22 dope, trustworthy? NRL22 TCGC

[Hueco]

Man I'm confused by TCGC schedule, one month it's the first Sunday, the next it's the 3rd.

No joke. At least this one isn't on Easter Sunday.

It's a play weekend for me - DRRC on Saturday, TCGC on Sunday. Woot woot.

That's like...maybe a few hundred bucks of .22LR about to be shot?

 

[mtjones12]

Strelok Pro using the RA4 ballistic coefficient was pretty on the money for me.

TCGC this Sunday: https://practiscore.com/tcgc-nrl22-match-may-1-2022/register

As of today, the May COF hasn't dropped yet...so...yay for no prep time.

There is no official May COF from NRL22. Since the nationals are later in May, they do not release a COF the month of nationals.

I am not sure what exactly Dave is planning for the COF, so unless the match documents end up posted on practiscore before Sunday, we all will be going in there with no prep time.

 

[Member 34319]

There is no official May COF from NRL22. Since the nationals are later in May, they do not release a COF the month of nationals.

I am not sure what exactly Dave is planning for the COF, so unless the match documents end up posted on practiscore before Sunday, we all will be going in there with no prep time.

I suck, so having everyone on the same playing field might help!

 

[The Heretic]

Usually the calculated dope is pretty close, assuming your input variables are correct.

garbage in, garbage out

I would verify inputs with a chronograph of the loads used. You can't trust manufacturer's claimed velocities.

 

[mtjones12]

You are very correct, I have seen speeds vary from the advertised velocities by as much as 70fps, which is a ton when your starting point is under 1100 fps. Also chrono if you have the availability to ( if you need, ask me at matches, i usually have my chrono in my car).

I was referring mainly to backing into your MV if you don't have chrono data available by truing up your solver outputs for known drop at 100 yards. (Which surprisingly is how Kestrel recommends doing it, albeit at 200 yards), even with a known MV. Your MV becomes a plug in the applied ballistics software.

 

[The Heretic]

I was referring mainly to backing into your MV if you don't have chrono data available by truing up your solver outputs for known drop at 100 yards. (Which surprisingly is how Kestrel recommends doing it, albeit at 200 yards), even with a known MV. Your MV becomes a plug in the applied ballistics software.

Certainly - with .22 LR ammo you have to dig a bit for BC data and at a given range MV is just a starting point if you don't have the BC.

Just guessing here - I haven't used any kind of calcs/etc. for .22 RF ballistics so I don't know what is available with ballistics calculators for rimfire ammo/bullets - I would guess that for the CF calculators that assume certain projectile shapes/etc., that the results may not be accurate at the lower velocities and shapes of rimfire ammo - especially if you are starting out at supersonic and then crossing back over to subsonic.

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[pdxglocker9mm]

Usually the calculated dope is pretty close, assuming your input variables are correct.

The best way to confirm dope without checking every possible distance, is to set up a board at 50 and 100yds when you set up your sight in target. Confirm zero and 50, and calculate your actual dope at 100. (As stated above, and my rifle shoots slower than the advertised speed as well)

Then you have an idea of the adjustment you need to make to the values given by your ballistic software. (Ie, your software says your dope is 5.5 moa, but your actual is 5.8, you know your rough adjustment needed). You can also back into your actual speed with this method, and get more accurate numbers out of your software. (Adjust your speed input so your 100 calculated matches your actual observed)

Let me know if you have any questions, and I'll be out there if you need help that morning.

Michael Jones

One thing i was told is that your best optical clarity will be in the middle of your scope adjustment range. So getting a sloped scope base that puts your zero at the bottom of your scope adjustment may not be best. When choosing a sloped base or ring inserts I try to keep my bottom zero about 1/4 up from the bottom of the adjustment. Granted my zero is 40m but that is pretty close to 50 yards and I still have enough bottom end to dial down to 25 yards. I have plenty of adjustment for my application of small bore silhouettes. It also means as the distance gets farther and you add more clicks the clarity is typically getting better. Small bore silhouettes is a standing un supported no sling game. Should be good practice for some parts of NRL22

 

[NiteQwill]

One thing i was told is that your best optical clarity will be in the middle of your scope adjustment range. So getting a sloped scope base that puts your zero at the bottom of your scope adjustment may not be best. When choosing a sloped base or ring inserts I try to keep my bottom zero about 1/4 up from the bottom of the adjustment. Granted my zero is 40m but that is pretty close to 50 yards and I still have enough bottom end to dial down to 25 yards. I have plenty of adjustment for my application of small bore silhouettes. It also means as the distance gets farther and you add more clicks the clarity is typically getting better. Small bore silhouettes is a standing un supported no sling game. Should be good practice for some parts of NRL22

View attachment 1337187

"Middle of the scope" elevation really depends on what scope you're using. If you're using a cheaper scope, this is certainly true. If you start to use the outlying ends of available adjustment, there will be issues with clarity. These rarely exist on higher end scopes like Zero Compromise and Tangent Theta.

On to the topic of dope for NRL22/PRS22 in regards to the OP. The best way to obtain your dope, in my experience, is to run a Drop Scale Factor for your particular lot of 22 ammo. A Kestrel makes this easy. For DSF, I obtain data on rounds on target at 100, 150, 200, 250, and 300 yards. This is by far the easiest, fastest, and most accurate way to understand and shoot precision 22 at long distances. I've done quite a few matches where targets were as far as 437 yards and outside of bad wind calls, a calibrated DSF has always allowed me to land rounds on target (Lapua Center-X).