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A little confused.

 
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  #1  
Old 11-24-2011, 12:29 AM
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A little confused.

Hello. I've just started re loading and am a little lost. I don't think this belongs in the reloading section though. I have a Sendero ll 300 RUM. Loaded to book. 3.600 OAL, 94 gr Retumbo Powder, 200 gr Accubond, Fed 215 Primers, Rem brass full length resized. Brass extensivley preped. De burred, primber pocket uniformed, weighed, etc.. I started with 94 gr, not sure why, but did. Book says 95 is max and 91 was most accurate load tested. Here's where I'm lost. With that caliber and bullet, does it take a certain distance for that bullet to stabilize, or is there just simply fine tuning to be had with bullet seating and powder? Here's why. I chronoed the rounds, got temp, elevation, humidity, etc.. all the works. Went to several ballistic calculators and printed out dope charts. Each bullistic calculator was about the same. I went to the range. Wanted a zero at 275 yards. Said I should be high 1.0 inches at 50 yards. So, I got on paper, got to exactly 1.0 inches high at 50. Shot 2 rounds. Punched paper in exactly the same hole. Thought, good start. Went to 100 yards. Dope chart said should be 2.5 inches high. I put 2 rounds touching right at about 2.25 inches. Roughly, hard to measure 200 gr bullet hole when talking half inch size holes. Ha ha. Anyway, I was like, wow, first time reloading and everything is amazing. Then, go to 300 yards. Chart said I should be 1.5 inches low at 300 yards. I was 3.5 inches HIGH. I shot 1 round, let barrel cool for about 5 min. Shot another, let cool. Shot another again. 3 total. All rounds could be covered with a copenhagen lid I would say. So, now I was wondering if I fouled my barrel up with a little copper. I spent the next hour running patch after patch of Tetra gun until there was no more blue to be seen. Went straight to 300 yards, same thing. 3.5 or so inches high. Went to 50 yards, 1 inch high. Whats the deal??? Why am I shooting high??? Is that bullet not stabilized yet, or does that round just not work out of that rifle and I need to do some fine tuning? I haven't tried 4 or 500 yards yet. I checked scope mount and everything felt tight as can be. Shooting a Sightron Slll 6-24X50. Can't remember the scope mount. Thanks for the help.
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Old 11-24-2011, 12:51 AM
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Re: A little confused.

Quote:
Originally Posted by shooters View Post
Hello. I've just started re loading and am a little lost. I don't think this belongs in the reloading section though. I have a Sendero ll 300 RUM. Loaded to book. 3.600 OAL, 94 gr Retumbo Powder, 200 gr Accubond, Fed 215 Primers, Rem brass full length resized. Brass extensivley preped. De burred, primber pocket uniformed, weighed, etc.. I started with 94 gr, not sure why, but did. Book says 95 is max and 91 was most accurate load tested. Here's where I'm lost. With that caliber and bullet, does it take a certain distance for that bullet to stabilize, or is there just simply fine tuning to be had with bullet seating and powder? Here's why. I chronoed the rounds, got temp, elevation, humidity, etc.. all the works. Went to several ballistic calculators and printed out dope charts. Each bullistic calculator was about the same. I went to the range. Wanted a zero at 275 yards. Said I should be high 1.0 inches at 50 yards. So, I got on paper, got to exactly 1.0 inches high at 50. Shot 2 rounds. Punched paper in exactly the same hole. Thought, good start. Went to 100 yards. Dope chart said should be 2.5 inches high. I put 2 rounds touching right at about 2.25 inches. Roughly, hard to measure 200 gr bullet hole when talking half inch size holes. Ha ha. Anyway, I was like, wow, first time reloading and everything is amazing. Then, go to 300 yards. Chart said I should be 1.5 inches low at 300 yards. I was 3.5 inches HIGH. I shot 1 round, let barrel cool for about 5 min. Shot another, let cool. Shot another again. 3 total. All rounds could be covered with a copenhagen lid I would say. So, now I was wondering if I fouled my barrel up with a little copper. I spent the next hour running patch after patch of Tetra gun until there was no more blue to be seen. Went straight to 300 yards, same thing. 3.5 or so inches high. Went to 50 yards, 1 inch high. Whats the deal??? Why am I shooting high??? Is that bullet not stabilized yet, or does that round just not work out of that rifle and I need to do some fine tuning? I haven't tried 4 or 500 yards yet. I checked scope mount and everything felt tight as can be. Shooting a Sightron Slll 6-24X50. Can't remember the scope mount. Thanks for the help.
What velocity are you getting from your Chrono?

Do you have your scope height correct? Measure center of bore to center of scope tube.
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Old 11-24-2011, 01:05 AM
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Re: A little confused.

Assuming 3100 fps, your numbers correlate to what my program says as well so you should be hitting low by 1.5 inches or so.

If you are getting tight groups then stabilization, rings and bases isn't likely the issue. Have you checked your parallax? How tight is your group at 300 yards?
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Old 11-24-2011, 01:06 AM
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Re: A little confused.

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Originally Posted by WildRose View Post
What velocity are you getting from your Chrono?

Do you have your scope height correct? Measure center of bore to center of scope tube.
Chrono is 3104. Scope height, I measured 2" which is where I probably went wrong. Thought it was 1.5". There Seekins rings and base. They sent me what they said were the correct height, which I think are medium for that contour barrel.
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Old 11-24-2011, 07:38 AM
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Re: A little confused.

Quote:
Originally Posted by shooters View Post
Chrono is 3104. Scope height, I measured 2" which is where I probably went wrong. Thought it was 1.5". There Seekins rings and base. They sent me what they said were the correct height, which I think are medium for that contour barrel.
Plug that into your program and see what it does.

Remember ballistics programs are limited in effetiveness/accuracy by a number of factors. The more correct your input data is, the closer it will give you to accurate info out.

Even at that you may end up needing to tweak your velocity and/or ballistic coefficient to narrow things down further.
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Old 11-24-2011, 08:19 AM
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Re: A little confused.

You are getting good groups and velocity with a proven bullet. The rifle/load seems fine, either your adjustments in your scope are way off or you and the ballistic calc aren't jiving. I doubt the your scope height being off 1/2" is gonna throw you off 5" @ 300 yards, maybe 1000. That just isn't helping. Check the scopes adjustments, then make sure you have the correct adjustments in the calculator.
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  #7  
Old 11-24-2011, 09:37 AM
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Re: A little confused.

I would do a 100 yard test to verify true click value. "0" the scope at100 an a tall target and then crank on 50 or 75 clicks and shoot again at the same spot. Measure the distance from the low group to the high group and divide the distance by the number of clicks. 1/4 minute clicks should be 1/4 of 1.047 inches or .26175 inches per click. More or less needs to be corrected for in the program. That is the great thing about the Best of the West and the G7 programs. You use what you have done so far as a guide to shoot data that is entered back into the program to give you a perfect chart for your gun and load. BC, velocity, click value and all the other variables must all fit togather to give you a good chart. All the programs depend on exact data to function properly .
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Last edited by paphil; 11-24-2011 at 09:39 AM. Reason: change MOA to clicks
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