Ruptured Case

[Skeld1]

I decided to do a little experiment today with my SPS Tactical and some Tula steel case 308. Apparently it wasn't a very good idea. My buddy was on the gun. On the second round, a lot of gas blew back in his face. I opened the bolt and the case was stuck. We removed it by popping it out from the barrel side. Everything seemed ok besides that, but now the gun won't extract very well. Also, when I dry fire the gun the bolt knob will actually pop up about a 1/4" which I don't recall happening before. What's going on here? Permanent damage to the receiver, barrel, or bolt? And what went wrong? I've fired about 200 to 250 of these same rounds out of my DPMS LR308 with no ill effects besides a few that didn't go off. I still have about 200 rounds of this stuff left and I don't know if I should just junk it or what...

 

[GongShow]

Normal for bolt lift on dry fire so disregard that.

 

[Skeld1]

Hmm, alright, well clearly I'm a noob. Hadn't noticed that before. Hopefully just an extractor repair then...

 

[sib1948]

I would dump the remainder of that cheap ammo. You get what you pay for! Cheap ammo=aggravation!

 

[NXS338]

Why would anyone use a steel cased cartridge in anything that isnt a cheap firearm! Why would you stick something like that into a good rifle with a good chamber? Steel case going into Steel chamber is just a bad idea unless its a piece of crap AK or some cheap AR that you don't care about. I would put that crap on internet and dump it!

 

[Skeld1]

I don't think it's much of a problem unless it ruptures. The cases are coated in polymer and I mainly had the ammo for carbine use. At this point I will get rid of it.

From other things I have read since this happened, perhaps this gun has a slightly excessive headspace that aggravates the situation?

 

[biffj]

Why would anyone use a steel cased cartridge in anything that isnt a cheap firearm! Why would you stick something like that into a good rifle with a good chamber? Steel case going into Steel chamber is just a bad idea unless its a piece of crap AK or some cheap AR that you don't care about. I would put that crap on internet and dump it!

Steel cases may or may not be as accurate as match quality but they don't cause any issues with chambers that brass doesn't. Since all the steel cases available are either coated with laquer or some other polymer the steel never actually touches the chamber. The coating is softer than the steel and won't cause scratches or other damage. Its a common misconception that steel cases are bad yet years of testing by numerous govts have shown they don't have any of the troubles normally ascribed to them. I've seen a reasonable number of brass cases that had a head let go and some steel too. Things happen but its not just because its steel.
For the original poster there are a number of things to consider. Make sure it headspaces right. Its possible the shoulders are too far back opening up the headspace. Its also possible it is crap ammo and in that case tossing it is a better idea. Don't blame it cause its steel .... blame it cause its no good.

Frank

 

[cramey74]

There is nothing wrong with steel cased ammo. The only thing that ammo is going to hurt is your feelings when you try to shoot tight groups with it.

 

[Sweetyzfd]

It's actually the bullet that's bad for your barrel. There is steel in the actual bullet......bi-metal

 

[Skeld1]

My understanding is that there is also XM80 spec brass stuff that has bi-metal projectiles, so I don't think that problem is confined only to steel case stuff.

 

[Sweetyzfd]

No...... but most of it has bi-metal bullets. Shortens barrel life

 

[biffj]

No...... but most of it has bi-metal bullets. Shortens barrel life

This is another myth. The bimetal bullets are plated with gunmetal....a combo of copper, zinc and tin. The whole point of this is to place a layer of softer metal against the bore to prevent wear and reduce friction. The test that everyone refers to in order to show that the steel cases and bimetal bullets are bad is a flawed test that gives an incorrect result. So for reality that you can see and touch for yourself go out and recover some of these bimetal bullets and see if there is any steel showing. I find that maybe one out of 100 has any of the copper worn down enough in the grooves to show any steel. If the steel doesn't touch the lands then it doesn't wear any more than standard gunmetal bullets like you get from Sierra, Berger and the others. Now I would not advocate the use of these plated steel jacketed bullets in shooting for accuracy. They weren't intended for that purpose and don't go through the rigorous QC that target bullets do. Point of all this is that steel cases and bimetal bullets get a bad rap that isn't deserved for wear and extractor damage. They don't deserve either of those.

Frank

 

[supercorndogs]

This is another myth. The bimetal bullets are plated with gunmetal....a combo of copper, zinc and tin. The whole point of this is to place a layer of softer metal against the bore to prevent wear and reduce friction. The test that everyone refers to in order to show that the steel cases and bimetal bullets are bad is a flawed test that gives an incorrect result. So for reality that you can see and touch for yourself go out and recover some of these bimetal bullets and see if there is any steel showing. I find that maybe one out of 100 has any of the copper worn down enough in the grooves to show any steel. If the steel doesn't touch the lands then it doesn't wear any more than standard gunmetal bullets like you get from Sierra, Berger and the others. Now I would not advocate the use of these plated steel jacketed bullets in shooting for accuracy. They weren't intended for that purpose and don't go through the rigorous QC that target bullets do. Point of all this is that steel cases and bimetal bullets get a bad rap that isn't deserved for wear and extractor damage. They don't deserve either of those.

Frank

you might want to check out the 10,000 round ar 15 torture test on accurate shooter. the bi metal bullets do in fact were out a barrel faster than copper.
but the amount of money you save on ammo over those 10,000 rounds by shooting the steel cased ammo would buy many barrels.

i used about 300 rounds of wolf to fire lap an ar15 barrel with a significant rough spot in the barrel. the barrel is now smooth and the gun shoots better

 

[biffj]

you might want to check out the 10,000 round ar 15 torture test on accurate shooter. the bi metal bullets do in fact were out a barrel faster than copper.
but the amount of money you save on ammo over those 10,000 rounds by shooting the steel cased ammo would buy many barrels.

i used about 300 rounds of wolf to fire lap an ar15 barrel with a significant rough spot in the barrel. the barrel is now smooth and the gun shoots better

That is precisely the test I was referring to. They had no standard or controls, used different make barrels and rifles and drew conclusions based on info that wasn't comparable. You can't compare apples and tuna so you can't really use any of that to show much of reality. They also beat the hell out of the guns by shooting them continuously til they ran out of ammo or broke them. Temps have a much bigger effect on wear than the bimetal jackets. As the temps go up wear goes up at a much higher rate. On the other hand a number of govts have tested steel cases and plated steel jacketed bullets for many years and come to the conclusion that the wear is similar but the costs are much lower with steel. For their purposes the steel makes a lot more sense. As I've noted previously the steel cases and jackets aren't intended for accurate fire so its not really a comparable for benchrest ammo but its not the wear demon its made out to be either.

Frank

 

[supercorndogs]

they used 4 bushmaster carbines. 1 changed for a spikes because the tula ammo did not make enough pressure to run the bushy.. the governments found just like the accurateshooter test that they saved more on ammo than the cost of the extra wear. not that it did not wear faster. the difference between barrels in the test is negligible. they were the same material chromoly. every steel jacketed bullet wore its barrel out where the copper jacket did not. both wolf and brown bear shot the barrel out at 6000 and the federal barrel was not shot out at 10,000. throat erosion of the wolf and brown bear unlimited at 10,000 fedaral .144. you can lie to yourself and say those results mean nothing but that does not make it so.

 

[rideHPD]

they used 4 bushmaster carbines. 1 changed for a spikes because the tula ammo did not make enough pressure to run the bushy.. the governments found just like the accurateshooter test that they saved more on ammo than the cost of the extra wear. not that it did not wear faster. the difference between barrels in the test is negligible. they were the same material chromoly. every steel jacketed bullet wore its barrel out where the copper jacket did not. both wolf and brown bear shot the barrel out at 6000 and the federal barrel was not shot out at 10,000. throat erosion of the wolf and brown bear unlimited at 10,000 fedaral .144. you can lie to yourself and say those results mean nothing but that does not make it so.

^^^ This. On the issue of steel casings you can have an issue if you have an oversized chamber or undersized ammo, as the steel is not as ductile as the brass and is more likely to fail as the OP found out. Most likely the gas pushed debris under the extractor and is causing issues, if it did not deform the extractor. Alas it is a Remmy extractor so you will have to replace it once you pop it out to clean it, but give it a good cleaning first, stripping the bolt down and popping out the ejector. Maybe that'll take care of it.

The pop of the bolt handle can happen if the handle is forced all the way closed such that the handle contacts the receiver. When the sear releases a torque is applied on the bolt and it can shift around during this process. Close the bolt fully, then tap the bolt handle back up lightly so it's not contacting and see if it does it again (during dry fire). You could also have excess gunk in the bolt now, or some shifted onto the threads, etc. Take it apart and clean it, and this might reduce the bolt handle pop.

 

[biffj]

they used 4 bushmaster carbines. 1 changed for a spikes because the tula ammo did not make enough pressure to run the bushy.. the governments found just like the accurateshooter test that they saved more on ammo than the cost of the extra wear. not that it did not wear faster. the difference between barrels in the test is negligible. they were the same material chromoly. every steel jacketed bullet wore its barrel out where the copper jacket did not. both wolf and brown bear shot the barrel out at 6000 and the federal barrel was not shot out at 10,000. throat erosion of the wolf and brown bear unlimited at 10,000 fedaral .144. you can lie to yourself and say those results mean nothing but that does not make it so.

One poorly run test doesn't mean its a done deal. Look through some of the tests done by the German govt....excerpts can be found in the book "Full Circle, A roller locking Treatise". Have a chat with some machinegunners as well. These guys are about as tough on barrels as anyone can be yet we can't see a difference between surplus gunmetal plated bullets and copper jacketed ones. Barrel wear is measured by the point where bullets begin to hit places they weren't aimed. Do some of your own tests using identical equipment and vary only the bullets to see whether bullets or powder are causing the wear. It is well known that some powders create more throat erosion so why blame the bullet when its a good possibility its the powder. In real life we can see differences in many things but ignore those that aren't convienient.
So as you told me....lie to yourself and believe as you wish.....or do a test on your own and get some useable results. Its always easier to believe someone on the internet than to do actual work on your own.

Frank

 

[supercorndogs]

yea buy me some ar 15s and 10,000 rounds of every kind of ammo there is and i will get right on that for ya. just because you do not like the results of the test does not mean it was poorly run. the difference in throat erosion from different powders is measured in tenths hundredths and thousandths .000 not inches 0.000. once again cost of extra wear vs cheapness of ammo. .144 vs inches of throat erosion is not from powder. excerpts really. so there are a couple sentences in this book i will never read that agree with you. i am not buying an $80 book to read about ww2 german gun testing. do realize how much better our steels and powder are today.