50D, thanks for the info. I was kinda speculating that a 1:8 would be in the neighborhood for the .257.

My remarks about the .408 Chey-Tac were directed at the brass performance regarding tolerance for pressure. I am aware of the other things you mention, wish Warren luck in sorting all that out. I too am a blasphemer in regards to solid copper. I have heard rumors that when loaded with lead core bullets the Chey-Tac performs well.

Anyhoo, your points are noted and again, good luck with this. Depending on circumstance and timing I might be interested in one of the .257's or more likely the 6.5. I Would like to QT the Bob or .25-06 for heavier bullets though, just an idle idea waiting for bullets. I always thought the 1/4 bore would sing with a high quality bullet in the 140/150 gr weight range.

You ever hear of Darryl Cassel, and the famed Darryl Barrel?

Bwana-be,

Well lets look at the 257 STW first. The rifle in the pics has a 30" Lilja 3 groove barrel and drives the 130 gr bullets which were used on the whitetail to 3467 fps average for 10 shots in 50 degree temps at 3000 ft elevation.

At 3500 fos the primer pockets begin to open up to the point that after the second firing they are basically to loose for my comfort to reload.

The 3467 fps load offers four firings but after that the cases are pretty much done. From my testing, to get 6 firings on a case, you need to drop the STW down to the 3380-3400 fps range.

Unfortunately, I do not have data for the 257 AM yet but I expect to get a solid 3600 fps pretty comforably, that being with +5 firings per case. Here is why I believe that.

I have compared the 7mm STW with the 7mm RUM. In fact I have tested them extensively to see which case would handle the most pressure before the case head expanded enough to cause primer pocket loosening.

Not only does the RUM case have a 12 to 13 percent case volume advantage, it also has a great advantage in case head strength. From the velocity I got with the STW, I precdicted that this case would handle in the 60,000 psi range and allow 5 firings per case with Rem brass.

The RUM loaded to its top levels had to be closer to 70,000 psi from the velocities it was getting with the 160 gr bullets and primer pockets were holding tight for 5 to 6 firings.

So combine the case capacity advantage with the strength advantage and you get much more velocity potential. Plus the shorter fatter case design of the AM compared to the STW will also increase powder burn efficency.

So lets see how they compare with the 257 Wby and STW. The better designed case in and of itself is worth going with this round over the 257 STW but lets look at the performance numbers.

I chose a 10" vital zone which is correct for northern whitetails, mule deer and caribou.

With a muzzle velocity of 3200 fps in the 257 Wby with the 130 gr pill(which is marginal for stability in a 1-10 barrel)here are the specs for 10" vital zone PBR

top trajectory: 180 yards
Zero: 332 yards
5" low at: 392
At 500 yards: -19.3" drop, 14.0" wind drift


257 STW @ 3400 fps

Top trajectory: 195 yards
Zero: 351 yards
5" low at: 412 yards
At 500 yards: -14.8" drop, 12.9 wind drift


257 AM

Top trajectory: 220 yards
Zero: 375 yards
5" low at: 442 yards
At 500 yards: -10.9" drop, 11.7" wind drift

Again, these numbers are proven for the Wby and STW but not in the AM which I believe are on teh conservative side so this is basically my best prediction, I am hopeful 3650 fps will be easily attainable.

Comparing the three as far as PBR goes, the AM offers 50 more yards over the Wby and 30 yards over the STW.

But lets put this into a little different perspective. The 25-06 should get nearly 3000 fps with the 130 gr bullet in a 30" barrel, here are the specs for the 25-06:

Top Trajectory: 175 yards
Zero: 312 yards
5" low at: 368 yards
At 500 yards: -24.6" drop, 15.3" wind drift

If we look at the numbers, the 257 STW offers 44 more yards in PBR over the 25-06.

The 257 AM will offer 50 more yards over the 257 Wby!

My main performance criteria is at the 500 yard drop here are those numbers again:

25-06: -24.6"
257 Wby: -19.3"
257 STW: -14.8"
257 AM: -10.9"

The AM has almost 65% less drop then the 25-06 at 500 yards. Nearly 44% less then the 257 Wby and 27% less then the STW.

In actual numbers this may not look like a lot but for 500 yard shooting at deer size targets, one only has to hold ont he line of a bucks back with the 257 AM to score a center chest hit.

Remember, it is not only performance advantages but also accuracy advantages(in theory so far ) and case life and strength.

Both the STW and AM rounds will cost roughly the same to get set up to load for.

Obviously with the heavier bullets such as the 145 adn 150 gr 257 bullets, Richard even mentioned that a 160 gr FBHP is possible, the AM will really start to pull away from the smaller rounds in 28" to 30" barrels.

I have not been able to test these heavies as of yet so I will not give data I do nto have.

So for the traditionalist, yes, many will say its not worth it, for those that want the highest performance they can get, it will serve them very well in my opinion.

Performance comparisions with the other two calibers will be very similar.

Good Shooting!!

Kirby Allen(50)

Digital Dan,

You are correct that the 257 has a more unique list of bullets so far only because it is the first to be developed. The bullets for the 6.5mm and 270 are basically the ones already offered by Wildcat Bullets. There will be others I assure you.

I have been shooting the 130 and 145 gr .257" bullets out of my 1-10" twist 257 STW and getting groups inthe .3"s at 100 yards as long as velocity is over 3300 fps. The 130 gr pills are shooting into 1 1/4" groups at 500 yards. Have not tested the 145's yet at 500 yards to see if they hold their stability but I am nearly positive they will since they are actually a bit shorter then the 130 gr BCFBHP bullets.

The 145 gr ULD Rebated Boattail and 150 and 160 gr BCFBHP will need a 1-8" twist.

I have both a 30", 1-8" Pac-Nor Super Match and a 30", 1-10" Lilja coming to test all bullets.

From what I have seen in my testing so far, the 1-8" should easily handle everything offered including the big 160 gr pills.

The 6.5mm bullets are still under developement and will be next on the list. We are looking at a 160-165 gr BCFBHP for the heavy hunting bullet in this caliber. While there are 6.5mm bullet in the 160 gr weight, most are round nose bullets. This bullet will be a very streamline bullet with a b.c. in the low .600 range. This will match even the best VLD bullets for B.C. but in a true big game bullet.

For long range shooting Wildcat Bullets will be building something in the 160 gr class for a ULD Rebated Boattail. This should have a B.C. in the very high .700 range. The 145 gr .257" ULD has a B.C. of .738 so this 160 gr 6.5mm version may well be at .800. This is certainly over what is offered by the masses.

In 270, wew are just starting to get ideas where we want to go with bullet weights. I have a 1-8" Pac-Nor Super-Match barrel of 30" ordered so we will see how it shoots and we will test many bullet weights.

The 169.5 gr ULD RBT has a B.C. of .748. The 240 gr .308" Matchking has a B.C. of .720 range so that shows you the long range potential of this bullet. As far as big game bullets, we will be looking at bullets in the 160 to 180 gr weights in the BCFBHP design which should have B.C.s in the .600 to .650 range. Far greater then anything offered at this time in a true hunting bullet.

The 257 caliber has beed the ballistic whipping boy simply for lack of proper bullets. This weakness will be solved with the 257 AM round I promise you.

IF you consider that the 130 gr BCFBHP has the same S.D. as a 160 gr 7mm bullet and actually higher then a 180 gr .308" bullet. IT also has a B.C. higher then a 180 gr Ballistic Tip.

And then take that bullet and load it to even 3600 fps. Imagine what kind of round it would take in 7mm or 308 to match the 257 AM ballistically. A 180 gr in the 30-378 with a 30" pipe may come close but at the expense of dramatically higher recoil and blast as well as in a round that is much more costly to produce.

Remember these rounds are designed specifically for game in the 200 to 400 lb range. There is no need for a 180 gr bullet or even a 160 gr 7mm for that matter.

The 6.5mm and 270 versions were offered as there jsut is nothing offered by the factory in these two calibers that will even remotely come close to teh 6.5mm AM and 270 AM. The two hottest rounds are the 264 Win Mag and the 270 Wby Mag. Neither will even come close.

I personally have not been inpressed with the performance of any of the LRB bullets. For that matter, I am not a solid copper bullet fan of any make. They simply do not offer the accuracy and consistancy to meet my requirements in my rifles. The Wildcat Bullets do, they offer very high B.C. values and are great performers on game. Plus they cost about 1/3 what the LRB bullets do and they actually do expand and shoot tight groups.

Everything I have heard about the LRB bullets for the 408 has been pretty dismal in performance. In fact I feel that is the reason why the 408 is in kind of a slump as of the last year or so. Its a hell of an extreme range round, the bullets just do not perform.

Good Shooting!!

Kirby Allen(50)

To all,

Over the last several months I have been in the R&D stage of developing a family of wildcats in the following initial calibers; 257, 6.5 and 270.

My design goals for these new rounds was to offer the deer and pronghorn hunter an honest 500 yard reach in a rifle and round with a trajectory flat enough to allow such shots with very little needed in the way of hold over.

My rifles chambered for these rounds will be in two basic forms, both with 30" #6 barrels from either Lilja or using Pac-Nor Super-Match Stainless barrels.

One will wear a laminated wood stock and have a rifle weight of 9.5 lbs.

The other will be a light weight version if you will and have an H-S Sporter stock and the barrel will be fluted with heavy .312" flutes for weight reduction. This version will still have the 30" barrel and will weight in at around 8.5 lbs, hardly light weight but for a 30" pipe pretty light.

Of course other barrel lengths and rifle configurations will be available but these will be the initial rifle design that these new rounds will be chambered in.

They are designed for upen country hunting where the longer barrel will not be a problem, in fact it will be an advantage.

Now for the rounds them selves.

The parent case is a large capacity non-belted magnum. I have built several 257 STW and while this is a very hot round offering extremely flat trajectory, I wanted to add at least 150 fps to its level of performance.

This raised several interesting problems, first off parent case to be used. Second, bullets that would survive this type of velocity accurately.

I looked at the 300 RUM necked down initially but felt its powder capacity was a bit to large for these rounds. Even the STW in 257 is a huge case but going up to the 300 RUM necked to 257 is just to large.

Case capacities of the three cases filled to the mouth with H-335(settles evenly) are as follows:

257 STW---------104 gr
257 Allen Mag---120 gr
25 RUM----------128 gr

This is total case capacity, actual usable case volume depending on bullet weights used will be roughly:

257 STW---80 gr
257 AM----95 gr
25 RUM----100 gr

IT is clear the 257 AM is a huge 257 round. In developing loads for the 257 STW is was clear the in the STW, 100 gr bullet uas about the lightest you could use and get respectible performance in reasonable extreme spreads. Moving up to the 115 gr weight in the STW turn the round into a pussy cat to load for and its a better big game bullet as well.

With the higher performance goals of the Allen Magnums, I knew that 115 gr bullets would probably be the lightest that would perform in this bigger case.

To make these rounds really work well though, I knew that factory available bullets would not give me what I wanted. I contacted Richard Graves, owner of Wildcat Bullets in Alberta, Canada and asked his opinion on these rounds and we were off an running.

Richard is designing all the bullets for these three rounds. Conventional bullets will certainly be able to be used in these rounds but with the new Wildcat bullets, these three roudns will take the 257, 6.5 and 270 to performance levels they have never seen when combined with the new AM case and these high performance rifles.

There will be no less then three Wildcat Bullet designes for each caliber. Here are the bullet weights, B.C. of bullets and projected velocity of each bullet in the AM rounds:

257 AM
130 gr Bonded Core FBHP(b.c. .550)------------3650 fps
145 gr FBSP(b.c. .540)-----------------------3500 fps
150 gr Bonded Core FBHP(b.c. .600)------------3450 fps
145 gr ULD(b.c. .738)-------------------------3450 fps
160 gr Bonded Core FBHP(under development and testing)

6.5mm AM
140 gr Bonded Core FBHP(b.c. .520)------------3550 fps
142 gr ULD(b.c. .700)-------------------------3500 fps
165 gr Bonded Dore FBHP(under development and testing)
160 gr ULD(under development and testing)

270 AM
130 gr Bonded Core FBHP(b.c. .500)------------3700 fps
140 gr Bonded Core FBHP(b.c. .525)------------3600 fps
150 gr Bonded Core FBHP(Under development)----3500 fps
169.5 gr ULD(b.c. .748)-----------------------3350 fps

My performance goals once I talked with Richard about the bullets was to design a bullet/round/rifle combo that would equal or exceed the ballistic performance of the 30-378 and 338-378 rounds in hunting weight rifles and with 1/3 the recoil of the big hammers.

These rounds will clearly do this if the numbers on paper hold true which I feel they will. In a 30" barrel, I feel these numbers are on the conservative side but I tend to lean that way anyway.



These are some of the 257 Wildcat bullets compared to conventional bullets. From left to right: 100 gr Partition, 100 gr Ballistic Tip, 115 gr Ballistic Silvertip, 100 gr Wildcat BCFBHP, 130 gr BCFBHP and the 145 gr FBSP.



Here are the three rounds in their virgin state. Fireformed roudns will have a sharper and fatter shoulder.

Loading these round will be easy. I will offer properly necked brass, all that will be needed is to load and shoot and they will be fireformed just as the AI rounds are.

Brass will run around $35.00 plus shipping for 50 brass.

Reamers have been ordered as have test barrels and Richard and myself are busy testing and designing bullets for these round. The largest 257 round I have to test the bullets in is my 257 STW and with the 130 gr BCFBHP's it will shoot into the .3's at 3470 fps and into the 1 1/4" range for three shots measured CTC at 500 yards.

My wife and I used this rifle and these Wildcat Bullets this year big game hunting and results were awsome.





This +150" B&C 4x5 tipped the scales at 340 lbs live weight.I am 6'3" and 200 lbs so that give you an idea of the size of this brute.

These are big game rifles, not match rifles or varmint rifles while they will make extreme performance coyote rifles if the pelts are of no concern to the hunter. With proper shot placement the 257 AM with the heavy bullets will serve well on elk size game but it is designed to be used on game up to the size of Caribou for best results as if the 6.5mm version.

The 270 Version with its heavier bullet weights, which may include a 170 to 180 gr vesion here soon will be better suited to elk size game but still they are designed for long range deer hunting .

There will be other calibers coming after these three that will be better suited for heavier game. Calibers ranging from 6mm(different case size) up to the 475 have been drawn up so we will see where the interest leads.

They will be easy to load for and they will fit in actions designed for any full length magnums with my preferred action being the Rem 700 long action to build on.

The first rifle produced is planned to be at or near the fisrt of the year with orders going out as soon as load data is available.

Yes these are over bored rounds but again they are designed for big game hunting and I expect to get around 1100 rounds of usible barrel life before a barrel set back is needed to clean up the throat, another reason for the 30" barrel.

If they are taken care of and not shot enough to over heat the barrel, they will last a lifetime for any big game hunter I know.

Just thought you may be interested on this load development. I will keep you posted as things transfer from research to actual field results.

Good Shooting!!

Kirby Allen(50)

DB Bill,

Exactly what are "Canadian" feet per second?

I thought FPS were FPS, at least last time I checked they were.

Kirby Allen(50)

I hate to ask but are these "Canadian" feet per second values?