I’ve switched to a 6:00 sight picture

[rjinga]

I have a PTR 91, GI model rifle (.308 win/7.62 x 51). It has the HK style, four-position, rotating rear drum sight, and a hooded front post (blade actually). Until yesterday, my sight picture, through a process of mostly trial and error, was to cover the POI with the upper part of the front post, at 25 yds, using my rifle's #2 rear sight aperture.

However, at 100 yds (the max distance of the nearby public range), my 1/16" wide front post pretty much totally covered the 8.5" width of an 8.5 x 11 target. And then, when I joined a gun club last week, and was able to shoot at 200, 300, and 400 yds, I discovered that even a full-size silhouette could be hidden behind my front post at those distances.

So, yesterday I went back to the public range to adjust my sight picture to a 6:00 hold with the #2 rear sight aperture at 30 meters. I read that being "on" at 30 meters will also put me on at 200 meters. Then, theoretically, I should also be on at 300 meters with the #3 sight aperture, and on at 400 meters with the #4 sight aperture.

Here’s a photo of three shots before any elevation adjustment. I tried to touch (or set) the bottom of the 3” red square on the top edge of the front post.

And here are the first three shots, with the same sight picture, after my initial adjustment. All three rounds are inside the 1” diameter bulls-eye. I’ll take it!

And then, three more shots at a different target (2” diameter red bulls-eye) at the same distance.

Next, I put a 23” x 35” BC-27 target at 100 yds. I tried to hold on the chest area and fired three shots. After checking with my binoculars, I tried to hold on stomach area and fired three more shots.

After walking out to the check the previous shots up close, I held on the bottom of the target and fired five more shots.

It would appear that with that target, at that distance, with German surplus ammunition, I’m getting a POI about 7-8” above the POA.

 

[rjinga]

Cont.

Then I switched to Wolf Polyformance steel-cased ammunition and fired at two more targets. The first was 11” (height) x 17” (width); the second was 8.5” (height) x 11” (width) with a 6” red bulls-eye. On both, I tried to hold on the bottom edge of the target.

 

[brasscollector]

I always go 6 or sub6. I never got accustomed to any sight picture that covered the target.

 

[bfoosh006]

Eureka !

 

[bamaranger]

POI v. POA

I'm having a hard time grasping whether or not you are now content with your new POA/POI arrangement?

I am not surprised that a sight setting yielding a POI 2-3 inches high from POA at 25yds, is landing shots 7-8 inches high at 100. I suspect that at 150, your shots will be close to 10- 12" or more from POA, still high around 200, and come "on" somewhere around 275-300.

I am not familiar at all with the PTR 91 or its drum sight.

 

[Slamfire]

I have shot for decades with a post, but, the eyes are not working like they used to. There is nothing sacred 6 O'C or center hold, it all really depends on the target you are shooting against and what you can see better.

The old 5 V target, I think it was a 5 target without the V, was used from WW1 (don't know how far before) through the 1960's. I have shot on the thing with Garands and M1a's. If you look at M1903 front sights, they are very thin because the bull was very small. I believe the sights were developed around the target, and then the target stayed around decades after the M1903 was out of service. I tried a center hold on the 5V target with issue Garand sights, and it was impossible, the bull blinked out. The issue service rifle sights, both Garand and M14, are too wide for the 5V, even with a 6 O'C hold as the target appeared to be a pin point on an infinite horizon. Wide sights and tiny targets don't mix well. However, with the thin NM Garand /M14 front sights, you can shoot a good score on the 5V but it will be with a 6 O'C hold.

On the wider NRA target, I preferred center hold as I was less likely to mess up my sight picture. With a 6 O'C hold, you have to be consistent about whether the post is in the middle, or the target. Get them confused, and the bullet will be stringing up and down on the target.

I think the wider post is a better combat sight but on paper, against targets, you have to play with post width for the best sight picture.

 

[rjinga]

I'm having a hard time grasping whether or not you are now content with your new POA/POI arrangement?

I am content with a 6:00 sight picture.

I am not surprised that a sight setting yielding a POI 2-3 inches high from POA at 25yds, is landing shots 7-8 inches high at 100. I suspect that at 150, your shots will be close to 10- 12" or more from POA, still high around 200, and come "on" somewhere around 275-300.

Actually, it was only a max of 2" (1.25" average) POI above the POA at 30 meters (32.8 yds). A couple of days ago I went to the rifle range at my gun club. I shot at this target at 100 and 200 yds:

At 100 yds I tried to place the orange bulls-eye on the top of the front post. The little green + symbol is the averaged center point of all of the shots.

At 200 yds, the whole target is about the width of the front post, so I tried to place it on the top of the front post.

I am not familiar at all with the PTR 91 or its drum sight.

https://www.youtube.com/watch?v=ctyKezaegds