Time to start applying centerfire logic to .22 (was just zero, now expanded to other areas)

[littlepod]

Scope height also has a good effect on the up/down between the 25-50 yards.

Brian Litz has a talk about why 100 yard zero is good on one of the Everyday Sniper podcasts.

Something about how 100 yard zero is is usually the apex of the bullet curve.
Wind has minimal effect at 100.
Good distance for an accurate zero.

 

[Jackomason]

For some people that missed the zero chart. Theres a difference when zero is at peak of bullet trajectory height and when its crossing the zero still going up and then dropping back down...

yeah I noticed that, its interesting because if we extrapolate that out to equivalent centerfire distance it just doesn't line up. but does it really need to transfer over? I'm not really huge into the rim fire side of things so my thinking could be way off.

why not a "rough" zero at 25 yards then on a nice calm day a refined zero at 50 yards with the reverse dope applied to bring you back to 25 yards. looks like they will be not far off from each other anyway. again this is an outside looking in perspective that isn't grounded in much.

 

[1moaoff]

I was just making sure that any new guys understood what was going on. Lots of newbie questions these days.

Whatever floats your boat

 

[CBeck]

If looking at a 25 yard zero being the equivalent of a 100 yard centerfire zero, what yardage do the 50 yard groups that seem to be the benchmark for rimfire accuracy equate to in centerfire?

 

[Dthomas3523]

If looking at a 25 yard zero being the equivalent of a 100 yard centerfire zero, what yardage do the 50 yard groups that seem to be the benchmark for rimfire accuracy equate to in centerfire?

Depends on the comparison. If you measure from the time they leave the barrel (using 0yds as your zero), a 10mph full value wind pushes a .22 the same at 50yds as a dasher running 109’s at 300.

 

[300ATT]

I set up the Local Denver Greenmill match as a "quarter scale" match (e.g. quarter scale targets at 1/4th the distance) The intent is to mimic PRS matches as closely as possible for experienced shooters and still be fun enough to encourage new shooters to step out on to the "slippery slope" of precision rifle shooting.

Here are some lessons learned (so far).

Optics:
- You don't need a ZCO to win (but if you can afford it, good on you).
- You MUST have a scope that will track and is repeatable - and you need to perform a box test to confirm.
- Turrets that match the reticle (mil/mil or moa/moa).
- A christmas tree type reticle is useful for stages when elevation changes (turret turning) is not allowed.
- Parallax that focuses down to 25 yds (otherwise you will need to zero at 50). Some matches have tiny targets set up at 25 yards.
- A zero stop is worth the extra $$ you have to spend - some can do without but I see shooters get confused if elevation changes require multiple turns.
- As mentioned, the scope on the 22 will get A LOT more use than the CF rifle ... will it hold up?
- Assuming the scope tracks, the advantage of a TT, S&B, Nightforce or ZCO is in the superior glass needed for resolving targets beyond 800 yards through heavy mirage ... this is not a factor inside of 300 yards so shooters can do well with a Vortext PST, Anthon Midas, Burris etc.
- A $4,000 scope does not buy you any advantage over a $500 scope except in duplicating ergos between your RF and CF rifles. Each person will need to decide if that is worth it.

Ammo:
- You have to test at 50, 100 and 200 yards as a minimum. Ammo that shoots great at 50 may not shoot well at 100. And ammo that shoots 1/2 MOA at 100 may not hold elevation as well as other ammo at 200. For example, Federal ultra match shot under 1/2 inch at 100 yards for me but could not hold under 3" at 200 so SK Plus was better choice for my gun. Run a "flyoff" and down select ammo at each distance in order to pick the ammo that works best across the distances you will shoot.
- Run your ammo over a chronograph and get a 20 shot average (low ES is your friend just like CF rifles). Variations will show up at distance (180+)
- True your ballistics using a target beyond 200 yards and tweak the BC until your predicted drops match what you see in the field.

Rifle:
- Must feed reliably
- Mags: an advantage of the Bergara or Vudoo/Zermat is that it is easier to do a mag change with their full-size mags under time pressure than with the stick magazines (e.g. Sako).
- Strive to hold 1/2 MOA inside of 50 yards and 3/4-1 MOA at 100 yards and 1 MOA-1.5 MOA beyond. Thinking that you will hold 1/2 MOA out past 200 yards is unrealistic but a noble goal.

Wind:
- you CAN think of your RF as a " 6 mph" gun at 10 yard increments just like your CF. Play with the numbers in your ballistics apps. This is really useful for estimating wind holds under time pressure.
- Set up your zero such that, for example, a 6mph direct crosswind requires .1 mil for each 10 yards beyond your zero.
- Terrain (e.g. berms) can have a nasty effect on .22 precision at distance (150+) and you will see elevation issues depending on how the wind flows over the berms. This is where the 22 diverges from CF. As the distance increases - 22's are plagued with wind-driven elevation inconsistencies that you don't see in CF.

.22's are NOT forgiving. Even though there is no recoil this does not mean that a 22 is easier to shoot well than a CF rifle. My experience is that CF rifles are more forgiving than .22's. Focus on your fundamentals ...

Shooters that practice with a .22's get 100x more shots downrange than with a CF rifle. My observation is that those who shoot more improve their skills more regardless of it being a RF or CF rifle.

Shooting .22's is much less of a production and more fun for the average new shooter and is critical for growing the sport.

So, is shooting a .22 a direct 1/4th comparison to CF? Except for wind-driven elevation issues, a rimfire closely approximates shooting CF rifles at distance at 1/4 to 1/5 the scale. It's close enough such that it WILL make you a better shot. It's all about practice, practice, practice ...

 

[Jefe's Dope]

^ His match is outstanding. Brown gophers on brown berms. And a weak side and off hand COF every single match. Makes you a better shooter.

 

[CBeck]

What’s the typical velocities and sd’s you guys see when checking ammo. I tried non lot tested sk standard and center x today with good results.

 

[littlepod]

What’s the typical velocities and sd’s you guys see when checking ammo. I tried non lot tested sk standard and center x today with good results.
View attachment 7374574View attachment 7374575

Buy up all that lot. < 8 is ridiculously good.

 

[rybe390]

Might be an idiotic question but I'm going to let it rip after reading the whole thread.

25 or 30 yard zero does a few things for us. It mimics the "everything not your zero" is dial up, and it reduces wind variation, correct? We treat it like our 100 yard rifle zero where everything is always up.

I guess I didn't know until changing my zero distance that anything closer than 50 yards was actually dial DOWN. And I don't like that....

With regards to folks asking about the Mph method. 1 mph is what you use, and use it just like the center fire method. Get more granular with your range. 150 yards =1.5 etc.

10 mph at 150 yards is 1.5 mils.
15 at 100 is 1.5
5 at 50 is .25

 

[Dthomas3523]

Might be an idiotic question but I'm going to let it rip after reading the whole thread.

25 or 30 yard zero does a few things for us. It mimics the "everything not your zero" is dial up, and it reduces wind variation, correct? We treat it like our 100 yard rifle zero where everything is always up.

I guess I didn't know until changing my zero distance that anything closer than 50 yards was actually dial DOWN. And I don't like that....

With regards to folks asking about the Mph method. 1 mph is what you use, and use it just like the center fire method. Get more granular with your range. 150 yards =1.5 etc.

10 mph at 150 yards is 1.5 mils.
15 at 100 is 1.5
5 at 50 is .25

What is your question?

 

[rybe390]

What is your question?

Wanting to confirm what I put is the gist of the conversation and I'm not missing anything or understanding incorrectly.

 

[Jefe's Dope]

What’s the typical velocities and sd’s you guys see when checking ammo. I tried non lot tested sk standard and center x today with good results.
View attachment 7374574View attachment 7374575

That's fantastic. What are the ES?

I have SDs of 8.9 but an ES of 42. One series had a ES of 46. That's A LOT for .22lr and the distances we're shooting at. Considering moving to Midas for matches.

 

[300ATT]

With regards to the mph method for guestimating wind holds - it works.

Here is what I do:

I true my elevation data out past 200 yards with a 50 yard
zero. Then I play with the ballistics software and enter various crosswind values (hunt & peck method) until the predicted wind deflection is .1 mils for each 10 yards. I then confirm those estimates with a kestrel in real conditions.

This gives me about a 10.3 mph gun for .1 mil at each 10 yards.

With respect to chrono numbers from .22 ammo - it varies widely. I have a lot of SK+ that has measured SD of 6.3 fps (10 shots in my Vudoo) whereas the Center-X I tested was 15.7 ... your mileage will vary.

Best I have seen is an ES of 3fps from Eley Tenex in my Sako Finnfire Range That stuff will hold 1/2" of elevation at 200 yards.

 

[CBeck]

That's fantastic. What are the ES?

I have SDs of 8.9 but an ES of 42. One series had a ES of 46. That's A LOT for .22lr and the distances we're shooting at. Considering moving to Midas for matches.

The sk had an Es of 27 for 50 shots and the center x was 26 for 60 shots.

 

[Powder_Burns]

Any of you guys clocked sk biathlon and got es/sd for that stuff?

 

[Deflagration]

Its funny because people zero at 100 YD with 22lr outdoors....

Looking over my data, with a scope height of 1.95 inches, 25 YD and 50 YD intersect at the same point which is nice.

While we're here and slightly off topic, why do people still use G1 drag functions for round nose 22lr projectiles when RA4 exisits?
I understand at the end of the day most of us have to "true" our BC anyways, however there is a pretty substantial difference between G1 and RA4
at distances beyond 200 yards.

 

[pucker]

What zero range for .22 matches?

I was curious what range shooters set their zero's at for .22. 50 yds/meters or 25? I understand that this will vary depending on the shooting discipline. I am interested in your thoughts on an appropriate zero range for Nrl .22 and ELR (beyond 200 yard) type competitions.

www.snipershide.com

I never understood zero'ing anywhere other than where it makes everything a dial-up. Been using a 38y zero on my Vudoo since day one. I never cared for hold-unders...and DOPE is just math, you should be able to use any zero your equipment will allow.

DThomas...thanks for starting this thread. Overdue.

 

[Raufoss]

It’s all a great debate and surely interesting but a 25 yards zero is simply not possible for many shooter.

The 22RF match we shoot it’s 50 yards to 400 yards. To have enough elevation many use a 40 to 60 moa base. I can tell you than many cannot zero a 25 and often I’ve seen people unable to zero at 50. I had numbers of time to explain to people how to use a zero offset in their Kestrel.

 

[Dthomas3523]

It’s all a great debate and surely interesting but a 25 yards zero is simply not possible for many shooter.

The 22RF match we shoot it’s 50 yards to 400 yards. To have enough elevation many use a 40 to 60 moa base. I can tell you than many cannot zero a 25 and often I’ve seen people unable to zero at 50. I had numbers of time to explain to people how to use a zero offset in their Kestrel.

If they don’t have an optic capable of 20 mil or so, this conversion is likely not for them anyway.

 

[Dthomas3523]

Not to mention, anything past 300 is getting a bit impractical for an MD to include. 400 is the equivalent of over 1500yds with a .308 and 175 fgmm.

This is a common issue with .22 matches. MD’s think oh “it’s just 400yds.” But we are in ELR territory. There’s very, very few centerfire PRS style matches where you shoot over 1200yds. And then it’s usually only one stage.

If a .22 match has only one stage past 300, holdover and zero closer for what you’ll mostly be shooting. If it’s mainly 250+, well, now you’re in an ELR match and the discussion is different.

 

[MDrimfirerookie]

Not to mention, anything past 300 is getting a bit impractical for an MD to include. 400 is the equivalent of over 1500yds with a .308 and 175 fgmm.

This is a common issue with .22 matches. MD’s think oh “it’s just 400yds.” But we are in ELR territory. There’s very, very few centerfire PRS style matches where you shoot over 1200yds. And then it’s usually only one stage.

If a .22 match has only one stage past 300, holdover and zero closer for what you’ll mostly be shooting. If it’s mainly 250+, well, now you’re in an ELR match and the discussion is different.

this is a great point and i think one that might be starting to get lost on people as the gear improves and the money being dropped on 22 matches increases. shooting out past 250 to 300 on rickety circus props at a 2 MOA target is either a dick move or not thinking it through properly

 

[TheGerman]

this is a great point and i think one that might be starting to get lost on people as the gear improves and the money being dropped on 22 matches increases. shooting out past 250 to 300 on rickety circus props at a 2 MOA target is either a dick move or not thinking it through properly

I've shot a ton of 200, 250+ with the 22. It basically starts coming apart due to the ammo at 200.

Even with Midas or CenterX and ES around 10, Ill see one impact over the target, then one under, then 1-2 hits, then one over/under again. Put cardboard up behind it and it draws almost a straight vertical line like I'm doing a ladder test. Had the velocity not have spread so much, it would be almost all hits.

The real 'fix' for this, as the ammo really is the limiting factor, is to make/use targets where your MOA size challenge level is the width of the plate and then you simply make a tall skinny shape thats 8+ inches tall; basically a bowling pin. So if your wind call is good (which is the hardest part by far) you're not screwed out of a shot because your rounds had a larger ES within a 5 shot group.

Putting larger circle plates out is easier as it lets you cheat on the wind, but I prefer the tall/skinny as it makes us focus on the wind call.

So for you 25 yard zero guys; I had something weird happen the other day when trying this. Usually I always zero'd everything at 100 in low/no wind as ebst as I could. Worst case, we'd measure the wind to 100, get a wind call, hold dead center and then compare where the group was in relation to center hold and what the wind should have done to the round.

Zero'd at 25 with 5 rounds ontop of each other. Then shot at 200 with a slow full value wind from the right and I was constantly to the right to where I technically would have been holding 2-3 times what the wind hold should have been. Is there a trick to refining this as I know what happened; the adjustments at 25y are so small you dont see them until you shoot further out. Even moving it .2 either way at 25 basically kept the rounds in the group. How do you figure this out without trial/error constantly at distance afterwards?

 

[Dthomas3523]

I've shot a ton of 200, 250+ with the 22. It basically starts coming apart due to the ammo at 200.

Even with Midas or CenterX and ES around 10, Ill see one impact over the target, then one under, then 1-2 hits, then one over/under again. Put cardboard up behind it and it draws almost a straight vertical line like I'm doing a ladder test. Had the velocity not have spread so much, it would be almost all hits.

The real 'fix' for this, as the ammo really is the limiting factor, is to make/use targets where your MOA size challenge level is the width of the plate and then you simply make a tall skinny shape thats 8+ inches tall; basically a bowling pin. So if your wind call is good (which is the hardest part by far) you're not screwed out of a shot because your rounds had a larger ES within a 5 shot group.

Putting larger circle plates out is easier as it lets you cheat on the wind, but I prefer the tall/skinny as it makes us focus on the wind call.

So for you 25 yard zero guys; I had something weird happen the other day when trying this. Usually I always zero'd everything at 100 in low/no wind as ebst as I could. Worst case, we'd measure the wind to 100, get a wind call, hold dead center and then compare where the group was in relation to center hold and what the wind should have done to the round.

Zero'd at 25 with 5 rounds ontop of each other. Then shot at 200 with a slow full value wind from the right and I was constantly to the right to where I technically would have been holding 2-3 times what the wind hold should have been. Is there a trick to refining this as I know what happened; the adjustments at 25y are so small you dont see them until you shoot further out. Even moving it .2 either way at 25 basically kept the rounds in the group. How do you figure this out without trial/error constantly at distance afterwards?

I haven’t experienced this problem personally.

.1 mil is .1 mil. But, I have seen where the hole gets larger than what you can see.

So, I only shoot 1 shot after an adjustment. Doesn’t matter where. The recoil doesn’t move the rifle enough to disturb the reticle. So, I put the center dot of reticle anywhere and pull trigger. If the bullet doesn’t impact exactly where my center dot is, I measure, adjust, and fire at another point.

I do this until I can put the center dot anywhere, pull the trigger, and the bullet impacts exactly where I aim.

Basically, I don’t shoot groups to zero.

 

[Jefe's Dope]

I zero at 25 for elevation and then move out to 100 for fine tuning of windage. I shoot indoors though. I have found that after zeroing at 25, I also get the 100 yard "drift" you describe.

 

[justin amateur]

Herr Oberleutnant...that tall skinny target y'er describing...that's my CAT200

The Crappy Ammo Target for 200 yards....allows for a 40 fps ES handicap and still allows a 10 to be scored.

10 shots at 200 yards for score. Even with the vertical target zone, it's a beast.

Links to download the 8.5x11 pdf

Google Drive: Sign-in

Access Google Drive with a Google account (for personal use) or Google Workspace account (for business use).

drive.google.com

Google Drive: Sign-in

Access Google Drive with a Google account (for personal use) or Google Workspace account (for business use).

drive.google.com

 

[TheGerman]

I zero at 25 for elevation and then move out to 100 for fine tuning of windage. I shoot indoors though. I have found that after zeroing at 25, I also get the 100 yard "drift" you describe.

What just hit me is I need to look on my Trimble as to what it says the spin drift is for it.

Usually leave it off. Curious now.

 

[Dthomas3523]

What just hit me is I need to look on my Trimble as to what it says the spin drift is for it.

Usually leave it off. Curious now.

I think it’s .1 @ 100

 

[justin amateur]

Playing with my calculator, 40 grain 22lr at 1074 fps MV
vs 77 gr smkbthp 223 at 2750 fps mv, the time of flight
for the 22lr at 200 yards matches the 223 at about 460 yards.
So a 5 inch 22lr group at 200 yards, is about the equivalent of a 5 inch 223 group at 460?

I can live with that.

I've produced a bunch of sub 3 inch groups at 200 yards with the 22lr.
That'd be what? Sub moa with the 223 at 460?

 

[A&8's]

What just hit me is I need to look on my Trimble as to what it says the spin drift is for it.

Usually leave it off. Curious now.

Turn all that stuff off, IF you actually collect hard data and true your ballistic app to the hard data.By leaving it on, you're basically entering it in twice. When you tell the calc, "THIS is what my gun shoots", you are already taking into account for spin drift, coriolis, etc.

 

[Dthomas3523]

Turn all that stuff off, IF you actually collect hard data and true your ballistic app to the hard data.By leaving it on, you're basically entering it in twice. When you tell the calc, "THIS is what my gun shoots", you are already taking into account for spin drift, coriolis, etc.

This is incorrect for spin drift as it is not linear.

 

[A&8's]

This is incorrect for spin drift as it is not linear.

I disagree. And so does @lowlight, if I'm not mistaken. At least that's what was told to us in his Oct 19 PR1/2 class. Although, I may have misunderstood him (I don't think so, though.)

 

[Dthomas3523]

I disagree. And so does @lowlight, if I'm not mistaken. At least that's what was told to us in his Oct 19 PR1/2 class. Although, I may have misunderstood him (I don't think so, though.)

Explain your disagreement.

You don’t true your data laterally. You true it vertically.

Aerodynamic jump can be factored twice as it affects the vertical.

What Frank says is that 1: spin drift gets lost in the noise of wind and 2: it’s not as much as some calculations say. Take notice when he talks about left hand twist helping cancel it out due to the recoil impulse with right handed shooter. He also talks about zero’ing .1 left with a right hand twist barrel.

 

[Dthomas3523]

Not to mention, we aren’t talking centerfire supersonic anymore.

We are talking .22 subsonic.

Not that it changes how spin drift works, but things that don’t matter in supersonic flight matter in subsonic. You’re going to pay more attention to spin drift in ELR. Which shares some of the characteristics of .22 subsonic flight.