ProgSpear Build thread - AR15 tack driver.

[Meketrefe]

I don't know who cuts the MT lowers but don't see that situation too often. Are you sure it is off or might be a small burr or something from being new?
If you put the front pin on can you tilt it in place or it hits into something? ...Just like lowering the hood on a car.
These things should be easy to spot if the slots are not large enough that is an easy fix but it might involve fitting and retouching. But if the thing is
off center or the wrong dimensions that is a different story.
Otherwise see if you can contact the seller or manufacturer and they can fix the problem for you.

[ProgSpear]

I need to clean up my bench and get some magnification and good lighting onto this problem. l'll check for burrs and such first. Also concentricity of the holes and pins. Then I get to panic and fume...

[Meketrefe]

I need to clean up my bench and get some magnification and good lighting onto this problem. l'll check for burrs and such first. Also concentricity of the holes and pins. Then I get to panic and fume...

Seems like a good idea. Clean the area, get good light and remember whatever happens fast it will also happen going slow in this case with the difference that if you go slow and paying
close attention you should be able to see what is going on. These type of things have a reason, and explanations, always. Nice and slow, see where the thing binds if you tilt it pivoting
in the front pin. The front slot should go fine into place and with the pin closed tilt it slowly. no carrier, no parts, no nothing, just those two pieces.
We will get there.

[ProgSpear]

OK, I got the pins to seat, but it's the first time I needed to use a little bitty hammer to get those suckers to move! I think the anodization on the new upper reciever might have made it tight. I put a little grease on the pin and drove it in and out a few times and now it almost moves with just pressure on the punch. (a tap still helps) Actually this is probably good, as the upper does not rattle around.

[Meketrefe]

OK, I got the pins to seat, but it's the first time I needed to use a little bitty hammer to get those suckers to move! I think the anodization on the new upper reciever might have made it tight. I put a little grease on the pin and drove it in and out a few times and now it almost moves with just pressure on the punch. (a tap still helps) Actually this is probably good, as the upper does not rattle around.

Anodizing is microns so I think it is just a tight fit and the parts cuts have microscopic rough spots (only removed when polished or use) so yes a bit of grease and a few taps with the rubber
hammer and presto! ... better tight than loose because it will loose with time and use.. same thing as sex... lol..

[Cgrutt]

So if I understand that chart correctly the holdover at 1000 yards is approx. 33'? Is that right?

[ProgSpear]

CG - that's what it looks like to me also, but cranking in the 38 MOA rise provides the ballistic compensation. Here's what the Hornady.com Ballistics calculator says. Slightly different, but mostly the same .

Your Input Variables

Ballistic Coefficient	0.51	Velocity (ft/s)	2500	Weight (grains)	123
Maximum Range (yds)	1100	Interval (yds)	100	Drag Function	G1
Sight Height (inches)	1.5	Shooting Angle (degrees)	0	Zero Range (yds)	200
Wind Speed (mph)	10	Wind Angle (degrees)	90	Altitude (ft)	555
Pressure (hg)	29.53	Temperature (F)	75	Humidity (%)	0.75

Ballistics Results - 6.5G 123 amax

Range (yards)	Velocity (fps)	Energy (ft.-lb.)	Trajectory (in)	Come UP in MOA	Come UP in Mils	Wind Drift (in)	Wind Drift in MOA	Wind Drift in Mils
Muzzle	2500	1707	-1.5	0	0	0	0	0
100	2342	1498	2.4	-2.3	-0.7	0.7	0.7	0.2
200	2190	1309	0	0	0	2.9	1.4	0.4
300	2043	1140	-9.7	3.1	0.9	6.8	2.2	0.6
400	1902	988	-27.7	6.6	1.9	12.5	3	0.9
500	1768	854	-55.4	10.6	3.1	20.1	3.8	1.1
600	1641	736	-94.2	15	4.4	30	4.8	1.4
700	1522	633	-145.9	19.9	5.8	42.3	5.8	1.7
800	1412	545	-212.7	25.4	7.4	57.2	6.8	2
900	1312	470	-296.9	31.5	9.2	74.9	7.9	2.3
1000	1224	409	-401.5	38.3	11.2	95.5	9.1	2.7
1100	1149	361	-529.2	45.9	13.4	119	10.3	3

[Meketrefe]

I think with holdover you mean actual adjustment. Most reticles will let you hold 4-5 mils or 15-20 moa depending on design but then you are out of lines in the stadia.
The correction you need will depend on your zero. It is not the same zeroing at 100 than 200 than 300 etc.. but let say you have plenty of adjustment and you
are zeroed at 200 like above. Then you will need to dial 11.2 mills to come up to hit the target and with a 10 mph wind you will need to put 2.7 mils. (1.3 if for 5mph)

Let me explain a bit more...

Alternatively one could dial 10 mils and hold the remaining for small adjustments. This will depend on how precise your stadia is (reticle). some come with 1/4 markings and
a bit of christmas tree edged on the glass so you can hold for final fine correction both drop and wind. In rapid scopes with the millradian (mrad or mil) system same used by military the 10 mils
will mean a full revolution of the elevation turret. With an MOA target scope this might mean more than 3 revolutions to get to the 38 moa.
The good thing about the mil system is that one radian at 1000 yards is 1000 yards. So a milliradian is 1000 yards / 1000 that = 1 yard. So 11.2 mils is 11.2 yards.
But in MOA is also simple .. to round it up lets say 1MOA is 1" at 100 yards that means 10 inches at 1000 yards. 38.3 MOA = at 100 yards is 10 x 38.8 that is 388 inches.
388 / 36 inches to the yard = 10.777 the nr. is different because 1 MOA is not exactly 1" but a bit more, 1.047" precisely. So there is a formula to calculate this
but you culd also take 10.777 and multiply by 1.047 at the end and that will give you the 11.2 yards. Just to show that you can actually derive this w/o a calculator
but these days everyone including the military use a computer also for several other reasons.

Sorry for the long explanation. I hope this makes sense.

[thughes]

什么他妈的

[Meketrefe]

什么他妈的

Translation: You zero at 1000 yards and then you don't need to touch anything !!!! LOL

[thughes]

I figured it was that simple.

[ProgSpear]

http://translate.ua/us/on-line

Do not stand down range
не терпите внизу ряд
exécrent au-dessous une file
範囲を下に立っ㠁¦ã„ません
nicht ertrag unten Reihe
non dimettersi gamma
不要站在下来范因´

hold my target please
عقد هدفي الرجاء

[Meketrefe]

This thread is going south...

Вы ребята должны быть высоки на этом PePeshiltata, который вы курите

[ProgSpear]

"You guys must be high there on PePeshittata that you smoke"

And you say this thread is going south? Now that's funny 'cause you smoke it too!

This is just distraction until I actually have a build. Then we get some smoke(less powder fumes)!

[thughes]

"You guys must be high there on PePeshittata that you smoke"

And you say this thread is going south? Now that's funny 'cause you smoke it too!

This is just distraction until I actually have a build. Then we get some smoke(less powder fumes)!

Exactly! We're all just killing time waiting for you to nut up with some hardware porn.....