ALLEN PRECISION Teaser...

Rocky Mountain,

The case volumes are filled to the case mouth, total case capacity. Since the 338 AX, 338 Raptor and 338 AM have roughly the same neck length and same shoulder angle, this still gives me an idea of case body capacity increase as the neck volume is nearly idential on all three so that is consistant. Only difference is the case body volume.
 
HARPERC,

Yes, 25-26" is what I consider conventional length barrels and the 300 Allen Xpress will easily drive a 200 gr Accubond to 3400 fps in these barrel lengths with the Raptor receiver.

In 30" barrel lengths, I have pushed the Accubond to over 3500 fps and the 240 gr SMK to 3250 fps.
 
Rocky Mountain,

The base 338 Excaliber case holds around 7-8 grains more powder then the 338-378 Wby case because its basically the same case only that the Excaliber is longer then both the WBy and Rigby. It also has a longer case body length.

My design relocates the shoulder position to increase the length of the case body even more over the 416 and Wby case.

As far as powder comparisions, inless we are using the same exact powder, the comparisions are not accurate because different powders weight different amounts per volume.

If you simply improved the Rigby case, the 338 Raptor should still offer around 7-8 grains more usible powder capacity. If you relocated the shoulder forward and improved it making a very short necked case, then yes, you will have similiar case capacities.

Only draw back I have seen with the 416 brass is that its designed for a very moderate pressure load and I have not seen to much brass that would support +65,000 psi in chamber pressure with usible case life. Also, its just a pain in the rear to take a 416 case down to 338 and then 30 cal as well compared to what the 338 Excaliber will be. Much more user friendly.

In my opinion, when Wby came out with the 338-378 Wby, it pretty much made the 338-416 Rigby an outdated wildcat that required much to much effort for the same performance.

The 338 Kahn which is a 338-378 Wby with a conventional 35 degree shoulder angle will easily match the numbers your listing as well as it should, nearly identical to the 338-416 Improved.

Improving the 416 really does not give you much volume increase as its pretty well improved right from the start.

Hope this clears something up.
 
The Excaliber is basically the same case as the 338-378 wby without a belt but its longer. Same diameter but longer.

It would not be possible to make excaliber cases from Wby or Rigby cases, they are to short.

You likely filled your case perfectly fine, your powder may weight more then BL-C2 per volume however. Unless your using the same powder you can not compare to different powders. This is why I always use BL-C2 for measuring case capacity. If you use the same fill material, comparisions are always accurate. Water is best and most accurate but a pain in the rear.
 
Camshaft,

The 30-378, 338-378, 378, 416 and 460 Wby are all on the same exact case, just necked down to different calibers.

The Pegasas and Excaliber are the same body diameter(not belt diameter) as these cases but it is a longer case.
 
My numbers are from many years ago. Right when the Excaliber and Pegasas came onto the market. I tried to get some from A-Square directly but at that time they were having some serious problems financially and it was nearly impossible to get brass from them. In fact for a time, it was rumored that A-Square was no more in business.

MidwayUSA had some brass and that is where I got it from, with shipping it came to $6.96 per case for 50 cases at that time. I believe it was 5-6 years ago.

With the problems with A-Square brass in the past, even paying $2 per case is to much!!! I can not prove this but I suspect that Jamison is now making brass for these two A-Square chamberings. The reason I say this is because Jamison would not make brass for these chamberings on their own, not enough money in it. BUT, if A-Square contracted them to build their brass, it would be better quality and cost less. The price you mention you paid for your A-square brass would be in the perfect price range for A-Square to have Jamison make it and then make a little extra in profit reselling to to the public.

I would bet your brass is Jamsion made brass.

If your only getting 3000 fps in a 36" barrel length you would say your running very comfortable pressures as my 338 Allen Xpress which is a much shorter 338 Lapua Improved design will do 3000 fps in a 6" shorter barrel length.
 
Rocky Mountain,

The base 338 Excaliber case holds around 7-8 grains more powder then the 338-378 Wby case because its basically the same case only that the Excaliber is longer then both the WBy and Rigby. It also has a longer case body length.

My design relocates the shoulder position to increase the length of the case body even more over the 416 and Wby case.

As far as powder comparisions, inless we are using the same exact powder, the comparisions are not accurate because different powders weight different amounts per volume.

If you simply improved the Rigby case, the 338 Raptor should still offer around 7-8 grains more usible powder capacity. If you relocated the shoulder forward and improved it making a very short necked case, then yes, you will have similiar case capacities.

Only draw back I have seen with the 416 brass is that its designed for a very moderate pressure load and I have not seen to much brass that would support +65,000 psi in chamber pressure with usible case life. Also, its just a pain in the rear to take a 416 case down to 338 and then 30 cal as well compared to what the 338 Excaliber will be. Much more user friendly.

In my opinion, when Wby came out with the 338-378 Wby, it pretty much made the 338-416 Rigby an outdated wildcat that required much to much effort for the same performance.

The 338 Kahn which is a 338-378 Wby with a conventional 35 degree shoulder angle will easily match the numbers your listing as well as it should, nearly identical to the 338-416 Improved.

Improving the 416 really does not give you much volume increase as its pretty well improved right from the start.

Hope this clears something up.

Thankyou Kirby for puting some light on my questions.

My 338-416 imp dose have a shortish neck with a little wider body than the Excaliber giving similar if not a little more volume than the basic 338 Excaliber.

Yes 416 is a alot of work to neck down over the 338-378 but not having a belt is an advantage and with the good 416 jamison brass can handle I believe more pressure.

Lastly I can see your new Excaliber design will have about 0.080 longer body length than mine giving 3-4 grains more volume which I'm picking will get you just over 3100fps. So fitting nicely between the lapua and cheytac improved versions giving about 30-50fps extra velocity over my design.

Good luck with your new action and excaliber designs I can see Jamison getting Quite a few orders for there new 338 excaliber brass for wildcating.
 
Just got my loading dies so now I have all the needed componants for complete testing, only problem now, customers projects are taking priority to my projects!!!

Hoping to get things built up and started testing one of these weekends.

Sorry for the long wait, just need to focus on customer projects during the week so have to see what I can get together in the evenings and weekends. Hopefully before big game season I will have bullets in the air with the 300 and 338 Raptor.
 
Kirby it will be interesting what velocities you get with your 338 raptor compared to the 338 excaliber improved I'm working on these are definatly interesting new 338 offerings and I can see alot of orders coming into your shop keeping you very busy:D
 
Warning! This thread is more than 14 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Recent Posts

Top