The 50 to 100 Yard 2" Difference...

[cshold]

Took a few shoots at the range this morning with my Winchester model 70 Lightweight in. 243.
Back in December during deer season it had gotten really wet the one day. I had taken it out of the stock and given it a real good cleaning & drying out.
I wanted to make sure she was still dialed in.
I was shooting my favored Deer round, Remington 100 grain Core-Loct PSP's
Smack on at 50 yards and identical at 100 yards, just exactly 2" higher.
A third shot made a joyous sound at 200 yards on the steel plate.
Conclusion, no change

[mod71alaska]

Nice shooting! Beautiful fox and rifle! The Rem. 100 gr. Core-lokt PSP is my favorite round in my .243 Sako, too.

What variable Leupold scope does your rifle wear? What power do you use for 100 yds.?

Thanks for posting your range report and photos!

[cshold]

3-9X power Leupold.

For rifle range shooting I go heavy on the X.

The 50 yrd. target I used 6X.

The 100 yrd. target & 200 yrd. steel plate shot I used 9X.

In the parts of Penn’s woods that I hunt thicket donkeys, 3 to 4X is about right.
Most all deer I have taken were well less than 100 yards.
That’s my reason for shooting dead-nuts on at 50 yards.

[ollogger]

Looks like the 243 is always on stand by great pix.



Brad

[FWiedner]

It's wierd how that fox fell asleep right there...

[Nath]

Good on the fox...how far was the shot?
I am somewhat puzzled by 2" difference between 50 & 100yds!

N.

[Gobblerforge]

Good on the fox...how far was the shot?
I am somewhat puzzled by 2" difference between 50 & 100yds!

N.

The height of the scope indicates that the bullet is rising to cross the line of sight at 50 and be 2" high at 100.
Gobbler

[cshold]

The Fox was about a 40 yard shot.

http://www.chuckhawks.com/bullet_trajectory.htm

[Nath]

Thanks for explaning the obvious Gents, most kind of you.
How ever it seems too drastic but only in my humble opinion .
If I wanted a rifle zeroed thus in that cartridge I would be adjusting the mounts so there was no more difference than an inch over the distance of 100yds. But that is just my take.

N.

[AJMD429]

Thanks for explaning the obvious Gents, most kind of you.
How ever it seems too drastic but only in my humble opinion .
If I wanted a rifle zeroed thus in that cartridge I would be adjusting the mounts so there was no more difference than an inch over the distance of 100yds. But that is just my take.

It just depends on how much past the zero'd distance you want to shoot without holdover.

Figure in this case, the bullet is about 2" below the line of sight at the muzzle, so if it is perfectly flat (and at > 3,000 fps it almost is*, arriving 300 feet 'out there' in less than a tenth of a second, so barely falling yet), it would cross at 50 yards, and be about 2" high at 100 yards.

*I think it would 'fall' about 1.9" in 0.1 second, but keep in mind it is actually going 'up' at about 48 inches per second when it leaves the muzzle, if it is aimed so as to potentially rise 2.4 inches in about 1/20th of a second but during that time also fall about 0.4" to cross the line of sight at 50 yards having risen two inches. (All these numbers are kind of guesstimates).

[cshold]

Nath, it can get deep.
http://www.shootingvoodoo.com/index.php ... management

[Nath]

Look, I will try again.

Our good friend Casastahle said he shoots most critters where he wants to use this rifle at less than 100yds.

With this rifle and cartridge (.243) there is no need to have a zero at 50yds and suffer a 2" rise over the next 50yds!
The front of the scope wants raising, then our friend will be "dead nuts on" to 100yds.

Why do people never consider the angle of the sight plane to bore relationship

N.

[Gobblerforge]

You sort of answered your own question. The line of sight and line of bore are the components. The bullet, line of bore, has to rise 2"to be zeroed at 50 yards. The bullet continues to rise until top of arc, thus being 2" high at 100. To do as you suggest would be the correct step to have the bullet only rise 1", and appear 1" low, at 50, and cross the line of sight at 100.
Gobbler

[AJMD429]

Or mount scope lower if wanting best close-in point-blank options, just like a very high mount extends the depth of your 'way out there' point-blank range.

[cshold]

All I know is I'm happier than a pig in stink with the way this little model 70 is setup & shoots.
It'll drop a deer with absolute confidence from 0 to 200 yards.
At 50 it's smack on, at 100 it's 2" high, at about 150 it's back to smack on, at 200 it's 3" low.
= meat in the freezer

[Borregos]

All I know is I'm happier than a pig in stink with the way this little model 70 is setup & shoots.
It'll drop a deer with absolute confidence from 0 to 200 yards.
At 50 it's smack on, at 100 it's 2" high, at about 150 it's back to smack on, at 200 it's 3" low.
= meat in the freezer

That is the way to go for sure

[ceb]

Sounds like a perfect sight setup to me. I wish I lived in a state that allowed rifle deer hunting.

[vancelw]

Nath, when I shoot my .243 loaded with 58 gr Hornady V-max or Z-max bullets, I use a 3" point blank range (6" vital zone)

My first Line of sight crossing is ~30 meters, I'm 3" high at 150m, second line of sight crossing is at ~260m, and I'm 3" low at 300m.

Point blank shooting at coyotes and bobcats. I'll grant, I may have to hold a bit for a grey fox. On prairie dogs, it depends on whether they are standing or horizontal how I hold. If I'm in doubt of the range, I simply hold a little low and let the ground splatter take them out.

If I change my vital zone to 4" then My first Line of sight crossing is ~30 meters, I'm 2" high at 130m, second line of sight crossing is at ~220m, and I'm 2" low at 260m

I personally (my opinion...others vary I'm sure) would never zero a flat shooting cartridge like a .243 at 100 yards or meters. I never zero my scoped guns at any set range, I always set them for my MPBR. I tend to shoot my iron sighted rifles by having them reach PBR at 200 or 150, depending on caliber.

[AJMD429]

Nath, when I shoot my .243 loaded with 58 gr Hornady V-max or Z-max bullets, I use a 3" point blank range (6" vital zone)

My first Line of sight crossing is ~30 meters, I'm 3" high at 150m, second line of sight crossing is at ~260m, and I'm 3" low at 300m.

Point blank shooting at coyotes and bobcats. I'll grant, I may have to hold a bit for a grey fox. On prairie dogs, it depends on whether they are standing or horizontal how I hold. If I'm in doubt of the range, I simply hold a little low and let the ground splatter take them out.

If I change my vital zone to 4" then My first Line of sight crossing is ~30 meters, I'm 2" high at 130m, second line of sight crossing is at ~220m, and I'm 2" low at 260m

I personally (my opinion...others vary I'm sure) would never zero a flat shooting cartridge like a .243 at 100 yards or meters. I never zero my scoped guns at any set range, I always set them for my MPBR. I tend to shoot my iron sighted rifles by having them reach PBR at 200 or 150, depending on caliber.

THAT is what I do, too.

1. Decide on size of vital zone.
2. Figure max PBR.
3. Sight at 100 yards to proper point hi/lo.
4. If you have to 'extend' a bit, a higher scope mount could be used, but it pushes out the close end of your zone. No big deal usually if you don't mind being off at 50 yards to bring in another 25 yards 'out there'.

[Nath]

You sort of answered your own question. The line of sight and line of bore are the components. The bullet, line of bore, has to rise 2"to be zeroed at 50 yards. The bullet continues to rise until top of arc, thus being 2" high at 100. To do as you suggest would be the correct step to have the bullet only rise 1", and appear 1" low, at 50, and cross the line of sight at 100.
Gobbler

I never asked a question Sir!

A bullet on leaving a barrel does not rise! It drops!

All sighting systems are angled at the front down some in relation to the line of bore thus inducing some elevation to the falling bullet.

Incline the sighting system to much but only wish to use a rifle for short distance and you get the above situation.

It matters not now as the OP has changed the criteria of this rifle from the earlier criteria. Had the criteria not changed rising the forward end of the scope would of flatted the two impact points out over 100yds.

I don't need it explaining to me, I was questioning why suffer that 2" when the user originally said 100yds will be a long shot where he intended to use the rifle

I give up....put the scope on upside down , back to front and sight it in just how you want.....

[cshold]

Let's just all take a break and play with a good calculator
Sure never intended for this post to cause anyone to get worked up or put their scope
on sideways or backwards.

http://www.handloads.com/calc/

[vancelw]

Just because 99% of your shots will be 100 yards or less doesn't mean you should not want to be prepared for a longer shot if the opportunity presents itself.

The bullet IS rising in relation to the line of sight and the level ground as it leaves the barrel, even though gravity is pulling it down from that instant. Bullet drop and path are two different things.

I know what you were trying to say Nath, it just doesn't make sense to me to sight in a rifle capable of 330 to 350 yard PBRs to zero at 100. If I were using a .25-35 with iron sights I might.

[cshold]

Yes, much like owning a ferrari.
chances are you'll never go 200 MPH.
But you know ya can if you want to and or have a place to do it

[cshold]

This thread got me to thinking about dropping that Leupold a little closer to the barrel.
After some research on scope mounts, I decided to order one of these setups.
DNZ game reaper 22600 scope mount.
I'm thinking with the scope being lower to the barrel,
50 yards will still remain my 0 point. 100 yards will drop down to 1" high at 100 yards.
Will see what happens.
I like to play.

[vancelw]

I use a lot of DNZ one-piece mounts and love them. They are not the prettiest, but are solid and lightweight. The only issue I've ever had was the gun's fault. Receiver was not parallel to the barrel and hard to shim that one-piece design.

[cshold]

I use a lot of DNZ one-piece mounts and love them. They are not the prettiest, but are solid and lightweight. The only issue I've ever had was the gun's fault. Receiver was not parallel to the barrel and hard to shim that one-piece design.

Thanks for the info. Vancelw.
I'll give it a try and see how it works out.
If it doesn't work, I'll send it back and put the
Leupold two piece mount back on.

[Nath]

I use a lot of DNZ one-piece mounts and love them. They are not the prettiest, but are solid and lightweight. The only issue I've ever had was the gun's fault. Receiver was not parallel to the barrel and hard to shim that one-piece design.

This is my point dear brothers, receivers or the mounting system are not parallel to the bore otherwise the sight plane would not cross the bullets path.

If the front of your scope Casthalls was shimmed about .020" up or away from the barrel the rifle will shoot flatter in relation to the sight plane over 100yds but be lower at the longer distances.

Be aware that just getting lower mounts may make you crowd the stock more and will in fact even make it shoot higher at 100yds!

Only trying to help. Born from my own experience!

Please show me the results when you are done.

N.

[madman4570]

Looking at those two groups. Knowing exactly where they shoot. And trust me that looks fine.
I would leave it as is and just grin.

Gave my daughter mine(1972 Feathweight M70 .243)looks absolutely identical and it is a fine weapon. I mean even look at windage. Dead nuts same!
That wood and bluing back then was very fine. Bet the action is "very slick too"

[vancelw]

I use a lot of DNZ one-piece mounts and love them. They are not the prettiest, but are solid and lightweight. The only issue I've ever had was the gun's fault. Receiver was not parallel to the barrel and hard to shim that one-piece design.

This is my point dear brothers, receivers or the mounting system are not parallel to the bore otherwise the sight plane would not cross the bullets path.


N.

Yes, ideally the scope is parallel to the bore. The scope's internal adjustments make the bullet cross the sight plane (twice-up and down). If the scope is not parallel to the bore, you may not have enough elevation adjustment in the scope (varies by manufacturer) to compensate for it. If you sight your rifle in to where the path is tangent to the sight plane (only touches once) you are severely limiting the capabilities of your cartridge.

[cshold]

Looking at those two groups. Knowing exactly where they shoot. And trust me that looks fine.
I would leave it as is and just grin.

Gave my daughter mine(1972 Feathweight M70 .243)looks absolutely identical and it is a fine weapon. I mean even look at windage. Dead nuts same!
That wood and bluing back then was very fine. Bet the action is "very slick too"

I'm intrigued by that one piece mount brother.
Life's short, just gotta give it a try.
I actually wouldn't mind having my cheek planted firmer on the stock for off bench shooting.
That lower mount should accomplish that.

Yes Nath bro I'll indeed keep y'all informed.