Posted: 1/23/2026 2:11:28 PM EDT
[Last Edit: KoreyKirsch][Edited]
|
I have answered this question a number of times on other forums, so I thought I would bring up the topic here. I may have brought it up in the past so I apologize if this is a repeat. I am not saying my way is the only way, or the best way, but it is what I have found works for me and has helped others. I get the comment or question a lot that people will say they are missing too often with their thermals. Besides the obvious like their gun isn't accurate or ammo that doesn't group, etc, one of the most common reasons is people zeroing their thermals like they do for glass scopes for big game hunting. Lots of people will tell me, I was taught to zero my scopes at 2" high at 100. That gives me a MPBR (Maximum Point Blank Range) out to 300 yards for instance. That is true, but there are two problems with this when using a thermal and especially shooting at a small target like a coyote. The first problem is that most thermals sit higher over bore than traditional glass scopes. This varies but the standard measurement for many glass scopes is 1.5" over bore. The standard height over bore for thermals is around 2.5" and some are over 3". This makes a noticeable difference in your ballistic data when you input this metric. On most guns if you zero it at 2" high at 100, you are over 3" high right through the sweet spot of where most coyotes are shot. It has always confused me why people would want to be so high at the distances they shoot most coyotes just trying to stretch their MPBR just a little further. Second and in the same thought process, a coyote is about 30lbs with a ton of fur. This makes them look way bigger than they really are. Once skinned, there isn't much actual body mass there. 3" high will lead to many misses high or spine shots at best. Lots of thermals have LRFs in them now, so stretching out a MPBR isn't as necessary. The scope can show you the drop when you have reached extended ranges. I zero my guns so they never reach more than .9" high through the sweet spot of where I am shooting most coyotes. Is there any hard science to the .9", no but I want to be at 1" or less. For my 22-250, it ends up being 70 yards, for my.204s that ends up being 74 yards and for my 20-250 it ends up being 80 yards. Here is the table for my 204 with a 74 yard zero and my optic being 2.5" over bore: Yards Drop 50 -.6 100 .5 150 .9 200 .3 250 -1.3 300 -4 This means from 50 yards to around 240 yards, my bullet is never higher or lower than .9" from my zero. That is a dead coyote, and also covers the majority of the coyotes I shoot. I am probably ok holding dead on until about 270 yards. With this load, my other zero is around 212 yards as it will cross my zero at that range as well. Now let's run the same data using my flat shooting 204, but putting in a 2" high at 100 zero and 2.5" over bore optic: 50 .1 100 2 150 3.1 200 3.2 250 2.4 300 .4 Would this push out the MPBR, yes (not really unless the MPBR is adjusted to a coyote sized animal), but this means that through the sweet spot of where most of your coyotes are shot, you are over 3"+ high throughout that range. That can mean lots of coyotes missed high. This is not including any elevation difference between you and the coyote and assumes a perfect shot and a perfect zero. I am not a ballistics expert and using jbm for my data. I am also not a long-range shooter or someone who competes in competitions. I am simply a guy who shoots lots of coyotes and want as many DRT as possible. To me, I want my bullet as flat as possible through the zone of where most of my coyotes are shot. Make sure to measure your height over bore on your thermals and plug that into your ballistics data. The 2" zero data improves a lot at 1.5" over bore vs 2.5". If you shoot most of your coyotes from 25-50 yards, or from 300-500 yards, then the conversation is very different. |
Korey Kirschenmann (Kirsch)
TNVC Thermal Product Specialist
https://tnvc.com/
TNVC Thermal Product Specialist
https://tnvc.com/
Joined:
Mar 2023
Posts:
337
EE: 0% (0)
NC, USA
Joined:
Mar 2023
Posts:
54
EE: 0% (0)
ITA
| Thanks Korey for your excellent explanation! I kindly ask you if you can set up a small drop column (50 y, 100y, 150y, 200y, 250y, 300y, 350y, 400y, 450y, 500y) for my commercial ammunition in .308W Hornady Superformance 150 gr sst (BC=0.415 ; V0=3000 ft/s)? The setting of my thermal riflescope on the Picatinny rail of the semi-automatic Benelli Argo rifle determines a sight height of 2.75". I would like to set the zeroing at a distance of 55 yards. Could you also calculate the MPBR, taking into account that the silhouette of my target is a hog with an average weight of 165 lbs? |
|
Originally Posted By Ernest49: Thanks Korey for your excellent explanation! I kindly ask you if you can set up a small drop column (50 y, 100y, 150y, 200y, 250y, 300y, 350y, 400y, 450y, 500y) for my commercial ammunition in .308W Hornady Superformance 150 gr sst (BC=0.415 ; V0=3000 ft/s)? The setting of my thermal riflescope on the Picatinny rail of the semi-automatic Benelli Argo rifle determines a sight height of 2.75". I would like to set the zeroing at a distance of 55 yards. Could you also calculate the MPBR, taking into account that the silhouette of my target is a hog with an average weight of 165 lbs? Download the Hornady app. It will provide the information that you seek. You can set the parameters. |
|
Ernest, Here you go. For some reason, AR15.com isn't liking to show the image, so here is a link to it. Table For Ernest I simply put your parameters into the website found here. https://jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi |
Korey Kirschenmann (Kirsch)
TNVC Thermal Product Specialist
https://tnvc.com/
TNVC Thermal Product Specialist
https://tnvc.com/
| Thanks excellent info Korey. I zero mine at 50 yards since 98% of my shots are 50-60 yards. Every couple of months I reconfirm that zero hasnt wavered and also shoot at 150 which puts me about an inch or so high at that distance. I figure I'm good from 25-150 yards without having to think about it much |
Joined:
Mar 2023
Posts:
55
EE: 0% (0)
ITA
| Thanks Korey, excellent table and very complete and useful ballistic calculator. Meanwhile, I realized that if I choose zeroing at 55 yards (50 meters.....), the average drop is very low. This allows me to shoot a hog out to a distance of 250 yards without doing too much calculations! |
