Custom BDC Turrets

MontanaRifleman

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May 21, 2008
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South of Canada and North of Wyoming
I'm starting this thread in order to not hijack another thread that this topic came up in.

http://www.longrangehunting.com/forums/f17/now-some-optics-46431/index2.html

I need to correct a statement I made in the other thread.

Let's take a 180 AB (BC, .507) @ 3000 fps load developed @ 3000' elev @ 40* temp...

...for the above info and everything but elevation remains the same but on hunting day we hunt on flat lands @ 4000' elevation our dfference in drops to 600 yds and 1000 yds respectfully are 12" and 43"...

Those drop numbers are out to lunch. Dont have a clue how I came up with them, so my apology. The real drop differences are .7" and 5"
 
Since I hunt with, and spend a good portion of my day laser etching custom turrets, you can guess that I feel they are a great LRH tool.

That said, MontanaRifleman's point that a single turret can't match every situation is valid. Regardless of what system you use, you need to know what your bullet will be doing in the particular shot situation. If we find ourselves in a situation where an extreme elevation, temp, or angle means the turret won't be correct, we adjust accordingly. Adding a minute or taking a minute off with our turret is just as easy as it is with any turret.

The advantage is that for 80% - 90% of the shots we encounter, we can just dial and shoot if our turret is within about 3000' of where we are hunting. That window can be smaller or larger depending on your loads performance. With a few simple "rule of thumb" formulas we can cover the other shots very reliably.

With 2 turrets you can cover a lot of North American hunts and you can be sheep hunting at 10,000' in the morning and in less than a minute put your second turret on and be dead on for a 3000' antelope hunt. We hunt WY, CO, & NM for the bulk of our hunts which generally takes us from 4,000' to 11,000' and we use a 7,000' dial for about everything in the west..

Second turret is free for LRH members this month and you always get a click or MOA (special request) dial with the scope that works great for load developement.


Don,

Your system sounds very interesting but I'm not sue I would go with just 2 turrets for all of NA or even just Montana. Each difference of 1000" elevation or 1" of baro pressure result in 5" (1/2 MOA) differenc at 1000 yds. I could live with this set up if I had just a dedicated antelope rifle,or put the turret on my scope for antelope and then switch back for deer and elk.

But, when traversing several thousand feet in mountian terrain, I am skeptical of getting accurate shots. You mentioned some rules of thumb. Would you like to expalin them and what do you do for angle shooting? You might make a convert out of me if you can convince me I can make accurate shots in wide range of conditions as well as angle shots.

Thanks,

-MR
 
MR:

Thanks for moving this subject, we did have the other thread pretty well hijacked. You obviously know your stuff and are confident in the system you use. I won't be trying to convert anyone and here at GreyBull we know as well as anyone that there's more than one method at arriving on target at extended ranges.

Here's an example of a "rule of thumb" we use when dialing with our drop compensating turrets.

The actual percentages and numbers can be load specific so a shooter needs to know what their performance is to come up with similar mental cheat sheets.

With a 30deg incline dialing to 10% under the actual range puts us on target.

Example

800 yard shot 30deg incline
We dial 800 - 10% (720)
That usually puts us within a click of what the actual drop is for the shot.

A true 30deg incline is steeper than most folks usually think and most shots we encounter are far less than that.

If I'm at the upper or lower general limit for a dial, (about 3000' away from what the dial was built for with high performing load) I know that at 600 - 700 yards a click puts me right where the data would and at 800 - 900 it's 2 clicks. Thats a very load specific mental note that will vary greatly based on an individuals load.

Thats less than a minute which can be tough to shoot well enough to notice under field conditions. If the temp is higher at the lower elevation, which happens alot (and visa versa at higher elevations), the differenence is smaller or almost nonexistent.

For us, most of our shots end up under 20 deg incline, within 3000' up or down from what our dial is set for and within 30 deg of the temp it's set for. With those conditions, dialing directly to the yardage makes for a lot of filled tags. The speed of doing it this way and doing the wind in the reticle with no dialing is a big plus for us.

Most of our customers get a dial to match their home elevation and a dial for hunting the west. For that 4500' $tone $heep hunt or that 12,500' 15deg marco polo hunt, most guys spend another $100 on a turret that matches the area.

I'm off to pack in for a high country muley hunt to help spot for buddy. We'll be at 11,500'+ and he has a 7000' turret...hmmmm:rolleyes:
 
Don,

I would love to be a convert if I thought the system would work for me. To be able to just dial in your range would be reeeeal sweet. The idea of getting one for Antelope and PD's sounds real interesting to me and I may go that route if it works with my scope, a NF.

Still a little skeptical on the mountain hunting but will definitely give it some consideration. In my rifle, 3000' difference in elevation equates to about 1 MOA in drop. That's not bad and could be fairly easily compensated for but when you start throwing a few other variables it could get a little tricky. You're right about 30* being a rare shot. It is steeper than most people think and most shots are well under 20* But there is always the possibility and I have seen critters a 1000-1500" below me at about 1000 yds away. I like hunting canyon rims and mountain ridges where these shots can pop up.

One more question... when swapping out turrets, does your POI remain the same or do you need to tweek it each time?

Have a good hunt, will be interested in the results.

-MR

Anyone else with who has hunted mountain terrain with this or similar system is sure welcome to give their $.02
 
I feel that for long range hunting applications the custom turrents are going to dominate the future. Myself and a good number of my fellow coues, muley, elk, pronghorn, and predator hunters here in Arizona have been using standard target turrents and or ballistic plex reticles for a long time with good success.

With the plex reticles, after alot of range time, load and scope tuning and testing we were pretty solid to 500 yds on a big game animal. Using standard target turrents with pocket pda and or a drop/adjustment chart taped to the rifle etc, you can dial in a significantly more precise point of impact at all ranges in comparison to using a plex reticle.

A turrent engraved with your base yardages greatly reduces the complexity and time it takes to make an accurate scope adjustment. Some of the guys in my circle of friends who are serious hunters but were not regular shooting enthusiasts, reloaders etc, were generally not confident and proficient making the calculations, adjusting the scope etc. Put a trophy big game animal out in front of you with limited time to set up and place a shot in the boiler room and errors in calculations and/or scope adjustments can happen to the best of us.

Having the yardage engraved on the turrent adds alot of confidence, simplifies and speeds the adjustment process. If needed, variables such as elevation, temp, angle etc can be handled quickly with a couple of clicks up or down from the base yardage setting. You get all the precision with a simpler, more efficient, user friendly system, that even a novice shooter can get a handle on in short order.

I have yet to see anyone who set their rig up with a custom turrent who was not amazed with the results. For me, it was very liberating. It is a night and day difference in precision compared to using a plex reticle and it greatly simplifys and speeds up the process of manually adjusting the scope to execute a precise long range shot.

It took a good 7-8 years after the plex reticles proved themselves to be popular with hunters before every single manufacturer got on board and offered a scope with a compensating reticle. I think Burris was the first to offer a ballistic reticle in a decent quality scope that Joe Hunter could afford. They capitalized on it and everyone else eventually followed suit.

We will have to wait and see how things pan out, but right now, myself and my circle of hunting buddies simply won't consider purchasing a scope for long range hunting (over 400yds), that cannot be equipped with a custom turrent. It is so effective and easy it makes you feel like you are cheating.
 
Big Mo,

I can see where these turrets have a lot of potential and I will probably get one (or Keaton) myself for antelope/deer hunting on the plains where there is little elevation change and angle shooting. I may even get one for 6000' elevation which is probaly middle of the road for my mountain hunting, to do some experimenting with. I think out to 600 yds or so, these turrets would work very well. The farther you go past that the more "fudgng" you have to do when things start changing on you, esecially steeper angel shots. I guess there's nothing better to do than maybe give it a try. We'll see eh...

-MR
 
MontanaRifleman: I was as sceptical as you currently are. Decided to make the switch to a custom turret after last hunting season. After wringing it out over the summer over various distances and circumstances I am confident (Should say positive enough) that I'll be using it exclusively this year. I finally drew a Brakes sheep tag here in Mt. after 39 tries and I have enough confidence that that the turret will be used on this hunt as well as all others this fall. Haven't drew blood with it yet but there are a lot fewer rocks in this part of Mt. than there were before I got it. Haven't even told my hunting partners I've switched to a custom turret as of yet as I know I'm going to get a ration of ____. In the bunch I shoot with I'm afraid admitting that you're using a custom turret is like coming out of the closet. I will say - it is very easy to use and very quick compared to doing all the calculation of variables and I hunt from 2850 to 9500 ft.
 
Muley hunt went well. The shot ended up being 5,500' above his turret (nose bleed section). It was only 410 yards so he just dialed and sent a 105gr on it's way.

WebShaneMuley09Pond.jpg
 
I cannot help but side with MontanaRifleman . After 600 yards things will change . I would love to see some video of custom turrets on steel targets out to 1000 or 1200 yards, make the steel 12x12 this size is smaller than big game kill zone but I feel this size will make you or break you . I feel like you cannot get the results you have with a good ppc system. I'm not saying you can't kill deere because obviously folks are doing just that, I'm saying try to hit a 12'' target at extended ranges.

BIGBUCK
 
Not to really make a fuss or anything, but just take a piece of masking tape and wrap around your turret. Use a calculator like biggameinfo.com type in your numbers for where your hunting and turn the dial and mark a hash on the tape and write a yardage increment above it. I know its not as nice as a custom BDC dial, but its worked for me for target practice out to 700 yrds with my 22-250. If your going somewhere else just take a printout with the conditions from that site and a little extra tape along and there you go. Personally I'd like a nice BDC knob for my rifles, but I cant really afford all those things. Just what I do anyway.
 
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