Rifle Scopes S&B Ultra Short 3-20 vs standard PM2 3-20

[TacticalPlinker]

Considering going the Ultra Short 3-20 route for an AR10 build. Liking the compact size and larger field of view for dynamic shooting.

Is there any change in eye box , exit pupil when compared to the longer PM2 3-20 ?

Not willing to give up any speed on target for a shorter package....

All replies are appreciated.

TP...

 

[longshot2000]

The Ultra Short is a newer scope, and last time I looked at factory pricing, the Ultra Short was a little more expensive, but not by much. A lot of good things have been said and written about the 3-20 Ultra Short. It is going on the US Army's new compact sniper rifle, so a good fit with a AR10 / AR308 build.

 

[hamstur]

Behind the scope they are fairly identical. Which means they are both great scopes. The 320US just always feels bigger than expected. Really feel the 520US is the winner.

 

[NotMalware]

Is the exit pupil diameter a measure of the "eye box"? It looks like 5-20US, the 3-20US, and the 3-20 PMii all have the same exit pupil diameter at 20X. I've heard that the 5-20US has a tight eye box. Is this a subjective thing, or a well defined property of the optical system?


http://www.schmidtundbender.de/en/pr...tra-short.html
http://www.schmidtundbender.de/en/pr...tra-short.html
http://www.schmidtundbender.de/en/pr...iilpmtclt.html

 

[hamstur]

I currently own (4) 520US, previously owned (2) 320 and (1) 320US. Also shot somebody else's 320US. Call that a sample size of 8. Re: eyebox, they are all the same. Don't over-analyze trivial differences, or get sucked into discussions around those matters. Being all equal "behind the scope" as I mention above:

- If you can live with the massive 15" size and huge locking turrets, get the 320 and save a ton of cash. But it is a big scope.

- If you are sold on needing down to 3x, and want to shave length, shave turret size, add capped windage, get the 320US. Be forewarned 3 people I know including myself kept lamenting there is just something funky and unbalanced about the way it looks -- think of it like a 320 ocular mated to a stubby 520US objective. The other 2 guys added a sunshade and magically, it's the same length as the 320 regular again! At 13.4" it really isn't that short ... almost an inch longer than a NF416F1 by comparison! But compared to the 320 regular, the US is a sassy scope.

- The 520US just has the right proportions from an aesthetic perspective. I used to think the Hensoldt were compact scopes, especially the Hensoldt 312 at 12.8". The 520US measures 11.8", and everybody I know who owns one marvels at how the hell they made it that size and so excellent.

Off-topic and call me a fanboy, but I chuckle everytime folk comment on how "outdated" S&B designs because I think they surely haven't tried an Ultra Short. The SB525 is a "legacy" product, and it's still a benchmark product ... why mess with a winning formula until it truly proves obsolete.

 

[longshot2000]

humstur: Great post, and nice to hear the comparisons first hand. What I would add, from what I heard from S&B, is that the 5x20 had some issues due to very limited mounting space, or unusual measurements on each side of the turret, and the 3x20 was released, in part, to solve that issue. Personally, I have not tried varies mounts with the 5x20, but that was the story I was given...

 

[Covertnoob5]

humstur: Great post, and nice to hear the comparisons first hand. What I would add, from what I heard from S&B, is that the 5x20 had some issues due to very limited mounting space, or unusual measurements on each side of the turret, and the 3x20 was released, in part, to solve that issue. Personally, I have not tried varies mounts with the 5x20, but that was the story I was given...

It's definitely limited mounting space, but I know there's a few different mounts that fit. Era-tac, spuhr, the arc m10 qd, the nightforce mount. I think the gdi prom as well not sure though. So there are options.


Better to have it and not need it, than to not have it and say oh shit.....

 

[jonthomps]

I've had both and still have a 3-20 Ultra Short. There's really no reason to own a standard 3-20 unless you really want high profile turrets. The 3-20 US does everything the standard model does in a more efficient package.

 

[hamstur]

If you're good with 1.35" mount height, the Spuhr 4036 is perfect. If it helps to see the difference, I had 2 pics on my phone that help visualize the mounting scenarios with the scope.

First pic has (2) 520US on TemplarV2/Deviant actions. Even with APA 1.031" rings, I'll admit I wish I could pull them back just a smidge more but it's fine where it's at. The bottom pic is a Deviant Hunter action. Notice where the rings sit between the closed vs open top actions. If you run an open top action you MUST go non-illuminated. No way in hell the illum bridges the gap due to mounting real estate issues. On the Hunter action, that is as far back as it goes.

The second pic is one I the sent the buyer of my 320US. It is sitting next to a Spuhr 4036. There is 1.6" more tube to play with total end-to-end tube space. if the exact measure helps, the 520US is 3.84" and the 320US is 5.44".

Overall, non-issue if you plan to run it on a flat-top AR because everything is mounted above the mounting surface. I've mentioned in old posts on Scout: if you ever consider moving it to a long action or 'longer' short action (e.g., Badger, AI AT without EO stubby rail, etc) -- that's the other scenario where the 320US is a must unless you have a giraffe neck.

 

[TacticalPlinker]

Thanks for the information fellas. The decision to go US over "standard" is a no brainer....

Going to run the 3-20 Ultra on a 5.56 gasser setup for PRS TacLite as well.

 

[Covertnoob5]

If you're good with 1.35" mount height, the Spuhr 4036 is perfect. If it helps to see the difference, I had 2 pics on my phone that help visualize the mounting scenarios with the scope.

First pic has (2) 520US on TemplarV2/Deviant actions. Even with APA 1.031" rings, I'll admit I wish I could pull them back just a smidge more but it's fine where it's at. The bottom pic is a Deviant Hunter action. Notice where the rings sit between the closed vs open top actions. If you run an open top action you MUST go non-illuminated. No way in hell the illum bridges the gap due to mounting real estate issues. On the Hunter action, that is as far back as it goes.

The second pic is one I the sent the buyer of my 320US. It is sitting next to a Spuhr 4036. There is 1.6" more tube to play with total end-to-end tube space. if the exact measure helps, the 520US is 3.84" and the 320US is 5.44".

Overall, non-issue if you plan to run it on a flat-top AR because everything is mounted above the mounting surface. I've mentioned in old posts on Scout: if you ever consider moving it to a long action or 'longer' short action (e.g., Badger, AI AT without EO stubby rail, etc) -- that's the other scenario where the 320US is a must unless you have a giraffe neck.

Hey Hamstur quick question, how much elevation travel are you getting with the Spuhr mount and on what caliber? Thanks.
I'm thinking about trying that mount.


Better to have it and not need it, than to not have it and say oh shit.....

 

[hamstur]

Single turn model maxes to turret's 16.7mil capacity. 6.5x47 dope runs to 1425 yards but never needed more than 11 mil!

 

[emulous]

I've been eyeing an S&B Ultra Short and noticed within the last few weeks a number of them have been popping up on the PX section. Are people buying them but having second thoughts after getting behind it? I'm sure the glass is top notch but what are the other reasons they are suddenly popping so often on the PX? It's a fairly exclusive optic mainly due to the price up until recently. Just fishing for opinions from owners selling theirs before I decide to dump $3K into one.