M!-Garand/ New Barrel & Can't Hit Anything!

[Devil Dog]

I knew you could dazzel me with Trig. but I'm still good at Arithmetic.....
.0004 Degrees equals .024 Minutes.
I believe you, but I still think 20 minutes is tough to do.

[Charlie59]

I wonder if we'll ever find out if his rifle is OK now?

[Mark in Rochester]

I knew you could dazzel me with Trig. but I'm still good at Arithmetic.....
.0004 Degrees equals .024 Minutes.
I believe you, but I still think 20 minutes is tough to do.

of course you are correct on the math. Never have had a barrel that I could not put spot on (both gages level)

[Dave Waits]

Not with Gus' method Mark.

[Mark in Rochester]

Not with Gus' method Mark.

Dave not sure what you are trying to say?

Using two levels is essentially the same as what Gus is doing. The machinists levels are incredibly more accurate than the angle finder - not sure it makes a huge difference at 200 yards - but it does not hurt

The least count of any measuring equipment is the smallest quantity that can be measured accurately using that instrument.Thus Least Count indicates the degree of accuracy of measurement that can be achieved by the measuring instrument.

More here: Least count - Wikipedia, the free encyclopedia

[Dave Waits]

What I'm trying to say Mark is that a 360 degree angle finder such as an Electrician's protractor can measure in degrees and parts of degrees. Granted, 20-minutes of angle is negligible but, I have done it with these. You oughtta try it sometime, I think you'll be surprised sir.

[Devil Dog]

Just for S's & G's, How much will the very top of the the front sight blade move if the barrel is off 1 degree of rotation? As I said, I don't remember trig. Your up Mark.
(Top of blade is 1" above the center of the bore)

[Ben Hartley]

Hi, DD...

Just for S's & G's, How much will the very top of the the front sight blade move if the barrel is off 1 degree of rotation? As I said, I don't remember trig. Your up Mark.
(Top of blade is 1" above the center of the bore)

Not Mark. And you don't need trig. Given that your 1" sight height is accurate, consider:

pi = 3.1416; circumference of circle described by sight rotation = 2 times pi, or 6.2832 inches; 6.2832 / 360 degrees in a full circle = 0.017453 ~ 0.0175 inches.

If that's correct, you're looking at approximately 2 inches change-of-impact at 100 yards, or two clicks appropriate windage.

Ben Hartley

[jmoore]

Roughly .018", I think.

ETA Too slow on the typing!

[Devil Dog]

Thanks, guys.
Then, if you are off a complete degree, your front sight would only be out of possition by less then .018". I think the sight being off that much would not be an issue. I do think the gas cylinder/op. rod position would be more of a problem. I use a Starret #12 machinest's adjustable bubble level that is graduated in one degree increments. I try to get the barrel "perfectly" indexed, but I'm sure it's never perfect. (I'm looking at a "bubble")