Zeroing with different types of ammo?

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  • pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    When you zero a rifle which ammunition do you choose to do it with? Match? Inexpensive range ammo? Does it matter?
     

    sxs

    Senior Member
    MDS Supporter
    Nov 20, 2009
    3,378
    Anne Arundel County, MD
    A 5 inch group at 50 yds is a pretty big group. Its not necessarily you since you shot a dime size group with the match ammo. Non match ammo can have greater variance in weight or even concentricity from 1 bullet to another, greater variance in powder weight from 1 cartridge to another, and even vaiances in weight or concentricity of the brass. The exact geometry of the bullet can add a variable as well ( i.e. hollow pt, spitzer, softpoint, spire point, how elongated the spitzer mught be, etc). Further, different weight of bullets, different manufactures, etc, will usually change the point of impact somewhat. In Hunters Safety we instruct the student to both sight in their fireams and practice with the ammo you expect to hunt with ....just because of potential variance in the point of impact. Oh, yeah, you can see some change in the grouping and point of inpact between a cleaned and oiled barrel and a fouled barrel. Thats why I am loath to do a cleaning of the bore of my rifles after I make the final sight in check just before hunting season. Unless I hunt in the rain or something, I try to leave the bore a bit fouled from that last sight in until I'm finished hunting for the season. Its not usually a huge difference between a clean and fouled bore , but often is a couple inches or more at 100 yds (double that at 200 yds).
     

    pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    My handloads that I load.

    I'm going to guess those loads are close to match quality.

    First time zeroing anything I used range ammunition and got mixed results. Switched over to match ammunition and hit the bullseye 3 times in a row.

    I'm guessing it was a coincidence as I was really making sure I had everything set. I didn't want to waste $1 per round ammunition. That maybe I wasn't so concerning with the cheaper stuff.

    All the zeroing articles and videos talk about distance to zero and how to do it but none talk about ammunition.
     

    Bountied

    Ultimate Member
    Apr 6, 2012
    6,894
    Pasadena
    When you zero a rifle which ammunition do you choose to do it with? Match? Inexpensive range ammo? Does it matter?

    What kind of firearm is it and what are you trying to do? I usually try to zero with what I'm going to be shooting with. I'll get on paper with cheap ammo then zero with the ammo I plan to use. If it's a target AR I use 55gr NATO to get on paper then my 77gr loads that I plan to shoot out of it the most. If it's a range toy with a red dot I zero with 55gr NATO at 50yds then confirm the 50/200 zero at 200yds and call it good.

    With a 22 I pretty much only use minimags and that's what I zero with too.
     

    pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    A 5 inch group at 50 yds is a pretty big group. Its not necessarily you since you shot a dime size group with the match ammo. Non match ammo can have greater variance in weight or even concentricity from 1 bullet to another, greater variance in powder weight from 1 cartridge to another, and even vaiances in weight or concentricity of the brass. The exact geometry of the bullet can add a variable as well ( i.e. hollow pt, spitzer, softpoint, spire point, how elongated the spitzer mught be, etc). Further, different weight of bullets, different manufactures, etc, will usually change the point of impact somewhat. In Hunters Safety we instruct the student to both sight in their fireams and practice with the ammo you expect to hunt with ....just because of potential variance in the point of impact. Oh, yeah, you can see some change in the grouping and point of inpact between a cleaned and oiled barrel and a fouled barrel. Thats why I am loath to do a cleaning of the bore of my rifles after I make the final sight in check just before hunting season. Unless I hunt in the rain or something, I try to leave the bore a bit fouled from that last sight in until I'm finished hunting for the season. Its not usually a huge difference between a clean and fouled bore , but often is a couple inches or more at 100 yds (double that at 200 yds).

    I didn't know any of this. I guess it is often assumed by the writer when writing zeroing articles.
     

    Biggfoot44

    Ultimate Member
    Aug 2, 2009
    32,884
    As generic answer :

    Do initial sight in with low to medium cost ammo of the same weight bullet . After sighted with that, then shoot your match/ premimum hunting ammo , to either verify same poi, or make final corrections.
     

    hillbilly grandpa

    Active Member
    Jan 26, 2013
    962
    Arnold
    If I'm preparing to shoot at a range, for competition or just for skill enhancement I use standard velocity for 22LR, or match ammo I plan to use. For hunting prep I zero with the ammo I will be using, at a zero distance about mid-range for the distance I anticipate shooting. For instance, in 6.5 Creedmoor for some game I might be using 140 gr. I've found for hogs I'm down to 100 gr Noslers. Hogs don't bleed a lot. On smaller size animals that are the best for eating, heavier bullets are often through and through, producing an animal that runs away and dies much later. Little blood trail means a lost pig. I want something that offloads more energy in the animal. I zero for the ballistic characteristics of that round. It's situational.
     

    pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    What kind of firearm is it and what are you trying to do?

    1:7 twist piston carbine. Manufacturer recommends 77 grain ammunition. They state they use BlackHills 77 grain OTM Mod1 when testing each build. I used this and was accurate. 62 grain Federal, significantly less expensive, was less so.

    So your recommendation follows the results I was having exactly.
     

    pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    I zero for the ballistic characteristics of that round. It's situational.

    So you end up having to go through the zero process quite a few times a year? I assumed it was a one time thing after buying a new rifle.

    Learning curve, for me, is sometimes steep.
     

    Bountied

    Ultimate Member
    Apr 6, 2012
    6,894
    Pasadena
    1:7 twist piston carbine. Manufacturer recommends 77 grain ammunition. They state they use BlackHills 77 grain OTM Mod1 when testing each build. I used this and was accurate. 62 grain Federal, significantly less expensive was less so.

    So your recommendation follows the results I was having exactly.

    Yeah the twist rate will definitely affect the stability of the bullet in an AR. I don't think the 55 grainers like the 1:7 at all. I still think if it's a brand new scope and has never been zeroed I'd get on paper with the cheapest stuff then zero with the 77gr black hills.

    An easy/cheap bore sighting technique that will get you close is to remove the upper and the bolt and carrier, then look through the barrel at a target as far away as you can. I put my upper on a bag so it won't move then I look through the scope and adjust until they match up. It's a rough gauge but it should get you on paper to limit the amount of rounds it will take to get a good zero.
     

    Bountied

    Ultimate Member
    Apr 6, 2012
    6,894
    Pasadena
    So you end up having to go through the zero process quite a few times a year? I assumed it was a one time thing after buying a new rifle.

    Learning curve, for me, is sometimes steep.

    Sometimes it can be a one time thing but not usually. If you zeroed in the summer then shoot in the winter your zero will be off and vice versa. The elevation you are shooting at can affect zero, pressure can affect zero etc. If the shot you're taking is important you will want to confirm your zero and make adjustments if necessary.
     

    pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    If the shot you're taking is important you will want to confirm your zero and make adjustments if necessary.

    This statement alone makes me realize I need to read a lot more about this to get it right.

    I'm guessing many of you were taught in either the military or at a very young age. Every time I think I know something I have to sit back down. Sometimes its fun to learn from mistakes and others its frustrating.
     

    pilot25

    Ultimate Member
    Jul 13, 2016
    1,822
    An easy/cheap bore sighting technique that will get you close is to remove the upper and the bolt and carrier, then look through the barrel at a target as far away as you can. I put my upper on a bag so it won't move then I look through the scope and adjust until they match up. It's a rough gauge but it should get you on paper to limit the amount of rounds it will take to get a good zero.

    Makes good sense.
     

    Bountied

    Ultimate Member
    Apr 6, 2012
    6,894
    Pasadena
    This statement alone makes me realize I need to read a lot more about this to get it right.

    I'm guessing many of you were taught in either the military or at a very young age. Every time I think I know something I have to sit back down.

    I should say if the shot you're taking is going to be important you will want to confirm zero beforehand and adjust if necessary.

    I went to Africa last year to hunt and my zero was only off by about an inch low at 100yds. At that range I didn't need to adjust zero because most of my shots were going to be inside of 200yds with a fairly large target like 6" vitals area. The more you shoot the more you'll learn. If I was going to be taking 500yd plus shots I would have re-zeroed for that inch of error.
     

    sxs

    Senior Member
    MDS Supporter
    Nov 20, 2009
    3,378
    Anne Arundel County, MD
    For reloaders, you can sometimes pick 2 bullet types that shoot quite similarly. For my Remington 700, I get superb accuracy using Sierra Match King 168 gr Boat tail hollow points. Match smmo is designed, however, for consistency for accuracy...not for consistent expansion and performance for hunting. My hunting load for that rifle is the Sierra GameKing 165 HPBT. The groups open from under an inch with the Match King to an inch and a half or slightly more with the Game King. There is no practical difference in where the groups center for each projectile. One more thing: my rifle is pretty close to sighted in at 200 yds. The causes me to shoot a group that centers about 2 to 2-1/2 inches high at 100 yds. FYI...the rifle is very nearly on at 50 yds as well). Once I acheived a good sight in, I usually shoot it mostly at 100 yds, but will occasionally shoot a 3 or 5 shot group at 200 just to verify what the gun (and me!!!) Can do. Rarely do I get a shot much beyond 100 yds (usually lesd than that), but I have made a few at 200 or slightly more. It's nice to know what I and the gun can do. Without knowing that, I would have to limit my shots.
     

    hillbilly grandpa

    Active Member
    Jan 26, 2013
    962
    Arnold
    I don't tell my hoplophobe friends that I'm going out to the range to shoot. I tell them I'm going into the field to work on some applied physics problems. They're one and the same.
     

    Biggfoot44

    Ultimate Member
    Aug 2, 2009
    32,884
    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.
     

    Pinecone

    Ultimate Member
    MDS Supporter
    Feb 4, 2013
    28,175
    As generic answer :

    Do initial sight in with low to medium cost ammo of the same weight bullet . After sighted with that, then shoot your match/ premimum hunting ammo , to either verify same poi, or make final corrections.

    This ^^^^^^

    Although, with optics and knowing what you are doing, you can zero in under 5 rounds, so I would just use the ammo you plan on shooting.

    100 yard zeros do not change much with temperature or pressure (altitude), but further out, the drop can change significantly. But that is why there are ballistic calculators.
     

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