Rocky Mountain
Well-Known Member
Fiftydriver when you did your case volume testing of your 338s using ball powder did you fill them to the top of the case mouth or to the shoulder neck junction?lightbulb
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ALLEN PRECISION Teaser...
- Thread starter Fiftydriver
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Franklin
Well-Known Member
Fiftydriver when you did your case volume testing of your 338s using ball powder did you fill them to the top of the case mouth or to the shoulder neck junction?lightbulb
Quote from his first post.
I used Hodgdon BL-C(2) powder, filled the cases full to the case mouth and find the case capacity for each.
HARPERC
Well-Known Member
I hope the results are as exciting as the post. I've read it through a couple of times buy did not find an answer. When you state the .300 Allen Express will drive a 200 grain Accubond 3400 fps in conventional length barrels-is 26 inches "conventional"? Thanks for the teaser.
Camshaft
Well-Known Member
From what I have seen on this site conventional is 28"-32".
Rocky Mountain
Well-Known Member
Quote from his first post.
I used Hodgdon BL-C(2) powder, filled the cases full to the case mouth and find the case capacity for each.
I did the same with my 338-416 imp and came up with 52.5gr Ball powder(jamison 416 perant cases)
kerby is hoping for 53grs (Ball powder case volume) in his 338 Excalibur Kerby imp I carn't see how he is going to get any improvement than I'm already getting 3050-3120fps depending on powder and barrel length used????
I'm using N570 and jamison 416 brass, 300 SMK and getting good case life at 3090fps, US869 will easily get 3100fps + with same good case life, this barrel is 30 inches long.
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Long Time Long Ranger
Well-Known Member
Rocky Mtn, The Excalibur case is slightly bigger than the 416 case we have been doing for years. I am not doubting you just wondering how you improved it to get the case capacity. Kirby said he cut the angle back and that could have decreased powder capacity back down to the 416 imp. Without seeing both designs I don't know so just asking.
Rocky Mountain
Well-Known Member
Rocky Mtn, The Excalibur case is slightly bigger than the 416 case we have been doing for years. I am not doubting you just wondering how you improved it to get the case capacity. Kirby said he cut the angle back and that could have decreased powder capacity back down to the 416 imp. Without seeing both designs I don't know so just asking.
I am unsure of the case measurements of the 338 Excalibur and was just interested in comparing its extra volume to my 338-416 imp and was shocked to find the same case volume Kirby was talking about for his new 338 Excalibur so that is why I asked the question. Dose anyone know the base, shoulder and length measurements of the 338 Excalibur?
One sight on the internet said you can make 338 Excalibur case from a 338-378 ?? which doesn't sound any bigger than what I've already got, dose anyone now the truth be interesting to know.
It is possible that I have measured my case to the wrong height with ball powder as I just filled the case, hopefuly someone can put some light on all this gray area
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Camshaft
Well-Known Member
.338 Excalibur
The a square design is based off of the 460 weatherby case. The 378 weatherby case as far as I know is a one off with no parent.
The a square design is based off of the 460 weatherby case. The 378 weatherby case as far as I know is a one off with no parent.
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Long Time Long Ranger
Well-Known Member
I think the old A-square you could make out of a 378 wby. The new one called the Excaliber is on it's own rocket ride and a huge non-belted case.
Camshaft
Well-Known Member
I think the old A-square you could make out of a 378 wby. The new one called the Excaliber is on it's own rocket ride and a huge non-belted case.
Yea the 338 Excalibur replaced the 338 a-square mag, which is what I think rocky mountain is thinking of.
Rocky Mountain
Well-Known Member
Dose anyone know the base measurement of the 338 excalibur???
be interested to compare to the 416???
be interested to compare to the 416???
Camshaft
Well-Known Member
.580 from jamisons website.
358sta
Well-Known Member
Kirby - Not sure where you are getting your A-Square Excalibur brass prices from as I purchased 100 cases directly from A-Square about a year ago and paid $4.00 a case. I just checked A-Square's website and the current cost of Excalibur brass is $40.25/10, $4.02 a case. Not sure where you found it for $6-$8 a case. I would agree that the A-Square brass leaves a lot to be desired and am glad to hear that Jamison is now offering it.
RM - I think you'll find the difference in case capacity between the Excalibur and 338-416 Imp lies in the length of the body. While one could use 338-378 Weatherby brass to make Excalibur, it would end up being shorter in length than the Excalibur case and the belt would have to be turned off. In short, there isn't an easy way to make Excalibur brass from another. Diameter at shoulder 0.566", length from head to shoulder/body junction 2.450", length to shoulder/neck junction 2.633", overall length of case 2.990".
My father and I both have 338 Excalibur rifles. My father's is built around a Ruger #1 in order to go with a longer barrel with muzzle brake and still have a cartable hunting rifle. He shoots 275 gr. Swift A-Frame bullets at 3025 fps from a 27.5" barrel. Mine is built around the Lawton 8500 action, single shot, right bolt/left port. Barrel is 36" plus custom muzzle brake. I'm shooting 300 gr. SMK at a little over 3000 fps.
Kevin
RM - I think you'll find the difference in case capacity between the Excalibur and 338-416 Imp lies in the length of the body. While one could use 338-378 Weatherby brass to make Excalibur, it would end up being shorter in length than the Excalibur case and the belt would have to be turned off. In short, there isn't an easy way to make Excalibur brass from another. Diameter at shoulder 0.566", length from head to shoulder/body junction 2.450", length to shoulder/neck junction 2.633", overall length of case 2.990".
My father and I both have 338 Excalibur rifles. My father's is built around a Ruger #1 in order to go with a longer barrel with muzzle brake and still have a cartable hunting rifle. He shoots 275 gr. Swift A-Frame bullets at 3025 fps from a 27.5" barrel. Mine is built around the Lawton 8500 action, single shot, right bolt/left port. Barrel is 36" plus custom muzzle brake. I'm shooting 300 gr. SMK at a little over 3000 fps.
Kevin
358sta
Well-Known Member
As far as the Excalibur's origin, it is a 300 Pegasus (A-Square creation) necked up to 338 caliber. A-Square's manually doesn't go into much detail about where the Pegasus case dimensions came from. They were looking to get a 180 gr. 30 cal. bullet up to 3500 fps at safe pressures and the Pegasus cartridge is what came out of that endeavor.
Kevin
Kevin
