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Discussion Starter · #1 ·
How much can I expect accuracy to be affected by using a scope with turrets calibrated to a specific bullet weight, and firing different weight bullets?

Specifically: .308 Win out of a 24" barrel, scope calibrated to 168gr bullets. Let's say I want to fire 150gr bullets, at 200, 400, and 600 yards. Will I be an inch off, or like missing the paper off?
 

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No sure what you mean because when you change bullet types or the angle of your shooting either uphill or donwnhill the hole "turret formula" will be very confusing. Better stick to simple, fast turrets if you want, and a good ballistics card and/or calculator. You can also pick up a dell axim in Ebay for 20 bucks or so that will do the basics for you. Software is free and can even run your own excel math if you use excel.
Anyway whatever reticle-turret combo you do, as you build your charts you will probably memorize many corrections.
Also it is not a bad idea to choose a scope reticle to learn how to estimate range w/o electronics, you know... electronics malfunction and batteries die. And write things down,... like the old spanish saying .... A short pencil is much better than a long memory.
.. never understimate a good old pencil.
 

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I think you are referring to manufacturers ballistic etched turrets. If they are done correctly they should be based on a certain bullet with a known muzzle velocity average and ballistic coefficient. Also this should be based on a standard atmospheric condition. So by changing a bullet the impact is generally changed dependent on range. At 200 yards probably inches at 1000 yards plus it would be feet.

Be aware changing a bullet changes more than just external trajectory, internal ballistics will be affected changing the impacts down range also. Barrel twist rate eat bullets differently; pressure affects accuracy nodes, you will not just see an elevation change, some windage change will also happen. There is alot to it for true precision if that is what you are after.


Now take into account atmospheric changes, even with the same bullet a 30 degree temperature change will create a 1 Mil+/- or 3.4 MOA+/- change in elevation at 1500 yards. Add station baro pressure changes and it gets even more involved.
So what range are we talking about? I suggest you get a standard MIL turret, test it for travel accuracy and learn the finer points of ballistic changes and work with that.

I see these guys on TV long range hunting pushing a scope (Huskey something) having etched turrets, shooting at rocks at distance and calling it spot on, well hunt mountain goats and climb 3000-4000 ft change in elevation between shots and it changes the firing solution. SWAG a little one way or another and it probably works OK? So long as you understand the changes in the first place.
 

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Discussion Starter · #4 ·
I'm looking at getting the Nikon M-308 scope for my new rifle with a 1:10 twist. It includes turrets which are calibrated for .308 Win/7.62 NATO Match round with 168gr. HPBT bullet. I would be doing a good deal of reloading, and have identified the Sierra Match 168gr HPBT bullet for such (MatchKing Bullets 30 Cal (308 Diameter) 168 Grain Hollow Point Boat Tail). However, if I buy 100 rounds of 150gr bulk ammo, I'd like to be able to use it.

Please keep in mind, if on a scale of seriousness about long range precision, OscarWhiskey is a 10, I'm about a 3 to 4. I won't be able to shoot further than 200 yards regularly, and if I can hit the center of the target at that range I'll be quite pleased with myself. If, at that range, the 150gr is going to be an inch low, I'm ok with that. If it's going to miss the paper, I'm not.

If/when I get to go past 200 yards, that will be a special occasion and I won't be using cheap ammo that came in an ammo can from a site, it will be my handloads that I'm confident in with the proper bullet.
 
G

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Turrets marked with yardages are popular with the, “close is good enough for government work” crowd.

Such markings can be found on the Leupold M3LR and M3A scopes as well as the USMC Unertl and the new USMC M8541 by Schmidt Bender.

Obviously these settings are only correct when using particular ammunition under one set of meteorological conditions.

As you already know when the ammunition varies and the conditions vary the relationship of these marks to the actual point of impact will also vary.
The closer the target the less these variances will be noticeable. (I suspect you already know this.)

I predict that as you become more familiar with precision rifle shooting your standards will begin to change. But for now, have a good time.
 

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Discussion Starter · #6 ·
I predict that as you become more familiar with precision rifle shooting your standards will begin to change. But for now, have a good time.
One can hope. I think it would depend a lot on my suddenly and unexpectedly inheriting 200 acres of land outside Rochester though...
 

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I see.. anyhow to keep it simple and more versatile maybe it would make sense you consider
a fast reticle than having that in the turrets. In the reticles one can resource to rapid correction using the picture
and reference charts.
The key is to understand well those reticles. Nikon is great, nice jap. glass and very crisp.
I think nikon also produces a BDC specifically for the .223 M-23 or something like that, I might be wrong.
Their line of BDCs track really well to the advertised data and designated yardages. The only thing is that
their reticles are a bit coarse (not huge deal) when you want to move further. Burris is pretty good too.
All great to start with. Again, it is key to get a good understanding in the different comp reticles.
Zeis, Pride, Bushnell also have great comprehensive comp reticles with windage correction as well .
Even the 3-9 22LR pride scope is a very nice starting scope for that type of work. Pride will send you all the
infromation you need to map your loads / trajectory into that 22LR reticle. It is not the most conventional but it works.
I know a guy that has been doing this to pop coyotes at 500 and 600 yards with this method and the 223 AI round.
Most makers have also online software to help you if you do not have any software or charts.
For your initial work you night not have the speed spreads but it always good to have. With a known load and bullet,
at known conditions you can determine the speed of the bullet by using the drop between two targets set at two
different know ranges. But you cannot beat having some chrono reads at some point.
For all this scope makers provide data with estimates for the most commonly used commercial loads.
Also for 200 yards you do not need much of a correction as it is easy to estimate the ~5" POI difference
below your 100 zero, assuming you want to zero at 100 obviously.

Here some examples with those fast reticles fyi...

SWFA Riflescopes Zeiss Rifle Scopes Zeiss Victory Diavari FL Rifle Scopes

Bushnell 3.5-21x50 Elite Tactical 34mm Rifle Scope

SWFA Riflescopes Pride Fowler Rifle Scopes Pride Fowler Rapid Reticle 900 Rifle Scopes
 

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I see.. anyhow to keep it simple and more versatile maybe it would make sense you consider
a fast reticle than having that in the turrets. In the reticles one can resource to rapid correction using the picture
and reference charts.
The key is to understand well those reticles. Nikon is great, nice jap. glass and very crisp.
I think nikon also produces a BDC specifically for the .223 M-23 or something like that, I might be wrong.
Their line of BDCs track really well to the advertised data and designated yardages. The only thing is that
their reticles are a bit coarse (not huge deal) when you want to move further. Burris is pretty good too.
All great to start with. Again, it is key to get a good understanding in the different comp reticles.
Zeis, Pride, Bushnell also have great comprehensive comp reticles with windage correction as well .
Even the 3-9 22LR pride scope is a very nice starting scope for that type of work. Pride will send you all the
infromation you need to map your loads / trajectory into that 22LR reticle. It is not the most conventional but it works.
I know a guy that has been doing this to pop coyotes at 500 and 600 yards with this method and the 223 AI round.
Most makers have also online software to help you if you do not have any software or charts.
For your initial work you night not have the speed spreads but it always good to have. With a known load and bullet,
at known conditions you can determine the speed of the bullet by using the drop between two targets set at two
different know ranges. But you cannot beat having some chrono reads at some point.
For all this scope makers provide data with estimates for the most commonly used commercial loads.
Also for 200 yards you do not need much of a correction as it is easy to estimate the ~5" POI difference
below your 100 zero, assuming you want to zero at 100 obviously.

Here some examples with those fast reticles fyi...

SWFA Riflescopes Zeiss Rifle Scopes Zeiss Victory Diavari FL Rifle Scopes

Bushnell 3.5-21x50 Elite Tactical 34mm Rifle Scope

SWFA Riflescopes Pride Fowler Rifle Scopes Pride Fowler Rapid Reticle 900 Rifle Scopes

...just my 2 cents.
 

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Couple of comments:

On your scale of 1 to 10 for LRP rifle; I'm about a 7.5, Kmussack is the 10+ but he plays the grey guy just going about his business.
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Willie Wonka posted "But you cannot beat having some chrono reads at some point."

You better have chrono readings!! And a good average of them (not just 5 shots) to make this work, do not go by what a box of ammo has printed on it or what a manufacturer says on the internet. Understand this, no matter how low your extreme spread number is, every round you send down range you really do not know what MV it truly is for that shot. It is an average that you base your ballistics on. Go long range and it matters A LOT.
 
G

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Hang on, we're taking a hard turn here.

Mention of chronograph readings reminded me of a new product.



Learn more at magnetospeed.com

I'll own one of these before long.........
 

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How much do chronographs cost? I know of a guy selling an old model (in perfect shape) for like $60.
 

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Couple of comments:

On your scale of 1 to 10 for LRP rifle; I'm about a 7.5, Kmussack is the 10+ but he plays the grey guy just going about his business.
---------------------------
Willie Wonka posted "But you cannot beat having some chrono reads at some point."

You better have chrono readings!! And a good average of them (not just 5 shots) to make this work, do not go by what a box of ammo has printed on it or what a manufacturer says on the internet. Understand this, no matter how low your extreme spread number is, every round you send down range you really do not know what MV it truly is for that shot. It is an average that you base your ballistics on. Go long range and it matters A LOT.
Yep. Agree, if LR is in the future menu for the OP better start collecting data as soon as you can.
Heading to the range in a while to measure 100 identical 6x45 loads and every string results land in excel.
 

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Hang on, we're taking a hard turn here.

Mention of chronograph readings reminded me of a new product.



Learn more at magnetospeed.com

I'll own one of these before long.........
Nice!
Does anyone have direct experience with them? Are they accurate/reliable?
Any first hand experience and feedback would be greatly appreciated.
It would make things a lot easier when one is not working in accuracy loads.
 

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Discussion Starter · #15 ·
So is it the general advice of the pros here (we'll call them the 7's and above on the 1-10 scale) that turret scopes are NOT the bee's knees? Here I thought turrets were the Cadillac model and reticles with elevation drop were the poor man's compromise.
 
G

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So is it the general advice of the pros here (we'll call them the 7's and above on the 1-10 scale) that turret scopes are NOT the bee's knees? Here I thought turrets were the Cadillac model and reticles with elevation drop were the poor man's compromise.
Marked turrets like the S&B have both the range number and the mil-graduations. This isn't a bad setup at all. The Leupold M3LR and M3A are full minute increments of elevation and will limit your ability to adjust precisely.

FWIW, that new chronograph retails for $250.......
 

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I am not familiar in use of custom turrets but a zeiss with rapid Z1000 is not exactly what I would call a poor's man compromise for $2.8 G's
I have to go but read this from Steve (sscoyote). I have been working with him in a new version of the VLD magazines. This might provide some light into your path to keep things simple yet more versatile if ever needed. That pride scope might not seem much but it actually a great value for a starter and nice american made product. Coyotes are small sneaky bastards that move quickly in the plains and fast follow up is the best so the light AR-AI combo it only makes sense for this. Lets say one shot they are at 500 and next one 540 yards already. No time to lift your head for turret work or they might be lost in the horizon.
Long Range Coyotes: A Custom AR-15 And The Little Scope That Could

By any means I am not saying do this or that. Like everything these are just personal opinions and preferences. Just inform yourself and take your time. The best thing is the thing that works best for you in the end.
Try some from friends if you can. If you are around Penfield and want to try the Nikon Monarch BDC comp I have different models. not a problem.

Cheers,
E.
 
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