The 22UM

[Robinhood21]

 

[JBradley500]

My question was because I am interested if high rpm concerns with bullets coming apart can be mitigated with different rifling styles or dimensions.

 

[Hoghead]

Any news?

 

[Formidilosus]

 

[Formidilosus]

 

[RockAndSage]

This was the goal from the very beginning (at least for me). A high BC .224 bullet at 3,500 to 3,700fps MV. Hit rates and danger space maximized, recoil minimized.

What's "danger space", in this context?

 

[Gstew1930]

, really looking forward to hearing more about this

 

[sierracharlie338]

View attachment 749602

Your bench looks like mine

 

[atmat]

What's "danger space", in this context?

Generally it’s the distance where a bullet stays within a certain area of space.

Another way to think of it is: amount of distance you could shoot from without having to dial and still hit an animal.

 

[AZ_Hunter]

Looking forward to results.

 

[RockAndSage]

Generally it’s the distance where a bullet stays within a certain area of space.

Another way to think of it is: amount of distance you could shoot from without having to dial and still hit an animal.

Ah - so, it's essentially how flat-shooting a cartridge is, similar to MPBR?

 

[B_Reynolds_AK]

What's "danger space", in this context?

Ah - so, it's essentially how flat-shooting a cartridge is, similar to MPBR?

Similar to the Weatherby philosophy, but with minimal recoil.

 

[atmat]

Ah - so, it's essentially how flat-shooting a cartridge is, similar to MPBR?

They are somewhat similar, but different concepts.

Reading my initial response, I didn’t do an awesome job explaining it (and the second statement I made sounded more like MPBR).

Danger space is in relation to a target at specific distance. So say at 500 yards you may have 50 yards of danger space. Meaning if you mis-range or the animal moved plus/minus 25 yards, you’ll still hit.

Edit: Just read Form’s breakdown below. It’s more coherent.

 

[Formidilosus]

Ah - so, it's essentially how flat-shooting a cartridge is, similar to MPBR?

No. Danger space is the amount of range error in front of, and behind the actual range that your bullet will stay inside the top of the target to the bottom of the target.

Look a the very left hand column for actual range, second from left beside it is the range short and long that the bullet will stay inside of a 10” circle.


This is 88gr ELD-M at 3,500
MV. At 500 yards it is 76 yards short, and 54 yards long= a 130 yard danger space.






This is a 6.5 PRC with 147gr ELD-M at 2,900fps. At 500 yards it is 51 yards short and 40 yards long= a 91 yard danger space.

 

[mxgsfmdpx]

So in theory, @Formidilosus... Could a guy take a factory 22" or 20" 8 twist .223 Tikka barrel, cut to 18" and thread, spin onto a Tikka action, have UM do some gunsmithing, and make this all work? Essentially a "factory tikka" 22 UM?

 

[atmat]

So in theory, @Formidilosus... Could a guy take a factory 22" or 20" 8 twist .223 Tikka barrel, cut to 18" and thread, spin onto a Tikka action, have UM do some gunsmithing, and make this all work? Essentially a "factory tikka" 22 UM?

I think you’d need a magnum bolt, too, right? And probably change out the bolt stop and mag (not sure what the loaded length is)?

 

[mxgsfmdpx]

I think you’d need a magnum bolt, too, right? And probably change out the bolt stop and mag (not sure what the loaded length is)?

Correct, I would assume go/no go checks, modify bolt face or change to magnum, bolt stop and go up in mag size. That would all be part of the smithing cost/portion. Even if it needed their expensive bottom metal and mags... Worth it.

 

[atmat]

Correct, I would assume go/no go checks, modify bolt face or change to magnum, bolt stop and go up in mag size. That would all be part of the smithing cost/portion. Even if it needed their expensive bottom metal and mags... Worth it.

Gotcha. If I didn’t live in an area with 6mm restrictions, I think I’d pony up to the 22UM.

As of now I want the barrel life and cheap ammo for 223.

 

[mxgsfmdpx]

Gotcha. If I didn’t live in an area with 6mm restrictions, I think I’d pony up to the 22UM.

As of now I want the barrel life and cheap ammo for 223.

Oh yeah my .223's aren't going anywhere! One of my Tikkas is up for another barrel going on Friday night before I go shoot Saturday morning. This 20" blued barrel finally started sucking after 8,500 rounds. Lightly cleaned once at 4,000 rounds (probably shouldn't have).

This 22UM theory gun would be a stainless, wood RokStok'd, save it mainly for hunts gun.

 

[RockAndSage]

No. Danger space is the amount of range error in front of, and behind the actual range that your bullet will stay inside the top of the target to the bottom of the target.

Look a the very left hand column for actual range, second from left beside it is the range short and long that the bullet will stay inside of a 10” circle.


This is 88gr ELD-M at 3,500
MV. At 500 yards it is 76 yards short, and 54 yards long= a 130 yard danger space.

View attachment 749840




This is a 6.5 PRC with 147gr ELD-M at 2,900fps. At 500 yards it is 51 yards short and 40 yards long= a 91 yard danger space.
View attachment 749839

Thanks for explaining that, I appreciate it. So, conceptually, the higher the arc a bullet needs to travel to hit at a certain distance, the narrower/shorter the danger zone is? As in, at 700 or 900 yds, etc, a .308 will have a narrower danger zone than something flatter shooting, like a .300WM or .22UM?