Reality Check on 338WM loads

Scoony

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Oct 5, 2017
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Starting some load development on a new to me Ruger #1 in 338WM with a 26” barrel.

The first loads I fired were what is printed on the H4350 can of 69.5 grain with a 225 SP. Listed velocity for that load is 2785. I loaded 10 of these rounds to get the scope zeroed. Actual velocities averaged 2883 fps with a SD of 12.7 for 6 of the rounds I fired.

I also had a 10 round ladder test with 230 ELD-X and H4350 which gave these results:
68.3 - 2821
68.6 - 2860
68.9 - 2882
69.2 - 2873
69.5 - 2889
69.8 - 2913
70.1 - 2924
70.4 - error
70.7 - did not fire
71 - did not fire

Chronograph was set up right at 15' from muzzle.
That dip right at 69.2 – 2873 fps is the area where I plan on testing next.

All these velocities are right around 100 fps above what the book gives. I am liking these velocities, but need a sanity check before further testing. Published data lists 24” barrels, my Ruger has a 26” barrel so my thoughts are that I am good to go. Interested in hearing from those of you that load for and shoot a 338WM.

Not sure what to look for in terms of pressure signs with a single shot/falling block action other than velocities and maybe hard to extract?? With a bolt gun, I look for ejector marks, hard bolt lifts, pierced or popped primers, as well as velocities.
 

tdot

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Aug 18, 2014
Messages
339
Do you know your Chrono is accurate?

From the testing I've read 2" of extra barrel in a 338wm would likely yield a 50fps gain at max.

How does your COAL compare to the load data? I've had fast loads when I was able to load more powder due to a longer throat then SAAMI.
 
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Scoony

Scoony

Senior Member
Joined
Oct 5, 2017
Messages
217
Location
Ky
Do you know your Chrono is accurate?

From the testing I've read 2" of extra barrel in a 338wm would likely yield a 50fps gain at max.

How does your COAL compare to the load data? I've had fast loads when I was able to load more powder due to a longer throat then SAAMI.
No reason to doubt the chrono. Seems to work fine.

I am loading just a hair over book COAL. I have not measured to the lands yet. Now that I have some cases formed to the chamber, I can make up a modified case to do that.
 

tdot

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Aug 18, 2014
Messages
339
No reason to doubt the chrono. Seems to work fine.

I am loading just a hair over book COAL. I have not measured to the lands yet. Now that I have some cases formed to the chamber, I can make up a modified case to do that.

I have used two optical chronograph's. Both were out by roughly 25 to 50fps after I shot the same loads over 3 different Labradars. It was irritating, cuz 4 different rifles and 7 loads were all slower then I thought they were.

I always use a cleaning rod to know where the lands are before I can make up a twice fired and modified case to confirm and test in the future.


You dont need the little clamps they use, there are other ways to mark the rod. It's generally a fairly accurate method, within a few thousands.
 
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Scoony

Scoony

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Messages
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Ky
Thanks, did not know that kit existed, going to order one asap.
 
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