: [url=http://www.oehler-research.com/specs.html]Oehler Research, Inc.--Ballistic Explorer[/url] "[I][B]ACCURACY[/B] The expected error on any one shot depends on both velocity and screen spacing. Typical errors are shown in the table. The table assumes good light conditions, dark bullets, exact screen spacing, and shooting through the center of the Skyscreen III window. Actual errors under your shooting conditions will be reliably indicated by the PROOF CHANNEL. _ _ _ _ _ _ 1 FT _2 FT _4 FT 8 FT 1000 FPS_ 5 fps _3 fps 1 fps 1 fps 2000 FPS 10 fps _5 fps 3 fps 2 fps 3000 FPS 16 fps _8 fps 4 fps 2 fps 4000 FPS 21 fps 10 fps 5 fps 3 fps You will typically see the above errors as differences between the primary and proof channels of a Model 35P as you shoot under "normal" conditions. Note: It's easy to claim fantastic accuracy with a chronograph measuring only one velocity. Who checks the claims? You know your accuracy [U]only with the PROOF CHANNEL, or by using two chronographs on each shot[/U]. We know our chronographs are more accurate and more reliable, so we invite you to check each shot[/I]." These single digit deltas in the "differences in velocity" are similar to what I see when my dual chronographs are healthy, and hitting on all cylinders. I can't even count how many times I've read Posts pooh-poohing the validity of chronograph data for establishing MV. Many Posts have taken the slant that a fellow is better off using measured down range drops to establish MV or BC. Time to get a decent chronograph if your's functions like a Mattel Jack-In-The-Box. If measuring drops gets the job done for the shooting scenarios a guy encounters, then that's certainly good enough for those uses. But trying to guesstimate MV or BC from down range drops is the equivalent of trying to pin the tail on the donkey - blindfolded, compared to establishing MVs with a dual set of quality chronographs. Using one chronograph is the equivalent of blind faith. Having two running in tandem provides some evidence the velocity data is "good" data. The 2nd proof channel recorded velocity on the 35P, or a second velocity value from a separate chronograph run in tandem, is the QA/QC needed to provide confidence the data meets a standard of quality suitable for use in your ballistics programs. [/QUOTE]

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