Range Report No chrono, so does this sound right?

[JGorski]

I zeroed my 6 Creed at 300, then went to 200 and it shot +3.3", 100yd shot went +2.6". Looking at my Hornady Ballistic calculator it tells me that the velocity is 3355fps, the load is 42grs RE17, 105 Hybrid/Hornady HPBT.
Have another load which is 42.2grs H4350 and should be right around 3158fps figuring from what Frank Green is getting from his 23' tube and 42grs H4350 from his 6 Creed. I know i should invest in a chronograph but it is what it is, so I use trajectory figures, that being said it looks good to me, your thoughts? Sound good to you guys?

 

[Archer762]

I don't think you can reverse engineer it like that. The difference of +/- .1" at 100 and 200 will change your results too much. 3355fps sounds awfully high for a 105 right?

 

[Darkphage]

I have to agree with Archer, you are making some assumptions that simply may not be true. That said, how important that is, is really dependent on what you are trying to accomplish with your Creedmore. There are many shooters that have done very well out to 4-500 yards without ever calculating an actual drop table using a software program, or knowing the MV. Assuming you have an accurate load worked up, you can shoot groups and keep a detailed log book of impacts to develop your own drop table without ever knowing the MV. The only real problem with this method arises if you want to shoot longer ranges. If you are wanting to shoot 800-1200 yards, I really believe you need to get behind a chronograph, and get some hard data. As a side note, regularly shooting behind a chrony lets you see how well your reloading techniques are developing. It's really helpful to know your extreme spread on muzzle velocities.

anyway -- my 2 cents

Dark

 

[Enough Said]

You are using drops from the flat end of the trajectory. You can get more accurate information if you gather drop data at longer ranges.

 

[JGorski]

Thanks for the replies, guys! Turns out that after I dialed up 6.5moa @100yds to be zeroed at 600 per the ballistic calculator my first sighter today was .5min under the sighter plate, so it turned out to be quite accurate this time.
I got the 200fps extra from using RE17 instead of H4350, in an article on 6mmbr.com German Salazar and Bob Jensen used RE17 in the 6XC and got the same 200fps more over H4350.

 

[JGorski]

Ordered me a chronograph & Tri-pod!
Amazon.com: Competition Electronics ProChrono Digital Chronograph: Sports & Outdoors
Amazon.com: Vista Explorer 60-Inch Lightweight Tripod with Tripod Bag: Camera & Photo

 

[SporterII]

I have that chrono.
I always look to see sun / cloud cover during strings. I do not know if I am paranoid but it is, to me, something additional to keep track of.
My computerized dope from chrono data has jived nicely with actual come ups to 1000.
So far so good.

 

[Prebanpaul]

invest in a magneto speed. One of the greatest tools ever made.