Rifle Scopes another mount thread

[Rockhopper]

ok, first i will start with the details of the rifle. i have an AR15 built off of mega recievers. it has a 4 lb timney trigger, nsr ff rail, and the barrel is a daniel defense 16" s2w in 5.56 (suppose to hold 1 moa, we shall see). i am building a spr/do it all rifle.

my optic of choice is the vortex pst 2.5-10x32 ffp mrad. this scope is listed as having 25 mrads (86 moa) of internal adjustment. i am going to be using the rifle for bench shooting and varmint hunting. most shots will be 50 to 200 yards. but i want to push the rifle to its max whenever i have the opportunity too. i have plenty of places to shoot a LOOONG ways.

ok all that said, i need to purchase a mount. this is my first AR built as an SPRish rifle, and have no experience with scope mounts for AR's. i see the majority of them seem to be 0 moa mounts. and a handful of companies offer 20 moa mounts. very few have a 30. so my first quesiton is why would you opt for 0 moa mount? is there any reason not to choose a mount with 20 moa built into it for my particular setup, shooting say 50 yards and out to maximum my rifle will allow me? (in the future i may build a 6.8 spc upper for this rifle) is there some benefit to having the 0 moa mount? why would i choose a 0 moa mount over a 20 moa mount? what is the advantage or disadvantage to having either one? why are 20 moa mounts not as popular?

then the second part of that is which mount? $200 budget, and cheaper is always better. i do not really plan to take the scope off and on much so i am impartial to QD or not, but would not mind something with a good rtz if necessary. no matter if it is bolt on or qd. i am not loyal to any brand. i want something solid that is going to do its job and not ruin the rail on my gun.

any and all help is appreciated.

 

[Rockhopper]

anyone?

 

[BobinNC]

I have a Leupold MR/T 2.5-8x36MM SKU: 112633 on my 5.56mm chambered 18" BCM Barreled AR. It has a single turn turret with 29 MOA (.50 MOA per click) available between the zero stops, and mounted in a Bobro 0 MOA Slightly extended 30mm mount. I use a Nosler 77 gr. CC loaded to 2700 FPS (+ or - 10 FPS). Here's my current drop table:

Calculated Table
Range	Drop	Drop	Windage	Windage	Velocity	Mach	Energy	Time	Lead	Lead
(yd)	(mil)	(MOA)	(mil)	(MOA)	(ft/s)	(none)	(ft•lbs)	(s)	(mil)	(MOA)
0	***	***	***	***	2700.0	2.423	1246.2	0.000	***	***
50	0.1	0.4	0.1	0.4	2583.2	2.318	1140.7	0.057	5.6	19.1
100	0.4	1.5	0.2	0.9	2469.2	2.215	1042.2	0.116	5.7	19.5
150	0.3	1.0	0.4	1.3	2358.0	2.116	950.5	0.178	5.8	20.0
200	-0.0	-0.0	0.5	1.8	2249.8	2.019	865.3	0.243	6.0	20.5
250	-0.4	-1.3	0.7	2.3	2144.7	1.924	786.3	0.312	6.1	21.0
300	-0.8	-2.7	0.8	2.8	2042.4	1.833	713.1	0.383	6.2	21.5
350	-1.3	-4.3	1.0	3.4	1942.9	1.743	645.3	0.459	6.4	22.0
400	-1.8	-6.1	1.1	3.9	1845.8	1.656	582.4	0.538	6.6	22.6
450	-2.3	-8.0	1.3	4.5	1751.0	1.571	524.1	0.621	6.8	23.2
500	-2.9	-10.0	1.5	5.2	1658.4	1.488	470.2	0.709	6.9	23.8
550	-3.6	-12.3	1.7	5.8	1567.9	1.407	420.3	0.802	7.1	24.5
600	-4.3	-14.7	1.9	6.6	1479.6	1.328	374.2	0.901	7.3	25.2
650	-5.0	-17.3	2.1	7.3	1393.6	1.250	332.0	1.005	7.6	26.0
700	-5.9	-20.2	2.4	8.1	1310.3	1.176	293.5	1.116	7.8	26.8
750	-6.8	-23.3	2.6	9.0	1229.9	1.103	258.6	1.235	8.0	27.7
800	-7.8	-26.8	2.9	9.9	1153.3	1.035	227.4	1.361	8.3	28.6

<tbody>
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Considering I'm not planning on shooting this round further than 800 yds. why in the world would I want or need a 20 MOA mount. Change the upper to something more potent, then sure, I would drag out my 22 MOA Badger AR Riser I keep in stock, and switch to a different scope and ring combo. But with a 5.56mm with common 77 gr bullets, that will actually feed from the mag. are about tapped out at around 800 yds. Yea, Single loading 80 grainers, is another question and it is not something I engage in with my use of an AR.

You could reach 1000 yds with my load combo and 12.8 MILS or 44 MOA of adjustment, but you'd be sub-sonic at that point, and your 16" 5.56mm barrel is not exactly made for long reach....

Of course my needs and wants may not match yours, but due consideration has to be paid to how your actually going to use the round and rifle at hand and for what purposes. IMHO and YMMV

 

[Rockhopper]

that is an awesome explaination, thank you!

with that said though...if you are spending the money anyways, why would you NOT get the moa built in? even if you dont need it for the particular cartridge...is there any reason NOT to get it. I buy stuff to keep. I could use it in the future on different cal uppers. is there any harm in having it? is there a benefit to not having it? regardless of needing it? what if i were to throw it on a dedicated .22lr upper?

i guess that is my whole point. if you are going to spend the money anyways on a new mount, besides the point of ballistics of the cartridge, why would you choose NOT to get it?




and can anyone follow up with mount recommendations?

 

[Magnumdood]

Near Mfg. would be, and is, my choice of mounts. Richard Near builds an Alpha Mount which is a unimount that bolts onto a rail. He has Alpha Mounts that go from 0 MOA to 45 MOA cant. His machine work is impeccable; his Alpha Mount looks like a functional piece of artwork. His price is right in there with Spuhr and the other custom bases/mounts. It wouldn't surprise me if he had AR risers with cant built into them. One of our own board members, Jon A, makes a mount he calls AADMOUNT. He's a Boeing Engineer by trade and he makes one helluva a mount too.

 

[Magnumdood]

that is an awesome explaination, thank you!...

Very few people can write as well as Bob, and in a way that his points are clear, concise and everyone can understand what he's explaining. He has a gift I wish I had.

 

[dylanmj]

If you need to buy a mount anyway, I don't see any harm in getting one with 20 MOA cant built in. Anyone feel free to correct me if I am wrong, but if your scope has 86 MOA of total internal adjustment, then 43 of that is up and 43 is down. Putting a 20 MOA canted rail will shift that ratio to 63 MOA down (POI goes up) adjustment and 23 MOA up (POI goes down). Should leave you plenty of adjustment to zero the rifle at whatever range you choose, and have a bit more reach to stretch the distance with the turrets.

 

[Snake CharmerXX]

Hard to add more than Bob has said. I'm making a similar decision and wanted 20 moa down for the same reason. Many suggested not, and as I looked at it I decided I had enough elevation to do just as Bob has done; go to a heavier bullet w/ a better BC.

What I also wanted, have been fighting, and haven't seen you mention, is a good cheek weld. i'm moving up to a 50mm objective, so I'm height restricted. You are not, and I assume using a 1" tube. Was I you I'd be thinking about how much ring height you want/need.

Just a thought, hope it helps.

 

[Rockhopper]

Its a 30mm tube. What mount did you ultimately decide on?

 

[goodmanfj]

What Bob said , a used Bobro mount goes for around $175.00 well worth it ,

 

[Snake CharmerXX]

Its a 30mm tube. What mount did you ultimately decide on?

I'm using a 50MM objective on a 30MM tube. With Butler Creeks I'm 1.31" radius. After WAY to much study, my final three choices were:

ADM Recon: 1.45" height, and enough forward mount that you can be leaned into the rifle and still have 4" of eye relief and keep the mount on the receiver.
I don't feel the need to spend the $ for QD. And it's a bit too many screws to come loose/star wars for something I think of as stick and stones purpose.

DNZ Freedom Reaper Forward Mount: 1.375" height, and enough forward mount that you can be leaned into the rifle and still have 4" of eye relief and keep the mount on the receiver.
If I was going to spend that much money I'd buy the ADM hands down. The ADM website is more informative and helpful in every regard, the mount is more flexible, and at this price point you might as well do QD

Leupold IMS Mark 2 w/integral Rails: 1.42" height, and enough forward mount that you can be leaned into the rifle and still have 4" of eye relief and keep the mount on the receiver. I think. This might be close.
But I also have full length rails, the thing is simple, looks well built, and for goodness sake I can have it to my door for $83!! This is THE best buy for this kind of purpose. Am ordering it as soon as I logout.


I'm not convinced I'll get the cheek weld I want, but I'm down to about 1/10" of an inch clearance and don't want to take off the scope caps. I'll look at adjustable check pads as I work out exactly what I want in a rise and once I know exactly what I want, well, we'll see.

 

[Rob01]

http://www.snipershide.com/shooting/options-accessories-sale/216558-nib-warne-ramp-mount-30mm.html

Very good mount. I have one sitting waiting for my Vortex. I have one on my other AR with a Vortex 1-6x in it. I am planning on mounting the 2.5-10 in it and putting a small red dot Fastfire III on the side rail. You can also put iron sights there are a back up.