Long Range - Hit Probability Analysis

[cheapmoa]

375 - 344 ULD - 3800 - 88% Hit

 

[cheapmoa]

344gr .375 projectile with G1 1.05 at 3800fps

It would be 99% with a .5 MOA precision rifle but i have been using 1 MOA for consistency on these calculations.

 

[SilentStalkr]

How about a 243 Catbird?

 

[cheapmoa]

How about a 243 Catbird?

I don't know anything about it. Velocity and projectile?

 

[SilentStalkr]

Sure 4200 FPS with 70 grain bullet

 

[cheapmoa]

243 Catbird - 70 VLD - 4200 - 9% Hit

 

[M47Patton]

How about a 265 nosler accubond longrange at 3000 fps out of a 338 lapua. Started playing with these and RL-33.

Nosler updated the BCs on the ablr, they are looking more realistic now:

https://www.nosler.com/accubond-long-range-bullet/

 

[cheapmoa]

338 LAPUA - 265 Accubond LR - 3000 - 40% Hit

 

[towerofpower93]

From a 338LM, 300gr Bergers and 300SMK at 2800fps and 2700fps, and 250gr Berger Hybrids at 2950fps and 2850fps...if you're so inclined.

Thanks

 

[jaybigboy34]

300 norma mag. 225eldm 3000fps

 

[cheapmoa]

300 NORMA - 225 ELDM - 3000 - 46%

 

[cheapmoa]

338 LAPUA - 300 OTM - 2700 - 32% Hit

338 LAPUA - 300 OTM - 2800 - 40% Hit

338 LAPUA - 300 SMK - 2700 - 31% Hit

338 LAPUA - 300 SMK - 2800 - 34% Hit

 

[jaybigboy34]

300 NORMA - 225 ELDM - 3000 - 46%

thank you!

 

[223762]

300 win mag-225 ELDM-2850
300 win mag-215 hybrid-2890

 

[SilentStalkr]

It would be 99% with a .5 MOA precision rifle but i have been using 1 MOA for consistency on these calculations.

Well that changes things. I think most rifles these days are better than moa.

 

[steve123]

How about a standard 375CT, say 361 flatline at 3100. 961 g1 or 480 g7

 

[cheapmoa]

Well that changes things. I think most rifles these days are better than moa.

It doesn't realiy change anything. As long as we use the exact same assumptions then the Hit % will all be relative to each other. It would be interesting to see how close these Hit percentages are for 1st Shot attempts at this distance. I bet this is closer to reality than you think.

If you on your rifle are a .5 MOA shooting system @ 1200 yards with perfectly still conditions and perfect range estimation which is roughly 6" groups (that is very unlikely) then it only increases your Hit % at an equal amount for each simulation. Think about how difficult it is to hit a target on the 1st shot at 1200 yards. What do you think the average 1st Shot Hit % is at 1200 yards for most long range shooters?

 

[cheapmoa]

375 CT - 361 FLATLINE - 3100 - 61% HIT

 

[cheapmoa]

300 WIN MAG - 225 ELDM - 2850 - 38% HIT

300 WIN MAG - 215 HYBRID - 2890 - 31% HIT

 

[lawofsavage]

What about a 6.5 shooting a 147 grain ELD-M at the following velocities: (2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300) fps.

Sorry if some of that is close to what you’ve done previously but I think it would be neat to see the incremental improvement in hit % as velocity is increased and everything else is held constant.

 

[223762]

Thank you cheapmoa

 

[cheapmoa]

I have been working on a matrix to demonstrate where we can look at the effect of velocity on our HIT%. +/- 3% but this should give you some real insight.

5.56 - 90 VLD - 2500 - 11% - Recoil Energy of 6.42 (ft.lbf)
5.56 - 90 VLD - 2600 - 13%
5.56 - 90 VLD - 2700 - 14%
5.56 - 90 VLD - 2800 - 18%
5.56 - 90 VLD - 2900 - 20%
5.56 - 90 VLD - 3000 - 23%
5.56 - 90 VLD - 3100 - 26%
5.56 - 90 VLD - 3200 - 30%
5.56 - 90 VLD - 3300 - 33% - Recoil Energy of 8.64 (ft.lbf)

6 - 115 VLD - 2500 - 11% - Recoil Energy of 8.33 (ft.lbf)
6 - 115 VLD - 2600 - 12%
6 - 115 VLD - 2700 - 14%
6 - 115 VLD - 2800 - 16%
6 - 115 VLD - 2900 - 18%
6 - 115 VLD - 3000 - 22%
6 - 115 VLD - 3100 - 26%
6 - 115 VLD - 3200 - 30%
6 - 115 VLD - 3300 - 32% - Recoil Energy of 11.59 (ft.lbf)

6.5 - 147 ELDM - 2500 - 18% - Recoil Energy of 11.13 (ft.lbf)
6.5 - 147 ELDM - 2600 - 20%
6.5 - 147 ELDM - 2700 - 23%
6.5 - 147 ELDM - 2800 - 27%
6.5 - 147 ELDM - 2900 - 31%
6.5 - 147 ELDM - 3000 - 35%
6.5 - 147 ELDM - 3100 - 38%
6.5 - 147 ELDM - 3200 - 43%
6.5 - 147 ELDM - 3300 - 49% - Recoil Energy of 15.99 (ft.lbf)

7 - 180 ELDM - 2500 - 28% - Recoil Energy of 14.45 (ft.lbf)
7 - 180 ELDM - 2600 - 31%
7 - 180 ELDM - 2700 - 34%
7 - 180 ELDM - 2800 - 38%
7 - 180 ELDM - 2900 - 43%
7 - 180 ELDM - 3000 - 47%
7 - 180 ELDM - 3100 - 52%
7 - 180 ELDM - 3200 - 56%
7 - 180 ELDM - 3300 - 59% - Recoil Energy of 21.27 (ft.lbf)

 

[cheapmoa]

Where is the highest HIT% for the lowest RECOIL?

 

[W54/XM-388]

So basically it looks like what would be a 7/300 shooting 180 ELD-M at 3300 gives you the best hit chance, but the most recoil.

 

[cheapmoa]

I have been working on a matrix to demonstrate where we can look at the effect of velocity on our HIT% and the corresponding RECOIL. +/- 3% but this should give you some real insight. The 90 VLD look very appealing for PRS style matches in a 22 Creedmoor or 22 Nosler for a gas gun and for the best of all worlds the 7mm because at low velocity it beats everything in Hit % with a manageable recoil and at high velocity it is a long range hammer.


5.56 - 90 VLD - 2500 - 11% - Recoil Energy of 6.42 (ft.lbf)
5.56 - 90 VLD - 2600 - 13% - Recoil Energy of 6.70 (ft.lbf)
5.56 - 90 VLD - 2700 - 14% - Recoil Energy of 6.98 (ft.lbf)
5.56 - 90 VLD - 2800 - 18% - Recoil Energy of 7.26 (ft.lbf)
5.56 - 90 VLD - 2900 - 20% - Recoil Energy of 7.54 (ft.lbf)
5.56 - 90 VLD - 3000 - 23% - Recoil Energy of 7.82 (ft.lbf)
5.56 - 90 VLD - 3100 - 26% - Recoil Energy of 8.10 (ft.lbf)
5.56 - 90 VLD - 3200 - 30% - Recoil Energy of 8.38 (ft.lbf)
5.56 - 90 VLD - 3300 - 33% - Recoil Energy of 8.64 (ft.lbf)

6 - 115 VLD - 2500 - 11% - Recoil Energy of 8.33 (ft.lbf)
6 - 115 VLD - 2600 - 12% - Recoil Energy of 8.74 (ft.lbf)
6 - 115 VLD - 2700 - 14% - Recoil Energy of 9.15 (ft.lbf)
6 - 115 VLD - 2800 - 16% - Recoil Energy of 9.56 (ft.lbf)
6 - 115 VLD - 2900 - 18% - Recoil Energy of 9.97 (ft.lbf)
6 - 115 VLD - 3000 - 22% - Recoil Energy of 10.38 (ft.lbf)
6 - 115 VLD - 3100 - 26% - Recoil Energy of 10.79 (ft.lbf)
6 - 115 VLD - 3200 - 30% - Recoil Energy of 11.20 (ft.lbf)
6 - 115 VLD - 3300 - 32% - Recoil Energy of 11.59 (ft.lbf)

6.5 - 147 ELDM - 2500 - 18% - Recoil Energy of 11.13 (ft.lbf)
6.5 - 147 ELDM - 2600 - 20% - Recoil Energy of 11.73 (ft.lbf)
6.5 - 147 ELDM - 2700 - 23% - Recoil Energy of 12.33 (ft.lbf)
6.5 - 147 ELDM - 2800 - 27% - Recoil Energy of 12.93 (ft.lbf)
6.5 - 147 ELDM - 2900 - 31% - Recoil Energy of 13.53 (ft.lbf)
6.5 - 147 ELDM - 3000 - 35% - Recoil Energy of 14.13 (ft.lbf)
6.5 - 147 ELDM - 3100 - 38% - Recoil Energy of 14.73 (ft.lbf)
6.5 - 147 ELDM - 3200 - 43% - Recoil Energy of 15.33 (ft.lbf)
6.5 - 147 ELDM - 3300 - 49% - Recoil Energy of 15.99 (ft.lbf)

7 - 180 ELDM - 2500 - 28% - Recoil Energy of 14.45 (ft.lbf)
7 - 180 ELDM - 2600 - 31% - Recoil Energy of 15.30 (ft.lbf)
7 - 180 ELDM - 2700 - 34% - Recoil Energy of 16.15 (ft.lbf)
7 - 180 ELDM - 2800 - 38% - Recoil Energy of 17.00 (ft.lbf)
7 - 180 ELDM - 2900 - 43% - Recoil Energy of 17.85 (ft.lbf)
7 - 180 ELDM - 3000 - 47% - Recoil Energy of 18.70 (ft.lbf)
7 - 180 ELDM - 3100 - 52% - Recoil Energy of 19.55 (ft.lbf)
7 - 180 ELDM - 3200 - 56% - Recoil Energy of 20.40 (ft.lbf)
7 - 180 ELDM - 3300 - 61% - Recoil Energy of 21.52 (ft.lbf)

7.62 - 225 ELDM - 2500 - 26% - Recoil Energy of 20.94 (ft.lbf)
7.62 - 225 ELDM - 2600 - 28% - Recoil Energy of 23.74 (ft.lbf)
7.62 - 225 ELDM - 2700 - 32% - Recoil Energy of 26.91 (ft.lbf)
7.62 - 225 ELDM - 2800 - 37% - Recoil Energy of 29.68 (ft.lbf)
7.62 - 225 ELDM - 2900 - 42% - Recoil Energy of 32.57 (ft.lbf)
7.62 - 225 ELDM - 3000 - 44% - Recoil Energy of 35.81 (ft.lbf)
7.62 - 225 ELDM - 3100 - 49% - Recoil Energy of 38.97 (ft.lbf)
7.62 - 225 ELDM - 3200 - 55% - Recoil Energy of 41.58 (ft.lbf)
7.62 - 225 ELDM - 3300 - 59% - Recoil Energy of 45.10 (ft.lbf)

338 - 285 ELDM - 2500 - 28% - Recoil Energy of 42.86 (ft.lbf)
338 - 285 ELDM - 2600 - 30% - Recoil Energy of 45.16 (ft.lbf)
338 - 285 ELDM - 2700 - 32% - Recoil Energy of 47.46 (ft.lbf)
338 - 285 ELDM - 2800 - 37% - Recoil Energy of 49.76 (ft.lbf)
338 - 285 ELDM - 2900 - 43% - Recoil Energy of 52.06 (ft.lbf)
338 - 285 ELDM - 3000 - 48% - Recoil Energy of 54.36 (ft.lbf)
338 - 285 ELDM - 3100 - 52% - Recoil Energy of 56.66 (ft.lbf)
338 - 285 ELDM - 3200 - 57% - Recoil Energy of 58.96 (ft.lbf)
338 - 285 ELDM - 3300 - 65% - Recoil Energy of 61.26 (ft.lbf)

 

[cheapmoa]

22-250 or even better a 22 Creedmoor

 

[Dfin]

Do you mind running a scenario for me? I'd get the software myself but I run a Mac.
I'm placing an order for a rifle this week and I'm between a 6.5 SAUM and 7 SAUM.
I'd run 147 elm and 150 smk in the 6.5, and 183 and 197 smk in the 7. Parameters - wind call error of 5mph, standard deviation of 4, and target range error of 3 yds.

 

[cheapmoa]

What velocity and BC? The assumptions don't matter in the comparison as long as they are the same for all the bullets fired in the simulation. What distance are you wanting to shoot out to. The 7mm is going to be a 20% or more increase in Hit% over a 6.5 at 1200+

 

[SilentStalkr]

Interesting findings nontheless!

 

[towerofpower93]

Would be interesting to see the recoil vs hit percentage scale for the 338LM with 250gr Berger Hybrids or the like.

 

[NLS7162]

tag

 

[reewik]

OK so let me see if I am following here. You are calculating a percentage of hits based on set parameters with minor variations. This based off of recoil impulse and velocity?

If I stated that right then at 1200 yard ( I am actually shooting 1250 because that is the set distance at the range I am a member of ) that using a .243 with a velocity of 2992 shooting the Hornady BTHP match 105's my hit rate is on a 12.5" target is on average, 21% out of 1000 shots right?

 

[BLKWLFK9]

6mm dasher, 95gr TMK, 3180fps if you would.

 

[cheapmoa]

OK so let me see if I am following here. You are calculating a percentage of hits based on set parameters with minor variations. This based off of recoil impulse and velocity?

If I stated that right then at 1200 yard ( I am actually shooting 1250 because that is the set distance at the range I am a member of ) that using a .243 with a velocity of 2992 shooting the Hornady BTHP match 105's my hit rate is on a 12.5" target is on average, 21% out of 1000 shots right?

This is a calculation based on 1000 - 1st Shot attempts with a standard set of assumptions that randomly change for each 1st Shot attempt.

We can't calculate after the 1st Shot because you should technically get more and more accurate after you get a read from your previous shots by correcting for wind, range and shooter error. That is why so many shooters use sighters and walk it on and then shoot a group. That is not a true test of their system capability.

What would you say your 1st Shot hit percentage is at 1250? If it is hgher than 21% then that means you are better than the set assumptions with your rifle system which would directly translate to another system. For example if you are currently shooting your 243 WIN -105 - 2992 then everything above 21% on that chart is going to increase your HIT% accordingly.

The recoil is listed so that you can make a decision based on the end use of the rifle. Most PRS shooters want as low of recoil as possible so they can always get a read and stay on target from awkward firing positions. That is why the 22 Nosler in a gas gun or a bolt in 22 Creedmoor looks so appealing with the 90 VLDs at 3000 - 3200. If rapid follow up shots are not as important or you can manage recoil well then the 7mm is the hands down best choice because it is so flexible and has the highest BC by a large margin. If you plan on shooting past 1200 yards then the 7mm really pulls away.

 

[reewik]

Got it... I missed the first round hit in the assumption. Sorry.

 

[steve123]

I have been working on a matrix to demonstrate where we can look at the effect of velocity on our HIT% and the corresponding RECOIL. +/- 3% but this should give you some real insight. The 90 VLD look very appealing for PRS style matches in a 22 Creedmoor or 22 Nosler for a gas gun and for the best of all worlds the 7mm because at low velocity it beats everything in Hit % with a managable recoil and at high velocity it is a long range hammer.


5.56 - 90 VLD - 2500 - 11% - Recoil Energy of 6.42 (ft.lbf)
5.56 - 90 VLD - 2600 - 13% - Recoil Energy of 6.70 (ft.lbf)
5.56 - 90 VLD - 2700 - 14% - Recoil Energy of 6.98 (ft.lbf)
5.56 - 90 VLD - 2800 - 18% - Recoil Energy of 7.26 (ft.lbf)
5.56 - 90 VLD - 2900 - 20% - Recoil Energy of 7.54 (ft.lbf)
5.56 - 90 VLD - 3000 - 23% - Recoil Energy of 7.82 (ft.lbf)
5.56 - 90 VLD - 3100 - 26% - Recoil Energy of 8.10 (ft.lbf)
5.56 - 90 VLD - 3200 - 30% - Recoil Energy of 8.38 (ft.lbf)
5.56 - 90 VLD - 3300 - 33% - Recoil Energy of 8.64 (ft.lbf)

6 - 115 VLD - 2500 - 11% - Recoil Energy of 8.33 (ft.lbf)
6 - 115 VLD - 2600 - 12% - Recoil Energy of 8.74 (ft.lbf)
6 - 115 VLD - 2700 - 14% - Recoil Energy of 9.15 (ft.lbf)
6 - 115 VLD - 2800 - 16% - Recoil Energy of 9.56 (ft.lbf)
6 - 115 VLD - 2900 - 18% - Recoil Energy of 9.97 (ft.lbf)
6 - 115 VLD - 3000 - 22% - Recoil Energy of 10.38 (ft.lbf)
6 - 115 VLD - 3100 - 26% - Recoil Energy of 10.79 (ft.lbf)
6 - 115 VLD - 3200 - 30% - Recoil Energy of 11.20 (ft.lbf)
6 - 115 VLD - 3300 - 32% - Recoil Energy of 11.59 (ft.lbf)

6.5 - 147 ELDM - 2500 - 18% - Recoil Energy of 11.13 (ft.lbf)
6.5 - 147 ELDM - 2600 - 20% - Recoil Energy of 11.73 (ft.lbf)
6.5 - 147 ELDM - 2700 - 23% - Recoil Energy of 12.33 (ft.lbf)
6.5 - 147 ELDM - 2800 - 27% - Recoil Energy of 12.93 (ft.lbf)
6.5 - 147 ELDM - 2900 - 31% - Recoil Energy of 13.53 (ft.lbf)
6.5 - 147 ELDM - 3000 - 35% - Recoil Energy of 14.13 (ft.lbf)
6.5 - 147 ELDM - 3100 - 38% - Recoil Energy of 14.73 (ft.lbf)
6.5 - 147 ELDM - 3200 - 43% - Recoil Energy of 15.33 (ft.lbf)
6.5 - 147 ELDM - 3300 - 49% - Recoil Energy of 15.99 (ft.lbf)

7 - 180 ELDM - 2500 - 28% - Recoil Energy of 14.45 (ft.lbf)
7 - 180 ELDM - 2600 - 31% - Recoil Energy of 15.30 (ft.lbf)
7 - 180 ELDM - 2700 - 34% - Recoil Energy of 16.15 (ft.lbf)
7 - 180 ELDM - 2800 - 38% - Recoil Energy of 17.00 (ft.lbf)
7 - 180 ELDM - 2900 - 43% - Recoil Energy of 17.85 (ft.lbf)
7 - 180 ELDM - 3000 - 47% - Recoil Energy of 18.70 (ft.lbf)
7 - 180 ELDM - 3100 - 52% - Recoil Energy of 19.55 (ft.lbf)
7 - 180 ELDM - 3200 - 56% - Recoil Energy of 20.40 (ft.lbf)
7 - 180 ELDM - 3300 - 59% - Recoil Energy of 21.27 (ft.lbf)

We sure appreciate you doing these hit% specs.

And not to take away from this or hurt feelings but I'd like to point out some things just to inform so people can consider them.

The first thing is barrel life, cranking speeds the highest with long baring surface bullets is going to substantially decrease barrel life. Here in the Beyond 1000 forum just a few days ago a guy was commenting on extremely low barrel life, 300-400 rounds, with huge 7mm's. It won't be too un-similar with other calibers.

Next is bullet failure at higher speeds, chasing the higher velocities, I've had this happen with different chamberings, so no free lunch so to speak. Sometimes the bullet you picked doesn't work in your barrel whereas another one will.

There really is a performance balance when "all things considered" come into play.

 

[cheapmoa]

Definitely. The system has to work but with cabon fiber barrels and melonite coatings the barrel life numbers are only going to get better. 90 VLDs are proven performers at 3000 - 3200 from 1:7 twist melonite barrels good for 2000+


7mm-08 - 180 ELDM - 2600 - 31% Hit with 1:7.5 Twist Barrel

In my opinion, this is the most balanced system for all around use. It beats the 6.5 CM across the board and has great barrel life. 3000+ and double that with Melonite.

 

[TimeWillTell]

Definitely. The system has to work but with cabon fiber barrels and melonite coatings the barrel life numbers are only going to get better. 90 VLDs are proven performers at 3000 - 3200 from 1:7 twist melonite barrels good for 2000+


7mm-08 - 180 ELDM - 2600 - 31% Hit with 1:7.5 Twist Barrel

In my opinion, this is the most balanced system for all around use. It beats the 6.5 CM across the board and has great barrel life. 3000+ and double that with Melonite.

I can see this argument for sure. I'd still lean towards a 6.5 Creedmoor personally as in all-around I'd consider prs stuff. A 180 gr out of 7-08 will be like shooting a 308 in terms of recoil which is fine but hardly ideal for match use. (Yes people do it, it's a personal choice). This thread has been great to show, if nothing else, there is more than one way to skin a cat.

 

[cheapmoa]

I'd still lean towards a 6.5 Creedmoor personally as in all-around I'd consider prs stuff. A 180 gr out of 7-08 will be like shooting a 308 in terms of recoil which is fine but hardly ideal for match use.

You are talking about 6.5CM @ 13lbs vs 7-08 @ 14.5lbs for similar HIT% and after a muzzle brake or suppressor is added to each you are talking about less than 1 lbs. of difference in recoil. In my opinion the energy and long range BC upsides on the 7mm is worth the added pound of recoil.

For PRS where most targets are under 900 yards and energy doesn't matter then I wonder if the 22 Cal. might get some action. If you could get the same HIT% @ half the recoil and get 2000+ rounds out of the barrel is that a good setup for PRS?

I appreciate your thoughts on this thread.

 

[W54/XM-388]

If you were going to shoot the .22 caliber range at long distance in matches, you might need to go with some kind of identifying flash rounds like these:

https://underwoodammo.com/product/rifle-ammo/300-aac-blackout-111-grain-match-solid-flash-tip/

Unless they have setup a more advanced way of checking hits & misses, as you might hit the target but not get noticed.

 

[cheapmoa]

6mm dasher, 95gr TMK, 3180fps if you would.

6 Dasher - 95 SMK - 3180 - 16% Hit

 

[Sheldon N]

Going down the path of assumptions and connecting the dots back to PRS shooting, I'd refine a couple things in the model.

I would assume rifle precision of 1/2 MOA and SD of something more like 6-7. That would be average for the PRS shooters I know. Some guys I know wouldn't even be happy with those numbers.

Vertical dispersion is usually very good for most shooters. I've got targets at 950 and 1225 yards and can say that essentially all of my misses are left/right due to wind and not due to vertical. A common competition cartridge like the 6 Dasher has no problem printing a 1/2 MOA or better waterline out at 1200 yards. At 1000 yards it's common for guys to be getting 3-4" vertical. So realistically the vast majority of misses in competition are due to shooter error (positional instability) or wind error.

The other bigger picture comment I would offer is that PRS shooting is fundamentally a feedback loop system. The key thing is the ability to see downrange hits and make corrections on the fly. While your model is assuming 2mph initial wind call error, that data could just as easily be tranferred to a 2mph change in wind that the shooter did not notice while they were shooting the stage - a very common thing. The feedback loop has two key components, lack of recoil to allow shooter to stay on target, and downrange energy to produce a result that's actually observable. Going too far down the light/fast small caliber bullet path can make it harder to see misses, especially on things like wet dirt or grass. And chasing a bit of ballistics at the cost of recoil can also be problematic. If you have one or two shots where you don't see where your miss was because of recoil, or also where you don't see where your HIT was (left/right/center of plate), you lose the ability to make a correction that can greatly outweigh a theoretical ballistic advantage.

Last thought would be totally unrelated to ballistics, just practical consideration on cartridge reliability. Shooters want a cartridge that is going to be predictable and stable over the course of barrel life. Last thing you want in a match is barrel slowing down or groups opening up due to throat erosion. It's this that I've seen bring some shooters back to cartridges like 6.5x47. It may not be the lightest recoiling, but it's very accurate and very predictable over the course of its barrel life. That same factor likely keeps guys away from things like 22 creedmoor or 22-250 which are a bit overbore with less barrel life.

 

[cheapmoa]

Going down the path of assumptions and connecting the dots back to PRS shooting, I'd refine a couple things in the model.

I would assume rifle precision of 1/2 MOA and SD of something more like 6-7. That would be average for the PRS shooters I know. Some guys I know wouldn't even be happy with those numbers.

Vertical dispersion is usually very good for most shooters. I've got targets at 950 and 1225 yards and can say that essentially all of my misses are left/right due to wind and not due to vertical. A common competition cartridge like the 6 Dasher has no problem printing a 1/2 MOA or better waterline out at 1200 yards. At 1000 yards it's common for guys to be getting 3-4" vertical. So realistically the vast majority of misses in competition are due to shooter error (positional instability) or wind error.

The other bigger picture comment I would offer is that PRS shooting is fundamentally a feedback loop system. The key thing is the ability to see downrange hits and make corrections on the fly. While your model is assuming 2mph initial wind call error, that data could just as easily be tranferred to a 2mph change in wind that the shooter did not notice while they were shooting the stage - a very common thing. The feedback loop has two key components, lack of recoil to allow shooter to stay on target, and downrange energy to produce a result that's actually observable. Going too far down the light/fast small caliber bullet path can make it harder to see misses, especially on things like wet dirt or grass. And chasing a bit of ballistics at the cost of recoil can also be problematic. If you have one or two shots where you don't see where your miss was because of recoil, or also where you don't see where your HIT was (left/right/center of plate), you lose the ability to make a correction that can greatly outweigh a theoretical ballistic advantage.

Last thought would be totally unrelated to ballistics, just practical consideration on cartridge reliability. Shooters want a cartridge that is going to be predictable and stable over the course of barrel life. Last thing you want in a match is barrel slowing down or groups opening up due to throat erosion. It's this that I've seen bring some shooters back to cartridges like 6.5x47. It may not be the lightest recoiling, but it's very accurate and very predictable over the course of its barrel life. That same factor likely keeps guys away from things like 22 creedmoor or 22-250 which are a bit overbore with less barrel life.

I agree with everything you stated above. Doesn't that seem to support a 7-08 shooting a 180 ELDM at 2500-600? That would increase HIT% by 10-15% over the 6.5CM and give you better energy on target to see splash and impacts and it costs you less than a pound of RECOIL.

 

[cheapmoa]

Added 338 and 308 to the first post to complete the table. Thanks for all the input!

 

[Sheldon N]

I agree with everything you stated above. Doesn't that seem to support a 7-08 shooting a 180 ELDM at 2500-600? That would increase HIT% by 10-15% over the 6.5CM and give you better energy on target to see splash and impacts and it costs you less than a pound of RECOIL.

A 7mm with a 180 at 2500-2600 is a LOT of recoil compared to a 6mm 105 at 2950 fps. Roughly double the recoil according to the little online calculator I played with. It does give you a bit of improvement on wind, miss your 1000 yard wind call by 2mph and you will be off target by 0.3mil with the 7mm and 0.4 mil with the 6mm. That might be an edge hit on a 2 MOA target. However, inside of 600 yards with all the positional shooting you'd be at a serious disadvantage.

A slow bullet also introduces difficulties such as being more susceptible to ranging errors, more susceptible to rifle cant errors by the shooter, hitting transonic a bit sooner, and having more vertical dispersion as a result of SD at the outer edge of the performance envelope.

Guys I know that are chasing ballistics tend to be shooting things like a 6.5 Addiction with a 140gr bullet at 3050ish, or 6 Creed with a 110 or 115 at 3100. Those are functionally as good as the 7mm 180 combo, with a lot better speed and both have less recoil.

 

[cheapmoa]

A 7mm with a 180 at 2500-2600 is a LOT of recoil compared to a 6mm 105 at 2950 fps. Roughly double the recoil according to the little online calculator I played with. It does give you a bit of improvement on wind, miss your 1000 yard wind call by 2mph and you will be off target by 0.3mil with the 7mm and 0.4 mil with the 6mm. That might be an edge hit on a 2 MOA target. However, inside of 600 yards with all the positional shooting you'd be at a serious disadvantage.

A slow bullet also introduces difficulties such as being more susceptible to ranging errors, more susceptible to rifle cant errors by the shooter, hitting transonic a bit sooner, and having more vertical dispersion as a result of SD at the outer edge of the performance envelope.

Guys I know that are chasing ballistics tend to be shooting things like a 6.5 Addiction with a 140gr bullet at 3050ish, or 6 Creed with a 110 or 115 at 3100. Those are functionally as good as the 7mm 180 combo, with a lot better speed and both have less recoil.

So 6 is the perfect caliber for PRS type competition because it has lower recoil than the 6.5 and 7 but still is visible over the 22 Cal. and the shooting distances in PRS are just not far enough to justify the much higher BC bullet in 7?

 

[morganlamprecht]

most of the top guys wont even consider anything but 6mm if they are seriously there to compete...i dont think most shooters understand the difficulty of shooting/spotting/correcting all on your own sometimes in field conditions with no berms while under time constraints in non ideal positions you had to build in a few seconds

 

[morganlamprecht]

So 6 is the perfect caliber for PRS type competition because it has lower recoil than the 6.5 and 7 but still is visible over the 22 Cal. and the shooting distances in PRS are just not far enough to justify the much higher BC bullet in 7?

6 is a really good balance but it largely depends on the range...at places like Rifles Only (if you catch a calm day) and Core, a 223 is pretty ideal...taking a 223 to some of the Oklahoma locations isnt goin to be a good time for many

 

[TimeWillTell]

You are talking about 6.5CM @ 13lbs vs 7-08 @ 14.5lbs for similar HIT% and after a muzzle brake or suppressor is added to each you are talking about less than 1 lbs. of difference in recoil. In my opinion the energy and long range BC upsides on the 7mm is worth the added pound of recoil.

For PRS where most targets are under 900 yards and energy doesn't matter then I wonder if the 22 Cal. might get some action. If you could get the same HIT% @ half the recoil and get 2000+ rounds out of the barrel is that a good setup for PRS?

I appreciate your thoughts on this thread.

I'm PRS I would use a 120-130 gr bullet. Even so, I've shot a decent amount of 308 with 175 and to me the difference is significant between that and a 6.5 with 140. Not saying the numbers are wrong and my "shoulder gauge" has poor calibration but it " seems" like a pretty decent difference to me. Again, more than one way to skin a cat.

 

[cheapmoa]

.5 MOA 6mm - 105 - 2950 - 47% Hit - 9.9Lbs. of RECOIL

.5 MOA 6.5mm - 147 - 2750 - 68% Hit - 13.58Lbs. of RECOIL

.5 MOA 7mm - 180 - 2550 - 69% Hit - 15.94 Lbs. of RECOIL