Longevity of plastic Smith carbine cases

[Hal]

How many shots should you expect to get from the plastic Smith carbine cases? I've not been keeping track, but I had 3 of them split on me yesterday. The first one I noticed was sitting bullet down in a cartridge box and I noticed a split from the flash hole around and partially up one side of the case. After that, I began checking each one before I fired them. Subsequently, I had two more split along their side when I fired them. Like I said, I've not been keeping track of the number of times I've fired each case, but I would estimate that it has only been 5-6 times. I would have expected them to last longer than that. Am I being unrealistic?

[ms3635v]

Since I started putting the hollow brass rivets in the flash hole of my plastic Smith tubes I haven't had any issues. Some of the cases with the rivets have been fired 15 to 20 times and they are still fine. The Northeast Trader, John DeWald, sells bags of 100 for $5.00.

[Hal]

I'll look into that, as that might have prevented the split in the first case that I noticed before firing. But after that, I experienced 2 more failures in the sides of the cases. These splits did not affect the flash hole. They were limited to the side wall of the case.

[jonk]

I haven't had any split, and some of them are probably fired 10 times. I have found that the neck tension gets bad and the flash hole enlarges before they split.

I don't care for grommets. One more expense, and they require wet cleaning of the tubes after every shoot to keep away corrosion. Plus the time to put them in. Plus they restrict the flash channel on a gun that already has iffy ignition; it really needs a hotter cap than what is available these days.

There are a number of resizing tools available that will bring the plastic back to size. My rule of thumb is, when 2f powder starts leaking out the flash hole, toss it.

If you resize after every firing, I could see that leading to split cases quickly.

[marv762]

my son being cheap has shot the same tubes for three years. he just bought new tubes last year.

[Hal]

You guys' experience, plus what I have read on other sites (One said you could expect 100 shots from them), make me wonder if I might have gotten some bad ones. While I'm certainly no expert, I used to work at a place that bought several injection molded parts that went into our product. We had to specify that the injection molding company not put over a certain percentage of "Regrind" (Ground up bad parts, sprues and runners, and such) into the parts we bought. If they did, the parts would be weakened to the point of early failure. I have no idea if that is what is happening with my Smith cases but I could see how it might cause a problem in this application.

I was not aware you could, or even needed to, resize the plastic cases.

[Michael Bodner]

I resize the plastic tubes after I load them. It 'seems' to help when inserting them into the chamber. But that might be wishful thinking. It certainly is not stressing the case or leading to early failure.

My experience shows that the inner diameter of the tube wears to the point that the bullet won't stay in dependably. The flash hole also wears out, but I always put a small hole-punch of waxed paper on the bottom before I load the powder (even new tubes) to prevent leakage...

I use the bullet-holding power of the tube as my only criteria for keep/toss. The waxed paper takes care of leakage regardless of the hole size. I'm estimating between 15-25 uses per tube (?)

BTW: You do NOT need to puncture the waxed paper before use. It burns through easily enough...

If the sides of your tubes are splitting, then you've got bad tubes OR they are too small for the chamber and are expanding too much. I presume your tubes a just under the diameter of your chamber...

Good Luck!!

-Mike

[John Holland]

Hal is correct about the "regrind", which is what has happened to the current generation of black Smith tubes. The original formula used when Roy Shaw first marketed the tubes made a product which was nearly indestructible, and they did not burn out, shrink, or expand. Roy passed away and today the quality of the product has been so denigrated you have to replace them every season. I don't know if this is intentional or not.

[jonk]

Makes buying brass or SS tubes look more attractive. Yeah, they're 4 times as expensive, but cry once and within a few years you're ahead.

As for covering the flash hole, be it with a small sticker outside or wax paper or whatever inside, I tried it. If I were using 3f, it would be needed. With 2f, which is what my gun likes, it isn't for a while. I did find though that the gun's already iffy ignition was made almost impossible by doing so; gun has a clear flash channel and I even opened up the nipple a tad. It's the damned weak caps... even the RWS ones often fail to touch off my sharps or smith, at least one time out of ten. I have a few tins of old copper navy arms caps made in england that go boom instantly and every time, and the old CCI 6 wing ones did too. But, each gun and each flash channel is different, so it's something each shooter needs to work out for himself.

As to sizing, yeah, there are some combo sizing/seating tools out there. I use it for sizing only, when the bullet starts to get loose. While some of the problem is erosion of the case itself, some of it is the swelling of the case. I don't use it regularly as I find it makes seating the soft lead bullet hard, and it reduces the diameter of the bullet 1-2/1000," which may or may not impact accuracy, I'm not sure. But it's a good tool to have.

[Jim Barber]

So am I the only Smith skirmisher left who uses rubber tubes affixed to a metal base? I eventually learned that the rubber tubes need to be replaced. The rubber metamorphosalizes into an unstretchable, steel-like material over a period of years, making loading bullets into them an exercise in thumb torture. Slipping new rubber tubes (cut to length on a lathe) onto the bases (Thanks Mike Rouch!) solved that issue, with minimal expense (again, thanks Mike!)

Perhaps someone with some machine shop tools ought to get rich quick making new metal bases. Mine, which my dad gave me, are of two types. One appears to be brass, the other is a horrific metal which can both rust (when exposed to water) and develop bluish corrosion (when exposed to pretty much anything). I dunno what that metal is. Strange stuff. For those who haven't seen these things, they're a short (~1/2") cylinder with a cup and a flash hole machined into them. They're sized so the rubber tubing friction fits onto them small enough to allow the whole mess to fit inside the breech channel. The brass bases, as near as I can tell, are totally indestructible. I suspect they're rather old, at least 20 years and maybe much older. They never require pliers, channel locks or brute force to remove from the barrel.

Cheers!
Jim B.
Grove City, OH