hometownhero
CGN Ultra frequent flyer
- Location
- Toon Town, Sk
Suggested to put it at 10 feet. Another thing why are they so slow? Data would suggest max at 47gr and 2812fps.
Why are my rounds dropping more then they should?
- Thread starter Ilove12gshotguns
- Start date
Suggested to put it at 10 feet. Another thing why are they so slow? Data would suggest max at 47gr and 2812fps.
I find the original post confusing.
Ballistics charts tell me
100 - zero'd
200 - 4.3" drop
300 - 15.3" drop
400 - 33.5" drop
I'm getting
100 - zero'd
200 - 6.5"
300 - 21.5"
400 - untested
When I read this, the phrase "I'm getting" means he has not adjusted the scope and has shot groups at 100, 200 and 300 and measured the drop of the average of each group.
But, I suspect he is a newbie and is actually talking about how much he had to adjust the scope to center the group at each distance.
If he did the latter, he has just assumed that a 1 minute scope adjustment moved the group 1 minute. Often, this is not so.
Personally, I zero at 100 and then shoot the rifle at each longer distance and note the scope elevation required for that distance. In 50 years of shooting I have never bothered to see how big the rise is and how it compares to a published number. All I care is that I need 12.2 minutes on MY scope on MY rifle with MY ammo to be centered at 500 yards.
Ballistics charts tell me
100 - zero'd
200 - 4.3" drop
300 - 15.3" drop
400 - 33.5" drop
I'm getting
100 - zero'd
200 - 6.5"
300 - 21.5"
400 - untested
When I read this, the phrase "I'm getting" means he has not adjusted the scope and has shot groups at 100, 200 and 300 and measured the drop of the average of each group.
But, I suspect he is a newbie and is actually talking about how much he had to adjust the scope to center the group at each distance.
If he did the latter, he has just assumed that a 1 minute scope adjustment moved the group 1 minute. Often, this is not so.
Personally, I zero at 100 and then shoot the rifle at each longer distance and note the scope elevation required for that distance. In 50 years of shooting I have never bothered to see how big the rise is and how it compares to a published number. All I care is that I need 12.2 minutes on MY scope on MY rifle with MY ammo to be centered at 500 yards.
ive shot 100-200 ND 300M THEN PUT THE INFO INTO JBM and worked out a rough figure for my velocity-----
i also aim at the X an see wher it hits....... im typically +2/100m , 0/200m and -15/300m which i work out my hold overs or reticle point hold over etc...........
i dont have a chrony an that was how i got my rough figure.
now days i still Aim at X with my guns and see where they land at 300m strictly for hold over on DEER sized game.
times i have problems is when published data may say EG 3000FPS, but off my 100-200 and 300m target , the drop is MORE an therefore my velocity is LESS than expected................
the numbers dont really matter for Speed- but Your own personal rifle DROP matters-
what i would do
shoot 100-200 and 300- 400m aiming at one point intially............ shoot one or two rounds to get an idea of POI at those ranges....
next work out from there if you think "adjusting Clicks" or just "Holdover" is what you;re after.
ps- im no paper puncher- animals only.
i also aim at the X an see wher it hits....... im typically +2/100m , 0/200m and -15/300m which i work out my hold overs or reticle point hold over etc...........
i dont have a chrony an that was how i got my rough figure.
now days i still Aim at X with my guns and see where they land at 300m strictly for hold over on DEER sized game.
times i have problems is when published data may say EG 3000FPS, but off my 100-200 and 300m target , the drop is MORE an therefore my velocity is LESS than expected................
the numbers dont really matter for Speed- but Your own personal rifle DROP matters-
what i would do
shoot 100-200 and 300- 400m aiming at one point intially............ shoot one or two rounds to get an idea of POI at those ranges....
next work out from there if you think "adjusting Clicks" or just "Holdover" is what you;re after.
ps- im no paper puncher- animals only.
Ilove12gshotguns
CGN Regular
- Location
- New Brunswick
Just wanted to say thank you for all the suggestions and great info.
I'm going to hit the range tomorrow with another I 100 rounds made up, while using the info provided in this thread it will give you guys the real deal of what's going on.
Rl-15 @ 43.5g is what I decided on, because it gives me great accuracy, with 44g and up starting to show pressure signs.
I will retest velocity, fire 8 round groups at 100m; 200m; 300m; and 400m; with using a 100m zero and measure how far the bullets are dropping from my POA in inches.
Then I will figure out if my scope is working correctly by conducting a box test.
Then reshoot 200m - 400m recording how much MOA up is needed to get the rounds to hit my POA.
***edited for grammer***
I'm going to hit the range tomorrow with another I 100 rounds made up, while using the info provided in this thread it will give you guys the real deal of what's going on.
Rl-15 @ 43.5g is what I decided on, because it gives me great accuracy, with 44g and up starting to show pressure signs.
I will retest velocity, fire 8 round groups at 100m; 200m; 300m; and 400m; with using a 100m zero and measure how far the bullets are dropping from my POA in inches.
Then I will figure out if my scope is working correctly by conducting a box test.
Then reshoot 200m - 400m recording how much MOA up is needed to get the rounds to hit my POA.
***edited for grammer***
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Scope 1.1 inches above the bore??? Normally 1.5" as you have to measure to the center of the scope.
The formula you should use is 1/2 the diameter of the bolt + the distance from the top of the bolt to the bottom of the scope + 1/2 the diameter of the scope tube.
You are mixing metric and Imperial. If you are using Imperial . . . why did you stop at 300 m.?
Using your figures and the Sierra Infinity, sighted in at 100 yards shows 5.5 low at 200, 19.7 at 300 and 44.4 at 400 yards.
Sighted in at 100 m., 7.2 low at 200 m., 25.3 at 300 m., and 56.8 low at 400 m.
I now see you are using metric for your testing but most charts are in yards.
While most calculations are almost insignificant when the scope height is 1.5-1.8", 1.1 is significant to the tune of about 0.5" at 200 yards if the measurement should have been 1.5.
I have been using 1.5 for so long that it was almost accepted so I measured my 25-06 which has a 30 mm tube and came up with 1.74
The formula you should use is 1/2 the diameter of the bolt + the distance from the top of the bolt to the bottom of the scope + 1/2 the diameter of the scope tube.
You are mixing metric and Imperial. If you are using Imperial . . . why did you stop at 300 m.?
Using your figures and the Sierra Infinity, sighted in at 100 yards shows 5.5 low at 200, 19.7 at 300 and 44.4 at 400 yards.
Sighted in at 100 m., 7.2 low at 200 m., 25.3 at 300 m., and 56.8 low at 400 m.
I now see you are using metric for your testing but most charts are in yards.
While most calculations are almost insignificant when the scope height is 1.5-1.8", 1.1 is significant to the tune of about 0.5" at 200 yards if the measurement should have been 1.5.
I have been using 1.5 for so long that it was almost accepted so I measured my 25-06 which has a 30 mm tube and came up with 1.74
Ilove12gshotguns
CGN Regular
- Location
- New Brunswick
I have to use imperial / MOA on account that the scope elevation turret is in MOA.
I will also re-measure the scope height above the bore.
I will also re-measure the scope height above the bore.
I know a few people that used a calculator based on yards, and their range is graduated in meters.
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I see it at the range all time.
That’s fine. But if you have data for say 300 yds but shoot at 300 meters, that is actually 330 yds.
Ilove12gshotguns
CGN Regular
- Location
- New Brunswick
Got out to the range as planned today. Fixed a few issue's and got everything dailed in.
1. Re-zero'd @ 100m / it was shooting 1" low
2. Last time I was using yards instead of meters for drop info.
3. Rear focus objective lens a 3/4 turn from being tight and caused some slop in the sight picture.
4. Fired at 0 degree angle to the target instead of -3 @100m
5. Tracking box test passed.
6. Re-measured my scope height properly @ 1.4"
New info
100m - 0"
200m - 6.6"
300m - 21.3"
400m - 45.9"
Made a COME UP chart in MOA for myself, and confirmed at each given range to make sure it all works out.
I do want to get back out and hit the 500m, and the 50m increments in between the ranges. I will do that at a later time, with no need to post it here.
Thanks for all the help getting me sorted out.
1. Re-zero'd @ 100m / it was shooting 1" low
2. Last time I was using yards instead of meters for drop info.
3. Rear focus objective lens a 3/4 turn from being tight and caused some slop in the sight picture.
4. Fired at 0 degree angle to the target instead of -3 @100m
5. Tracking box test passed.
6. Re-measured my scope height properly @ 1.4"
New info
100m - 0"
200m - 6.6"
300m - 21.3"
400m - 45.9"
Made a COME UP chart in MOA for myself, and confirmed at each given range to make sure it all works out.
I do want to get back out and hit the 500m, and the 50m increments in between the ranges. I will do that at a later time, with no need to post it here.
Thanks for all the help getting me sorted out.
