22lr/centerfire distance equivalents

[caesAR15]

Over the last couple months I've started .22lr out to 200 pretty regularly. It's been immensely valuable for developing a variety of skills. One thing I keep coming back to is equivalent distances -- basically what does a 200 yard 22lr shot translate to with my 6.5 creedmoor?

I realize it's a trivial thing and the real value is trigger time, fundamentals, etc., etc., but I am genuinely curious if there's an accurate way to gauge distance equivalents between rimfire and centerfire cartridges. And if there is, what's the proper metric for gauging this? Mils dialed? Time of flight? Ballistic chart comparisons? What say you, and why?

 

[68hoyt]

Check these guys out , I play around with the 22lr 250 yard to .308 168gr at 1000 comparison

Long range 22LR trainer - how to get best out of it?

22LR rifles have always been very popular. Most of us have one sitting in safety. Some of us have also spent quite a bit hard-earned money to make their small rimfire feel and look similar to favorite big center-fire. All in sake of realistic low-budget training. It is also not too uncommon to...

finnaccuracy.com

 

[FromMyColdDeadHand]

I have a post about 18-24 months ago where I compared 22lr to . 308. It is about a 1/4 scale to 308. Compared to 6.5, it would be probably 1/5 or more. I even got some 1/4 scale IPSCish targets made.

It looks like my local range is open this weekend and I'm going to do some more extensive testing of my 22lr and 308.

 

[Lsmart95]

I’ve been toying with the below function to get a feel for long range and extreme long range for subsonic cartridges. It’s back of the envelope but it could be used to compare cartridges too.

A distance can be found by varying “c”. I’ve used a “c” of 2 rounded to the nearest 50 yards to define long range and a “c” of 1.5 to define extreme long range. I’d love to hear other opinions on it.

Yds = (sqrt(bc)*mv)/c

Examples:
LR in yds = (sqrt(bc)*mv)/2
ELR in yds = (sqrt(bc)*mv)/1.5

Please note this is not exact. It should get you in the ballpark of comparable elevation and windage for dissimilar rounds though.

Edit: my graph looked bad so I replaced it with a disclaimer. Also flipped c definitions.

 

[Lsmart95]

I’m looking at the function again. A cube root fits 308 and 22lr a bit tighter than a square root. I’ll probably revise.

 

[justin amateur]

Compare 22lr ballistics to a 308 for equivalent points of trajectory?

I can run a quick calc for that...10 mph full value crosswind

Comparing time of flight, drop and wind drift, there does not appear to be a consistent relationship.
Similar time of flight does not match similar drop or drift, from a quick look at the chart.

 

[hlee]

Reading the wind is soooooo much easier at 200 yards that a rimfire to centerfire yardage comparison is essentially meaningless.

 

[FromMyColdDeadHand]

The only way I can make sense out of it is to run MIL, not drop. TOF would be interesting though too.

This is the old thread on a target. I also did some excel spreadsheets looking at 22lr and 7.62x51 175gr.

Take my dope from my 40X and some calculated dope for longer distances for my 7.62-175gr out of an LMT MWS.

Red line is mil drop for the 22lr, the blue line is the 7.62 data. The green line is the mild drop for 22lr, but with the distance times 4. Pretty close at relevant distances.

I was running the equations to try to divine out some kind of relationship.

To me, it wasn't so much the wind as an issue, it was that the 22lr seems really sensitive to ammo, gun and air temp for 200+ yr shots. Still looking to do a day long look at ammo temp, cold bore and gun temp affect come ups at 200. I saw 1 mil differences from morning to noon (50F to 80F) that I could never get to calc out in a ballistic calculator the differences based on air temp alone.

 

[Dthomas3523]

Reading the wind is soooooo much easier at 200 yards that a rimfire to centerfire yardage comparison is essentially meaningless.

I dunno. I find it much easier to shoot my centerfire at 600-1k than I do my vudoo at 250-350. Especially if there’s no berm to see splash on a miss.