.257, 6.5mm and 270 Allen Mags, New Family or Rounds...

[Fiftydriver]

Littledevil,

I am just waiting for the reamer to get here, They said roughly 3 weeks so we will see.

Once the rifle is built and I can get the fired cases off to Redding, it will just be a matter of when they get things ready to ship.

Personally. the 6.5mm AM interests me a bit more then the 257 AM but it will be the second round tested. When I get teh 257 AM going, I will order the 6.5mm AM reamer so I am looking at around the middle to end of December for the 6.5mm AM to be up and running.

Capacity wise, the STW will not even compare to the AM rounds, as this case design will offer roughly 16 grains more capacity over the STW case.

Your 700 action would be so easy to build one of these on it would be scary, all that is needed is a rebarrel job, action printing and a new fatter mag box adn your off and rolling.

My parent case is the 338 RUM and I am working with Redding on the dies.

Good Shooting!!

Kirby Allen(50)

 

[Fiftydriver]

Jerry Tao,

You are correct the Dakota rounds are very similar to the STW in case volume so the AM rounds will provide roughly 16 grains more case volume over this case.

I looked hard at the Dakota case when designing this but then figured that teh 338 RUM would offer even more but not so much that it would be unpractical with 115 gr class bullets.

Certainly my rounds will run harder in the longer 28-30" barrels but they will still be around 100 fps faster then the STW/Dakota class of rounds in a 26" barrel. I would not recommend going down to a 24" barrel with these AM rounds.

They would still be faster then the smaller rounds but muzzle blast would greatly increase and your velocity advantage would be trimmed as well.

Where these rounds will shine will be with the very heavy, unconventional bullet weights such as the 145 adn 150 gr .257" Wildcat Bullets. This is where the true advantage will be for these new rounds.

That along with a case properly designed to push them very fast and accurately.

I have an XP-100 that I built myself in 6.5mm WSM and I am very impressed with the round. It is very accurate and plenty of power for deer out to a very long range even out of my handgun. I havested a mule deer doe with it a week ago with it at a measured 332 yards with a single 120 gr Ballistic Tip through the shoulders. Performed flawlessly.

Still I am striving for the ultimate in trajectory and on game performance, that is why I designed teh AM rounds.

Good Shooting!!

Kirby Allen(50)

 

[Mysticplayer]

Well Kirby, that is way too much fun. I have heard that using the STW case, many were running into problems in the 25 and 6.5 cals. Probably using bullets on the light side and not getting the right powder burn/pressure. Using the super heavies is the way to go.

I have a very soft spot for the 6.5 and the 6.5AM sounds like a winner. I wonder if the MK/Lapua's are going to like going that fast? Most soft shell match bullets tend to distort over 3100fps. Going 3500fps might just blow them up.

I would suggest the 140gr SST in a 9 twist. I doubt they will blow up and getting these 500fps faster then where I am is just way too much fun. Easily a 800 to 900yd hammer.

These wildcats could use much cheaper bullets but still offer similar on game terminal performance at long range. They might just be better in the wind too due to such short transit time.

Only area undetermined would be the powder to use and the actual case capacity with the bullet of choice. The best slow powder I know of is H50BMG. If that will not load to near 100% load density, ES numbers might not be too favorable.

I guess you could look at wet sawdust as a duplex load.

These are not overbore cartridges!!! Just barrel life challenged A 220Swift for big game. Roy Weatherby would be proud...

Jerry

 

[shortround]

FIFty , I know that I am new to this board but I would like to say that your rounds sound like they will be awsome to shoot, I can't wait to get feedback on the 6.5 from actual field trials. Well done

 

[Guest]

Great job Fifty! Keep us updated on your progress bro. Looking forward to it!

 

[ohnomrbillk]

Fifty driver,
I am incredibly interested in the 257. Can you point me to a website where I can find out more about the wildcat bullets you are suggesting? Thanks

 

[Fiftydriver]

375-06 JDJ,

I am also very excited to get these rounds off the ground. I guess they are off the ground but until I have hard data to offer everyone, I can't say for sure how these big rounds will run.

On paper they look very impressive but as we all know this does not always transfer to the real world.

I think alot of quality homework has been put into these rounds by Richard Graves on the bullet end and myself on the case design and rifle design.

Richard does not have a Web site for Wildcat Bullets but you can E-mail him at:

[email protected]

Ask him for information on any bullets your interested in and he will freely give it to you. Hell of a guy to work with and I feel he is as large a part of these new rounds performance levels as I am, that is how advanced his bullet designs and weights are.

Here are some pics of his bullets compared to others of the same caliber.

These are 6mm bullet starting from left to right:87 gr HPBT Hornady, 95 gr Nosler Ballistic Tip, 105 gr A-Max, 105 gr Berger VLD and the last two are the Wildcat Bullets 110 gr Bonded Core FBHP.

These FBHP have a B.C. higher then the 105 gr A-Max and just under the 105 gr Bergers. Not to bad for a FB big game bullet.

These are .257" bullets. Left to right: 100 gr Partition, 100 gr Ballistic Tip, 115 gr Ballistic Silvertip, 100 gr Wildcat Bonded Core FBHP, 130 gr Wildcat Bonded Core FBHP and finally the 145 gr Wildcat FBSP.

As you can see the 145 is the same length as the 130 so B.C. will be nearly the same but penetration will be deeper and it will still stabilize very well in the 1-10" twist range just like the 130 gr Wildcat.

The 150 gr version which is yet to be built may be a different story as will the 145 gr ULD rebated boattail.

Comparing the 130 and 145 to the 115 gr Ballistic Silvertip really puts these bullets into perspective. They will penetrate every bit as deep as teh 160 adn 175 gr 7mm bullets or any other bullets with this S.D. and with a B.C. much higher then most big game bullets. The 130 gr FBHP has a B.C. in the .560 range. The 150 gr version should be in the .6 range and the 145 gr ULD shoudl be at least in the .650 range, probably closer to .7 in B.C.

Here is the 115 gr Ballistic Silvertip flanked on the left by the 130 gr Bonded Core FBHP and on the right by the 145 gr FBSP Wildcat bullet.

These are 6.5mm bullets from left to right: 120 gr Ballistic Tip, 140 gr Wildcat Bonded Core FBHP, 140 gr A-Max and the 142 gr Wildcat ULD rebated boattail.

As you can see the 140 gr BCFBHP is nearly as long as the 140 gr A-Max bullet with nearly identical B.C.

The 142 gr ULD is a great long range bullet for the 6.5mm rounds. SO far I have found it to have a higher B.C. then the 142 gr Sierra Mk and on average will out shoot it as well.

Finally, here is a pic of the three new rounds. These are virgin brass rounds so when fireformed the shoudler will be sharper and fatter at the shoulder as well.

They will look quite different in fired cases but this gives an idea of what they will look like.

Get ahold of Richard and he will give you all the information you want.

Good Shooting!!!

Kirby Allen(50)

 

[Fiftydriver]

Jro45,

Rl-25 is a good powder and a pretty good match for the 257 Wby with most bullet weights especially the 115 and 120 gr class bullets.

There are slower powders out there though, much slower. This is a good thing as RL-25 is a great powder in the 257 STW with 100 gr bullets but it is really to fast in burn rate for anything much higher to get peak velocities.

In teh 257 STW, Retumbo is a much better powder for bullets in the 115 to 145 gr weight as it will provide better consistancy and higher velocity the Rl-25 because it is a slower burning powder.

In my 257 AM, Rl-25 is very fast for even the 100 gr pills which I do not recommend in this round. I will develope loads for the 100 gr Bonded Core FBHP but velocity spread will be relatively high as it generally is in the STW, just worse in the larger AM.

I recommend startign with the 115 gr bullets as light weight options in the 257 AM and preferably the 130 gr Bonded Core FBHP from Wildcat Bullets.

With this bullet weight Retumbo will be the best powder I suspect along with the 145 gr pill.

There will also be a 150 gr FBHP but testing needs to be done to see if this bullet will stabilize in the 1-10" twist barrel or if it will need a 1-9" twist to keep the bullets on point.

Other powders that will be tested with the 145 adn 150 gr bullets will be H-50BMG(possible powder bridging problems may occur with this powder at the case neck, we will have to see) and AA 8700 which is nearly the same as H-870 which would have been a hell of a powder for this round if it were not dropped from the Hodgdon line.

Only one person I know of is making these weights in the 257 caliber and he is Richard Graves, owner of Wildcat Bullets in Alberta Canada. His bullets have performed to perfection in high velocity testing with the 257 STW and I suspect will perform the same in the larger 257 AM as well.

Good Shooting!!!

Kirby Allen (50)

 

[jro45]

I have the 257 Wby mag and I have reloaded all my rounds to: 100gr bullet does 3500fps,
87gr bullet does 3700 fps, 117gr bullet does
3300 fps,and the 120gr bullet does 3200fps.
I use RL25 powder. I don't think there is a slower powder but I could be wrong. I didn't know they made a 130 for the 257.