NEW WILDCAT REPORT: 25 Stalker

Fiftydriver

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Jun 12, 2004
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Fort Shaw, Montana
As the title states, there is a new wildcat in the stable at Allen Precision. Before I give the details, i think a bit of a history lesson is in order to put this new wildcats heritage into perspective.

Way back in 2002, when i started rebuilding Remington 700 rifles in high performance wildcats, the first reamer i ever had made to my specs was the 257 Shooting Times Westerner. Now i am not saying this was my design, only had the reamer made to my specs. Made many 257 STW rifles for locals and after a year or so, another local builder started attacking me saying that "I stole HIS design and that I was only a copy cat builder!"

Not only was the 257 STW NOT his design, but this other smith was claiming velocity numbers from his STW rifles that simply were silly. Namely 4100 fps with a 100 gr. Barnes X bullet (remember those...) and all out of a 28" barrel. After his attack on me being a COPY CAT, i called him out because his velocity claims were flat out laughable. I knew this because i had developed loads for a dozen 257 STW rifles in 28" barrels and in that barrel length 3800 fps is about max wih decent case life.

Anyway, this local fight got real heated. To the point i got real tired of it. As such, i sat down and designed my own wildcat design that had never been done before. Took the 338 RUM parent case, necked down to 257 cal and fireformed to my then brand new case shoulder and case body taper design which would become the familiar look of all following APS wildcats.

Once testing was done, in a 28" barrel, the new 257 Allen Magnum would drive a 100 gr. bullet to a legit 3950 fps. In a 30" barrel it would do 4050 fps. Easily and dramatically outpacing anything the hotly debated 257 STW could produce. However, at this time, i had hooked up with Richard Graves, owner at that time of Wildcat Bullets and he had made me some very special 130 gr. Bonded core HP, 142 gr. ULD RBBT HP and a monster 156 gr. ULD RBBT. With these new bullets, nothing could really run with the new 257 Allen Magnum ballistically as its 156 gr. Had a BC of .820 and could be driven to 3300 fps!! Not even the largest 7mm and 30 cal magnums of the time could run with this new wildcat.

However, all was not roses for the 257 Allen Magnum. Although its performance on deer size game was EXCELLENT, the fact that it was based in a parent case that was not overly strong and over the years, became nearly impossible to even get to make brass.

As such, at the end of 2015 i decided i needed to upgrade my wildcats based on the 338 RUM parent case. About this same time i was designing my APS Stalker receiver. Defiance machine would make these for me to my specs. These Stalker receivers were much smaller and more refined compared to my big APS Raptor and designed for the purpose of building lighter weight rifles. With the new Stalker receiver, i decided to design three new wildcats to go with this new receiver. The first two were the 27 Stalker and the 26 Stalker. Both have been fully tested and rifles have been shipping in these wildcats for some time. These new Stalker wildcats are based on the then new 300 norma magnum parent case. These are basically a 338 lapua diameter case with a shorter 2.5" case length.

The third sibling in this trio of new wildcats, and the reason for this report is the 25 Stalker. Some may ask why do a 25 Stalker when you already have a 26 Stalker (6.5mm). The reason simply put is because the 25 cal is an all American caliber and some just want a red hot, laser flat shooting 1/4 bore. Plus i like ultra performance 25s!!!

Like the 26 and 27 Stalker, the 25 Stalker has slightly less capacity then its much longer 257 Allen Mag predecessor. However, both the 27 and 26 Stalker have proven capable of exceeding the performance of the older Allen Mag designs, or often matching 30" barrel performance of the older wildcats in 27" barrel lengths with the new Stalker wildcats.

I was hoping to see similar in this development. Now into this wildcats initial load development. This test rifle will be used in just a few weeks for an early season whitetail hunt in Sask. Canada with Northern Giants Trophy Ranch. I decided i better get my rifle built so this labor day weekend i took a couple days and put together a rifle. This one uses a 27" benchmark #3, 10 twist barrel. Because of the 10 twist, i am somewhat limited to conventional commercial bullets. Production rifles will likely use 8 or even 7 twist barrels to allow the use of heavier, longer custom solid bullets such as the 128 gr. Hammer Hunter from Hammer Bullets. However, with this rifle, i will be using the 110 gr. Nosler Accubond.

When the 257 Allen Magnum was in its hayday, we had to use mainly US869 or other ultra slow burning ball surplus powders. This was to prevent dangerous powder bridgings issues that resulted from using stick powders in the large capacity design.

The 25 Stalker, being slightly smaller in capacity but with larger diameter powder column would also have this same problem, however, last year, Ramshot powders developed and released the new LRT ball powder. Have found this powder to have a burn rate slightly slower then RL33 but noticeably faster then US869 making it my first choice to try in the 25 Stalker.

This weekend with the rifle finished, it was time to form some brass and get bullets over the chrono. I ran into a speed bump right off the bat. I had designed the reamer based on some Peterson Brass 300 norma mag brass samples. However, with my new lot of brass from peterson, the neck thickness is roughly 1.5 thou thicker then the original lots i designed the reamers for. As such, loaded cases had neck diameters to large for the chamber necks. As such, a couple hours had to be burned turning the case necks down for proper clearance to the chamber.

Here you can see the case being formed:
6D58FFF2-D19C-4487-9C54-49C01C1A16A4.jpeg

On the left is the parent 300 norma mag, middle is the 25-300 norma ready for fireforming and on the right is the formed 25 Stalker design.

May need to get new reamer made as i do not like to have to turn necks.

Anyway, got 50 pieces of brass formed up and prepped. You can see the stark difference between the old AM and new Stalker design:
B7FD73BC-24A8-4FA7-A538-FAAE262A5C3C.jpeg

Two 25 Stalkers on the left, two 257 Allen Mags on the right.

Testing started with the 110 gr. Accubond seated to an OAL of 3.300" giving it a 90 thou jump to the lands. I so this with all new designs to offer me a bit more margin of error as it will flatten the pressure curve. Since this is a brand new design, the first powder charge is honestly and educated guess.

With Ramshot LRT, i started at 87.0 gr. Which produced 3524 fps and had some very slight hang fires. Seeing this was a very mild load, i stayed at 87.0 gr. but increased OAL to 3.380" oal which is 10 thou of the lands, which is my standard distance off the lands for my hunting rifles. This load produced 3565 fps and still very mild.

From here i increased powder charges until i reached max pressures:
90.0 gr..............3577 fps
93.0 gr..............3644 fps
96.0 gr..............3764 fps
98.0 gr..............3838 fps
99.0 gr..............3877 fps
100.0 gr............3914 fps
101.0 gr............3948 fps
102.0 gr............4001 fps

102.0 gr load did not loosen primer pockets in any noticable degree, however, the outer edge of the ejector ring was noticeable on the case head. Outside air temps were 85 degrees. At normal hunting temps, 70 and below, i am fully confident this load would be totally safe and acceptable, however, as i will not be using this rifle at ranges over 800 yards, i decided to use a slightly throttled back 100.0 gr. load which averaged 3914 fps and had an extreme spread in the teens. Quite happy with that in a 1/4 bore rifle with this capacity.

Zeroed at 300 yards, the 25 Stalker in a 27" barreled Stalker Hunter rifle with a bare rifle weight in the 7.2 lb range, the 110 gr. Accubond will barely break 2" high at midrange and will only be 5" low at 400 yards. At 800 yards it will only need 7 3/4 moa dial up. Not bad for a 110 gr. bullet weight.

Now again, many of you will already be screaming that a higher BC bullet at lower velocity will do better at long range, and yes that is true. The 25 Stalker is the speed demon of the family. If someone wants an ultra performance 800 yard deer rifle with laser flat trajectory and ZERO recoil, this is it. If someone wants more long range performance, the 26 Stalker with 156 gr. berger or 27 Stalker with 170 gr. Berger will be recommended.

The 25 Stalker is a specific purpose designed wildcat and its looking like its going to do exacrly what i want it to do. For an apples to apples comparison with the older 257 Allen Magnum, thats a bit hard to do. In a 30" barreled rifle, the 257 AM will do 3900 fps with a 110 gr. Accubond. With a throttled back load, in a three inch shorter barrel, the 25 Stalker will improve on that slightly. With full pressure max loads, the shorter barreled 25 Stalker will top the 257 AM by a full 100 fps.

In same 30" barrel lengths, i would estimate the 25 Stalker will push 4100 fps pretty hard which would give it nearly a 200 fps advantage over the old design......

I only wise we had the old 156 gr. ULD RBBT in production still, that bullet at 3300 fps in a 27" barrel or 3400 fps in a 30" barrel would be very impressive for long range ballistic performance.

Long range accuracy testing next, the. Drop chart development and in just s couple weeks, will be heading north to see how it performs terminally in a big bodied norther Sask. whitetail. Stay tooned!!

Nearly 18 years ago, a local feud with another local builder started me down the road of ultra performance 1/4 bore wildcats resulting in this latest wildcat, the 25 Stalker.
 
Can't wait to see what that Accubond does to a big bodied Northern whitetail! What a neat round!!!

I am very curious also. Last year i used the 127 gr LRX in my then new 27 Stalker loaded to 3750 fps. Not much of a test, found my buck bedded down one wet morning soaking up some sun on a south facing valley wall. Pinned both shoulders in his bed and he never got up. Bullet made a caliber entrance wound, 3/4" exit, mess in the middle and that bullet is still several feet into that canadian hill side!!

I suspect the accubond 200 fps faster will not penetrate like that but i am sure it will get the job done. We will hopefully know soon.
 
All three are neat and it's refreshing to have/see you back on here with your cutting edge designs. Thanks for keeping "Rifle Life" fun (need a sticker for my back glass!).

My favorite time in the past 18 years of doing this has been designing and testing my wildcats. It was fast and furious for many years, then the rifle orders started rolling in hard which is a good thing, just take all the time away from designing and testing. Good to get back into that a bit when i can.

The Stalker line will likely get more family members. Time will tell but more likely then not!!
 
Once testing was done, in a 28" barrel, the new 257 Allen Magnum would drive a 100 gr. bullet to a legit 3950 fps. In a 30" barrel it would do 4050 fps. Easily and dramatically outpacing anything the hotly debated 257 STW could produce. However, at this time, i had hooked up with Richard Graves, owner at that time of Wildcat Bullets and he had made me some very special 130 gr. Bonded core HP, 142 gr. ULD RBBT HP and a monster 156 gr. ULD RBBT. With these new bullets, nothing could really run with the new 257 Allen Magnum ballistically as its 156 gr. Had a BC of .820 and could be driven to 3300 fps!! Not even the largest 7mm and 30 cal magnums of the time could run with this new wildcat.
.

I know the british use 25-06 a lot for deer, but all the 25cal is not popular here because there is a weight limit of 9 gram and impact energy of 2700joule at 100meters. You can get away with 2200joule if the bullet is 10grams or more. 142grain 257 bullets would with enough velocity match this numbers and a 156grain would easily do it. This bullets would make it worthwhile to get a 257 weatherby, 25-06 or your wildcat.
How is the availability? Sorry for hijacking
 
I know the british use 25-06 a lot for deer, but all the 25cal is not popular here because there is a weight limit of 9 gram and impact energy of 2700joule at 100meters. You can get away with 2200joule if the bullet is 10grams or more. 142grain 257 bullets would with enough velocity match this numbers and a 156grain would easily do it. This bullets would make it worthwhile to get a 257 weatherby, 25-06 or your wildcat.
How is the availability? Sorry for hijacking

Right now, there is no availability. Looks like 140 gr is about as heavy as you can get. I wish the 25 cal got more attention. Tried to push it starting in early 2000s with the heavy bullet concept but just not enough demand. The 270 caliber has been similar but finally we are starting to see some movement in that caliber, only took 15 years.......
 
Right now, there is no availability. Looks like 140 gr is about as heavy as you can get. I wish the 25 cal got more attention. Tried to push it starting in early 2000s with the heavy bullet concept but just not enough demand. The 270 caliber has been similar but finally we are starting to see some movement in that caliber, only took 15 years.......

9grams is 138,9 grain so it will do if get enough velocity to reach the required energy levels. I'd love to see it happen.
 
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