Thursday, September 20, 2012

Range Report: New Optics

Another day at the range, this time with a new toy:

2012-07-28_11-19-51_2

That’s a Sightmark 5x slide-to-side magnifier to go with my Sightmark holographic sight.

A magnifier, like any scope, has a quality called “eye relief”.  Position your eye too far away from the lense, and the result looks like this:

DSCN1030

Get too close, and you see this:

DSCN1031

Positioned correctly, you see this:

DSCN1029

That’s the front sight post partially obscuring the view.  One of the disadvantages of this arrangement.

The second disadvantage is, this isn’t actually what I see when I look through the magnifier.  When I actually put my eye to it instead of the camera, the red holograph in the center is distorted.  I don’t mean the fairly mild lens flare seen here.  I mean the dot looks like somebody smeared it upward with his thumb.

The third disadvantage is that my shooting was actually worse than when I shot without it.

2012-07-28_11-31-35_226

Crap!  Out of 30 shots fired, five to each target, I can’t even swear I hit the board more than 10 times at 100m, let alone put my shots on the target at which I was actually shooting! 

I need to bring this back in to 50m and see what happens.

American Eagle XM855F 62Gr FMJ-BT Ball:

American Eagle XM855

Please ignore the .45ACP you’ll see scattered around the targets

Black Hills 55Gr FMJ “Remanufactured Seconds”:

Black Hills 55Gr Seconds

Don’t pay attention to the XM856 in the upper left corner.  I did fire that ammo at this target, but it didn’t hit it, nor did it hit anywhere else on the board.  So I tried again with the Black Hills.

Black Hills 60Gr. Soft Point:

Black Hills 60Gr Soft Point

Again, pay no attention to the “Fiocchi” in the upper right.  I ran out of that ammo trying to hit the board at 100m.

PMC Precision 75Gr. Match:

PMC Precision 75Gr

Reliably the tightest group, but the zero is way off from where it was previously.  Could the quick-detach be catching up to me?  Could the magnifier be moving the zero?

Sellier & Bellot 55Gr. SP:

Sellier & Bellot 55Gr SP

I seem to be missing one (the whole in the right not belonging to me).

Tul Ammo 55Gr. FMJ:

Tul Ammo 55Gr FMJ

With the exception of the shot that went wide on the left, this wasn’t a bad group.  I actually haven’t been disappointed with the performance of the ultra-cheap Russian ammo.  Too bad the steel cases are so hard on the rifle.

Okay, let’s do a side-by-side comparison.  Picture sizes have been approximately adjusted to match target sizes.

XM855:

American Eagle XM855[Federal%2520American%2520Eagle%2520XM855F%252062gr.%2520Penetrator%255B3%255D.jpg]

Black Hills Seconds:

Black Hills 55Gr Seconds[Black%2520Hills%252055gr.%2520Remanufactured%2520Seconds%2520FMJ%255B3%255D.jpg]

Black Hills SP:

Black Hills 60Gr Soft Point[Black%2520Hills%2520Soft%2520Point%252060gr_hilite%255B5%255D.jpg]

Tul Ammo:

Tul Ammo 55Gr FMJ[Tula%252055gr.%2520FMJ%255B4%255D.jpg]

PMC Precision:

PMC Precision 75Gr[PMC%2520Precision%252075gr.%2520BTHP%2520Match%255B3%255D.jpg]

Sellier & Bellot:

Sellier & Bellot 55Gr SP[Sellier%2520%2526%2520Bellot%252055gr.%2520SP%255B3%255D.jpg]

My off-hand estimation is that the magnifier has made me slightly more consistent at 50m, although that could be a marginal improvement in technique or just day-to-day variation.  But dagnabit, I bought a magnifier to make me more consistent at 100m! 

4 comments:

Professor Hale said...

I admire your persistence. As us professional process controllers like to say, "if your aren't measuring your process, you aren't controlling it.

At what range did you zero? Hint: It matters.

Also. I am no longer certain the steel case is so bad. Thee are now millions of people using it and I am not hearing about lots of problems with excess wear and tear.

Professor Hale said...

looking back at it, part of your problem is that bipod of yours. It is OK for daily use but if you are trying to minimize other sources of variation so you can see how the sight is performing.

Try again with sandbags or a shooting stand.

Dr. Φ said...

Yes, when I get to the point where I'm chasing the last decimal point, then actually measuring my spread will be important. As it is, though, I should be looking for much more significant factors.

I zero'd at 25m. But that should be an issue only affecting accuracy, not precision. My 100m work here is still showing more gross sources of variation.

I'd like to think the steel case is ok. I've shot 1000 rounds of it through my .45. I can see scratch marks in the barrel, although I'm not sure the casings have anything to do with that. Otherwise, no complaints: both the pistol and the ammo still perform well. OTOH, the gun store that rents guns at its range won't allow steel cased ammo to be used on their rentals.

The bipod isn't as stable as sand bags, but it's a lot more stable than the usual tactical positions. I'll try to get some sandbags though.

I have some more pictures from last weekend that I'll put up soon, the main addition being the use of a sling. I'm not sure the sling is a good idea though. My performance degraded throughout the afternoon; the sling may have aggravated sources of error brought on by barrel heating. I'm going to try again next weekend.

Dr. Φ said...

Cheaper 'n' Dirt has an article on steel case ammo. Bottom line is that it's okay IF you keep the barrel and bolt carrier well lubricated.