He said to move the rear sight .020" left.

http://forums.accuratereloadin...0101804/m/6341018221

I moved it .020 left. Here is the results. Standing at 25 yards but this time with my front hand supported on a padded rest.

Searcy 470 NE Left Hand rifle. Load - 106 grains of IMR4831 and Woodleigh 500 grain soft points.



Targets. Fired LR, LR, LR



Composite of both groups superimposed on one target.

No magic there :

(error in " x line of sight in yds) : range in yds = correction in ".

Et voilà...

Andre,

Interesting tag line. Here in America the group size varies, depending on the firearm and the intended use. That based on the number of shots that may be fired. Most DRs that I have seen with factory targets included show L-R, L-R. The thought is that if you don't get it done with four shots you are roadkill. Hunting bolt, rifles 3-shots is the standard. Logic says if you don't get it done with three you should stay home and practice. Competition rifles is where the 5 or even 10 shot group group size becomes an issue.

It seems a bit arbitrary, to lump all rifles together.

regards,

Rich

Arbitrary, maybe. But then, being an uncompromising accuracy freak I won't keep a (single barrel) rifle that doesn't shoot under MOA (for 5 shots, no less). This is for hunting rifles, I'm more demanding still for my target rifles (<.3 MOA). Limiting the selection to top quality (and mostly German) rifles, you'll find that most of them are MOAers right out of the box with quality ammo (RWS or handloads).

Regarding double rifles, I'm satisfied if both barrels shoot together (I mean together, not close) at 50 m. This is how my o/u 9,3x74R groups (scoped, w/ elbow rest and 8-10 seconds timing between shots)).


This being said, I"ll stand by my tag line

that's okay with me. Hard to argue with your results.

Rich

I'll argue.

I have never been in a hunting situation that required sub minute of angle accuracy. So there, I said it.

I have to admit I am somewhat like Andre, I am an accuracy FREAK. If I can't get a rifle to shoot to at least one inch or less at 100 yards I get rid of it.

HOWEVER one has to remember to ask, just like Muletrain said, "What hunting situation (especially with a double in 470 equipped with iron sights) do we need SUB minute of angle??"

The most accuracy I ever "needed" out of a hunting rifle was when I shot a crock in TZ in 2003. I used my 300 Win and I put a bullet right into his eye.

Other than that a 3 inch group at 100 yards would of worked fine for every thing else I have ever killed anywhere.

I don't know about you guys but the deer, elk, bears, coyote and all the African animals I have killed are usually a little bigger than one inch around..

BTW Muletrain, nice group. I have aSearcy on order and I can;'t wait to get it. Show us some pics if you can.

I have to admit I am somewhat like Andre, I am an accuracy FREAK. If I can't get a rifle to shoot to at least one inch or less at 100 yards I get rid of it.

HOWEVER one has to remember to ask, just like Muletrain said, "What hunting situation (especially with a double in 470 equipped with iron sights) do we need SUB minute of angle accuracy??"

The most accuracy I ever "needed" out of a hunting rifle was when I shot a crock in Tanzania in 2003. I used my 300 Win and I put a bullet right into his eye at about 80 yards. I am told I had about a 2 inch target. Personally after I saw how my 200 grain x bullet blew his brains completely out the back of his head I now feel that the margin for error is a little larger!!

In most hunting situations 3 inch group at 100 yards would of worked fine for every thing else I have ever killed anywhere. BTW I don't shoot prairie dogs and I don't hunt sheep, so 600 yard shots at ANYTHING is out of the question for me.

I don't know about you guys but the deer, elk, bears, coyote and all the African animals I have killed are usually a little bigger than one inch around..

BTW Muletrain, nice group. I have a Searcy on order and I can;'t wait to get it. Show us some pics of the rifle if you can.

I won't pretend I need target accuracy in hunting situations and I don't believe I've shot more game because of my accurate rifles. However, knowing that you can trust your rifle to hit a rat in the head at 200 m instills quite a sense of confidence. It's all in the head, I know, I've been told before...

Andre,

Very accurate rifles are a total joy to own and shoot. There is nothing quite as satisfying as shooting a clover leaf group with a hunting rifle using ammunition that you have crafted with your own hands. And as you say, it really increases your confidence to take a shot knowing that the rifle will put the bullet exactly where the cross hairs are aiming, every time, under any conditions.

I have owned rifles that were not very accurate and had to pass up very long shots knowing that a 2 1/2 minute of angle rifle will scatter shots all over the place at 300 yards. And just like you I have eventually sold them.

My first .375 was a Left Hand Remington push feed that would shoot minute of angle. I never liked it because it was a push feed and also the barrel was sort of fat. It was just not pretty. Eventually I got a Winchester Model 70 CRF in .375 that was a very beautiful rifle but it would not shoot worth a crap. The first couple of trips I just limited my shots to under 150 yards. Then in an attempt to find out what was making it inaccurate I discovered that the recoil lug was bedded with some sort of very soft crap that resembled Hot Glue. After a proper bedding job the rifle now shoots very well.

quote:

Originally posted by Andre Mertens:
No magic there :

(error in " x line of sight in yds) : range in yds = correction in ".

Et voilà...

I don't quite understand this formula - could you explain?

quote:

Originally posted by Antlers:

quote:

Originally posted by Andre Mertens:
No magic there :

(error in " x line of sight in yds) : range in yds = correction in ".

Et voilà...

I don't quite understand this formula - could you explain?

a.tinkerer
one of us
Posted 21 December 2009 21:52 Hide Post
Looks like you're on the right track!


For future reference, the formula (which I've found to work perfectly) from the Brownell's gang is as follows:

To Determine Sight Adjustment:

Use the following equation to determine the change you need to make:

Sight change = Sight Radius (multiplied by) Impact distance (that quantity, dividied by) Target distance

Sight Radius: Distance between front and rear sight

Impact distance: Measurement from point of aim to bullet impact

Target distance: Measurement from muzzle to target

Sight change: Amount of correction needed

Sight rule: Move rear sight in the direction you want the bullet to move. Move front sight the opposite direction you want the bullet to move.



Hope that helps!



Cheers
Tinker
Posts: 399 | Location: oakland CA | Registered: 26 April 2005