Assistance please: SCR reticle zeroed @ 100 yards 168gr FGMM

[navyman8903]

So I zeroed my Steiner T5Xi 3-15x50 Mil SCR on my HK MR762 the other day with the Federal GMM 168gr. I was very pleased with the performance after I was done zeroing..... but I picked the shittiest day for zeroing because there was about a 10-15 mph gust towards us so it would move the target as I was pressing shots. I did manage a sub MOA group at 100, and put two..2 shot groups on top of each other. I got frustrated and once I was in the ball park I just started shooting steel at 100 and 200 yards. While I had a very solid hit ratio, I have zero idea where I'm supposed to hold at 200 yards with a 100 yard zero. I did my best to zero at 100 in the prone on my Magpul bipod which is soon to be replaced by an ATLAS. Like as soon as I get the money after recovering from Xmas expenses.

But I was hitting almost dead on with the 100 yard zero I should have put a target at 25 then 100 so zeroing was easier but I was also zeroing my KAC with the Comp M5 (love that rifle). I pretty much rushed it all around. It was one of my last days on leave and my wife started patrol the next day, so it was our only shooting day together.

Anyway, sorry for the long wind. I have the Strelok app, but it doesn't have any of the reticles for my scope or my Trijicon 1-8 on my MR556. Is there something close I can use or a different app I should get? I know how to use them, but I just can't find a reticle I can use and I would like a calculator. Or if someone knows the reticle holds. The SCR is in a few scopes so I figured it would be in there, but alas.......I'm not that lucky.

Please help.


Edit, I also looked at the manual and the SCR has the most complicated and convoluted breakdown ever. It doesn't tell you any zeroing info, just the breakdown of the sub tensions and measurements. It's super detailed in that regard. And I know where to measure on the reticle for 1 mil. But the rest is all Greek to me.

[Backspin]

Short answer: you need to hold about .6 mils (just below the first short horizontal hash mark in your SCR reticle).

How I arrived at the answer:
168 FGMM muzzle velocity from 16.5” barrel = 2466 FPS (close enough number for 200 yard shooting. You will need to chronograph your gun/load combination to get a more accurate number)
https://rifleshooter.com/2014/12/308...ty-28-to-16-5/

168 grain SMK ballistic coefficient = .447 G1
https://www.sierrabullets.com/store/...HPBT-MatchKing

Sight height (centerline of bolt to centerline or scope) = 2.75 inches (educated guess)

Plug the above numbers into the following free calculator:
https://www.hornady.com/team-hornady...alculators/#!/

That calculator will give you pretty solid numbers. I’ve used that calculator to shoot .223 out to 500 yards.

Know your reticle’s subtensions:
https://www.burrisoptics.com/reticles/scr-mil

[navyman8903]

Short answer: you need to hold about .6 mils (just below the first short horizontal hash mark in your SCR reticle).

How I arrived at the answer:
168 FGMM muzzle velocity from 16.5” barrel = 2466 FPS (close enough number for 200 yard shooting. You will need to chronograph your gun/load combination to get a more accurate number)
https://rifleshooter.com/2014/12/308...ty-28-to-16-5/

168 grain SMK ballistic coefficient = .447 G1
https://www.sierrabullets.com/store/...HPBT-MatchKing

Sight height (centerline of bolt to centerline or scope) = 2.75 inches (educated guess)

Plug the above numbers into the following free calculator:
https://www.hornady.com/team-hornady...alculators/#!/

That calculator will give you pretty solid numbers. I’ve used that calculator to shoot .223 out to 500 yards.

Know your reticle’s subtensions:
https://www.burrisoptics.com/reticles/scr-mil

I really appreciate it. I'm just getting into this long range shooting game and I'm taking my first steps with this. I want to make sure my zero is as perfect as I can make it and I understand my reticle as much as I can before renting out the 1000 yard range for a day because $$$$ and I'm not made of money so it's going to be a special occasion to shoot at that range.

I'm going to take it back out and make sure my zero is a tidy as possible before running it again and with the info you gave me here I'll make a cheat sheet as well.

Thank you again.

[jellydonut]

Use a ballistic calculator, like Strelok Pro as you mentioned. You don't need the app to have your reticle, you just need the drop and wind holds in mils. Your reticle is in mils so with the subtension dimensions from Steiner you can count them out.

Still, Strelok is usually good about having reticles. You could try sending the author a message. Normally the only reason a reticle is missing is if the manufacturer is litigious (which is why Horus reticles are missing), or he just hasn't gotten around to it.

[5pins]

You may look into going to a heavier bullet. The 168 Sierra goes subsonic at around 900 yards with a velocity of 2466fps. The 175 Sierra at 2350fps and the 185 Burger at 2300fps should get you to 1000 yards.


Also getting accurate muzzle velocity will be very helpful. I just took a WAG on what you will get with them.

[JM Campbell]

The FGMM 175gr will get you out to 1000 yards.


Sent from my iPhone using Tapatalk

[Andy T]

As other said, get a decent ballistic calculator. I use Strelok +. Also SCR has a fairly simple reticle, but don't be afraid to dial for range as well.
To use a reticle with a calculator:
Calculators will give you the amount of mills to hold over. Start at the center of the reticle ( zero ) and count down the appropriate number. You may also need to hold for wind.
Regarding MV: I found that the value that's printed on FGMM 168 was pretty close across a wide spectrum of barrels/barrel lengths compared to Magneto Speed I was using - enough that I don't think a MV measuring devices a must have initially.