30-30 Case Life Test

[LeverGunner]

I posted this on the Castboolit forum originally (2019), but after reading another thread here though it'd be of interest.

I posed the question of "How many loadings to expect on full length sized 30-30 brass?" sometime back. The responses I received were anywhere from "not many" to the usual suggestion of "why full length size when neck sizing is better for brass life".

So I decided to do a little test. I took a once fired winchester case and loaded it until failure, keeping a record of each loading. I marked it's head with 4 file marks so I could easily distinguish it. I loaded it anytime I loaded a batch of 30-30, and sometimes loaded it singularly as well.



The case was full length sized after each firing, and then measured. From the first trimming until the case grew past the maximum length it wasn't trimmed. Then, it was trimmed to minimum length after each firing. Sometimes the trim length was short due to my inconsistent use of the trimmer or using the test casing to set the trimmer. I inside chamfered and outside deburred every time the case was trimmed. A roll crimp was used every loading. I did not anneal the case during this test.

The gun is my Winchester 94 30-30 made in 1970.

Tools used, Lyman FL sizing die set (a few times I used a CH FL sizing die but did not record which times), Lyman M die, lyman universal case trimmer. I used both a Lyman Spartan and a Lee hand press. For lube it was imperial sizing wax or Hornady one shot with no recorded distinction. RCBS calipers.

Cast bullets were all from air cooled, clip on wheel weights, sized .309 with Hornady gas checks. Lube was BAC on the Lyman 31141, LLA on the Lee 309-150-FN.

Times fired, powder & charge, bullet, length after sizing, trim to length.

1. Factory fired, trimmed to 2.029
2. W748 29.0 gr, Lee 309-150-FN, 2.029
3. W748 29.0 gr, Lee 309-150-FN, 2.032
4. W748 29.0 gr, Lee 309-150-FN, 2.032
5. W748 29.0 gr, Lee 309-150-FN, 2.035
6. W748 29.0 gr, Lee 309-150-FN, 2.036
7. W748 29.0 gr, Lee 309-150-FN, 2.0365
8. W748 29.0 gr, Lee 309-150-FN, 2.038
9. W748 29.0 gr, Lee 309-150-FN, 2.039
10. W748 29.0 gr, Lee 309-150-FN, 2.041, TTL 2.027
11. Misfired factory bullet & powder, 2.032, TTL 2.028
12. W748 34.0 gr, Lyman 31141, 2.027, no trim
13. W748 32.0 gr, Lyman 31141, 2.029, TTL 2.026
14. W748 32.5 gr, Lyman 31141, 2.027, no trim
15. W748 32.5 gr, Lyman 31141, 2.031, 2.029
16. W748 32.5 gr, Lyman 31141, 2.032, 2.027
17. Unique 9.2 gr, Lee 309-150-fn no GC, 2.030, TTL no record
18. W748 32.5 gr, Lee 309-150-fn, 2.030, TTL 2.028
19. W748 32.5 gr, Lyman 31141, 2.032, TTL 2.028
20. W748 32.5 gr, Lyman 31141, 2.029, TTL 2.028
21. W748 32.5 gr, Lyman 31141, 2.029, TTL 2.027
22. IMR 3031 27.0 gr, Lyman 31141, 2.030, failure

That is a total of .040 trimmed off by my figuring, giving a value of .003 for number 17 which I forgot to record the trim length.

After load 22 was fired, I resized using a Lyman full length hand die. After sizing, inspection revealed a crack on the shoulder. I decided to size with the hand die as the base of the body just above the web was slightly bulged and beginning to chamber with a slight resistance. This was the only time using the hand die, and I wonder if it caused the crack prematurely. Probably not.



After each firing I carefully inspected the case for cracks and defects. I paper clip tested many times, and every time when I started getting up in firings. The primer pocket remains tight.

I started this test with the intent to record the number of times fired between trim to length and max length. It then turned into a longevity test. Obviously this isn't conclusive as it dealt with only one case of one manufacture. Not to mention the variables I introduced with varying trim lengths, size dies (mostly Lyman), presses used, and case lube used. It has been fun for me, and I've learned that full length sizing is not the 5-8 load brass killer I've heard, at least in my chamber with my dies, and my loading techniques.

Using a 357 magnum case as a comparitor, my die is moving the shoulder back .039. I still have some ammo that was loaded back when I did this test, and the test case was probably loaded in that batch even. That older loaded ammo, and a newly sized case both measure the same .039 of setback from a fire formed case. I checked to make certain that the shell holder was indeed bottoming out when sizing as I have some spring in my press. I was quite surprised at this level of movement and the amount of loading cycles I got before failure. 

That brings me to another facet of the test, how much can I trim off before I need to worry about the brass thinning and incipient case head separation. Of course that would depend on the thickness of the brass, which will vary from lot to lot and manufacturer. The Lyman manual in a round about way suggests that .060 is the safe cut off spot.

I eventually plan to do a test of 3 cases, and record the group size for them to see how that changes over the course of their lifespan.

[45MAN]

REMINDS ME OF A SAYING I LEARNED IN THE ARMY BACK IN THE 60's: a short pencil is better than a long memory. VERY GOOD REPORT.

[Fowler]

Shooting cast bullets in 30/30s is about as much fun as you can have with a rifle, mild loads, no recoil, lots of fun, cheap to feed.

The biggest variable I would see in this test is the chamber of your rifle and your die matching that chamber fairly well. A lot of 30/30s have a rep for sloppy chambers but then I have a number of cases that I have shot many times with these mild cast bullet loads.

[LeverGunner]

Loads 2-10 were mildish, but the other loadings were full power, not mild by any means.

I do enjoy working with the 30-30. It's a joy to both carry and load for.

[lar4570]

That is a pile of reloads on a single case.
I think where you run into case head separation with full length resizing is with rimless cases.

With a rimmed case, 30-30, the body of the case is held in position by the rim. When you fire it, the case will expand forward to take up any slop between the shoulder of the cartridge and the shoulder area of the chamber. So when you are full length sizing, the shoulder is getting worked more each time. It probably became work hardened and is why it split.

With a rimless case, 30-06, The body of the case is held in position by the shoulder. When you fire it, the case gets knocked forwards in the chamber until the shoulder stops it, then it expands rearwards until the base of the case meets the breach face. Most of the stretching happens near the head. So with repeated full length sizing, it will stretch in the same place near the head each time until it becomes thin and brittle and separates.

At least that's the way that I see it.

[Encore64]

From my experience, case head separation has two main causes.

A "springy" action will cause premature case head separation regardless of case design. Unfortunately, the unknowing usually blame this on weak cases.

The other cause is repeatedly setting the shoulder back during reloading. This is well known by long term TC Contender Shooters.

Like the O.P., I'm a huge fan of the 30-30 Case.

This was an excellent test and passing on of accurate information.

Kudos!!!

[bigbore5]

That's good case life. If you're like me and load a thousand at a time, you'll get a few years out of your cases for certain.

[Fowler]

Aug 30, 2024 22:14:09 GMT -5 LeverGunner said:

Loads 2-10 were mildish, but the other loadings were full power, not mild by any means.

I do enjoy working with the 30-30. It's a joy to both carry and load for.

Not knowing your load off the top of my head I didn’t know how hard you leaned on that load. I seldom run cast to even 2000fps, sort settled on 2 cast loads for my old Win, that 150gr Lee powdercoated and running 1250fps I’d guess as a plinking small game load and the 180gr RCBS that drops more like 190gr PC and gas checked at 1850fps or so.

I lose very few cases loading the 30/30, I am a bit lazy and have never trimmed a 30/30 case so the mouth flairing can sometime be a little inconsistent causing split mouths. But these are for fun plinking/steel plate shooting so I am not trying to get perfect accuracy out of the gun.

I have a bag or 2 of new unfired 30/30 cases in the stash. It would be a fun test to see what could be done, perhaps one load at plinking level and one case at full power hunting level load and see how they hold up. But unless I drag all of my reloading stuff to the range it would take years for such a test. Fun to think about at least

[LeverGunner]

Thanks for the kind words all.

I think this took me about a year to compile. I have owned this rifle since 2015, right after my house burnt. I got it and tinkering with it helped me to cope. In that time I've shot at least 4 pounds of powder through the gun, mostly W748.

It helps that I live on farmland where I can go out my door and shoot, and I'm mighty thankful for that.

[boolitdesigner]

Your statement: The primer pocket remains tight.
Is unimportant as that occurs about 1,700 firings. If you don’t rework the case, the primer pocket will become loose before the case gives up.