Different cases

[Fyodor]

Actually I've never seen a tangential crack that far up on a case. They usually happen just above the case head. At that portion of the case the cracks I've seen usually are along the case. Did you cut the case open and see what it looks like from the inside at that spot?

[Ranch Dog]

Actually I've never seen a tangential crack that far up on a case. They usually happen just above the case head. At that portion of the case the cracks I've seen usually are along the case. Did you cut the case open and see what it looks like from the inside at that spot?

No I haven't, got busy with other things today. I took a fine wire and could not feel anything on the inside of the case.

[Model 52]

A few comments:

The differences in US made 5.56mm NATO and US made .223 commercial brass are insignificant. You'll find as much variance within a brand as between them or between military and commercial brass. BHA for example mixes the head stamps in their blue box ammo and the accuracy level they achieve is still outstanding. I don't bother sorting 5.56mm/.223 brass by head stamp unless I am planning on really focusing on maximum accuracy in a load and particular rifle.

7.62mm NATO brass is different. It is significantly thicker walled than commercial .308 brass.

I don't bother sorting most pistol rounds either. In some rifle calibers it can make a difference. You can determine that by weighing the water capacity in cases, but be aware there will still be some variation so you need to weigh a sample of 30 or so cases from each head stamp to get a relabel average, and then the resulting standard deviation in each sample will tell you if the results are statistically significant. Or in practical terms, load up rounds in each head stamp and run them over a chronograph to determine if there is any significant differences in velocity. If not, you can freely mix those head stamps.

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I visually inspect my brass for defects and I will put long in the tooth brass into boxes that I anticipate will not be recovered after firing (tactical matches, hunting, etc). However I do not retire brass at a fixed number of firings. I shoot it until it cracks or fails.

Cracks in the sidewalls look scary but they are occurring ahead of the point in the case where the brass seals against the chamber wall, Even in the case of a total head separation, the gas will still be contained as the point of the separation is still sealed in the chamber.

The only rifle case failure I've ever encountered resulting massive gas in the action with was a TW 73 5.56mm NATO M193 case and it was a new case that happened to have a soft head from an error in the factory annealing process.

The only failures I have had in pistol cases that resulted in any gas in the pistol were a batch of once fired cases that failed right above the feed ramp in a high power, and then it was a noticeable event but not a damaging event. They came in a large batch of once fired brass and I pulled all of them out of the batch after having a couple of them fail.

[Ranch Dog]

Actually I've never seen a tangential crack that far up on a case. They usually happen just above the case head. At that portion of the case the cracks I've seen usually are along the case. Did you cut the case open and see what it looks like from the inside at that spot?

The only time I've seen it is a complete separation aft of the shoulder with the 30-30 AI. The crack wasn't as clean of line as present on this 35 Rem case. I did not have any problems removing the top half of the case from the 30-30 AI's chamber, ran a brush on a cleaning rod through it from the chamber end and pulled it right out on the return. Chamber was as clean as a whistle. I had a lot of case failures and short case life with the AI and that case is a lot like the 35 Rem.

I'm not sure it is a crack as there is no evidence of it inside the case. I've got an inquiring mind so I shot it again at the same 40.0K PSI load. It is less evident now so I decided to press on with the loading cycles on this brass lot. Shot into round 13 for the brass yesterday afternoon.

I was looking for the case that seperated in my junk bin but could not find it but found these two typical samples of failure.

split_cases.jpg

Like I noted with the 35 cases, I've been recording some specifics that my reloading software requires for computations. I did this at the when I started using this lot and have done it in increments of 5 cycles. I went ahead and recorded the case length and depth, rim thickness, and the weight of water the case holds. Here are the screenshots at the first cycle and then the twelfth cycle.

I've done quite a bit of searching and reading and the general consensus is that 35 Rem brass production is dead. All the sources of once fired brass are gone as well. If I can go 12 cycles with what brass I have, that means I have about 2800 shots left. I've got to feed this CVA for Joe and my Marlin 336D so I'm probably going to cancel my purchase of the CVA CR5804.

[62chevy]

Is it possible to turn a .308 or 30-06 into a 35 Remington?

[Ranch Dog]

Is it possible to turn a .308 or 30-06 into a 35 Remington?

I suspect you could but the 35 Rem is it's own genesis. I've had to make cases in the past for the 219 Zipper, 30-30 AI, and 405 JES and decided then that I would never get to that point again. I end up not shooting the rifles.

[Ranch Dog]

I redid the case data. I realized that I needed to take all the appropriate measurements, not just the case length and depth, and the water capacity. Here are the difference of the two.

RP01_01.jpg

RP01_12.jpg

I was very careful in all the measurements but the bottomline is that over 12 cycles of the brass, not much has changed. There is a bit more thickness at the web and less at the neck but that is a good thing. Honestly, I feel that the brass probably has a lot of life left it and will continue to monitor it and see what changes. Will take the measurements again at the 15th cycle and see what changes have taken place

TMT's Arms & Load Development Pro has some great features. Here is a image of the sectionalized cartridge, bullet, and load.

TLC359190RF.jpg

[akuser47]

Nice write up thanks RD