- Thread starter cstmwrks
- Start date
Re: Have you ever blown the base clean off?
Sometimes my .223 barrel on my contender will have case head separation, but only if I use cheap brass. Hasn't happened in several years.
Check your load count for your brass, and when sizing consider only neck sizing. Some brass you may see a sign of incipient case head sep, but most have a small ring about 3/8 inch above the rim, from the sizing die. This is where the case separates.
Make sure you are not overloaded, and that your round seats in the chamber properly. I take a ramrod and a small dental pick with me to the range just for that reason.
Sometimes my .223 barrel on my contender will have case head separation, but only if I use cheap brass. Hasn't happened in several years.
Check your load count for your brass, and when sizing consider only neck sizing. Some brass you may see a sign of incipient case head sep, but most have a small ring about 3/8 inch above the rim, from the sizing die. This is where the case separates.
Make sure you are not overloaded, and that your round seats in the chamber properly. I take a ramrod and a small dental pick with me to the range just for that reason.
Re: Have you ever blown the base clean off?
nope, never, sorry.
nope, never, sorry.
Re: Have you ever blown the base clean off?
Yeah did that with some BHA brass, but it had 7 reloads and had originally been used for my hot load (45.5 varget/175)...
Exactly 3/8" up as well, so I'm guessing you FL resize your brass?
Got a pic of it somewhere.
My gunsmith explained that a bit of excess headspace can cause this, warned on my K98K that if I did not do the brass correctly (Neck only) it could happen.
I used to always FL my BHA brass and before I got rid of it you could see the lines on some of them, tossed em...
Then sometimes it just happens.
Yeah did that with some BHA brass, but it had 7 reloads and had originally been used for my hot load (45.5 varget/175)...
Exactly 3/8" up as well, so I'm guessing you FL resize your brass?
Got a pic of it somewhere.
My gunsmith explained that a bit of excess headspace can cause this, warned on my K98K that if I did not do the brass correctly (Neck only) it could happen.
I used to always FL my BHA brass and before I got rid of it you could see the lines on some of them, tossed em...
Then sometimes it just happens.
Re: Have you ever blown the base clean off?
You can detect imminent case head separation by using the paper clip test.
When you are using reloads i.e. cases that have been fired, especially multiple number of time, there is always a chance for this. A paper clip straightened out with the tip bent 90 degrees will allow you to find that big dip inside the brass i.e. in the thin area that is just about to give. There should also be a bright ring on the outside.
Avoid using brass with these symptoms and use loads within max working up from low to high should allow you to avoid this problem
You can detect imminent case head separation by using the paper clip test.
When you are using reloads i.e. cases that have been fired, especially multiple number of time, there is always a chance for this. A paper clip straightened out with the tip bent 90 degrees will allow you to find that big dip inside the brass i.e. in the thin area that is just about to give. There should also be a bright ring on the outside.
Avoid using brass with these symptoms and use loads within max working up from low to high should allow you to avoid this problem
Re: Have you ever blown the base clean off?
Probably not headspace on the rifle...but reloading practices. You are over sizing the brass when full length sizing. Each firing then stretches the brass just ahead of the web. BINGO...case separation. Read some manuals and posts...bump the shoulder JUST enough...neck size when you can. When you check fired brass look for the shiny ring with a slightly dark ring in that 3/8 inch area ahead of the base...if you see it...toss the case. It is imminent separation. JMHO
Probably not headspace on the rifle...but reloading practices. You are over sizing the brass when full length sizing. Each firing then stretches the brass just ahead of the web. BINGO...case separation. Read some manuals and posts...bump the shoulder JUST enough...neck size when you can. When you check fired brass look for the shiny ring with a slightly dark ring in that 3/8 inch area ahead of the base...if you see it...toss the case. It is imminent separation. JMHO
Re: Have you ever blown the base clean off?
Former navel person is right on the mark and with a few good measuring tools and die selection it will never happen to you again. Here's how:
First off get a good micrometer and good calipers. Measurement on cases is made in several places. First is the base dimension which is measured .200" up from rim (where your case separated). Measure this on fired cases and cases that are FL sized. On the 308 with US factory chambers a fired case will give you about .4714 to .4734 after firing. If it is bigger don't be surprised as I have seen 308 cases come out at .476 diameter.
Next measure your cases in same place after FL sizing and I suspect they will be in the .468/.469 range. If you happen to have a die that is "small base" they run a variety of sizes. I have seen SB dies that size .468 and I have 308 standard dies that size .468.
The problem shows itself quickly when commercial cases are used. If you measure new commercial 308 rounds (Rem, Win, Fed) I think you will find they measure .465 at the base dimension and right there you can go from .465 to .473 on first firing. I have yet to find a 308 die that will take a case below .468. However there is hope. If use LC cases they have a bigger base and new LC cases are .468 as loaded thusly you have the benefit of a bigger case to fit the bigger chambers and they are heavier and will take more movement.
As indicated above the case shoulder may be getting "overworked". The best way to figure this out is get two gages, one is a adjustable case gage and they are available from RCBS and Mo's Competitor Suppies in Deerfield, Conn. Also L.E. Wilson case gages available from several places. The Wilson gage is a min max condition set up and if case is too long it will stick out the front above the surface. If it is sized too much it will let the case go below a indicated shelf surface.
If not sized enough it will stick out the back above the die. The MO Gage (is what I use and most long range shooters use) allows you to measure just how far your case shoulder goes forward on firing and how much you FL size die moves the shoulder back on sizing. Most "shooters" I know go with Mo Gages to adjust their size die to only move the case shoulder back .001/.002.
Now here is the big problem. The industry NORMALLY has a .006" range to headspace their 308s in a new barrel. Ones I have measured generally have shoulder movement about .004/.005" forward and I have seen them close on a NO GO gage in unfired condition.
On a used rifle the industry says the shoulder can go forward .010" ! ! ! ! ! which is what a FIELD SERVICE gage goes out to. Thusly if you have a LONG CHAMBER and you set your die to go all the way to min your shoulder can move .010" forward on firing and .010" to the rear on sizing. Just a few rounds of this and you get what you just got which is case separation.
Case in point I just picked up a 1903A3 Springfield and I test fired it and gaged the fired case and shoulder had moved forward .007" and probably more as cases tend to "spring back" a tad on firing.
If you are observant you can figure out with a case trim gage how bad things are. I have L.E. Wilson case trimmers set up to trim cases to a given length and thusly when I trim I can tell by the amount of brass removed from case mouth how I am doing. If you are getting just a little bit of brass being cut off indicated movement you are good. If you are cutting off large amounts of brass the die is not adjusted correctly for your chamber.
Logic here is if you are taking brass off at the mouth where did it come from? Obviously from the case body and when it stretches you see the results with the ring inside the case as described by the paper clip test above.
There is however a cheaper way to do this than paper clip. Go outside and stand with your back to the sun and hold the case so that sunlight enters the case mouth all the way to the base and rotate the case. On a new case down at the bottom you will see an even condition all the way around. On used cases at some point you will see a thin black ring (where your case separated) and the more you shoot it the darker the ring appears and you will learn to judge when they are getting tired and before they became "two piece".
Is there a way to get around this condition? Yes there is but you have to be very experienced and it involves getting custom reamers ground to min dimension in what I refer to as the 222 method which means on firing the case body doesn't expand over .002", the case shoulder doesn't move over .002" forward and the case neck doesn't expand over .002".
My match chambers have been so cut since about 1981 and I use LC or FA cases. I have one batch of 30.06 cases I have used for about 29 years and they are on their third barrel and they show no signs of wearing out as primer pockets are still tight and there is no evidence of the black ring starting. Some BR boys shoot cases with necks only .0005 smaller than their chamber while most run about .001".
What else does this do? For instance 30.06 cases LC and commercial new unfired measure .465" at the base. My reamer is .467 on the base. I fire the round and measure the fired case and it measures .4658 to .4612 and visually you cannot detect the case has expanded at all. My FL die sizes cases to .466 thusly the case body for all practical purposes does not move any significant amount. I have another 30.06 custom reamer that gives birth to fired cases at .469 and I have a FL die that sizes it down to .468.
On the rounds I use alot I pick up several sets of used dies at flea markets etc and I have found they all size from .466 to .469 and I have them marked thusly I don't ever over work brass. With the cost of brass these days you can (if you are a shooter) easily justify your own reamer and have your barrels chambered with same reamer every time. But what about the factory chambers that give birth to fired cases in the .471 to 473 range? I chucked one of my used dies up in lathe and polished that one out to size cases at .471.
Ray Steele (former armorer who built the US Secret Service Sniper Rifles- who unfortunately passed about 18 months back) got me on min chambers in 82 and I have been there ever since. Dave Manson has also been extremely helpful in recommendations for min reamers and matter of fact he is making me a 6.5X06 A Square Improved reamer now which I am expecting to arrive this week. Usually the term "improved" means blow the shoulder out for incrased capacity but in this instance it is a reamer that will adhere to the 222 rules.
I have already determined necking down 30.06 LC cases gives me a .294 range necks(with bullet seated) so I ordered reamer to cut at .292 and I have already neck turned cases that will give me a .290 loaded round condition and the Marquart turner just cleans up the neck 360 around.
What else can a custom reamer do for you? Here is where it gets real nifty. On a new barrel you always whack off last inch at muzzle as they are tapered internally from the manufacturing processes. You take your custom reamer and run it in this section of barrel till it stops about .050" before the neck section comes out the front and face it off a little at a time so you have a little shelf. Now you have a gage that you can insert every loaded round into to insure there is no tight neck condition that would raise pressures and you also know exactly where your case neck is in relation to the end of your chamber.
Done correctly you can also use this little gage with your calipers by placing a fired case therein and measure from end of gage to the case head and adjust your die to where it moves the shoulder back .001/.002" and visually you know when it is getting time to trim your case. And you are doing it with the shoulders being identical in length. It doesn't get any better than that ! ! ! !
Bottom line is if you are doing EVERYTHING CORRECTLY you should only retire cases with loose primer pockets and never from neck splits or case separations.
Former navel person is right on the mark and with a few good measuring tools and die selection it will never happen to you again. Here's how:
First off get a good micrometer and good calipers. Measurement on cases is made in several places. First is the base dimension which is measured .200" up from rim (where your case separated). Measure this on fired cases and cases that are FL sized. On the 308 with US factory chambers a fired case will give you about .4714 to .4734 after firing. If it is bigger don't be surprised as I have seen 308 cases come out at .476 diameter.
Next measure your cases in same place after FL sizing and I suspect they will be in the .468/.469 range. If you happen to have a die that is "small base" they run a variety of sizes. I have seen SB dies that size .468 and I have 308 standard dies that size .468.
The problem shows itself quickly when commercial cases are used. If you measure new commercial 308 rounds (Rem, Win, Fed) I think you will find they measure .465 at the base dimension and right there you can go from .465 to .473 on first firing. I have yet to find a 308 die that will take a case below .468. However there is hope. If use LC cases they have a bigger base and new LC cases are .468 as loaded thusly you have the benefit of a bigger case to fit the bigger chambers and they are heavier and will take more movement.
As indicated above the case shoulder may be getting "overworked". The best way to figure this out is get two gages, one is a adjustable case gage and they are available from RCBS and Mo's Competitor Suppies in Deerfield, Conn. Also L.E. Wilson case gages available from several places. The Wilson gage is a min max condition set up and if case is too long it will stick out the front above the surface. If it is sized too much it will let the case go below a indicated shelf surface.
If not sized enough it will stick out the back above the die. The MO Gage (is what I use and most long range shooters use) allows you to measure just how far your case shoulder goes forward on firing and how much you FL size die moves the shoulder back on sizing. Most "shooters" I know go with Mo Gages to adjust their size die to only move the case shoulder back .001/.002.
Now here is the big problem. The industry NORMALLY has a .006" range to headspace their 308s in a new barrel. Ones I have measured generally have shoulder movement about .004/.005" forward and I have seen them close on a NO GO gage in unfired condition.
On a used rifle the industry says the shoulder can go forward .010" ! ! ! ! ! which is what a FIELD SERVICE gage goes out to. Thusly if you have a LONG CHAMBER and you set your die to go all the way to min your shoulder can move .010" forward on firing and .010" to the rear on sizing. Just a few rounds of this and you get what you just got which is case separation.
Case in point I just picked up a 1903A3 Springfield and I test fired it and gaged the fired case and shoulder had moved forward .007" and probably more as cases tend to "spring back" a tad on firing.
If you are observant you can figure out with a case trim gage how bad things are. I have L.E. Wilson case trimmers set up to trim cases to a given length and thusly when I trim I can tell by the amount of brass removed from case mouth how I am doing. If you are getting just a little bit of brass being cut off indicated movement you are good. If you are cutting off large amounts of brass the die is not adjusted correctly for your chamber.
Logic here is if you are taking brass off at the mouth where did it come from? Obviously from the case body and when it stretches you see the results with the ring inside the case as described by the paper clip test above.
There is however a cheaper way to do this than paper clip. Go outside and stand with your back to the sun and hold the case so that sunlight enters the case mouth all the way to the base and rotate the case. On a new case down at the bottom you will see an even condition all the way around. On used cases at some point you will see a thin black ring (where your case separated) and the more you shoot it the darker the ring appears and you will learn to judge when they are getting tired and before they became "two piece".
Is there a way to get around this condition? Yes there is but you have to be very experienced and it involves getting custom reamers ground to min dimension in what I refer to as the 222 method which means on firing the case body doesn't expand over .002", the case shoulder doesn't move over .002" forward and the case neck doesn't expand over .002".
My match chambers have been so cut since about 1981 and I use LC or FA cases. I have one batch of 30.06 cases I have used for about 29 years and they are on their third barrel and they show no signs of wearing out as primer pockets are still tight and there is no evidence of the black ring starting. Some BR boys shoot cases with necks only .0005 smaller than their chamber while most run about .001".
What else does this do? For instance 30.06 cases LC and commercial new unfired measure .465" at the base. My reamer is .467 on the base. I fire the round and measure the fired case and it measures .4658 to .4612 and visually you cannot detect the case has expanded at all. My FL die sizes cases to .466 thusly the case body for all practical purposes does not move any significant amount. I have another 30.06 custom reamer that gives birth to fired cases at .469 and I have a FL die that sizes it down to .468.
On the rounds I use alot I pick up several sets of used dies at flea markets etc and I have found they all size from .466 to .469 and I have them marked thusly I don't ever over work brass. With the cost of brass these days you can (if you are a shooter) easily justify your own reamer and have your barrels chambered with same reamer every time. But what about the factory chambers that give birth to fired cases in the .471 to 473 range? I chucked one of my used dies up in lathe and polished that one out to size cases at .471.
Ray Steele (former armorer who built the US Secret Service Sniper Rifles- who unfortunately passed about 18 months back) got me on min chambers in 82 and I have been there ever since. Dave Manson has also been extremely helpful in recommendations for min reamers and matter of fact he is making me a 6.5X06 A Square Improved reamer now which I am expecting to arrive this week. Usually the term "improved" means blow the shoulder out for incrased capacity but in this instance it is a reamer that will adhere to the 222 rules.
I have already determined necking down 30.06 LC cases gives me a .294 range necks(with bullet seated) so I ordered reamer to cut at .292 and I have already neck turned cases that will give me a .290 loaded round condition and the Marquart turner just cleans up the neck 360 around.
What else can a custom reamer do for you? Here is where it gets real nifty. On a new barrel you always whack off last inch at muzzle as they are tapered internally from the manufacturing processes. You take your custom reamer and run it in this section of barrel till it stops about .050" before the neck section comes out the front and face it off a little at a time so you have a little shelf. Now you have a gage that you can insert every loaded round into to insure there is no tight neck condition that would raise pressures and you also know exactly where your case neck is in relation to the end of your chamber.
Done correctly you can also use this little gage with your calipers by placing a fired case therein and measure from end of gage to the case head and adjust your die to where it moves the shoulder back .001/.002" and visually you know when it is getting time to trim your case. And you are doing it with the shoulders being identical in length. It doesn't get any better than that ! ! ! !
Bottom line is if you are doing EVERYTHING CORRECTLY you should only retire cases with loose primer pockets and never from neck splits or case separations.
Re: Have you ever blown the base clean off?
Always carry one of these with me just in case:
http://www.midwayusa.com/viewproduct/?productnumber=250034
When using an AR, the pistol grip storage area is a perfect place to keep one.
Always carry one of these with me just in case:
http://www.midwayusa.com/viewproduct/?productnumber=250034
When using an AR, the pistol grip storage area is a perfect place to keep one.
Re: Have you ever blown the base clean off?
Dr. Phil, good info on the ruptured shell extractor. Did not know Midway had them.
cstmwrks: yep a guy has to have good measuring tools to know where he is. I try not to throw away any brass as sometimes it comes in handy for different projects. For instance if you have a lever gun, pump gun or semi auto take a 30.06 or 308 case, chuck in lathe and drill out head with drill close to inside dimensions of case, neck it down in a 260 Rem die and use it as a muzzle protector to clean 30 cal barrels. I have such on every cleaning rod I have.
While in Ohio last year I saw how Swiss cow bells were made and a cartridge case is used as brazing material to hold the parts of the bell together. One man's trash is another man's treasure.
You can also make a case remover by taking a piece of gas welding rod about 1/8" thick and clamp it in a vise leaving about 1/8" exposed on top and beat it one direction to form a small lip and grind of excess material about 270 degrees leaving a small shart lip on one side. Make it about 6 inches long and you can ease it up in chamber, hook it on case mouth and pull it out.
I had not thought of a pipe time for such use, good idea though.
Dr. Phil, good info on the ruptured shell extractor. Did not know Midway had them.
cstmwrks: yep a guy has to have good measuring tools to know where he is. I try not to throw away any brass as sometimes it comes in handy for different projects. For instance if you have a lever gun, pump gun or semi auto take a 30.06 or 308 case, chuck in lathe and drill out head with drill close to inside dimensions of case, neck it down in a 260 Rem die and use it as a muzzle protector to clean 30 cal barrels. I have such on every cleaning rod I have.
While in Ohio last year I saw how Swiss cow bells were made and a cartridge case is used as brazing material to hold the parts of the bell together. One man's trash is another man's treasure.
You can also make a case remover by taking a piece of gas welding rod about 1/8" thick and clamp it in a vise leaving about 1/8" exposed on top and beat it one direction to form a small lip and grind of excess material about 270 degrees leaving a small shart lip on one side. Make it about 6 inches long and you can ease it up in chamber, hook it on case mouth and pull it out.
I had not thought of a pipe time for such use, good idea though.
Re: Have you ever blown the base clean off?
I bought a shoulder bump gauge at sinclair. Measure like 10,20, 50 cases, before you fire them and after, average the results, and set your die accordingly. Mine were growing about 0.002 to 0.003 so i set the die to bump the shoulder back about 0.0025. For what its worth i wrecked a whole case, 200 pieces, of Winchester brass in 3 firings by overworking the brass wi an improperly set sizing die.
Rich
I bought a shoulder bump gauge at sinclair. Measure like 10,20, 50 cases, before you fire them and after, average the results, and set your die accordingly. Mine were growing about 0.002 to 0.003 so i set the die to bump the shoulder back about 0.0025. For what its worth i wrecked a whole case, 200 pieces, of Winchester brass in 3 firings by overworking the brass wi an improperly set sizing die.
Rich
Re: Have you ever blown the base clean off?
+2 using paperclip test in all brass. Have not had a case head separation since. Toss the brass when you feel a ridge, brass is cheap.
Good luck
Jerry
+2 using paperclip test in all brass. Have not had a case head separation since. Toss the brass when you feel a ridge, brass is cheap.
Good luck
Jerry
Re: Have you ever blown the base clean off?
Yep did it on a factory reloaded .223 cartridge... it was the first i had heard of it happening too when i did it so i showed the range master and he said to look for shiny rings in the brass. that may mean it has been reloaded to many times and is thin in that area. mine made a clean break right near the halfway point in the case. yhe rifle still ejected the back half of the case just fine...
Yep did it on a factory reloaded .223 cartridge... it was the first i had heard of it happening too when i did it so i showed the range master and he said to look for shiny rings in the brass. that may mean it has been reloaded to many times and is thin in that area. mine made a clean break right near the halfway point in the case. yhe rifle still ejected the back half of the case just fine...
Re: Have you ever blown the base clean off?
yep 2nd time loaded on neck sized Fed brass.thats why I do not use Fed brass.just too soft for me.and yes the load was not hot.
yep 2nd time loaded on neck sized Fed brass.thats why I do not use Fed brass.just too soft for me.and yes the load was not hot.
Re: Have you ever blown the base clean off?
I have a buddy of mine in Georgia. His shooting buddy is having the same issue with L.C. brass with like 4-6 X fired. Neck sized only.
I have a buddy of mine in Georgia. His shooting buddy is having the same issue with L.C. brass with like 4-6 X fired. Neck sized only.
Re: Have you ever blown the base clean off?
I was annealing brass the other night and culled out 16 cases that had obvious signs of imminent separation, or had actually partially separated. Took the rifle over to have Moon check it out and after going so far as to pulling the barrel off to check the chamber, we determined there was nothing wrong with the rifle, barrel, headspace, anything. It was a brass issue. I'm scrapping the entire lot (for safety reasons) and getting a brand new lot of 500 cases where I can more easily track the reload count on the brass, and have more consistency.
I tried the paperclip test, and on a cases that had completely separated on one side, I couldn't feel a dip, I don't believe in that method. The surefire method is to get the micrometer that you can measure case wall thickness, but that's the slow, expensive way to check.
Branden
I was annealing brass the other night and culled out 16 cases that had obvious signs of imminent separation, or had actually partially separated. Took the rifle over to have Moon check it out and after going so far as to pulling the barrel off to check the chamber, we determined there was nothing wrong with the rifle, barrel, headspace, anything. It was a brass issue. I'm scrapping the entire lot (for safety reasons) and getting a brand new lot of 500 cases where I can more easily track the reload count on the brass, and have more consistency.
I tried the paperclip test, and on a cases that had completely separated on one side, I couldn't feel a dip, I don't believe in that method. The surefire method is to get the micrometer that you can measure case wall thickness, but that's the slow, expensive way to check.
Branden
Re: Have you ever blown the base clean off?
I only use brass that I:
a) have bought
b) have bought and only used in my rifles
Bet you have gas cutting in your chamber.
Not kewl in a non chrome-lined chamber.
If that was factory fodder, they would owe you new barrel.
I'd have it checked out.
Best to you.
I only use brass that I:
a) have bought
b) have bought and only used in my rifles
Bet you have gas cutting in your chamber.
Not kewl in a non chrome-lined chamber.
If that was factory fodder, they would owe you new barrel.
I'd have it checked out.
Best to you.
