Hang in there...my first attempt posting w/ pics.
I had a chance to finally get to the range with both my BC and 308 survivor. The 45-70 had 60 rounds through it and the 308 was unfired.
The BC first.
I'd like to do some long range shooting with it so I installed a Smith ladder rear sight in combination with the original front globe. This trip was to try and learn what the sight adjustments equaled at 100yards. I wanted to eliminate as many variables as possible so I used a simple load used prior; Winchester brass, Federal 210 LR primers, 39.0 grains of IMR 3031 pushing hideous Western Nevada hard cast 405 grain FP chunks of lead. Previously this load Chrony'd at an average of 1408 fps 10' from the muzzle. (Black hills 405 grn Cowboy loads were 1222 for comparison) My bore is a consistent .456 and the 405's are .458. Conditions; steady 50 deg F and 28.65 station pressure with a light tail wind.
All shots (except one where noted) were aimed at the center of a large 17'' shoot-N-see target at 100 yards. The 60 rounds fired prior were with the buckhorn portion of the Smith sight and was found to impact dead on at 50 yards.
At 100 yards the first 5 shots hit on average 5.25" below point of aim with the buckhorn. My sight picture is the front globe centered in the "notch" of the buckhorn. I have replaced the standard front sight apurature with a fine crosshair insert from Lee Shaver.
With the ladder portion of the sight folded up and the slider almost* bottomed, POI (point of impact) was 5.25" high on average. Note* the slider "bottoms" in between clicks, therefore the actual bottom is .5 click up. This POI effectively is the rifles current 100 yard "ZERO" with this load.
The horizontal lines seen on my target are 1.047 inches apart = 1 MOA (minute of angle) @ 100 yards. The change of impact from buckhorn to the ladder at it's lowest position was 10.47" = 10 MOA. I use this type of target to check true tracking in optics to confirm ACTUAL click value compared to manufactures declared adjustment values. These discrepancies can be minimal at moderate range but can "add up" at extreme range and lead to a complete miss.
You can see I took only a few shots per adjustment. Normally I would take an average of at least 10 shots to get a more accurate representation - however I was a bit short on time and round count.
Two clicks up = top edge of the slider was "underlining" the number 3. POI was 8.4" (8 MOA) above the "zero".
Three more clicks up underlines the number 4. POI was 11.5" (11 MOA) above the first adjustment impacts.
So far it looks like each "click" is worth approximately 4" (3.8 MOA) @ 100 yards. Just under 4" actually - but I can't hold that kind of precision ; )
I plugged this data into a ballistic program I use in other forms of shooting and was pleased to ring steel at 200, 300, 400, and 500 yards.
Does anyone know if this sight was designed for a specific ballistic curve. The gradations on the ladder get "wider" the farther up the scale - indicating someone had something in mind. I plan on finding a bullet the BC likes then tweaking the velocity to try and match the slider gradations.
I do not care for the fact the set screw on the slider must be loosened / tightened every time an adjustment must be made (otherwise recoil moves it). I have a sneaky suspicion I will move on to another form of sight at some point.
The 308 Survivor....I have allot of work to do with this one. I had a fixed 10x scope with Mil-dot reticle collecting dust so I mounted it on a set of med rings and grabbed some extra ammo. My "watermark" cartridge is Federal Gold medal match, loaded with both the excellent 168 and 175 Sierra match kings. Any 308 I have ever owned shot either of these two factory loads VERY well....until this one. I even tried my current 308 tactical match load; 43 grains of Reloader 15, Fed 210M primers pushing 175 match kings (2.810 OAL). No Joy.
The 100 yard target is attached. The dots are 1". I expect not to miss dots of this size and will work toward .5 MOA accuracy. One must be realistic for sure - this rifle will live in my Jeep and travel with an additional .22 and 12 gauge barrel. I want to give this little rifle a go at one of our local tactical matches - so I gotta figure out how to get it to shoot!
As discouraged as I was following the survivor's short range precision I decided to see how it would do at longer range. I pulled a range card out of my data book from a Rem 700P using 168 FGMM I used to shoot and was pleasantly surprised how little I missed out to 700 yards. Most targets were generous 12"x22" Larue silhouettes - but it raised my spirits a little.
The survivor is a nice, quick handling little rifle. It points well sitting, kneeling, and offhand.
Initial probes with the stoney point OAL gauge shows me it is a LONG way to the rifling in this chamber. Is this typical for a 308 barrel from NEF?
For sure I will show the triggers on both rifles a little TLC in the very near future. I hope to get them as close to 2-2.5 lbs as safely possible. I have a low grade RCBS trigger scale and the hammer will not fall well above the max indicated on the gauge. This must be well over 7-8 lbs. (they both break nice though).
Thanks for taking the time to read over my observations. Any insight and experiences you could help me with would be appreciated.
DSMcG
