Zeroing with different types of ammo?

4guyz1stool · Aug 11, 2017

For my precision rifle, I have two different zeroes marked on my scope caps. One for 168 match ammo and one foe 175 match ammo. This probably wont work with a red dot, but you will still be within minute of man at 100 yards with one zero.

outrider58 · Aug 11, 2017

Biggfoot44 said:
Lots happened in the thread while I typed.

SxS is both correct, and "sort of, sometimes " . Yes, there are a gazillion factors, and you should never *assume* two different loads will have identical POI .

That said , bullets of same general shape and configuration ( for hunting example , say .30 cal lead core Spitzer 180gr ) at same nominal velocity , will "often" be reasonably close, at least at 100yds . Reasonably close meaning withing 2 inches, if not within 1 inch . The more variables in play, the more likely for different impacts .

Close enough to get you on paper at sighting distance to fine tune with $$ load. Ideally close enough, or off set in predictable manner to be useful for high volume practice .

I get the concept of practice with what you will hunt/ use for serious purpose , and it's not a terrible idea . BUT that works best with a convergence of both medium price, and plenty good enough performance. Following through with hunting examples , if you were going deer hunting with .308 rifle , there are any number of 150gr lead core pointed soft points that would all slay Bambi quite well , available at competitive prices . With further luck 147-150gr fmj generic would be close enough for economical extended shooting sessions.

BUT if you used radically different bullet configuration, like say an all copper, or an extra low drag bonded , probably major shift. Likewise if you handloaded to either reduced velocity for a youth , or extra hot to squeeze every last fps , then expect meaningful differences.

If a rifle is giving 5in groups at 50yds, there are problems . If not severe operator error, then the gun or ammo is screwed, OR they are severely mismatched to each other.

10Moa isn't possible to meaningfully zero . Get to bottom of lack of accuracy before attempting to zero.

Added - It can happen that a particular rifle/ scope/ ammo combination holds zero for years, or decades . But you don't Assume that . You periodically, and before anytime hitting is important to you ( hunting trip, big match, etc) verify, and make corrections if needed.

[/THREAD].

Blacksmith101 · Aug 11, 2017

Ammunition used can change both group size and point of impact. This tends to be less noticeable in center fire rather than rim fire however here is actual testing results with pictures of testing a number of different .22 rim fire rounds in several different rifles at several ranges. You can see the group sizes and the points of impact change. There are multiple threads on this forum on the subject.
http://forums.accuratereloading.com/eve/forums/a/tpc/f/8711043/m/7531057281

No single ammo is best in all rifles or even best in two different rifles of the same model. You need to test to find which ammo is best in your particular gun for what purpose you are using it for and adjust your zero accordingly. Anything you change may change your zero, like shooting in a tee shirt vs a heavy winter coat. Your position and how you hold the rifle will change your zero which is why seldom do two different individuals shoot to the same zero.

Ely engineers identified nearly 1,000 variables that can effect the accuracy of a simple .22 rim fire cartridge during its manufacture which is why match shooters test to find the what specific batch of ammo shoots best in their specific rifle and stock up on that particular batch number of that maker.
http://www.shootingtimes.com/ammo/ammunition_eley_101405/

Eley even has special test ranges in several countries, the U.S. one is in Texas.
http://www.eley.co.uk/test-ranges

For most people ammunition that is accurate to minute of soda can, or for a clean kill on a deer is good enough because most people can only shoot that well with even the best ammo. But if you are interested in ultimate accuracy and want to perfectly zero your gun you need to be aware of all the factors that effect accuracy and do your own testing.

pilot25 · Aug 11, 2017

Pinecone said:
.....knowing what you are doing, you can zero in under 5 rounds,...

Kind of a key statement that doesn't apply to me.

I have just enough knowledge to get to zero but it was expensive. Fun until about the 20th round when I was getting frustrated. Still glad I was able to walk away happy that I didn't waste match ammo and had the rifle zeroed at 50 yards when I was done.

pilot25 · Aug 11, 2017

Blacksmith101 said:
Ammunition used can change both group size and point of impact. This tends to be less noticeable in center fire rather than rim fire however here is actual testing results with pictures of testing a number of different .22 rim fire rounds in several different rifles at several ranges. You can see the group sizes and the points of impact change. There are multiple threads on this forum on the subject.
http://forums.accuratereloading.com/eve/forums/a/tpc/f/8711043/m/7531057281

No single ammo is best in all rifles or even best in two different rifles of the same model. You need to test to find which ammo is best in your particular gun for what purpose you are using it for and adjust your zero accordingly. Anything you change may change your zero, like shooting in a tee shirt vs a heavy winter coat. Your position and how you hold the rifle will change your zero which is why seldom do two different individuals shoot to the same zero.

Ely engineers identified nearly 1,000 variables that can effect the accuracy of a simple .22 rim fire cartridge during its manufacture which is why match shooters test to find the what specific batch of ammo shoots best in their specific rifle and stock up on that particular batch number of that maker.
http://www.shootingtimes.com/ammo/ammunition_eley_101405/

Eley even has special test ranges in several countries, the U.S. one is in Texas.
http://www.eley.co.uk/test-ranges

For most people ammunition that is accurate to minute of soda can, or for a clean kill on a deer is good enough because most people can only shoot that well with even the best ammo. But if you are interested in ultimate accuracy and want to perfectly zero your gun you need to be aware of all the factors that effect accuracy and do your own testing.

Thank you. Very informative links.

Biggfoot44 · Aug 11, 2017

In theory , if you know what you're doing, and can shoot, you can zero in 5rds, or 9rds, or whatever. But Murphy is over represented at Sight In Days .

Inbetween personal experience and working the line for Sight In events , I have seen :

Loose scope base screws
Loose scope rings
Incorrect bases, or front & rear bases switched.
Bases in need of shimming
Bad scopes, both broken & defective new from box
Screw holes on the gun misplaced or out of square.

And of course actual problems with gun ( as opposed to sighting equipment).

Personal luckiest - A cpl of timed bore sighted (old school) well enough to be dead on windage with minor elevation tweak .

Personal most frustrating - A Norinco SKS wearing cheap red dot, and using commie steel case ammo . - The gun & ammo I estimated to expect 3-4 MOA .Eventually concluded the red dot randomly bounced internally about 6 MOA . Drove me freaking crazy . I kept questioning the accuracy of the actual gun, and my shooting abilities . I'd try to pass off as a really bad lot of ammo, but the corrections I made never moved the POI predictably.

More than 100rds later, I happened to be looking thru optic when I bumped it, and saw the dot noticably move , clued me somthing was wrong.

DaemonAssassin · Aug 11, 2017

It depends on the intended application for the rifle.

If it is a plinking/HD rifle, I'll zero with bulk pack ammo.
If it is a hunting rifle, I'll zero it with the hunting ammo I will be using.
If it is a precision rifle, I'll zero with precision ammo.

Blacksmith101 · Aug 11, 2017

A friend bought a used Renegade muzzleloader with a load in the barrel for who knows how long. I got the load out for him and the bore where the load was is rough as a cob definitely pitted. The gun had no sight or ram rod which he has since replaced with aftermarket substitutes. He took it to the range to zero the new sight with patched round ball and the first shot at 25 yards was dead center on the bulls eye without touching the newly installed sight. Even with the rough bore it groups well at least to 100 yards. Some people are just lucky, he has more in the parts he replaced than the gun cost.

Pinecone · Aug 11, 2017

pilot25 said:
Kind of a key statement that doesn't apply to me.

I have just enough knowledge to get to zero but it was expensive. Fun until about the 20th round when I was getting frustrated. Still glad I was able to walk away happy that I didn't waste match ammo and had the rifle zeroed at 50 yards when I was done.

Mentioned in a number of threads, but glad to provide it again.

Start by bore sighting. Place rifle in a rest. For bolt action, remove the bolt. For AR type, just use the upper.

Adjust rifle, while looking though the bore, to be on a bullseye at 25 yards. Adjust scope to be in the middle of the bullseye, without moving the rifle.

Reassemble firearm.

Fire one shot. If you are happy with that shot (broke well, did not pull it), use it. If not fire one or two more.

Set rifle in rest with the cross hairs centered on the bullseye. Without moving the rifle, adjust the scope to put the crosshairs on the bullet hole.

To be a bit better, adjust the cross hairs about 1 inch below the bullet hole.

If you feel like you need it, fire one round. It should be pretty much on target.

Move to 100 yards, repeat.

Done.

Can be done in 2 rounds, but 3 - 5 is more typical.

Doco Overboard · Aug 11, 2017

As a matter of semantics, zeroing a rifle and sighting it in are two different things and one in the same....sort of. Zero your rifle to achieve the alignment of bore and sights to target for a reference. Sight your rifle to adjust for point of impact with different types of ammo distance to target etc. Use your zero as the baseline to return to when determining what type of ammo combination works best in your rig. Keep notes pertinent to the ammo, outside temps/ conditions time date round count etc at the time of firing that can be used as a reference later on. Soon you will see a pattern develop that can be relied on for making informed choices when you want to try something new.
Advice from advanced shooters like the ones who already responded can sometimes be confusing when starting out or getting your own routine. Keep your notes regimented in a book/binder that can hold targets to check out later on. What I do is check my rifles before hunting against my log at about fifty yards just to make sure they are good every year. Just remember that significant changes in group impact size may require further testing because your so close and the spread will be greater at extended ranges. The more rifles you get the more confusing it can be so notes are important but part of the fun. this is just works for me and if I told you I had a book for every rifle I own Id be lying but there is always some sort of info either in the butt-stock glued to the scope or taped to the stock written in a load manual somewhere.

Pinecone · Aug 12, 2017

I disagree with your definitions.

Sighting in is the process of getting the firearm to shoot where it is aimed. It will probably require shooting at various ranges.

Zeroing is doing so at a specific distance to set your baseline, i.e. 100 yard zero. For those that dial corrections, the zero is the where the rifle will shoot when you return all settings to the "zero" positions (elevation all the way down, windage to mid point).

You sight in to get your rifle zeroed.

outrider58 · Aug 12, 2017

Doco Overboard said:
As a matter of semantics, zeroing a rifle and sighting it in are two different things and one in the same....sort of. Zero your rifle to achieve the alignment of bore and sights to target for a reference. Sight your rifle to adjust for point of impact with different types of ammo distance to target etc. Use your zero as the baseline to return to when determining what type of ammo combination works best in your rig. Keep notes pertinent to the ammo, outside temps/ conditions time date round count etc at the time of firing that can be used as a reference later on. Soon you will see a pattern develop that can be relied on for making informed choices when you want to try something new.
Advice from advanced shooters like the ones who already responded can sometimes be confusing when starting out or getting your own routine. Keep your notes regimented in a book/binder that can hold targets to check out later on. What I do is check my rifles before hunting against my log at about fifty yards just to make sure they are good every year. Just remember that significant changes in group impact size may require further testing because your so close and the spread will be greater at extended ranges. The more rifles you get the more confusing it can be so notes are important but part of the fun. this is just works for me and if I told you I had a book for every rifle I own Id be lying but there is always some sort of info either in the butt-stock glued to the scope or taped to the stock written in a load manual somewhere.

Pinecone said:
I disagree with your definitions.

Sighting in is the process of getting the firearm to shoot where it is aimed. It will probably require shooting at various ranges.

Zeroing is doing so at a specific distance to set your baseline, i.e. 100 yard zero. For those that dial corrections, the zero is the where the rifle will shoot when you return all settings to the "zero" positions (elevation all the way down, windage to mid point).

You sight in to get your rifle zeroed.

Somewhere within these two posts, the term "doping" should/could be presented. Something I don't thin the OP is quite ready for.

Doco Overboard · Aug 12, 2017

Pinecone said:
I disagree with your definitions.

Sighting in is the process of getting the firearm to shoot where it is aimed. It will probably require shooting at various ranges.

Zeroing is doing so at a specific distance to set your baseline, i.e. 100 yard zero. For those that dial corrections, the zero is the where the rifle will shoot when you return all settings to the "zero" positions (elevation all the way down, windage to mid point).

You sight in to get your rifle zeroed.

I see what your saying, Im just considering that Zeroing would be done with a specific ammo that has been designated a standard to achieve mechanical settings and then used as a base line when other types are used where the repeat ability or performance of them is unknown and could vary to some degree until tested out to satisfaction.
When I have my rifle zeroed, I know it will shoot inside a specific arc with a certain ammo and can reasonably be estimated though testing where bullet strike would be. I can sight with my rifle to change the impact inside of that arc just by changing point of aim. Kind of like the same thing but two different ways. Help me with the definitions if that's not coming on right.

Pinecone · Aug 12, 2017

I see sighting in as the process.

And zeroing the goal.

lazarus · Aug 12, 2017

Biggfoot44 said:
Lots happened in the thread while I typed.

SxS is both correct, and "sort of, sometimes " . Yes, there are a gazillion factors, and you should never *assume* two different loads will have identical POI .

That said , bullets of same general shape and configuration ( for hunting example , say .30 cal lead core Spitzer 180gr ) at same nominal velocity , will "often" be reasonably close, at least at 100yds . Reasonably close meaning withing 2 inches, if not within 1 inch . The more variables in play, the more likely for different impacts .

Close enough to get you on paper at sighting distance to fine tune with $$ load. Ideally close enough, or off set in predictable manner to be useful for high volume practice .

I get the concept of practice with what you will hunt/ use for serious purpose , and it's not a terrible idea . BUT that works best with a convergence of both medium price, and plenty good enough performance. Following through with hunting examples , if you were going deer hunting with .308 rifle , there are any number of 150gr lead core pointed soft points that would all slay Bambi quite well , available at competitive prices . With further luck 147-150gr fmj generic would be close enough for economical extended shooting sessions.

BUT if you used radically different bullet configuration, like say an all copper, or an extra low drag bonded , probably major shift. Likewise if you handloaded to either reduced velocity for a youth , or extra hot to squeeze every last fps , then expect meaningful differences.

If a rifle is giving 5in groups at 50yds, there are problems . If not severe operator error, then the gun or ammo is screwed, OR they are severely mismatched to each other.

10Moa isn't possible to meaningfully zero . Get to bottom of lack of accuracy before attempting to zero.

Added - It can happen that a particular rifle/ scope/ ammo combination holds zero for years, or decades . But you don't Assume that . You periodically, and before anytime hitting is important to you ( hunting trip, big match, etc) verify, and make corrections if needed.

I personally zero with what I plan to need the most. My .308 hunting rifle is zero'd with 150gr PPU softpoints because they are pretty accurate and plenty for deer. Especially around here. PPU 147gr M80 is what I stock in bulk and the POI is only 1" off at 100yds. I don't adjust for the POI shift, I am content myself with small groups at the new POI.

My AR-15 is zeroed for M193 IMI, an inch shift with M885 IMI and about 2" shift with 64 and 75gr Gold dots. If I am going to take it hunting I'll re zero for which gold dot I might use.

Between the gold dots and various 67, 75 and 77gr .223 and 5.56 match ammo the POI all shifts around about an inch at 100yds in my experience. All good enough unless I am going to decide to start shooting competitively.

My 22lr if I am going to take it squirrel hunting has to be pretty accurate, but I only use minimags for hunting. So itnis zeroed for those. If I was going to go turkey hunting or fox hunting with it, I'd use velocitors and I'd go re zero it for them. Both are very accurate in my 10/22

Anything else, again I just live with having a 1-2" POI shift at 50yds and figure my grouping is maybe say 3 o'clock and 1.5" out.

My ML is zeroed for the only load I'd use, which is .44 240gr XTP on top of 95gr of FFFg 777.

Shotgun is zeroed for federal truball 2 3/4" 12ga slugs. It patterns close enough with target shells that the ghost ring sights aren't far enough off the make a difference at 20-30yds compared to the 75yd zero on the slugs.

outrider58 · Aug 12, 2017

Pinecone said:
I see sighting in as the process.

And zeroing the goal.

Now that's semantics(psssst, "zeroing" is a verb...

)

Magnumite · Aug 12, 2017

Ah, gwamma'!

When I shot Hunter's Pistol I kept a 'dope booklet' of several different guns, loads and ranges. I kept track of other arms I typically used.

AlBeight · Aug 12, 2017

Pinecone said:
Mentioned in a number of threads, but glad to provide it again.

Start by bore sighting. Place rifle in a rest. For bolt action, remove the bolt. For AR type, just use the upper.

Adjust rifle, while looking though the bore, to be on a bullseye at 25 yards. Adjust scope to be in the middle of the bullseye, without moving the rifle.

Reassemble firearm.

Fire one shot. If you are happy with that shot (broke well, did not pull it), use it. If not fire one or two more.

Set rifle in rest with the cross hairs centered on the bullseye. Without moving the rifle, adjust the scope to put the crosshairs on the bullet hole.

To be a bit better, adjust the cross hairs about 1 inch below the bullet hole.

If you feel like you need it, fire one round. It should be pretty much on target.

Move to 100 yards, repeat.

Done.

Can be done in 2 rounds, but 3 - 5 is more typical.

I too learned this method years ago & found it very quick and efficient. I get zeroed quicker and spend the rest of the time shooting for groups or for fun instead of chasing the crosshairs all over the place. 70% of the time it works every time.

Biggfoot44 · Aug 12, 2017

With good light conditions I use the lower corner of barn roof @ aprox 55yds . The longer distance seems to result in more precise bore sighting.

One time did a M70 @ 95yds . Good boresighting, but required a sandbag rig, and a bullseye target with the black just the right size . At the 50-ish yards I can get away with resting on the windowsill .

Minuteman · Aug 12, 2017

Great question OP.

I didn't read this thread, I'm sure its full of excellent advice.

My 2cents: I just start close with a big piece of paper or cardboard, using moderately priced ammo, not the super cheap stuff that you'll never shoot through a precision rifle. Then as I get it closer and closer, I'll move the target further away, until I'm out to the distance I want to zero. Then switch to better ammo, then ideally the ammo I would actually use. You should be close enough to zero with almost any ammo that is at or near the same weight. In the military we just shot at 25m to zero, and called it a day. I've also tried a buddies laser zero'ing device, that was hard/impossible to see the red dot, I do not recommend.

Zeroing with different types of ammo?

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