MOA bases, 223, Do I need them??

Just ordered a 10 FCP-K in 223. I plan to put a Sightron SIII 6x24x50 on it. This scope has 100 MOA adjustment per the manufactures data. If my thinking is correct, since the scope is some number higher than the bore, I already have some elevation built in (more than 50 moa) I'd think. This is going to be my effort to shoot prairie dogs and cans at 300 to 500 yards. My specific question is: Do I need an additional 20 MOA built into the base? If I'm shooting farther than 500, I'll use the 6mm. Your thoughts and experience?

You shouldn't. Just plugged this into Sierra Infinity using a 52gr SMK as an example, but assuming you're zeroed around 200 yards, it should only require 11 or so minutes of elevation to get you on target at 500. You'd still have 39 minutes to work with. Basically you'd run out of adjustment somewhere around 900-1000 yards

You won't even approach needing a tapered base with a .223 out to 500 with that scope. I'm shooting a flat base out to 375 with considerably less scope adjustment available without coming anywhere near the end of the scope adjustment. With a 60gn Vmax and its relatively crappy BC fired at 3100fps and a 100yd zero, you only need 11MOA to get to 500. There are much better bullets available for the purpose like the 53gn Vmax which at 330fps only needs 9MOA to get to 500.

I like the 40gr vmax

thanks for the input. I'll concentrate on bases and rings and skip the moa base. I've got the same scope on a sporter barrel 6mm. I used high rings. It got the scope off the barrel more than I like, but mediums would have caused issues with the bolt handle clearing. I'll work on getting this scope lower to the bore.

If you're having problems with bolt handle clearance, don't rule out a new bolt handle as part of the solution. Unlike many other rifles, it only takes the removal of a single bolt to replace the bolt handle.

thanks helotaxi, I won't rule out anything. I've gotten modestly familar with this platform now. I've rebarrelled and restocked a 10 model todate. I get the bolt mods. I stripped one when I headspaced the barrel change. I'm having a blast with mine and my shooting partners guns. Not scared to mess with most anything now.

I use medium Burris Signature Zee rings on all of my Sightron SIII scopes on rails,and have no clearance problems with any of the bolt handles.

I found that the Burris Signature Zee rings are too high if used with a rail. With a set of 2-piece Weaver bases, they are just about right. I prefer other bases for use with a rail.

Gulf,

If your only limiting yourself to 500 yards, you won't need the 20 MOA base. I just bot (well....now it's old as I bot it this past summer ;) ) the Model 10 Precision Carbine. It also has a 1-9 barrel twist and for my rifle (yours may or may not like this bullet) I have found it really likes the Hornady 68gr. BTHP over the max charge of Varget. Now, I do have my VX-3 mounted with Signature Zee rings on a 20-MOA base. This causes the cheek piece to be too low, so I bot and just installed a Karsten's custom cheek rest. I really like the factory accustock on this rifle, I just needed a bit more cheek weld rise. This did the "trick."

http://www.tacticalworks.com/images/P/p-16142-01.jpg

And should I ever decide to part with the rifle, ( however....with this accuracy and the fact that I'm customizing it....this one will probably stay with me until I ask the gatekeeper if there is a shooting range and if hearing and eye protection is required) I'll just let the Karsten rest go with it, or with some Davcon and a some cammo paint.....call it a day!!!

Love the rifle!! I know you will love the accuracy!! (Well....I think you will!!)

Dave

this may help just a bit!
http://www.egwguns.com/moa-faq

I used the one piece weaver base with the Weaver "low" 6 screw tacticle rings. It put that Sightron III about 3/64 off the barrel. Just where I'd hoped. I believe the Weaver tacticle rings are "higher" generally than their typical rings. I took to the range yesterday and had a blast. Took 5 loads with 3 bullets weights and 2 different powders. I got 2 keepers for sure. The tables at the range I used have high tables and short chairs. Not the greatest setup. Most of my longer range shooting is done at a friends farm. My table/chair set up there is better for me. That will determine if the scope height/cheek weld is ok. Yes, this gun will shoot! Dave, I like that cheek rest!