Should 308 AR uppers have built-in cant?

hypertex

hypertex

Sergeant
Full Member
Minuteman
Nov 5, 2007
457
58
Bullhead City, Arizona
#1
When I mounted the scope directly to my rifle, I realized there was a problem. When zeroed @100yds, I couldn't dial up 13 mils to 1000 yards, not even close. I calculated that if I wished to use the entire range of my scope's turrets, I would need a 30MOA base.

Is this true of all 308 variants?

Should cant at least be an option?

Or is it just me...?

DPMS SASS 308
Falcon Menace 5-25
LaRue LT-107
 
#3
Re: Should 308 AR uppers have built-in cant?

What bullets are you using? I haven't ran a 308 in a while but 13 mils seems like a lot to get to 1k.

I like the idea of moa built in, but it does limit other options. Flat top lets you use the mount that you want for your particular application, bullet, barrel, etc.

Get the LaRue 50bmg mount, 30moa built in.
 
#5
Re: Should 308 AR uppers have built-in cant?

The Iron Ridge has 23MOA built in, that way it covers mounting a S&B or Hensoldt to the rail and not needing a riser with an additional cant built it.

the less between the rifle and scope is better if you ask me.

That said, If you need the new Spuhr Mount has a 30MOA canted model available, comes in a 30MM or 34MM. it's expensive but worth it.

Look up the SPUHR mount on here.
 
#6
Re: Should 308 AR uppers have built-in cant?

i wouldn't cant the upper i would buy a unimount with a built in cant. i think uppers need to be able to be built into carbines as well and i think a built in cant would be a pain
 
#7
Re: Should 308 AR uppers have built-in cant?

What is there to think about ?

If the scope is zeroed, and you have full elevation there is absolutely nothing extra to think about.

The cants' are 20 thousand of an inch from front to back... 20 thousandths you're not thinking about that.
 
#8
Re: Should 308 AR uppers have built-in cant?

eh i guess. I'm still for a canted scope mount but to each their own.

lol, lowlight i have no real reason for it other then i'm vain and like my uppers flat
laugh.gif
leave me alone!
 
#9
Re: Should 308 AR uppers have built-in cant?

I had a LT-104 cantilever and the eye relief was just right. I called LaRue and asked them if there was an unlisted option for cant(e.g.LT-112) They wouldn't even make me one. Now I love my LaRue gear, I ordered the LT-107, but I was surprised with this answer. The SPUHR mount is trick. Group buy aside, I PM'd Victor for a 30MOA cantilever mount.

Thanks for the heads-up Lowlight
 
#10
Re: Should 308 AR uppers have built-in cant?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jasonk</div><div class="ubbcode-body">What bullets are you using? I haven't ran a 308 in a while but 13 mils seems like a lot to get to 1k.
</div></div>

Playing around with the heavies i.e. the 208 AMAX At 2300fps it's 12.2 mils, but I've reduced my loads down to 2211 -those are 13.5mils and just supersonic. I'll find a happy medium with a little more work. Regardless of bullet, having the 30MOA mount means I only have about 2.5mils below my 100yd zero.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hellbender</div><div class="ubbcode-body">The Iron Ridge Arms uppers have a 20 MOA built in cant, don't know of any others. </div></div>

The LaRue OBR had 20MOA built-in, but no listing for just the upper

 
#13
Re: Should 308 AR uppers have built-in cant?

Really with what is supposed to be a precision rifle you want a more secure mount like the Spuhr.

it's why I like using Nightforce scopes on my AR10 type rifles because I can mount them flat on the rail, straight from the rings. I like the NF unimount that is a good, lightweight and simple mount, but more robust is certainly better.

A lot of mass moving in an AR10, so I want the mount to be as secure as possible so the less points of contact and the least number of attachment points between the scope and the rifle the better. If I'm using a mount, give me a torque value.

Seems odd we'll obsess over torquing our rings to 65 inch pounds with our bolt guns, but then guys will use a throw lever on their AR10s... doesn't quite add up for me.
 
#14
Re: Should 308 AR uppers have built-in cant?

Hadn't heard about SPUHR before today. I had heard nothing but <span style="text-decoration: line-through">good</span> great things about the LaRue mounts - I needed the cant and the LT-107 had it. The SPUHR looks even more solid - I'm getting it to replace the LaRue.
Now I've only put about 2000rds downrange using the LaRue, but it has lived up to all the hype.
 
#16
Re: Should 308 AR uppers have built-in cant?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KevinB-KAC</div><div class="ubbcode-body">M118LR will make to 1000m with about 9mils of elevation in a 20" bbl</div></div>

Not really... 9 Mils is not happening, an 18.5' 260 uses 9.6" mils, good 260 uses 8.8 Mils, and the average MV for M118LR is between 2650fps and 2700fps which puts it in the 11 MIls zone.

Even your own KAC Bulletflight shows the M110 w/ M118LR is 11.9 Mils to 1000 yards..

The average for M118LR is between 10.5 mils and 11.5 Mils depending on the rifle. In order to use 9 Mils to 1000 yards you need 2885fps which isn't happen on anyone's best day.

Kevin, you need to get out of marketing mode. LOL
 
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