What caused the Rokslide shift to smallest caliber and cartridges?

[Harvey_NW]

This thread is what I imagine a debate between Ron Spomer and Gavin from Ultimate Reloader would sound like if someone said "show him the results"..

 

[DJL2]

Sometimes, a minor point in a post has no hidden meaning.

I don't believe that is true, but feel free to find ballistic charts from the same ammo manufacturer that demonstrate what you think. Or ... don't.

It’s 100% correct - crack open your Litz and read up. You cannot add enough pressure and velocity in the same cartridge for a bullet of similar design to overcome a BC deficit.

The short version - wind drift is caused by drag. The bullet is not blown sideways. The bullet weather vanes into the wind and the horizontal drag component becomes the wind drift. Drift is proportional to the difference between “vacuum time of flight” (the no drag condition) and actual time of flight.

The flip side is that bullet design matters a LOT. A .308 155 TMK has a higher BC than a .308 175 SMK… and will beat the pants off it at everything, in every way because it’s faster and more aerodynamic.

 

[sickles107]

Late to this party, but ill chime in. Went to a 6cm/6x swfa this year for my do all antelope, deer, elk gun out to 500 yds.

Above all, primary benefit with the 6cm for me is being able to stay in the scope and spot impacts. For hunting, seeing the animals reaction, what they do, where they go, quick follow up shots if needed. For practice, seeing where you miss. This includes effect of wind changes on bullet path, and also validating dope and velocity. Seeing where you miss in real time makes you a better shooter, allows you to have a better understanding of your system, and ultimately helps you not miss in the future.

For me, the small bore is just a part of the big picture "shift" over the past few years on rokslide, that includes multiple hidden gems of wisdom throughout a few threads, that have no doubt made me a better thing hitter with a rifle.


1. Start with solid repeatable equipment (scope drop test threads) ie Tikka, UM rings, swfa. Chased my tail for years with junk scopes not knowing any better.

2. Use good bullets (why match bullets for hunting thread) ie hit rate and wound channel. Always thought you needed an accubond for elk.

3. Have realistic understanding of your systems capabilities and don't waste time chasing unicorn groups (painless load dev thread) ie zero off ten round groups, 2moa = 10" @ 500 = dead deer. chased my tail for years wondering why my 1/2 MOA gun was throwing fliers.

4. Actually practice with it, how you use it hunting, alot (equipment vs practice thread) ie get off the bench and shoot if field positions, alot. spent years at the range just "checking zero" off a bipod with 3 round groups.

5. And last but not least, use smaller caliber (223, 6mm thread success threads) ie low recoil, watch impacts, higher hit rate, adequate wound channel. The smaller bullets kill well, but when you can shoot them better than big bores, THEY KILL BETTER

 

[MT_Wyatt]

So.......to steer the topic away from the arguments, wihch I think are pretty well flushed out:

I've read and will summarize for newcomers what the practical "limits" have been put out there as for recoil tolerance, because I find it personally interesting. The "what cartridge" post comes up a TON, thus this post. I believe the caveat here is field positional shooting, and pressure being part of the equation. @Formidilosus mentioned in Post #245 of this thread a bit of that:
"What I have seen consistently under any stressor whatsoever, is that going from 4-5lbs of recoil (223) to 15’ish lbs of recoil (6.5cm) almost doubles the group sizes. Going from 15’ish Ft-lbs of recoil (6.5cm) to 25ft-lbs of recoil (30/06/7 mag) almost doubles it again. Etc, etc." This is interesting (to me) and very useful because it relates recoil to downrange effectiveness on target, and is put in terms of cartridges, which are asked about so much

We don't talk about it a ton, but suppressors cut recoil by ~ x% (40% or so on average? And Brakes pretty much cut it in half? I find the lack of shockwave with a suppressor immensly helpful and the recoil impulse isn't nearly as bad - but I'm not sure it jumps you from magnum to "standard" cartridge level recoil. Pretty close though?

Everyone please feel free to correct anything I'm getting wrong here, but from memory, it sounds like for cartridges, the limits are about 6.5PRC for most adults (~16.5 ft-lb), 6.5CM (13 ft-lb) is even better, 6CM (9.5 ft-lb) or < 10 ft-lb is where "average" people start to really shoot better, and .223 (3.5-4 ft-lb) being optimium. I believe that is based on field observations. I'm literally just repeating what I have read related to this topic, but find the "limit" interesting. I can't recall what the 6UM recoil is.

All the 20+ stuff (7 SAUM, the wonderchild of 2 years ago, .280AI, etc) all start to get past that line in the sand. I haven't seen it acknowledged on here much, but assuming you are suppressing some of these larger cartridges, you are basically just knocking them down to the acceptable "limit" per above.

So question: are the 6.5 PRCs SO many people were doing 2 years ago, and 7 SAUMs, just useless? If we suppress them, then I think we're plenty good, right? It appears the consensus is that we should just dump them for 6CM, but that's a tough one to swallow in my mind.....

 

[Marshfly]

The general consensus is that suppressor use drops you one recoil "level."

Levels being 223/5#, 6CM/10#, 6.5CM/15#, 270win:6.5PRC:similar/20#, and up.

That said I can tell you that my son's 6.5CM with my Griffin 338 UL Sportsman can on the muzzle ends up feeling very similar to my Tikka 223 but sounds like a quiet 22LR.

Stock design plays a huge role in that as well. Much more than a lot of people (not our people,LOL) think.

 

[ozyclint]

Anyone built a .222 rem mag to shoot those 77tmk's?

 

[4cMuley]

If the .223 is good is the 22-250 more gooder? I really really like my tikka 8 twist. Shoots most 75-77 grainers very good and even shoots 55 grainers quite well

 

[Formidilosus]

Everyone please feel free to correct anything I'm getting wrong here, but from memory, it sounds like for cartridges, the limits are about 6.5PRC for most adults (~16.5 ft-lb), 6.5CM (13 ft-lb) is even better, 6CM (9.5 ft-lb) or < 10 ft-lb is where "average" people start to really shoot better, and .223 (3.5-4 ft-lb) being optimium. I believe that is based on field observations. I'm literally just repeating what I have read related to this topic, but find the "limit" interesting. I can't recall what the 6UM recoil is.

Mostly you have it, Though the hunters are kind of off. A suppressor rescues recoil about 30%, but it also greatly slows the impulse so the total recoil is the same, but it spread over more time. Which, in general makes it more comfortable to shoot. The only con is that they don’t control muzzle movement as much as an aggressive brake does. Even though the brake reduces more recoil the blast effects and distraction from debris throwing up is a major contributor to anticipation/flinch even when plugged and muffed. For most people the brake just becomes a wash in their shooting ability- yes it hurts less to shoot, but they still anticipate, close eyes, brace, etc. because of the muzzle blast and debris even with ear pro.

As stated, a suppressor moves you down about one category of recoil. Your numbers are off for sporter weight rifles though- in 8lb rifles, the 6.5 cm is about 15-16 ft-lbs of recoil and is right at the top of, or just over the level for the vast majority to start having noticeable recoil effects. 6.5 PRC is about 20 ft-lbs of recoil, and is defiantly over where the vast majority will have anticipation and reduced shooting ability.

 

[Formidilosus]

If the .223 is good is the 22-250 more gooder? I really really like my tikka 8 twist. Shoots most 75-77 grainers very good and even shoots 55 grainers quite well

Fast twist 22-250’s and 22CM’s have the highest hit rates from 400’ish to 600 or 700 yards of anything. Below 400’ish 223’s are a bit more shootable. But from 350 to 400 yards to around 700, good .224’s shooting .5 G1 BC bullets above 3k FPS MV rule.

 

[Choupique]

Do you guys who used to shoot boomers and made the switch still use the boomers for hunting?

 

[TaperPin]

I do have to say I'm shocked there hasn't been more challenge to the idea.

Why you guys have shown is that it can work within constraints. Many of us who will continue to use larger calibers, agree with you a bit, but don’t buy the whole argument that all a North American hunter needs is a tiny cartridge, and never will. I like a bullet that expands and doesn’t come apart - it’s proven itself - nothing I’ve seen will convince me otherwise.

You’d gain more support for the ideas if the threads weren‘t such echo chambers with guys repeating half ass arguments against proven game getting combinations.

 

[wyosam]

Nice try. Maybe use the full quote next time bud.


Exact same chambering meaning same MV.

Why would exact chambering mean same MV? It’s a different weight bullet.


Sent from my iPhone using Tapatalk

 

[Reburn]

Do you guys who used to shoot boomers and made the switch still use the boomers for hunting?

I still have boomers and shoot them sometimes but I am moving to nothing more then a 6.5 for hunting. I will shoot my 300 prc at a nilgai in Feb as the outfitter is requesting.

I just shoot better with lower recoiling and quieter guns.

If I got out and shoot and take a boomer I will shoot 20ish rounds of it and 50-60 of a 6cm or less.

When I burn up the 30 cal barrels I dont know what I will do.

 

[Hnthrdr]

Do you guys who used to shoot boomers and made the switch still use the boomers for hunting?

Used to shoot boomers, now I primarily archery elk hunt and used a 6.5 cm for my rifle deer tag. Sold my 7 mag / most of my .300 wins off, now my big 30 cal is a .308, love the 6.5cm I used this year and thinking about turning an old savage 6.5 into a 6cm

 

[Fartrell Cluggins]

So no experience with any version of projectiles that are being discussed here?

The 77gr TMK at the same impact velocity creates a larger wound on average than that 30cal 150gr Power Point does. How that is that “fringe”?

How does the shape of those wound channels compare in terms of penetration and temporary stretch cavity?

I think it could help satisfy some of the naysayers to demonstrate that the TMK has a larger wound by demonstrating in a side by side gel test. Then simulate hitting bone in a gel test.

The readers on this site seem to largely have the understanding of wounding down. On other sites when these conversations pop up, I have comparatively few anecdotes to draw from when I try to convince folks that their 7mm-08 isn't going to demolish heart and lungs any more than my .223 or 6 Creed. Having a gel test could be useful to point to.

 

[Formidilosus]

How does the shape of those wound channels compare in terms of penetration and temporary stretch cavity?

I think it could help satisfy some of the naysayers to demonstrate that the TMK has a larger wound by demonstrating in a side by side gel test. Then simulate hitting bone in a gel test.

The readers on this site seem to largely have the understanding of wounding down. On other sites when these conversations pop up, I have comparatively few anecdotes to draw from when I try to convince folks that their 7mm-08 isn't going to demolish heart and lungs any more than my .223 or 6 Creed. Having a gel test could be useful to point to.

We are working on it.

 

[Fartrell Cluggins]

Mostly you have it, Though the hunters are kind of off. A suppressor rescues recoil about 30%, but it also greatly slows the impulse so the total recoil is the same, but it spread over more time. Which, in general makes it more comfortable to shoot. The only con is that they don’t control muzzle movement as much as an aggressive brake does. Even though the brake reduces more recoil the blast effects and distraction from debris throwing up is a major contributor to anticipation/flinch even when plugged and muffed. For most people the brake just becomes a wash in their shooting ability- yes it hurts less to shoot, but they still anticipate, close eyes, brace, etc. because of the muzzle blast and debris even with ear pro.

As stated, a suppressor moves you down about one category of recoil. Your numbers are off for sporter weight rifles though- in 8lb rifles, the 6.5 cm is about 15-16 ft-lbs of recoil and is right at the top of, or just over the level for the vast majority to start having noticeable recoil effects. 6.5 PRC is about 20 ft-lbs of recoil, and is defiantly over where the vast majority will have anticipation and reduced shooting ability.

I have found that recoil calculators can vary widely as can tables that are hosted online. Do you have a calculator or source that you trust more than others?

 

[Fartrell Cluggins]

We are working on it.

Awesome brother, I am looking forward to it.

 

[Formidilosus]

I have found that recoil calculators can vary widely as can tables that are hosted online. Do you have a calculator or source that you trust more than others?

I haven’t seem too much variability in JBM, Shooters Calculator, or Bison Ballistics.


JBM-





Shooters-





Bison-

 

[Marbles]

It absolutely is overblown. What I was trying to get at, is that this isn’t- “lead is the devil, copper/tungsten is jesus”. If lead is a concern then so is every other metal.

That is a false equivalence. It is like saying because rattle snakes are venomous and a concern, king snakes should be a concern too because they are a snake. Even when one considers that tetanus can be gotten from a king snake bite, the two warrant vastly different levels of concern.