25 yard sight in???

[widgeon]

Got to sight in a fresh scope using new ammo. :shock: Fortunately I have some randome reloads I can use to get me on paper.

Have any of you tried this? Would it be reasonable, considering my longest shot on an upcoming hog hunt will be under 150 and probably much less?

Thanks,
Tony

 

[Guest]

I don't like the idea. Sure, a 25yd sight in is great for getting close, but the difference at 100yds (much less 150yds) can be a few inches or more. Get it on paper at 25 and test at 100, if you can. That's my preferred course in this situation. Heck, I don't like to shoot at game at ranges beyond what I've tested the weapon, in any situation. I have access to a 500yd shooting range, and won't take a shot at game longer than that. I won't take a 500yd shot unless conditions are perfect and I have my favorite rifle with me, but that's another story entirely. Check that rifle at distance.

 

[widgeon]

I tend to agree with you, which is why I am asking. The problem being that the nearest, 100 yard public range ( that I know of) is about a 2 hour drive. I may have the time before the hunt to drive down there, but it depends on work. My buddy offered to let my shoot at his 25 yard, home range.

 

[1Shot]

You can get it on the paper at 25 yards but you need to move out to at least 100 yards to zero. I do A LOT OF ZEROING FOR PEOPLE so I know the business. I can't ever recall having a rifle perfectly zeroed at 25 yards that was reasonably zeroed at 100 yards. Most will shoot 4 to 8 inches high and will be off a little in the windage.
Here is how I zero a rifle quickly and with just a few shots. Bore sight the rifle first. If it is a bolt action I remove the bolt and place the rifle in my front press with the butt on the rear sandbag. Look through the bore and center on a 1" orange sticker at 25 yards. Dial the scope to the center of the orange sticker. Shoot a shot and if the bullet does not strike where I was aiming I adjust the cross hairs of the scope by placing them where I was aiming and dialing them to the bullet hole. Then move to 100 yards and shoot on a target with a 1 inch grid. Fire a good shot. Do the math from where the bullet struck to where I want my zero. Most scopes are 1/4" per click at 100 yards. If the shot was 1" higher and 2" to the left of where I want my zero I would dial the elevation turret 4 clicks down and the windage turret 8 clicks right and tap on the turrets with a screw driver or something a few times because some scopes are a little sticky and don't adjust until they are shook a little. Shoot to confirm the adjustment. If the rifle will shoot and your scope is a good one that actually goes where you click it and you can shoot you can zero a rifle with three shots one at 25 two at 100 yards and the third will be your confirmation of zero shot.

 

[SJB358]

If you zero at 25 yards, make sure your target is square to your rifle and perfectly zero it. 1/2" at 25 yards amounts to quite alot of difference at a 100 yards for something flat shooting like a 270.. Like Dubyam, I would at least to verify at 50-75 if you could pull it off. That would be the safest bet... Good luck buddy.

 

[joelkdouglas]

I zero at 25 yards often. With a 30-06 it makes it a couple inches high at 100 and dead on near 225 or 250 again. I believe it's about the perfect way to sight in for hunting season.

Other cartridges I don't know enough about, but you can find a ballistics calculator and plug in your info with a 25-yard zero, and it will tell you a pretty close trajectory. Of course, there's no substitute for actual testing, but it gets you close.

 

[JD338]

Rule of thumb for 30-06 class is a 25 ys zero will be roughly on at 250 yds.

Get on paper at 25 and start at 100 yds for zeroing.

JD338

 

[widgeon]

Thanks guys. All things considered, I will do my best to get to the 100 yard range. Either way, I'll post the results here. :mrgreen:

 

[nvbroncrider]

With an AR a group at 25 meters is the same impact point as 100 meters. I like to zero at 25 with a new rifle scope so you don't burn up so much ammo. Especially when your shooting by yourself.

 

[meatmachineman]

It really depends on the caliber and speed and weight etc. For many cartridges, shooting dead on at 25 yards will put you a bit high... to a lot high at 100 yards. Essentially what is happening, the aim line of your scope and the center bore line of the rifle actually cross paths... they are not parallel. So if your scope is aimed perfectly level, your barrel is tilted up slightly. In theory, if the aim line of your scope and the bullet cross paths in the neighbor hood of 25-30 yards (bullet hitting exactly where you aim at that distance), the bullet will still be traveling upwards in relation to the line of aim although gravity will be taking more and more of an effect on bullet height as speeds diminish. Bullet weight and speed dependent, you CAN (not will) get pretty close to where you want at 100 yards. I recently set up a scope on a 7mm mag and set the target out at 29 yards (based on a range finder). Because of its higher velocity and moderate weight bullet, I was about 7" high a 100. I've had the 25yard sight in work very well with an 06. So it really depends on what your shooting. The 25yard can work, but it is really no substitute for checking at 100 or further....

Basically my long winded way of saying... I agree with the others! LOL!

 

[widgeon]

Thanks, meatmachineman. I'm shooting my .270 win. I also agree with the masses. Iwill hane to make the time to get down to the 100 yard range. :mrgreen:

 

[nvbroncrider]

That was 300 meters not 100 .

 

[meatmachineman]

Thanks, meatmachineman. I'm shooting my .270 win. I also agree with the masses. Iwill hane to make the time to get down to the 100 yard range. :mrgreen:

LOL... I just took an older 270win Vanguard I picked up recently out a couple weeks back at the same time as the 7mm. It was all over the place at 29 yards... the old junky rings and bases have been replaced and awaits the next range session...

 

[RiverRider]

If the center-line of the scope tube is 1.50 inch above the center-line of the bore, I'd set the 25-yard POI to about 1 inch below the point of aim (if I had to sight in at 25 yards). Pure guesswork on my part, though.

 

[Polaris]

The biggest difference is the height of your scope. You are raising your trajectory considerably to bring that bullet up to point of aim at 25 yards. If your scope is 1" above center of bore (a typical 40mm scope is closer to 1.25), that's aprox 4MOA which will translate into MORE than 4" over at 100 yards as you are imparting an upwards velocity also. The old 25 yard sight in=zero at 100 yards is based on the military M1 garand or springfield sights which were considerably closer to bore. 25 yard shooting was done as a wartime expedient to get recruits to the front quickly when proper shooting facilities and ammo were limited. It has been espoused by many "knowledgeable" gunwriters as gospel over the years.

I've found in practice with a reasonably flat shooting rifle that +.75" at 50 yards or -.25" at 25 yards is much closer to proper zero for 200 yard hunting with a typical 40mm scope set up with minimum ring height but is still no substitute for 100 yard hard zero. If you must shoot at 25 yards, I'd carefully measure the distance of your reticle above center of bore and set your zero range at 200 yards and run it through a ballistics calculator to get your proper POI at 25 yards. If you can get to 100, zero should be +2-3" depending on your scope height and ballistic efficiency of your load.

 

[cloverleaf]

Just a guess on my part, but I would say polaris is right. I would also say that for optimal accuracy the "x" on the target and the cross hairs need to be as close to square and level as possible, You should be able to find a simple balistics program on line that will give you a point of aim and point of impact for 25 yds with a given zero. Remmington "Shoot" used to be available on line on the remington web site.
Seems to me that the military sights in at 25yards. Guy Miner or Scotty or somebody will know. CL

 

[Oldtrader3]

The Sierra Suite I6 bullet software with using the Partition 130 gr, .277 bullet says the with a 1.5 inch high scope mounting, the rifle zero at 25 yards should be -.75 inches at 3060 fps muzzle velocity.

 

[widgeon]

I guess I forgot to mention what I'm using. I'll be shooting my M70 in .270win. 22" tube. I will be firing Federal, factory loads with a 140 gr AB. The box claims a MV of 2950 fps, but doesn't give info on lenght of tube. I don't have a chrono, so generally use the charts in back of some reloading manuals to determine how high to be at 100 for a theoretical 200 zero. The only issue with this is that I am taking an educated guess as to velocity.

I really appreciate all of the advice and information. At this point, I think I'll be able to get a day off and drive down to the 100 yard range. I'll keep you posted.

Thanks,
Tony

 

[300WSM]

Now that I know what you are using, you could get away with a 25 yd sight in. I would never recommend such but with a 270 you could get away with it. Also if you are sure you will only have some moderate rage shooting on the animal...(150yd and closer)...yeah you would be ok.

I say about a 270 because it is fast. If you were off on the left or right at 25 yds...a little tiny bit...it wont be that far off at 100. Not far enough to take you out of the kill zone....however
if you were shooting a 35 rem or 30/30 or something slow like that then being off the slightest at 25 would be off a huge amount at 100 and beyond.

Get to the longer range if you can but if you can't the 25yd verify shot will be ok.

 

[wildgene]

...gotta go w/ everybody else, 25yds. will get you on paper...

...but you need to verify your "Zero" (top 2/ first rounds @100yds.)...

...lots of things can affect your actual "Zero", something as simple as having 1.4" or 1.6" from the center of the bore to the center of the reticle, & using 1.5" can change the angle of trajectory by a considerable amount. If you plan to shoot 200yds., 300yds., 400yds. you really need to verify your POI (point of impact) @ those ranges...