Questions for Form and other "small caliber for big game" folks

[mxgsfmdpx]

My 20" 6CM hits about 1800 FPS at 825 yards using factory 108 ELD-M. That is with an Ultra 7 on it and at an elevation of 5500ft.

This had me crunching some numbers.

My Tikka 22 Creedmoor with the factory cut/threaded 19” barrel and 80 ELDX hits 1800 FPS right at 900 yards at 5,000 feet and 50 degrees. Energy shows somewhere around 600 ft lbs. Wind drift for full value 10 MPH shows 1.5 MILs at 900.

My Tikka 6 Creedmoor with factory cut/threaded 18” barrel and 108 ELDM hits 1800 FPS right at 800 yards at 5,000 feet and 50 degrees. Energy shows somewhere around 775 ft lbs. Wind drift for full value 10 MPH wind shows 1.3 MILs at 800.

 

[roadrunner]

A mature cow elk went 8 yards and died in less than a minute. I put 4 shots into it with ease and though my shooting form and position was far from ideal, I still watched it all happen through the scope, which I had never done before.

Did the same thing once with a .270 WSM and a 140 gr bullet, prone on rim rock in 8" of snow. Cow went 10 yds or so with one shot. "Jellyfied" the lungs. Shot was 295 yds with approx 125' of elevation change downangle.

 

[Flynhunt]

Have you listened to the two part podcast from Exo with Form discussing this exact topic in depth for 3+ hours? If you haven’t, you really should, it was pretty much made to address every concern you’ve raised. I say this after acknowledging that I was basically you about 2-3 years ago. I was going to build a 7mm Rem Mag for elk because it’s “good elk medicine”.

Then I got on rokslide and started learning all about the idea of shooting smaller calibers because you will shoot them better and almost certainly will practice more. I bought a .223 and practiced a ton (1000+ rounds), which is about 900 rounds more than all combined rifle practice in the prior 30 years of my life. That fall, I killed an elk with that .223 even though everyone thought I was insane, because I loved that gun and shot it well. A mature cow elk went 8 yards and died in less than a minute. I put 4 shots into it with ease and though my shooting form and position was far from ideal, I still watched it all happen through the scope, which I had never done before.

I say this with the best intentions, having been in your shoes recently. You don’t know what you don’t know. Listen to the exo podcast with form and take it all in. You may need to listen a few times. I can almost guarantee you wouldn’t want the magnum for the elk or the grizzly in your scenario once you understand how significantly the recoil affects your hit rates and how irrelevant the larger wound it has the potential to create is.

Rokslide is a wealth of information. Continue asking good questions and keep an open mind when people respond, then you’ll be well on your way to maximizing your abilities as both a shooter and a hunter.

Podcast links for reference:

Hunt Backcountry Podcast 469 | Why Smaller Calibers May Be Better For Big Game Hunting — The Experience Project

This podcast will challenge decades of

exomtngear.com

Hunt Backcountry Podcast 470 | Why Smaller Calibers May Be Better For Big Game Hunting (Part 2) — The Experience Project

This is the second half of a conversation that explores why smaller rifle calibers may be better for big game hunting. This Hunt Backcountry Podcast episode explores how different types of bullets create different wound channels, the relationship between impact velocity and bullet...

exomtngear.com

Thanks for the info. I will check out those podcasts

 

[E.Shell]

Your cult point got a chuckle out of me. So true. But our great-grandfathers' generation got a lot of side-eye from their Boomer kids and grandkids for shooting things like .220 Swift and .22-250 at big game. And they slayed damn well.

^^ Truth ^^

When I was about 15 or 16 (50 years ago), my father bought me my first "deer rifle". He let me pick it out and gave me a budget. He suggested a Remington 788 in .30-30.

I decided to get the 788, but in .22-250 because I was also interested in shooting groundhogs. Although he eventually agreed, we had quite a bit of debate about it and he really wanted me to get a real deer caliber, not a varmint rifle. He was sure the .22-250 wouldn't kill a deer, but I showed him the energy figures and that the .22-250 had at least as much power as a .30-30.

I think I made the best choice and have killed dozens of deer with that rifle and with two other .22-250s I later had. Not only was it very effective on deer, but I shot almost everything with it, even had reduced loads for squirrels. After shooting groundhogs to 400 yards pretty routinely, deer at normal hunting ranges were a foregone conclusion.

Now, having drunk the kool-aid here, I have gone with the .223/5.56 and 77 TMKs for this season and have complete confidence in my rig. If my current .22-250 wasn't a heavy rifle, I'd just keep using that, but I'm getting too old to drag around a 10+ pound rifle.

 

[Marty]

@Formidilosus, fellow RokSliders:

• Are there statistically significant sample sized experiments that compare the same bullet type to caliber with respect to terminal performance? (ie. 6mm 108 ELDM compared to a 6.5mm ELDM compared to a 7mm 180 ELDM) Controls would include impact velocity, terminal media consistency, and angle of entry, etc. The purpose would be to understand what is being gained or given up by bullet caliber.
• Are there statistically significant sample sized experiments that compare recoil energy and velocity to probability of hit rates for centerfire rifles? I recall reading a military study that concluded recoil energy in excess of 8-12 ft/lbs yielded a significant reduction in hit rates. The purpose would be to understand where the tipping point of shooter performance degrades significantly enough to consider a lower recoil cartridge (just a deliver system for the desired terminal performance) or start adding recoil reducing features (if not already present) like a suppressor, properly shaped stock, weights, etc.
• Are there any recoil calculators for which you can plug in bullet weight, powder, and rifle weight and it would produce an estimated recoil energy and velocity value? I'm curious about adding weights to my chassis for training and competition and remove them for hunting.

Thanks!

 

[DagOtto]

@Formidilosus, fellow RokSliders:

• Are there statistically significant sample sized experiments that compare the same bullet type to caliber with respect to terminal performance? (ie. 6mm 108 ELDM compared to a 6.5mm ELDM compared to a 7mm 180 ELDM) Controls would include impact velocity, terminal media consistency, and angle of entry, etc. The purpose would be to understand what is being gained or given up by bullet caliber.
• Are there statistically significant sample sized experiments that compare recoil energy and velocity to probability of hit rates for centerfire rifles? I recall reading a military study that concluded recoil energy in excess of 8-12 ft/lbs yielded a significant reduction in hit rates. The purpose would be to understand where the tipping point of shooter performance degrades significantly enough to consider a lower recoil cartridge (just a deliver system for the desired terminal performance) or start adding recoil reducing features (if not already present) like a suppressor, properly shaped stock, weights, etc.
• Are there any recoil calculators for which you can plug in bullet weight, powder, and rifle weight and it would produce an estimated recoil energy and velocity value? I'm curious about adding weights to my chassis for training and competition and remove them for hunting.

Thanks!

Hi,

I've used this recoil calculator a lot.

ShootersCalculator.com | Recoil Calculator

An online calculator that calculates the recoil energy, impulse, and velocity of a firearm according to the firearm's weight, powder charge, bullet weight, and bullet muzzle velocity.

shooterscalculator.com

Keep in mind it does not introduce a reduction for recoil pad or muzzle brake. I do believe that a suppressor's added weight does roughly cover a suppressor's recoil reduction in this calculator but that is guess work on my part.

I've also attached backfire's recoil table. you can get this raw file at backfire.tv I've found this to be very helpful. Note that I have edited it to show all systems with 6.5 fp our less of recoil in yellow. This is the approximate line below which Form and others say recoil has minimum impact on shooters performance.

 

[bergie]

That fall, I killed an elk with that .223 even though everyone thought I was insane, because I loved that gun and shot it well. A mature cow elk went 8 yards and died in less than a minute. I put 4 shots into it with ease and though my shooting form and position was far from ideal, I still watched it all happen through the scope

I am not sure where I sit on this debate, I think both sides have valid points, but this contradictory statement to me is wild.

1. You love your .223 and you shoot it very well and you are convinced that the bullet you have selected will quickly and efficiently render the target incapacitated due to the large wound cavity that is 14-16" deep from a fragmenting bullet. - Obviously I have to believe this is true as you took it on an elk hunt.

2. You shot an elk FOUR times even though it only made it 8 yards and you spotted impact on all FOUR shots. - If true, how can this statement possibly follow the first?

If I trust my rifle (6.5 PRC, 147 ELD-M) which I do, I shoot once and if I spot my impact, which admittedly is not as often as I like (+1 point for small caliber folks). But for the sake of argument I do spot it and that sucker is 3" behind the shoulder, mid body in both lungs, the only thing I am thinking about is watching the animal tip over. The last thing I am thinking about is putting 3 more shots in it to potentially ruin more meat, which those match bullets certainly will do if I don't put it behind the shoulder where I want.

 

[Marty]

Hi,

I've used this recoil calculator a lot.

ShootersCalculator.com | Recoil Calculator

An online calculator that calculates the recoil energy, impulse, and velocity of a firearm according to the firearm's weight, powder charge, bullet weight, and bullet muzzle velocity.

shooterscalculator.com

Keep in mind it does not introduce a reduction for recoil pad or muzzle brake. I do believe that a suppressor's added weight does roughly cover a suppressor's recoil reduction in this calculator but that is guess work on my part.

I've also attached backfire's recoil table. you can get this raw file at backfire.tv I've found this to be very helpful. Note that I have edited it to show all systems with 6.5 fp our less of recoil in yellow. This is the approximate line below which Form and others say recoil has minimum impact on shooters performance.

Awesome, thanks for sharing! Great stuff.