U.S. Optics SR-8c: Test 1 Results

I shot five tests with the SR-8c, and will shoot the same courses of fire with each optic in this test.  I originally intended to include all the results in one post, but the word count was astronomical.  As a compromise I decided to put the results for each test out on consecutive days.  Yes, that means a post per day for five days in a row.  Dont’ get spoiled.

The measurement tools I have on hand to help me in assessing the performance are a shot timer (iPhone app), a target with scoring rings, and the On Target TDS program.  Distances beyond 9 yards have been verified with a laser rangefinder.  I pace off everything shorter.

Measuring results is the easy part.  I have so many ways of measuring that finding meaningful ways to compare results is a bit dizzying at the moment.  I’m still working through what is important, and how to get at what I’m trying to measure, so better to have data and not need it than need it and not have it.

One difficult aspect of this testing is that although I’m not performing up to what I would consider acceptable standards, I’m not doing any practice to improve them.  Any improvement on my part over the course of this testing would skew the results.  Therefore there is no specific practice on these drills and this testing encompasses the totality of my shooting with the AR.  There is typically 2 weeks or more (usually more) between the beginning of each round of tests.

Test 1: Single shots at 7 yards.

The starting position for this test is butt in the shoulder pocket, and muzzle depressed, probably pointing at the ground 2-3 yards in front of me, and trigger finger indexed.  A round is chambered, the safety is on, the scope illumination is on, and there are no scope caps on the scope.  The magnification was set at approximately 1.8x, which provided an image size approximately in accordance with what I was seeing with the naked eye.

The rifle has been configured with an Atlas bipod and a light rear bag (I think it’s about 2oz.) for a while now, so I leave it as is.  I have to pause after each shot to record the time.  The iPhone sits on the clip board, so after I record the time I hit “Start”, drop everything on the ground next to me, and assume the ready position.

New Target

The target for these tests consists of an ~8.4” ring for 1 point, a 4.2” ring for 5 points, a 2.1” ring for 6 points, a 1.05” ring for 7 points, and a half inch ring for 8 points, all on an 8.5×11” sheet of paper.   Since my goal is to hit a 4” circle at any distance inside 200, and I conflated inches and minutes for whatever reason was in my brain at the time, I ended up with even minutes at 100 even though I use the target at various distances.  I have been coming up with an average score per shot, so I can compare apples to apples for any course of fire involving any number of shots.  If I average 5 points per shot or greater I feel pretty good about things at the moment.  In addition to my numeric scores, I also kept track of my hit ratio on the primary 4.2” scoring ring.

I fired 20 single shots at the target for this test.  My slowest time was 1.32.  My fastest was 0.84.  My mean was 1.04.  The hit rate was 85% (17/20).  The total score was 104 and the average per shot was 5.2.

7 Yard Snapshots- resized

As I look at the raw numbers, several strategies for evaluating them come to mind.  I have to decide what is most important to me.  That would be hitting the target.  I can’t separate out the need for speed, because a slow hi                                  .  See how that sentence could never be completed?  I was too slow to finish it.  A slow hit may not ever happen.

In USPSA shooting (they called it IPSC back in my day) they come up with a hit factor by dividing points by time. That’s a good idea.  I’ve figured out that my point scheme is not as important to me as getting a hit.  I define a hit as more than half of the bullet hole in the scoring zone.  I decided that I could also look at hits over time.  That would be my hit ratio over my average time, which would more properly be called “hit factor” than what USPSA does.  I therefore am calling the other way to measure score, points over time, “point factor”.

In this case my hits over time (“hit factor”) was 0.82.  If I got one hit in one second my hit factor would be 1.  If I got one hit in a half second my hit factor would be 2.  To me a hit factor of 1 would be the least acceptable score and a 2 would be exceptional, but that speaks more to abilities than the equipment at hand, so that’s really neither here nor there at the moment.  This is a baseline.

Looking instead at points, my “point factor” was 5.02 points per second.  This shows my performance in a better light, because some of my better (more centered) hits made up for some of my misses.  Since the basic “hit zone” is 5 points, it looks like just over 1 hit per second.

Since I have completed this test with only 3 of the optics (this being the first), I’m still working out which measurement I think will compare results most meaningfully.  When I get them all done I make y’all a nice graph and pie chart or something.

Final Subjective Impressions on the U.S. Optics SR-8c

On Power

This optic was on my AR for quite a while, approximately 3 months.  During that time I think I got to know it pretty well.  I did most of my shooting within 100 yards, with a minimum of probably 7 yards, and a maximum of 330 yards, some known distance and some unknown.  Besides shooting I spent a lot of time handling the rifle while it was equipped with this optic, and spent a lot of time carrying the rifle outdoors while on walks or sometimes runs.

One thing I noticed when outdoors is that while I kept the power pretty religiously set at 2x (which afforded me an image that appeared to be pretty close to what the naked eye sees) I almost always turned it up when sighting targets at realistic outdoor distances, even ones that seemed relatively close.  After a while I started to keep the scope at about 4x when on walks outside.  When sighting things like deer between 200 and 500 yards (no shooting, just looking) I invariably set the power at 8x.  I think that the lower powers only make sense as a “must have” at indoor distances.  For outdoor use I think I could live with giving up some of that low end to gain a little more high end, which ran counter to my expectations and really surprised me.

Turrets

I didn’t do a box test.  I zeroed the rifle and the knobs seemed to do what they should have done.  They had a very confidence inspiring feel- sturdy, positive, with a really no-nonsense/all business air about them.  The scope adjustments are set in 0.2 mil increments, which is consistent with the wide hash marks in the reticle.  0.2 mils is equivalent to about 2/3 of a minute of angle.  I see why they made the turrets “match” the reticle (2 mils at the long marks), but in my opinion 0.2 is too coarse an increment.  I can also see the rationale that the scope is basically tailor made for ARs, and that a finer adjustment is unnecessary.

The way I see it, the turrets are capped, and are pretty low profile.  That means to me that they are better left alone and the reticle should be used for correcting for trajectory and wind drift.  That makes perfect sense on an AR.  So as long as the units are the same in both turret and reticle, who cares if the increments are on the fine side?  Furthermore, the fact that the scope appears to be designed to zero the rifle and then leave the turrets alone, using holdovers instead of dialing, would make having a more precise zero all the more important.  I could not establish as precise a zero as I would have liked.  I would rather have 0.05 mil adjustments on this scope.  I think they went with 0.2 mils for people who still would like to dial.

I took the rifle out one day and shot a smaller piece of steel, approximately 6” from varying distances (about 150 to 350 yards) as I walked around finding different terrain and objects for rests.  I had forgotten what the reticle subtensions were, and found the actual dimensions a little counter-intuitive, which made it difficult to get on target.  Once I figured it out (actually looked at the manual) it was actually pretty easy to get on target.  I believe that the coarseness of the reticle and subtensions is probably a necessary compromise due to the 8x zoom.  Overall the compromises are pretty insignificant compared with the advantages.

Scope brightness and low light.

I did not complete a real low light test with the scope.  I did shoot a qual course at night and found that compared to an EOTech, the SR-8 was seriously like cheating.  Not just a little bit easier to use, but significantly.  I did not find the comparative dimness of the scope to be at all detrimental at night.  ARs typically have lights, and lighting up the target makes it easy to see.  I actually didn’t even have a light, but depended on ambient light from people next to me.  No problems.

Ergonomics

The scope is well built and easy to handle.  It’s on the heavy side, but I just got used to the weight.  It’s also big, and the peculiarities of its shape limit the mounting options.  That was probably the biggest issue I had with the scope.  I either need a higher comb or a lower scope.  The SR-8 needs to be mounted really far forward.  My friend at USO sent the scope in an extended Larue mount, which had T1 written on it (the forward-most rail slot).  That was just the ticket.  Any farther back would be a no-go.  The complication is that you can find low mounts, or you can find extended cantilevers.  I could not find one that did both sufficiently to my liking as far as height and forward enough to make for adequate eye relief.  I believe this compromised my tests to some degree, as all the other scopes will be tested with my Nightforce Unimount, which is quite low at 1.125” from the top of the rail to the centerline of the rings.  With the standard AR sight height, I have what can best be described as a floating cheek (non) weld.  This bothered me when trying to do anything precise or when using the scope at 8x, where the eyebox is less forgiving.

Is the scope as quick and easy to use as an Aimpoint?  I think it’s pretty darn close if not as close.  It takes just a bit more practice to get used to finding the eyebox and it takes up a bit more of the peripheral vision.  The difference is minimal.

On 8x is it the equivalent of a precision rifle scope?  No.  I wouldn’t put it on a bolt gun.  The scope has a different character than a standard scope.  It’s hard to explain, but they are just different things.  Power does not seem to necessarily equate to the same character.  It does, however, seem to have most of the practical capabilities of the 3-9 scope that I am used to.  In today’s market, I think that on a bolt gun the 8x zoom is wasted with the low power.

In the next article I’ll share the results of the SR-8c’s performance in the shooting tests.  It won’t be very interesting without anything to compare with, but a baseline is important to have.