Does anyone know what the average case capacity of a 338LM is in water? Sources vary from 108 to 115 and that seems to be too big a variation to account for brass thickness, so I do not want to trust published tables. I do not have any readily available to measure. If anyone can measure what theirs actually are, I would appreciate it.

I have been told this cartridge failed to meet specs on initial attemps due to weak cases - supposed to do 3000fps with 250 gr bullets. The cases were then strengthened, i.e. 'thickened', until these specs were met.
This is the most precise data I can find:
"Extremely thick-walled brass results in a 7.402 ml (114.0 grains) H2O cartridge case capacity for the .338 Lapua Magnum. The exterior shape of the case was designed to promote reliable feeding and extraction in bolt action rifles and machine guns alike, under extreme conditions."
Not sure of the source as it is a quote of a quote but think it may have come from Wikipedia.
Hope this helps.

Hi Gerard,
Ditto TrapperP.

I have two rifles in .338 Lapua mag., and have wildcatted the .338 Lapua Mag. some: .375, .423, .458, and a .395/.338 Lapua Mag. and .300 Lapua Mag (standard CIP) in progress at the moment.

I have detailed records of weighings of gross water capacity of fireformed .338 Lapua Mag. cases from different lots of that made by

1) Lapua
2) Norma

I would be happy to dig up the data and share it with you if you will but answer this two part question:

Any word on getting .395 bullets to Neal Shirley and a .395 barrel to you?

IIRC, the data I have shows about 114 to 117 grains of water gross for the the different makes of brass I have on hand. But I would have to consult my records to be sure.

I do have a picture of a sectioned Lapua case head versus a Norma case head too ...

IIRC

Gerard,
5 cases each of 3 lots, after fire forming with spent primer in place:

1. Norma made .338 Lapua Mag.:
brass weight = 345.1 grains
gross water = 114.9 grains

2. Lapua made .338 Lapua Mag., Lot "A":
brass weight = 337.2 grains
gross water = 117.1 grains

3. Lapua made .338 Lapua Mag that has been fire formed to .375/.338 Lapua Mag.: Lot "B":
brass weight = 349.8 grains
gross water = 116.7 grains (but increased by necking up)

The variation of brass weight within a single lot of Lapua brass was the smallest of any makes I have ever measured. However I did find two distinctly different lots, A and B, by brass weight.

Saeed has quoted 114 grains here as a generic .338 Lapua case capacity.

You can use that number to be on the conservative side.

Or you can use the 115-grain number that you found as a more average number for calculation purposes across the variety of brass.

Now what about those bullets and that barrel?

the lapua brass lasts a long time in this round.

Thanks Guys, I am going to go with 114gr as the safe bet. I started with 108gr as per Quickload but went nowhere fast.

RIP
Neal has extended his order and we are running some of it at the moment, but it will be faster to mail to you direct. I will have a tracking number early next week or die trying to get it.


I have done the forms for the barrel(application to import) and have arranged for an importer close by to handle the barrel when it arrives. First step is the import permit. I have a P14 action and will be using an Armtec stock, probably a thumbhole, to keep the middle finger away from the back of the trigger guard. The rifle will be braked and scope base and rings will be custom made. I cut the rings from the blank below and bases are one piece rails.

Thanks, Gerard.
Keeping the dream bore alive.

Yours:


I can respect that, especially on a .395 GSC.

I've got an ARMTEC on a .375/.338 Lapua Mag. aka 9.5x69mm Tornado. Mine is on a CZ 550 Magnum, but here is a pic of the stock they list as the "Jeffrey" model, not the usual "Jeffery" spelling:


Sounds like you are putting together an excellent platform for all kinds of field testing of the ".395 Trio" of bullets.

Hey RIP,
Any cast off in that ARMTEC stock?

LD

Bro'Dart,
I never paid any attention to cast-off there. I got the stock used from Nickudu. I like the feel of it. Will cheek and check.

I have not tried getting any from RSA. Since we have McMillan in USA.

It has some imbedded aluminum pillars, and even an aluminum bedding block for the recoil lug contraption on the barrel of the standard CZ 550 Magnum Safari. This got glassed over on my Lilja-barreled 9.5 Tornado.

ArmTec stocks remind me of Bell and Carlson stocks with aluminum pillars and bedding blocks, and molded checkering panels ... and that is fine.

I would go with ArmTec or McMillan, whichwever I could get first.