Fastest Cartridge in a R700 (.308 Boltface) ❓🤔❓

[CaseFinder]

22CM hands down! 22-243 isn't going to give you much more unless your running a 28"+ barrel and running heavies. And you can kiss that 1000 round barrel goodbye!

Those figures I posted earlier are at 62k psi. If you wanted to lean on it get some peterson or alpha srp brass and run 65k loads
not to mention there is a ton of support for the 22cm. Brass, dies, even pre-fits I bet.

I could reach out to my buddy who spun my barrel up and see if he'd be interested doing another? Were in AZ too.

He's an IT nerd that does this as a hobby. But he does nice work!
Here's mine, not done doing load dev yet but so far I'm tickled pink! 5 shot group, 88gr eldm, alpha srp brass, CCI 450, N165, 100yds, ~3050 ft/sec no pressure so I'm going to shoot for the next node.

Have you done a 220 Swift AI with these variants? They say a 220 swift AI will send a 40gr Vmax over 5000 fps all day which translates to almost 500 yards with minimal bullet drop. Has that been your experience? Also in AZ btw.

 

[whatsupdoc]

Wildcatting: Warp Speed Mr Sulu

Bruce Potts might have just created the ultimate barrel-burner with his latest whacky, wildcat creation, how does 5000 fps+ sound?

www.gunmart.net

 

[CaseFinder]

Wildcatting: Warp Speed Mr Sulu

Bruce Potts might have just created the ultimate barrel-burner with his latest whacky, wildcat creation, how does 5000 fps+ sound?

www.gunmart.net

Best point taken: "Never listen to people who have not shot or owned a particular calibre; there are so many ‘internet’ experts these days rehashing old material"

 

[squirrel_slayer]

On that note, is a 7 twist problematic for jackets coming apart on the Swift? I have been slowly acquiring new 22 caliber barrel factory pull-offs with the intent to go to the smith and have them all barreled to 220 Swift AI. Already have the reamer and gauges with smith telling me I will be lucky to get more than 700-800 rounds out of each barrel; that my brass with the 40 degree shoulder will last longer.

RPM is related to velocity and rate of twist so yes you will likely have the same issue with lighter cup and core bullets.

As for the 220s ai do you already have cases and a reamer? The reason I ask is in QL I only see about a 3.5gr increase in capacity over the 22CM but the max pressure is 57k. Pressure is king and it would quickly offset any gains the extra capacity is going to give you.


I'd say if you didn't have a big ass pile of brass on hand and a reamer already I would abort the 220Sai idea personally.

I'd also say ditch the idea of going with light for caliber bullets in a 7 twist unless your going to run mono metal bullets like barnes tsx, lehigh, ect...

 

[squirrel_slayer]

Have you done a 220 Swift AI with these variants? They say a 220 swift AI will send a 40gr Vmax over 5000 fps all day which translates to almost 500 yards with minimal bullet drop. Has that been your experience? Also in AZ btw.

Where do you see 40gr vmax over 5k ft/sec? QL is showing 4500's at 62k psi (greater than what's outlined in QL) Even that link shows 4500's with 40's from a 22-284 which has a bit more capacity. The 5k figure was with a 30gr berger.

It is cool that in his example he didn't blow up the bullets (granted it was a 1:7.7 twist)

 

[CaseFinder]

RPM is related to velocity and rate of twist so yes you will likely have the same issue with lighter cup and core bullets.

As for the 220s ai do you already have cases and a reamer? The reason I ask is in QL I only see about a 3.5gr increase in capacity over the 22CM but the max pressure is 57k. Pressure is king and it would quickly offset any gains the extra capacity is going to give you.


I'd say if you didn't have a big ass pile of brass on hand and a reamer already I would abort the 220Sai idea personally.

I'd also say ditch the idea of going with light for caliber bullets in a 7 twist unless your going to run mono metal bullets like barnes tsx, lehigh, ect...

Yea, already got the reamer and gauges with new old stock barrel pull-offs that did not cost me more than $50; throat erosion is not a concern for me: just yank and throw on a new factory pull-off after chambering. So I figured with the only real money in the reamer, fireforming while varminting using factory Hornady would not be too much of a big deal. As of this writing, other caliber considerations like 22 Creedmoor ammo are about $40/box of 20 off the internet and 204 Ruger is $46 while 220 Swift is cheaper at $32 for Hornady 55gr off places like GB. So given that this project will be a high-speed under-700 yard rig, I am thinking for its purpose, its the best bang for the buck for initial brass collection efforts given finding factory Norma 220 Swift is a bit scarce these days.

 

[CaseFinder]

Where do you see 40gr vmax over 5k ft/sec? QL is showing 4500's at 62k psi (greater than what's outlined in QL) Even that link shows 4500's with 40's from a 22-284 which has a bit more capacity. The 5k figure was with a 30gr berger.

It is cool that in his example he didn't blow up the bullets (granted it was a 1:7.7 twist)

I was just going by what Scope-Eye was saying.....

22 creed or 220 swift

Looking to build a long range varminter. Wanting to shoot 55 grain or higher. . Looking to reach out and touch at 500.....maybe 700

www.longrangehunting.com

 

[squirrel_slayer]

Hmm gonna have to call BS on that one....but that's purely on calculated data. Over 4k sure 5k mmm no! lol

So while I get your path I still think 22cm would be the better route. Hornady brass isn't the toughest and unless you have a swack of LR primers having the ability to go with premium srp brass is a bonus IMHO. Being that your going to be loading after you fireform why not save money buying 100 premium cases like alpha or peterson for less than you'd spend on the Hornady factory ammo and no fireforming necessary.

If you already have dies then I guess you'll only be out labor and buying ammo to proceed forward with what you got. Just saying I think there are better options available. Heck even a 22GT would be a riot!

What are the take off's chambered in? if 223 22cm would clean that up no problem.

 

[CaseFinder]

Hmm gonna have to call BS on that one....but that's purely on calculated data. Over 4k sure 5k mmm no! lol

So while I get your path I still think 22cm would be the better route. Hornady brass isn't the toughest and unless you have a swack of LR primers having the ability to go with premium srp brass is a bonus IMHO. Being that your going to be loading after you fireform why not save money buying 100 premium cases like alpha or peterson for less than you'd spend on the Hornady factory ammo and no fireforming necessary.

If you already have dies then I guess you'll only be out labor and buying ammo to proceed forward with what you got. Just saying I think there are better options available. Heck even a 22GT would be a riot!

What are the take off's chambered in? if 223 22cm would clean that up no problem.

Yes, take-offs are factory new 223. Guess if I go the 22 Creedmoor or 22GT route for speed, got to get another reamer....

If only I could find some 45gr Barnes Solids:

Barnes Banded Solid Bullets 22 Cal (224 Diameter) 45 Grain Spitzer

Barnes Banded Solid Bullets feature rings cut into the shank to reduce pressures and allow higher velocities. These bullets have a wider meplat and are...

www.midwayusa.com

 

[squirrel_slayer]

I want to say the gheyTF dropped the ban hammer on those as elite was converting them into that trident round they make. I think they deemed it as "Armor Piercing" and even nuked the barns in the process.

 

[CaseFinder]

I want to say the gheyTF dropped the ban hammer on those as elite was converting them into that trident round they make. I think they deemed it as "Armor Piercing" and even nuked the barns in the process.
View attachment 8209203

Sad it seems....

ATF Bans Barnes Banded Solid Bullets

http://www.barnesbullets.com/wp-content/...Solids-2012.pdf Dumb.

www.snipershide.com

 

[Boatninja]

.22 Creed, Spife and a few other have already been down the road your headed.
I started out hitting the gas pedal hard with heavier bullets from Berger and Hornady, after some aggrevation with 1 MOA results took the barrel off the action.
From the very beginning a friend had been telling me to try the 75 -80 gr stuff, some time later, mounted the barrel up for one more try, I found the sweeeet spot with my Criterion 7.5tw barrel spinning 75 gr Berger VLD's @ 3225fps. Hornady 75 gr ELD-X's @ 3400 were very close, I went for the slower of the two. Now one of my two favorite rifles.
Next project is going to be a .22GT, I have an ARC Coup de Grace action begging for a barrel.
Many times the hunt is more fun than the kill and I shouldn't be so hard headed.


.

 

[Potsy]

Interesting thread and somehow I had missed it.
I’ve been musing a new factory deer rifle and chopping/threading the barrel lately. Something not pretty or expensive that I can stick a 6x swfa on and beat the crap out of and not feel bad.
Anyhoo, one candidate that intrigued me was the Ruger American Predator. They chamber it in .22-250 w/1:10” twist. It occurred to me that even after a 17” chop, 55 TSX’s and 53 V-Max’s (Gawd I love that bullet!) will still be honking along at 3,500fps.
If I do it, it’ll likely be the 6.5 Creed model (maybe a Tikka) but the .22-250 with those two bullets intrigues me and would certainly fill the OP’s requirements, especially with a 22”-24” barrel.

 

[rlsmith1]

Go magnum for real speed, I talked to the guys at LRI and they had a shop gun shooting 125 gr ballistic tips at ~5k fps. 300 NM with a 1-20" twist loaded with Varget I believe. Said it punched through steel at 600 yds and the 1000 yd hold was like 4.3 MILs or something crazy like that!

 

[XP1K]

Go magnum for real speed, I talked to the guys at LRI and they had a shop gun shooting 125 gr ballistic tips at ~5k fps. 300 NM with a 1-20" twist loaded with Varget I believe. Said it punched through steel at 600 yds and the 1000 yd hold was like 4.3 MILs or something crazy like that!

Do huh?

I did have a winmag over 4k with 110 Sierra hollow point one time.

 

[CA48]

Go magnum for real speed, I talked to the guys at LRI and they had a shop gun shooting 125 gr ballistic tips at ~5k fps. 300 NM with a 1-20" twist loaded with Varget I believe. Said it punched through steel at 600 yds and the 1000 yd hold was like 4.3 MILs or something crazy like that!

???
26” 300Rum will only push 125s at 4100-4200fps. A 125BT won’t even be close to stable in a 1-20” twist.

 

[rlsmith1]

Just passing on what I heard, I never saw it and we were really just enjoying the conversation about wildcat cartridges. I called him about necking a 338 LM to 358

 

[CaseFinder]

???
26” 300Rum will only push 125s at 4100-4200fps. A 125BT won’t even be close to stable in a 1-20” twist.

If it is about speed, just stick with a 29gr 220 Swift at 4665fps per P.O. Ackley (current examples might be a Barnes 30gr Fran bullet or Cutting Edge Raptor 30 or 32gr pills). Granted, it does not have the range of the 300NM, but neither does it have the recoil or the price of the 300NM. Thankfully, Hornady and Norma still make factory rounds for this oldie but goodie for about 25%-33% of the price of the 300NM depending where you buy from as of the time of this writing.

 

[carbonbased]

308 boltface, pshaw!

.17 Incinerator — Ultimate Varmint Cartridge with Mach 5 Speed « Daily Bulletin

In the world of varmint cartridges, it's all about speed. Higher velocity delivers flatter trajectories, and more dramatic impacts on critters. To achieve higher speeds, handloaders have experimented with many extreme wildcats -- big cases necked down to a smal...

bulletin.accurateshooter.com

(Note the date)

 

[OlsenG_360]

If you're not limited to a short action, 243 Catbird could be a contender. 270win necked to 6mm and 35 degree shoulder. 70gr bullets around 4100fps

 

[CA48]

22-243 vs 22CM

That’s what’s in my head right now.

22CM would be the easy button. Run 35-50gr bullets in the upper 4000 range. Only way I see a a 22-243 to be worth it is by improving it to get the extra capacity. Other wise it will be similar to the 22creed. There is a guy on another forum running hammer monos out of a 6.5 twist 22creed AI a little over 5000fps. Although I personally don’t see much gain in improving the 22creed.

 

[CaseFinder]

22CM would be the easy button. Run 35-50gr bullets in the upper 4000 range. Only way I see a a 22-243 to be worth it is by improving it to get the extra capacity. Other wise it will be similar to the 22creed. There is a guy on another forum running hammer monos out of a 6.5 twist 22creed AI a little over 5000fps. Although I personally don’t see much gain in improving the 22creed.

Link? I am interested to know what bullet is being used.

 

[CA48]

Il pm you, not sure if it’s allowed to post links from other forums. But I assume he was using the 35gr hammer hunter. As he stated the bullet min twist requirement was 1-14.

 

[iceng]

If you're not limited to a short action, 243 Catbird could be a contender. 270win necked to 6mm and 35 degree shoulder. 70gr bullets around 4100fps

You had me at 243. You lost me, youself, all respect, and potentially your soul at 270win.
You testimony has been stricken from the record, a warrant has been issued for your arrest and the FBI is enroute to kill your dog.

This is all your fault for playing with that parent cartridge which shall longer never be named or spoken of.

 

[Taylorbok]

Going Back To Where I Started........... Kinda

Everyone knows I live on the borderline and I push everything including myself to the absolute, so after the 25 cals and the 30 cals with the Mule I'm gonna go back to where I started with the 22 calibers . The 220 Swift and I have killed a many deer back in the day and everyone knows that light...

www.longrangehunting.com

22-06 with light bullets. He got 5100 and change out of it IIRC

 

[Yondering]

20+ years ago I was pushing 4,250 with 60gr V-max in a 28" 1:10 6mm Rem AI from Benchmark. Pretty sure one could add a couple hundred more with more appropriate powders we have now. I did blow up some 70gr TNT bullets with that one; pushed them up to 3,900 and had a few come apart.

For something that's not as much of a barrel burner, but gives speed - I'm getting almost 4,900 fps (4,880) from a 20 Tactical with 24gr NTX bullets in a 24" AR15. I'd have to double check load data, but the powder charge weight is right in the same range as typical 223 varmint loads. That one's super easy, if you have a 223 bolt face. Just run 223 brass into the 20 Tac FL die and trim, then load as normal. (All the writings about 20 Practical being easier/better are a bit myopic, to be honest.)
My standard varmint load for that one is a 40gr V-max at a piddling 3,900 fps though; it's better at distance.

Or just use a 204 Ruger for a factory round that does the same thing, although it can't use 223 brass.

A 20 BR or something like that should be able to push even faster with relatively small powder charges in a .473" bolt face, but I haven't tried it. Just going by the difference in powder capacity.

 

[iceng]

223 wssm ? (Yes its magnum.. but its short action, and bolt faces can be opened up easy)

 

[OlsenG_360]

You had me at 243. You lost me, youself, all respect, and potentially your soul at 270win.
You testimony has been stricken from the record, a warrant has been issued for your arrest and the FBI is enroute to kill your dog.

This is all your fault for playing with that parent cartridge which shall longer never be named or spoken of.

i mean if it makes you feel better it could be formed from 25-06, lol

 

[Mike Casselton]

???
26” 300Rum will only push 125s at 4100-4200fps. A 125BT won’t even be close to stable in a 1-20” twist.

A 1/17tw will stabilize them at 2900 in a 21" barrel.
30 BR parent case.
They are marginal in an 18tw.

At the above posted speed, they would most likely stabilize.

Probably true at 4200 fps also.


Now, getting 5k speed? Hmmmm, not so sure about that.

What say you Chad? Am I incorrect about the 5k?
@LongRifles Inc.

 

[FuhQ]

You had me at 243. You lost me, youself, all respect, and potentially your soul at 270win.
You testimony has been stricken from the record, a warrant has been issued for your arrest and the FBI is enroute to kill your dog.

This is all your fault for playing with that parent cartridge which shall longer never be named or spoken of.

The only thing a .270 Win is good for (IMO) is forming .25-06 Ackley brass from it.

 

[CA48]

A 1/17tw will stabilize them at 2900 in a 21" barrel.
30 BR parent case.
They are marginal in an 18tw.

At the above posted speed, they would most likely stabilize.

Probably true at 4200 fps also.


Now, getting 5k speed? Hmmmm, not so sure about that.

What say you Chad? Am I incorrect about the 5k?
@LongRifles Inc.

1/17 twist at 2900 will stabilize a 125gr flat base BR bullet but will it with a Nosler 125BT boat tailed bullet? Because it shows a stability factor of 1.0 which doesn’t look ideal but I’ve never loaded and shot anything with a stability factor that low so I’m not sure how they would shoot?

300rum 20twist pushing 125bt at 4100 shows a stability factor of 0.83 which doesn’t seem ideal but then again I’ve never tested a combo like that for accuracy

 

[Mike Casselton]

Yes, the 125 NBT is what I was referring to, since that's what I quoted from CA48's post.

A flat based 125 (specifically the 125gr 308 Speer TNT) has zero issues at even 2600fps at 148' above sea level.


Re, the 125 Nosler, they get better above 2900 fps but my particular barrel/rifle doesn't like that load due to the pressure it generates and the powder compression.
The powder used is LT-30.

It actually shot better using Benchmark at 2735fps, but the powder was also severly compressed.

I will probably have to go to a ball powder to get enough in the case and still generate the speed I want with the Nosler BT.

I don't have that issue with the flat based 125.

 

[MOshooter]

Anyone played with the 22-6mm AI?

 

[4O6shootist]

I'd get a bartlein 22 cal 219/224 bore/groove config barrel that's a 9 to 8 gain twist and chamber in 22cm for simplicity. You'll be able to stabilize up to 85gr bullets(my 8tw did) ran 72gr absolute hammers at 3700fps, 77tmk at 3450, 85.5 hyb at 3300. But with the gain twist likely keep lighter jackets intact, especially sierra tgk and tmk as they're a lil thicker than most. Look at hammer bullets for solids, although that bc sucks, but when they're flying Mach Jesus, drops aren't much a concern out to 400y.

If you want a straight varmint smoker with highest velocity stuffed into a sub 3" coal, it's gonna be a slow twist 6x284 on necked down 6.5x284 lapua brass. It'll be the largest vessel to burn powder in your action length. Feeding might be a pain in the ass with the fatter rebated rim. I'd run ARC aics mags as they take 2.97 internal length and could open the feed lips up a bit. Or run it M5 Oberndorf bdl with a cfe5/mbe4 mag box. These allow 3" cartridge length, yes your actio may need some machining to get these to fit.

Guys have also built 22x284 as well, but in my opinion that's too much of a good thing!

 

[Yondering]

If you want a straight varmint smoker with highest velocity stuffed into a sub 3" coal, it's gonna be a slow twist 6x284 on necked down 6.5x284 lapua brass. It'll be the largest vessel to burn powder in your action length. Feeding might be a pain in the ass with the fatter rebated rim. I'd run ARC aics mags as they take 2.97 internal length and could open the feed lips up a bit. Or run it M5 Oberndorf bdl with a cfe5/mbe4 mag box. These allow 3" cartridge length, yes your actio may need some machining to get these to fit.

Honestly if a guy is looking strictly for speed, I don't think you need to go with so much powder capacity, especially if it'll actually get used in the varmint fields. It kind of sucks blasting 55+gr of powder every shot to accomplish the same thing a little 223 sized case can do, and then have to wait for the barrel to cool after 3-4 shots.

Handloaded well, the 204 Ruger and 20 Tactical I mentioned earlier are 400 yard laser beams, and can approach 5,000 fps with light bullets and the right powders. Although like I mentioned as well, the heavier (for a 20 caliber) bullets work better at distance and still can hit the 4K fps mark with long barrels and spherical powders, without being too hard on barrels for long strings in a varmint field. Nearly zero recoil doesn't hurt either; with those 24gr NTX bullets knocking on 5K fps, in a 10 lb AR15 the only recoil I feel is the bolt carrier cycling.

 

[LRI]

A 1/17tw will stabilize them at 2900 in a 21" barrel.
30 BR parent case.
They are marginal in an 18tw.

At the above posted speed, they would most likely stabilize.

Probably true at 4200 fps also.


Now, getting 5k speed? Hmmmm, not so sure about that.

What say you Chad? Am I incorrect about the 5k?
@LongRifles Inc.

One of my staff has messed around with a "ludicrous speed" 20-6mm XC. He's figured out how to pirate one of my mills and turn it into a machined bullet factory.

Gang up a few tools in a block and clamp to a baseplate.
Use a long-winded ER32 collet tool holder and load a stick of brass in it.
Bang the brass off the tool presetter to set a zero point.
Face the stock
Contour the stock with a back facing boring tool
CD a hole
Finish the hole with a drill
Part it off.

They end up weighing around 19.5 grains and buzz at 5200fps. He's made some 17g that went over a mile a second, but they didn't do much for accuracy.

 

[Mike Casselton]

So, essentially a super light bullet, 20-250, somewhat improved?

 

[D̷e̷v̷i̷l̷D̷o̷c̷A̷Z̷]

One of my staff has messed around with a "ludicrous speed" 20-6mm XC. He's figured out how to pirate one of my mills and turn it into a machined bullet factory.

Gang up a few tools in a block and clamp to a baseplate.
Use a long-winded ER32 collet tool holder and load a stick of brass in it.
Bang the brass off the tool presetter to set a zero point.
Face the stock
Contour the stock with a back facing boring tool
CD a hole
Finish the hole with a drill
Part it off.

They end up weighing around 19.5 grains and buzz at 5200fps. He's made some 17g that went over a mile a second, but they didn't do much for accuracy.

Where do I email my CV?

Do you help with relocation assistance?

 

[Yondering]

One of my staff has messed around with a "ludicrous speed" 20-6mm XC. He's figured out how to pirate one of my mills and turn it into a machined bullet factory.

Gang up a few tools in a block and clamp to a baseplate.
Use a long-winded ER32 collet tool holder and load a stick of brass in it.
Bang the brass off the tool presetter to set a zero point.
Face the stock
Contour the stock with a back facing boring tool
CD a hole
Finish the hole with a drill
Part it off.

They end up weighing around 19.5 grains and buzz at 5200fps. He's made some 17g that went over a mile a second, but they didn't do much for accuracy.

That's pretty cool, and it'd be neat to see pics of some of the bullets. Any idea if they open up (varmints, water jugs, etc) at that speed?

Just a thought though - in the same caliber, I'm getting a 24gr NTX bumping against 4,900 from a little 223 case (and not trashing brass with pressure either, same load workup methods as normal); I'm thinking with that bigger XC case and a lighter bullet there might be a lot left on the table at only 300 fps more. That may likely be a function of the powder used most likely; one of the ball powders like maybe TAC could potentially speed things up more.

 

[CaseFinder]

That's pretty cool, and it'd be neat to see pics of some of the bullets. Any idea if they open up (varmints, water jugs, etc) at that speed?

Just a thought though - in the same caliber, I'm getting a 24gr NTX bumping against 4,900 from a little 223 case (and not trashing brass with pressure either, same load workup methods as normal); I'm thinking with that bigger XC case and a lighter bullet there might be a lot left on the table at only 300 fps more. That may likely be a function of the powder used most likely; one of the ball powders like maybe TAC could potentially speed things up more.

Assuming that 24gr NTX bullet is used in a .204 caliber necked down 223 case in a .204 caliber barrel or does anyone make a .22 caliber solid in the 20gr range? Just asking for a friend, of course, with a 220 Swift Ackley whose lightest options seem to be 30gr variants...a mile a second.....a varminter's dream.....

 

[Yondering]

Assuming that 24gr NTX bullet is used in a .204 caliber necked down 223 case in a .204 caliber barrel or does anyone make a .22 caliber solid in the 20gr range? Just asking for a friend, of course, with a 220 Swift Ackley whose lightest options seem to be 30gr variants...a mile a second.....a varminter's dream.....

It’s a 20 caliber.

Cartridge is a 20 Tactical, a 223 necked down to 20. It changes the shoulder angle slightly and makes the neck a little longer but no fireforming or multi step case forming (vs the 20 Practical which is a straight neck down but same load data). Easy to load for and very fast with small powder charges.

I was a proponent of larger cases to get high velocity for a long time (like 6mm Remington Ackley) but have been seeing just as much red mist and air time on ground squirrels and other small-medium varmints. Also near zero recoil without needing a loud muzzle brake to do it. I really like it.

 

[LRI]

That's pretty cool, and it'd be neat to see pics of some of the bullets. Any idea if they open up (varmints, water jugs, etc) at that speed?

Just a thought though - in the same caliber, I'm getting a 24gr NTX bumping against 4,900 from a little 223 case (and not trashing brass with pressure either, same load workup methods as normal); I'm thinking with that bigger XC case and a lighter bullet there might be a lot left on the table at only 300 fps more. That may likely be a function of the powder used most likely; one of the ball powders like maybe TAC could potentially speed things up more.

I don't know about the terminal performance stuff. This has been a personal project of his that I've just watched from a distance. I know he played with a variety of shapes before settling on one. He's since put together a small CNC hobby lathe at home for this.

 

[Yondering]

It’s a 20 caliber.

Cartridge is a 20 Tactical, a 223 necked down to 20. It changes the shoulder angle slightly and makes the neck a little longer but no fireforming or multi step case forming (vs the 20 Practical which is a straight neck down but same load data). Easy to load for and very fast with small powder charges.

I was a proponent of larger cases to get high velocity for a long time (like 6mm Remington Ackley) but have been seeing just as much red mist and air time on ground squirrels and other small-medium varmints. Also near zero recoil without needing a loud muzzle brake to do it. I really like it.

I came across some pics from a few years ago, and thought of this thread; figured they might be worth sharing. This first pic was a single round each of 40gr 20 Tactical (3,900 fps) and 75gr 5.56 (2800 fps) into high strength (strong, but not hardened) steel plate. The effects of high velocity can be fascinating.

Cases formed by a single pass into these off-the-shelf dies:

 

[carbonbased]

I came across some pics from a few years ago, and thought of this thread; figured they might be worth sharing. This first pic was a single round each of 40gr 20 Tactical (3,900 fps) and 75gr 5.56 (2800 fps) into high strength (strong, but not hardened) steel plate. The effects of high velocity can be fascinating.

Cases formed by a single pass into these off-the-shelf dies:

is that a Vmax bullet in the 20 Tactical? What bullet in the 5.56? And how thick is that plate?

 

[Yondering]

is that a Vmax bullet in the 20 Tactical? What bullet in the 5.56? And how thick is that plate?

Yes, 40gr Vmax. The common weights are 32gr and 40gr, with a few outliers on either side.
75 BTHP Hornady in the 5.56
I don't recall the plate thickness; between 5/16" and 3/8". Maybe just 3/8". We had a few different thicknesses. That 20 Tac won't punch holes in my 1/2" AR500 if you're wondering, but it will leave little pock marks at 100 yd and larger marks up close.

 

[carbonbased]

Yes, 40gr Vmax. The common weights are 32gr and 40gr, with a few outliers on either side.
75 BTHP Hornady in the 5.56
I don't recall the plate thickness; between 5/16" and 3/8". Maybe just 3/8". We had a few different thicknesses. That 20 Tac won't punch holes in my 1/2" AR500 if you're wondering, but it will leave little pock marks at 100 yd and larger marks up close.

I love my .204, and it sounds like the speeds for Vmax 40gr (& 32gr?) of 20 Tactical and .204 are identical.

I’m surprised at the mild-steel punching power of that frangible bullet!

 

[Yondering]

I love my .204, and it sounds like the speeds for Vmax 40gr (& 32gr?) of 20 Tactical and .204 are identical.

I’m surprised at the mild-steel punching power of that frangible bullet!

Yes, pretty similar velocity capability from either round. The 204 does have a little more flexibility to get there with different powders due to its higher case capacity, but the 20 Tactical and 20 Practical have the advantage of using common 223/5.56 brass.

My 20 Tac brass is all just LC 19 headstamp 5.56 brass, and it shoots little bitty groups with that cheap/free range pickup.

 

[culater]

Try this one

22-06 (also 223–06) - necked down to accept a .224 caliber bullet - The 22-06 uses the same caliber bullet as the 223 Remington. This round is frequently used for varmint hunting, offering the shooter a long range, high-velocity, and therefore flat shooting, chambering suitable for that sport. The similar 226 Express, in addition to reducing neck diameter, reduces shoulder diameter to impose a long, slender body taper on the 30-06 case.[6] Extensive experimentation during the mid-20th century indicated no practical benefit from the incremental volume increase of the 63 mm-long 30-06 case over the 57 mm-long 7mm Mauser case for .22 caliber bullets.[7]

That will increase your powder capacity

 

[supercorndogs]

Yes, pretty similar velocity capability from either round. The 204 does have a little more flexibility to get there with different powders due to its higher case capacity, but the 20 Tactical and 20 Practical have the advantage of using common 223/5.56 brass.

My 20 Tac brass is all just LC 19 headstamp 5.56 brass, and it shoots little bitty groups with that cheap/free range pickup.

I loaded up a few 40 v max in my 20 practical with a little less powder than I was using with my 32g Noslers. I went out and was pretty impressed with what the v max did to prairie dogs. I chronoed them and they were only going 3400fps. I will have to bump the charge up and revist. Actually just picked up a diffrent powder to try with them also. Mine is an 18" Ar15 my current ammo with the 32g is going 3950. No recoil is the operative term. I haven't shot enough 40g stuff out of a 223 ar to say if I think there is a real difference. I know my dad was shooting 40g bullets over 4k with 2200 in a 26" bolt action. I like my 20 practical though. I only made it because I got a bunch of bullets cheap.

 

[Yondering]

I loaded up a few 40 v max in my 20 practical with a little less powder than I was using with my 32g Noslers. I went out and was pretty impressed with what the v max did to prairie dogs. I chronoed them and they were only going 3400fps. I will have to bump the charge up and revist. Actually just picked up a diffrent powder to try with them also. Mine is an 18" Ar15 my current ammo with the 32g is going 3950. No recoil is the operative term. I haven't shot enough 40g stuff out of a 223 ar to say if I think there is a real difference. I know my dad was shooting 40g bullets over 4k with 2200 in a 26" bolt action. I like my 20 practical though. I only made it because I got a bunch of bullets cheap.

Top powders for the 20 Practical and 20 Tactical are Lever, TAC, Xterminator/2230, and 2200 IME, depending on bullet weight. Lever for the heavy stuff, but you can't get enough in the case for the lighter bullets. 2200 was at the top end for my rifle with the 24gr NTX, with 29.4gr doing 4,817 fps avg. That's in a 24" AR though; will be a bit slower in an 18" and by more than the common "25 fps per inch" guesstimate.

I use Lever with the 40gr V-Max, because of the combination of accuracy at top velocity.