Help Please - External Dimensions of 338 Win Mag Case

[Stevesdl]

I have the Frankford Arsenal Digital Caliper.
1. I turn on the tool
2. Set to inches
3. Verify caliper jaws are completely closed
4. Reset to o.ooo (a blinking 5 is in the bottom right corner of display?)
5. Display flashes (not sure if it is supposed to continue to flash)
6. I measure the external dimensions of 5 338 Win Mag cases
A. 2.102
B. 2.101
C. 2.098
D. 2.099
E. 2.100

According to both Nosler and Speers reloading manuals, the maximum case length is 2.500". Speers states to trim to length 2.490" (I did not buy a trimmer or deburrer as of yet)

Something is not right here and here is where I am confused:
1. If I remove the casing from the caliper and just open the jaws barely, the measurement reverts to a lesser measurement (e.g. 2.004)
2. After sliding the jaws open just a tad more I can then see some measurements in the 2.645 range

3. I select MM and test the maximum case length size of a casing. Speers has the case size at 63.50mm

A. 63.54
B. 63.53
C. 63.45
D. 63.46
E. 63.50

Do I have a defective caliper or am I just on bad drugs.

Thanks ahead of time
Steve

 

[DrMike]

Stevesdl,

It sounds like a faulty caliper. I'd contact Frankford Arsenal. If there is a step that you are omitting, they will be able to tell you. It is not obvious from what you have written, however. You are correct that you will want to purchase a case trimmer at some point. The Redding 2400 is one really fine model that permits reproducibility with needing to buy shell holders.

 

[Stevesdl]

Seeing it was brand spanking new, I did not think to change out the battery. Usually these little batteries (like watch batteries) last for years.

Changed out the battery after reading your post that this was not correct behavior and the caliper is now working.

So I remeasured and some are over the maximum of 2.500 and some are over the 2.490 recommended length, so it looks like I have to trim just about all of them to 2.490. That has to be a tinee bit of trimming? Going to go look at your suggested trimmer.

Should I be considering "annealing" for longer life with these 338 Win Mag cases? According to Speers manual, this cartridge is not know for long case life.

Thank you DrMike
Sincerely
Steve

 

[JD338]

Steve,

I would start out with just resizing the cases and loading them.
After 2-4 loadings, you will need to trim and maybe anneal the cases.

JD338

 

[DrMike]

I didn't consider the battery because you reported that it was working fine on the mm setting. Glad you worked it out. Usually, you don't need to trim on the first firing of a case. It is possible that after the first firing you may need to trim, though that would be unusual. The case will stretch to fill your chamber, but the neck should not stretch excessively. JD338 has given you good advice. There is little need for the average hand loader to complicate matters. As you gain experience, you may make the decision to become very precise, but more likely you will learn where to be precise and where to be relaxed based upon your own needs and style.

 

[Stevesdl]

Hi DrMike,
yup the mm side of measure worked just fine but the inches was really messed up. I did reset the tool and removed battery, waited 30 seconds, and then replaced before I wrote the post though. I should have known that blinking display was not a good thing.

I remeasured 5 shells and majority are over 2.500 or very close to it within 1-2 thousands so I am just going to try to approach this perfectly right and "perfect" as I can the first time and trim to as close to 2.490 as possible once I get my new trimmer. All these rounds are Federal Premium 338 Win Magnum 225 Grain Nosler AccuBond. Now when I tumbled them, I did not separate casings per separate box lot so there are 60 shells mixed together. Perhaps I should look at them before tumbling?

I see JD and your comments regarding trimming and annealing and will use them in my brain's database. Very good thoughts and veteran comments to apply.

One last thought Dr. Mike. I researched trimmers and found that Wilson's trimmer with a micrometer was also reviewed very highly. In addition the Redding Trimmer got more than just 1 or 2 bad reps from those stating that they could not get "close consistent same length" trims? Have you found this to be the case or is it just that they are not approaching their step by step in trimming correctly? Both Trimmers are around $140.00.

Thanks
Steve

 

[DrMike]

The Wilson is an excellent trimmer. I have had no problems with my 2400. You do need to ensure that you lock the thumb screws. The RCBS and the Forster trimmers work well also. Any will work well, I should imagine, if we do our part.

 

[SJB358]

Mike, I have the older style RCBC trimmer and it works fine for me. Pretty consistent if I pay attention and keep my eyes fixed on my work. Another note, I have those same Frankford Arsenal digital calipers and they never read exact. I ended up setting them aside and just getting a pair of Lymans with a dial. Still very easy to use and seems to allow more precise measurements, and no batteries! Either way, looking forward to seeing your first loaded rounds. Scotty

 

[DrMike]

I still have the older style RCBS case trimmer on my bench. It works very well. I had the opportunity to upgrade some time back to the Redding 2400, and I really like it. It moved to the front of my bench. I purchased a dial type calipers many years ago, and I just purchased another. The digital are fine, but the cheaper ones can mislead an individual.

 

[SJB358]

Yeah, I learned how to use calipers with a dial, but thought the digital would be easier. All in all, I should have saved my duckets and just stuck with the dial! Easy to use and always accurate enough for me. Digital always leaves me guessing if something is messed up. Scotty

 

[DrMike]

Moreover, I prefer my micrometer to have a vernier! Easy to calibrate and quickly read.