ALLEN PRECISION 338 Raptor update....

Fiftydriver

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Jun 12, 2004
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Fort Shaw, Montana
Well, its been a very busy spring, have not been on LRH much in the past 4-5 months working hard to get customer projects out. In the mean time, I have been working on my new wildcat projects. A bit of back ground for those that are new.

Early last year I came out with my APS Raptor custom receivers and also released two new complete rifle packages available for order, the Raptor LRSS and Raptor Stalker. The development goal of the Raptor receiver was to offer the ultimate platform to build a precision big game, long range rifle on. With the Raptor receiver released and ready to go, the second part of this project was started. With the size and length of the Raptor receiver, we now had a conventional sized receiver that was long enough and strong enough to house some truely impressive performance. That said, we were tapping out long range performance with current chamberings such as the 338-378 Wby, 338 Kahn, 338-416 Rigby Imp, 338 Lapua Impoved and my 338 Allen Xpress. All of these are within 100 fps performance of each other producing in the relm of 2950 to 3050 fps with 30" barrels and conventional, long accuracy life throat designs.

Those that know me know that I am never one to SETTLE for the estabilised norm. My 338 Allen Magnum was already in production and selling well. With its 3400 fps performance level with a 300 gr bullet weight, far exceeding anything on this lower class group of chamberings. Still, these rifles were very large because of the size of the 408 Chey Tac parent case the 338 Allen Magnum is based off from. Large diameter receivers were needed, large diameter barrel shanks also required to house these monsterous wildcats. Minimum rifle weight was in the 15-16 lb range but only with some compromises to the rifle system. The standard finish weight of the ALLEN PRECISION XHS single shot in 338 Allen Magnum was roughly 18 lbs ready to hunt with.

Back to the Raptor project. The APS Raptor receiver took the best features of the current kings of the custom receiver market and then added many unique features. Its over-engineered for brute strength, FAR stronger then anything that could be built on its bolt face. That said, it did not have a receiver thread large enough to house the massive 408 Chey Tac based wildcats.

Many of my customers were VERY interested in the performance level of the 338 Allen Magnum but wanted a more portable rifle design and some wanted a bit better barrel life.

These inquiries started me on the path of designing two new rounds specifically for use in my new Raptor receiver. They were the 300 and 338 Raptor based on the 338 Excalibur parent case. The shoulder was moved forward and sharpened up to my Allen Magnum design. Case body taper was slightly increased to improve extraction performance with top pressure loads.

P9120032.jpg

left to right: 300 Win Mag, 300 Allen Xpress, two(2) 300 Raptors and finally a 30-338 Excalibur fireforming load.

In the end, I was very impressed with the performance but just as I finished initial load and ballistic testing, Jamison International, the company that produced the only good source of 338 Excalibur brass suddenly went belly up and my Raptor wildcats were stopped dead in the water as well.

Over the next couple months I started working with Bruce Bertram in Australia as he has shown some interest in making custom brass for me. I sent my ideas to him and after some time he agreed to the project and we started the long process of making some brass. Instead of just making a 338 Excalibur parent case, it was decided that if we were going to make custom brass, it would be a totally new design.

Changes made compared to the standard 338 Excalibur case were as follows:

- Case body diameter increased to the same diameter as the Rigby and Lapua (Excalibur case diameter is slightly smaller in diameter)

-Case length increased to 3.050", same as my 338 Allen Magnum and noticably longer then the 338 Excalibur.

- Case shoulder was moved forward significantly to increase body length and thus case capacity. Because of the length of this new case, it would be mainly designed to be used in single shot rifles(repeaters are possible) so a long neck was not a real requirement. Settled on a 0.280" long neck which is plenty.

- Shoulder angle and body taper set up the same as the 338 Allen Xpress to maximize capacity but also ensure top extraction performance while using high pressure loads.

- Case would be fully formed from the manufacturer. No fireforming needed by me or my customers, first APS wildcat to be offered in this form.

- Headstamped for 300 and 338 Raptor.

Well, long story short, last week, a package arrives from down under. The first prototype cases of the new 300 Raptor and 338 Raptor. To say I am impressed with the quality of these initial prototype cases would be an understatement. Everything I hoped for and then some. The case head thickness of these Raptor cases are very thick for maximum strength. Heavy case walls again for addes strength. Seeing this, I am ready to proceed to the next stage, get them throwing bullets and see exactly where we will top out in pressure.

Just for some reference, here is a picture with the current heavy hitters in the long range, big game precision hunting rifle market:

P6040001.jpg

left to right:338 Lapua, 338 Edge, 338 Ultra Maxx(APS), 338 Allen Xpress, 338-378 Wby, 338 Kahn, 300 Raptor (Excalibur version), 338 Raptor (New Bertram design) and finally the big 338 Allen Magnum.

To get an idea of how all these compare, we have to look at case volume comparisions but this is a tricky comparison as well. If we measure total case capacity of each filled to the case mouth, some will have a very unfair advantage and their REAL usible powder capacity will not be represented. As such, I decided to take each case and fill it to the base of the neck. I decided to use H-110 handgun powder because its a very fine ball powder that fills evenly and consistantly. Measurement method was as follows.

-Weigh each primed case and record empty case weight.

-Fill each case to the base of the neck and weigh powder filled case. Repeat 5 times for each case and average all 5 fill weights.

-Subtract empty case weight from the average full case weights to get the case volume or each case.

Since the same powder was used to measure the case capacity of all of these cases and all cases were filled to the base of the case neck, its a fair and realistic comparision between them all and telling a realistic comparision between actual USIBLE powder capacity. I also decided to figure out the OAL of each with a 300 gr SMK seated with the base of the bullet body to the base of the case neck for all.

Here are the results from these measurements:

Case...........................Grains of H-110 held by ea case...........OAL
338 Edge...................................116.3 gr...............................4.030"
338 Lapua.................................117.5 gr...............................3.900"
338 Ultra Maxx..........................121.1 gr...............................4.050"
338 Allen Xpress........................122.7 gr...............................3.900"
338-378 Wby............................128.2 gr...............................4.030"
338 Kahn...................................136.4 gr...............................4.060"
338 Raptor (Excaibur based)......144.6 gr...............................4.200"
338 Raptor (Bertram made)..150.8 gr..............................4.285"
338 Allen Magnum.....................176.6 gr................................4.265"

Again, this comparision is as far as possible. All OAL are with 300 gr SMK seated to the base of each case neck to maximize case capacity volume on EACH chambering so there is no bias in this comparision, its the honest, greatest, usible powder capacity of each case design.

As you can see, there was a large gap between the best conventional chamberings and the huge 338 Allen Magnum. While the 338 Allen Xpress has a smaller case capacity then the 338-378 Wby and 338 Kahn, it will easily match these larger chamberings simply because its superior case strength allows it to be used at higher chamber pressure and do so with even longer brass life in spite of the higher chamber pressures. So from this level of performance, around 3050 fps with the 300 gr bullet weights, up to the huge 338 AMs performance level at 3400 fps, there is a large gap.

The redesigned 338 Raptor case now almost exactly splits the difference between these two levels of performance.

ALLEN PRECISION 338 Siblings
P6040003.jpg

left to right: 338 Allen Xpress, 338 Raptor and 338 Allen Magnum

P6040004.jpg

First ever 300 Raptor and 338 Raptor headstamped brass.

Now, we are not ready to ship rifles just yet but I think we are pretty much ready to start place a production order on this new brass. When that happens and I get load and ballistic testing done, they we will be ready to take rifle orders on the newly designed 300 and 338 Raptor wildcats.

The 300 Raptor will be able to be easily chambered in a repeating version of the Raptor LRSS or Stalker. The 338 Raptor however, because of the length of the best long range bullets will have more issues. The 300 gr Berger will simply be to long for any current magazine systems. That said, the 300 gr SMK and the new 300 gr Nosler Accubond should be able to be made to work in the Seekins 3.990" DM systems.

But as with most of these high performance chamberings, loaded with the bullets seated out where they should be and in single shot rifle platforms, ballistic performance should be simply outstanding compared to all conventional chamberings. Should add an EASY 100 to 150 fps on top of THE BEST current conventional wildcat chamberings and do so in conventional 30" barrel lengths and with conventional, long accuracy life throat designs. No tricks with these new cases, just flat out Horsepower the old fashion way, with a larger displacement engine!!!

Performance numbers, my goal is to see +3200 fps with the 300 gr bullet weights in the 30" barreled Raptor LRSS, possibly up to 3250 fps, again, at conventional pressures.

More to come soon. If you want more information, feel free to send an e-mail to [email protected] if you have any questions about these new wildcat offerings.
 
Holy cow batman, those things dwarf my Lapua improved!!!

I look forward to reading/hearing about these 2 new chamberings as they progress.
 
Well Kirby, it looks like things are finally coming together for the Raptors. If Bruce's brass is anywhere near as good as Lapua's you'll have several winners. It looks like it's going to be an exciting summer of R&D!!!!
 
Kirby

I'm not sure how much testing you've done to date so if you can't answer with certainty I understand but what FPS do you think the 300 will do w/230 Bergers and your new 338 w/300's???

Thanks
Bryan
 
B23,

I can not say on the new 300 Raptor. The original design based on the Jamison 338 Excalibur parent case would break 3350 fps with the 230 gr Berger bullet with no undue stress and that brass was not overly strong, similiar to a Remington RUM case in handling pressure.

The new production version of the 300 Raptor made by Bertram has a noticable increase in capacity and from tests I have run comparing Jamison and Bertram 408 Chey Tac brass, the Bertram was significantly stronger.

I feel VERY confident that 3350 fps will be easy to get in the 300 Raptor and possibly 3400 fps with the new brass with the 230 gr Berger. That said, will the berger handle that velocity is the question. In my original rifle, I had a 1-9 twist, 3 groove Lilja barrel which is about as bad as it gets on berger bullets. Because of that, this test rifle perferred the 240 gr SMK loaded to 3300 fps.

Berger recommends a 1-10 twist and I believe a standard 6 groove would produce fine accuracy with the berger 230 gr.

The 338 Raptor should drive the 300 gr Berger to 3200 fps. Possibly slightly more but my goal right now is 3200 fps in a 30" barrel length.
 
Glad your project is going well.

I think you have just about got your 338 bases covered for any hunters needs.
 
Yes, we have a great selection of 338s to choose from. Only goes to show their great performance potential. From the 338-06 and 338 WSM up to the 338 Sniper Tac and 338 Allen Magnum, we have alot to choose from. Anything from mild to WILD!!!:D
 
If we were racing gunsmiths like horses the Allen would be the results of crossing Weatherby with Ackley blood. Just born and bred to push ballistics to new heights. I admire your work Kirby.
 
If we were racing gunsmiths like horses the Allen would be the results of crossing Weatherby with Ackley blood. Just born and bred to push ballistics to new heights. I admire your work Kirby.

WEATHERBY, Come on fella, can't I get something better then that!!!:D

I am kind of a performance junky, that is for sure, in every thing I do, 700 HP camaro, 300 HP jet ski, 3000 yard reach in ballistic performance, its all good!!!
 
i'm really liking the 338 allen express. can you post some picks of your new receiver? i'd love to see some of your work. these new cartriges are awesome! i think they will be a hit with the speed junkies and big game hunters.
 
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