25-223 Remington wildcats

[tx65]

Been doing a little research and there has been some discussion on other forums were a couple of people have put together some 257 caliber versions on the 223 Remington.

First, one person has taken a 223 Remington, necked it up to 257 caliber and trimmed the case to a 43mm case length creating what would be a 6.35x43mm - First photo on the left.

Second, another person is doing something they call the 25x40 which is made by running 223 Remington brass and running it through a custom die pushing the shoulder back and trimming the overall case length to 40mm.

Some interesting ideas and the 6.35x43mm writer is reporting just below 2500 fps with a 100 grain bullet out of a 16 inch barrel upper they put together. The cartridge is appearing to like H322 which is one of the classic bench rest powders known for producing incredible accuracy.

A similar wildcat that has been around for years was known as the 25 Copperhead which has now been rebranded as the 257 Kimber. This was a 222 Remington Magnum necked up to 257.

Of course, there is the 25 TCU which is a 223 Remington necked up and sporting less taper and a 40 degree shoulder.

What are your thoughts and ideas of a 257 in the AR-15? Open discussion welcome.


25-223B.jpgviewFile-2.html.jpegviewFile-3.html.jpegviewFile-1.html.jpegviewFile.html.jpeg

[speederx7]

i think it fills the gap between a 6.5 grendel and a .223. I actually think it (.257/.223) has a bit more merit than a 6.8... just because there is better bullet selection, uses standard mags, etc.

I am not sure if it is really a gap that needs to be filled though. The 6.5 grendel, 6mmbr, 6XC all offer much superior ballistics than anything based off a .223 case, with out giving up much round capacity. All the arguments against the 6.5 grendel (lack of ammo/availablity, etc) are really no longer valid

[tx65]

i think it fills the gap between a 6.5 grendel and a .223. I actually think it (.257/.223) has a bit more merit than a 6.8... just because there is better bullet selection, uses standard mags, etc.

I am not sure if it is really a gap that needs to be filled though. The 6.5 grendel, 6mmbr, 6XC all offer much superior ballistics than anything based off a .223 case, with out giving up much round capacity. All the arguments against the 6.5 grendel (lack of ammo/availablity, etc) are really no longer valid

The 6XC is not an AR15 solution, it requires an AR10. 6 BR gives up substantial capacity when placed in an AR15... About 7 rounds in the space of a 20 round 5.56 magazine. (I have a 6.5 BR AR-15).

[speederx7]

The 6XC is not an AR15 solution, it requires an AR10. 6 BR gives up substantial capacity when placed in an AR15... About 7 rounds in the space of a 20 round 5.56 magazine. (I have a 6.5 BR AR-15).

my mistake on the 6xc...

i also didnt realize the 6mmBR magazine capacity was that reduced. Can you use 6.5 grendel mags for more capacity? The case diameter (~.460) is pretty close to the grendel (~.440)

to reclarify my point (a little better this time), the "PPC like" cartidges (6.5 grendel, 6mmAR, 6mmPPC), IMO provide the most power and round capacity for the AR-15 platform at a normal magazine length. If you are going to spend the $$$ to custom build a .25-223 wildcat, might as well spend a few more $$$ to buy a 6.5 grendel (or similar) cartidge to get the most out of the ar-15 platform.

[tx65]

my mistake on the 6xc...

i also didnt realize the 6mmBR magazine capacity was that reduced. Can you use 6.5 grendel mags for more capacity? The case diameter (~.460) is pretty close to the grendel (~.440)

to reclarify my point (a little better this time), the "PPC like" cartidges (6.5 grendel, 6mmAR, 6mmPPC), IMO provide the most power and round capacity for the AR-15 platform at a normal magazine length. If you are going to spend the $$$ to custom build a .25-223 wildcat, might as well spend a few more $$$ to buy a 6.5 grendel (or similar) cartidge to get the most out of the ar-15 platform.

The 6 BR has a .473 Rim Diameter and a .471 body diameter at the base. The cases only seem to function reliably in single stack mode within the width of AR15 magazines. The rim and case diameter is better suited to stacking within the width of an AR-10 magazine.

I am very familiar the Grendel and the PPC's in the AR15 platform.

[speederx7]

I am very familiar the Grendel and the PPC's in the AR15 platform.

yea i know your history.

I am simply adding to the conversation about the .25x.223 with my impressions. I obviously dont have anywhere near the history/experience that you do. I can just state my beliefs and impressions publicly and see how they hold up. I might even learn something by doing so!

what are YOUR thoughts on the recent emergence of the .223 based wildcats?

[tx65]

yea i know your history.

I am simply adding to the conversation about the .25x.223 with my impressions. I obviously dont have anywhere near the history/experience that you do. I can just state my beliefs and impressions publicly and see how they hold up. I might even learn something by doing so!

what are YOUR thoughts on the recent emergence of the .223 based wildcats?

For many people, the 223 Remington or 221 Fireball based wildcats are simple making use of almost all standard 5.56 parts while providing the performance needed to be effective medium game hunting cartridges within a 300 yard range. Add on top of the equipment simplicity is the reality that 223 Remington and even 221 Fireball brass is 50% of the cost of any Grendel brass.

A little known fact from my original experiments back in 1998, a .257 caliber 115 grain was my first choice for a 1.5 inch (39mm cartridge length). Unfortunately, the selection of 257 bullets for my intended application (competition) was very limited. If my primary emphasis was hunting, 257 would have been the winner hence my intrigue with the wildcats others have been playing with.

I have no belief that there is one do all cartridge and everyone should stop thinking of ideas. Actually, in 6.5mm, I think what JD Jones did with the 6.5 MPC is pretty intriguing for the AR15. Unfortunately, it appears to not being going anywhere.

[320pf]

Been doing a little research and there has been some discussion on other forums were a couple of people have put together some 257 caliber versions on the 223 Remington.

First, one person has taken a 223 Remington, necked it up to 257 caliber and trimmed the case to a 43mm case length creating what would be a 6.35x43mm - First photo on the left.....

First let me introduce myself. I am the person that came up with this wildcat. Here is an update on the development of the 25-223AR (6.35x43mm).

http://www.beyond556.com/bboard/atta...0&d=1295358329

With a 16" 1:10 twist, the following ballistics have been optained:

70 gn Sierra BK 2950-3050 fps
80 gn Barnes TTSX 2800-2850 fps
87 gn Speer HotCore 2800-2850 fps
90 gn Sierra BK 2650-2700 fps
90 gn Sierra GK 2750-2800 fps
100 gn Sierra (MK PH, and GK) 2550-2600 fps
100 gn Speer SPBT 2550-2600 fps

AR-15 rifles wiht 16-18 inch barrels have been making kills on woodchuck out to between 200-300 yrds.

In 24-inch bolt guns kills have been reported out to 700 yards on Prairie dogs.

If you are interested you can start reading here:

http://www.ar15.com/forums/t_3_121/4...3.html&page=46

There are some pictures on the cartridges handiwork with the read. If you want to get to the pictures stright away start on page 47.

[Brakeman]

Hello to all.
I'm new here and found my way by searching on the web for 25 calibers options on the 5.56mm case. I'm interested in building a 25 caliber AR15 platform walkabout hunting rifle for small to medium size game, but from my POV, it's all a bit confusing getting there.

Appears the postings from 320pf and others who've been down this road have quite a bit of thought and research behind them. What I'm looking for is a clear path to building an AR15 in this caliber with a case that's going to work with standard magazines with the least amount of grief. So am I in reality looking for a 25x223AR, 25x45 or 25x40 or...?

This would include sourcing a complete upper (20" standard contour barrel), dies and anything else that's relevant. Would really appreciate the opportunity to tap into the observations you guys have accumulated in the process of your own experience with this.

BTW: whatever happened to the 25x45 Sharps?

Thanks to all,
Brakeman

[Tripledeuce]

Actually, the origional 25 Copperhead was a 25-.222. Standard .222, not mag. It was designed by gunwrighter John Wooters, and written ip in Rifle Mag #22.

respectfully
Terry