Is Starline 45-70 brass weak in the expansion-ring area?

[BigBrass]

I handload fairly stiff loads for my Marlin 1895 using Starline brass. Recently, I have been trying neck-sizing and partial full-length sizing. This weekend, at the range, I experienced my second complete case-head separation, in the area of the expansion ring. The load was 60 grains of Ramshot X-Terminator, with a Barnes 300 grain X Bullet. I had worked up that load previously, and had not experienced any problem with it. It should be a safe load in the Marlin, although it is near the upper end. The brass had been fired 7-8 times before, and trimmed about three times.

This makes two recent case head separations and two other instances in which a crack appeared after firing in the expansion ring area (not all with the same powder or load). In each case the brass had been fired several times; but it had not been showing any external evidence of distress. I am trying to figure out what is going on. Your opinions would be appreciated.

I have been using Starline brass because it is thicker than Winchester, and I had thought that it would last longer. Is it possible that despite the extra thickness, Starline is more brittle, and is weak in the area of the expansion ring? Is is possible that neck-sizing or partial full-length sizing has something to do with this? (I had thought that neck- or partial full-length sizing would be easier on the brass. Could it be having the opposite effect? ) Is it possible that when the loads are at max for the Marlin, we simply cannot expect the brass to last for 7-8 firings?

[RugerCal480]

When I flew scale model airplanes (valued between $1000-$2000+) guys would try using batteries 4-5 years. Batteries cost about $18.95..... Is that economical or DUMB? Go figure....the same applies for brass....yes, you might be able to get 10 loads from it, someone may even claim 20,..... but 4-5 loads is a lot safer. How much is a hand, face, eye, life, gun. scope.... worth to you? $20 for 100 pcs of brass??
If you are shooting the same ammo from the same gun...accuracy is better if you don't full size the brass. On a straight walled piece of brass you really shouldn't need to size the case at the opening everytime unless it really exceeds specs. Trimming the brass may be needed after shooting it 2 or 3 times or when it exceeds specs and would otherwise cause a jam. I know reloading saves money...but good sense should outweigh frugality by 100 to 1.

[BigBrass]

RugerCal480: Thanks for your comments. I agree with you that it is "dumb" to use brass for more firings than it will handle. I had assumed, though, that it would handle 7-8 firings in the 45-70 without coming apart, even at the upper levels of pressure in the Marlin. I had also assumed that Starline would have an even greater margin of safety than Winchester, because it is thicker. I am trying to figure out if those assumptions are wrong. I would appreciate hearing about that from anyone who handloads at the upper end of the pressure scale for that rifle.

[1895GG]

BigBrass, I don't have loading manual info for your particular load, so I don't know how "hot" it is. However, comparing two loads, both being the same except for the brass, the thicker brass will produce higher pressure (same outside dimensions means less volume inside for thicker brass, therefore higher pressure). This does not mean it is the only factor, but could contribute to shorter brass life. By the way, Starline is my favorite brand and from what I understand, one of the best quality brands of brass available.

[big medicine]

Cant comment about the starline brass, have never used it. I can tell you that I have used the Federal Nickel cases and they hold up great. I started with 100 cases in 1998 and have 99 left. I lost one out hunting. I dont count the number the of times I load cases, I toss them when they split or look stressed. My 45-70 gets shot a lot with stout loads. The brass has help up well.

[Masterifleman]

I have used Starline brass and consider it to be at least the equivalent of Federal, Winchester or any other. Garrett Cartridges uses Starline also and he has some tremendous loads in his cartridges. I would recommend it to anyone.

[Masterifleman]

I have used Starline brass and consider it to be at least the equivalent of Federal, Winchester or any other. Garrett Cartridges uses Starline also and he has some tremendous loads in his cartridges. I would recommend it to anyone.

[reflex264]

I have personaly tested with Starline brass up to 50,000cup with no failures.Thats good enough for me. reflex264

[BigBrass]

My loads are not generating 50,000 CUP. I suspect that the brass failures that I have experienced have to do with overworking the brass in the expansion-ring area during the period in which I was full-length sizing those cases, before my recent excursion into neck-sizing and partial full-length sizing. Here is what I suspect is going on. The chamber in my Marlin seems to be cut rather generously, back near where the walls of the case meet the rim. I say this because after firing a new case I get a lot of easily-visible-to-the-naked-eye expansion in the expansion-ring area about 1/4" above the rim. (That's the area where the case transitions from thick to thinner.) There is a-- well, I guess I would call it a symmetrical and visible "bulge" -- all the way around the case at that location after the brass has been fired. Back when I was full-length sizing those cases, my sizing die would work the brass a lot there, in order to resize the "bulge". Recently I started neck-sizing, or partial full-length sizing that brass. I suspect that at some point or another, that area on the cases got worked so hard in the resizing process that it weakened the cases there, and some of them have been failing after only 7-8 firings. What I don't understand, though is this: do you all see the same fairly dramatic expansion about 1/4" above the rim? And is so, why doesn't the same thing happen to your cases?

[reflex264]

Cases loaded in the 50,000 range do show some expansion in this area but shot in my Ruger #1 it is not excessive. I don't have any handy to mic where I'm at but best I recall nothing unusual. Even repeated loadings on my Marlin loads don't have problems at 10 shots. I hate to even post it but I proofed a Marlin with Ruger loads to see what would happen. Even this brass which was new and unfired didn't show an excessive ring. It is possible that your chamber is slightly large. I'm not familier enough with the powder your using to even guess at your pressures. When developing loads for commercial use I stayed in constent contact with the lab. Using their W-W brass data I backed off charges per their instructions. What we discovered was that the thicker Starline cases raised pressures much more than anticipated. Further when Starline nickel cases were used the pressures went up even more. Using data for W-W cases in Starline cases is a no no. Powder charges should be backed off in Starline cases until you reach approximatly the same velocity as the W-W data and then back off a hair more. If I hadn't had access to pressure testing I would have thought I was really accomplishing something with higher velocities. Where did you get the data from? reflex264