Have you ever kb'd with a published load?

[GLOOB]

I was wondering if anyone has had a case head separation while following a reputable recipe, published in a manufacturer's reloading guide or in a published loading manual. Maybe the powder was bad? The brass was weak? Maybe a bulged base caused an OOB ignition? Or maybe some other factor came into play? If so, please share your story! I am relatively new to this hobby, and I find myself sometimes skipping the published starting loads and even going straight to max - depending on the nearest sized dipper I have on hand. Am I headed towards disaster? Or is manufacturer's published data so far below the danger level that "max" loads are a misnomer?

 

[Walkalong]

I find myself sometimes skipping the published starting loads and even going straight to max .................................Am I headed towards disaster?

That is certainly one way to get into trouble.

Start low, work up, watch for signs of trouble along the way. No shortcuts. As you gain experience you can start in the middle sometimes. Not before.

 

[traveling1253]

Starting at the max listed loading doesn't sound like a very good idea. Then again I've just started this madness myself, what do I know?

 

[Sport45]

Start low, work up. This is a time-honored and well proven method for keeping all fingers attached to your hands.

For my autoloading handguns, however, I've been known to start at mid-range loads since the minimums have resulted in cycling problems in some of my guns.

I was wondering if anyone has had a case head separation while following a reputable recipe, published in a manufacturer's reloading guide

Never a complete head separation, but I've had brass stretch pretty thin above the web when I loaded them too many times. But this doesn't fall into the "kb" category.

 

[LiveLife]

I take my incremental test loads (from just below starting to near max load data) all together to the range. As I am shooting the test rounds at increasing powder charges, I note any indication of over-pressure.

I do not exceed "current" published max load data, so I have not experienced signs I would be concerned with other than flattened primers at near max loads.

I have pushed my 115 gr FMJ 9mm loads to max load data to shoot out of Glocks, but was not worried as I have shot Hirtenberger +P+ without blowing them up. Recoil of max load data and hottest factory JHP is nothing compared to Hirtenberger +P+ recoil which is hand numbing shocking severe.

 

[GLOOB]

I agree with you concerning the safety margin of 9mm in a good platform. The only loads I've gone slightly beyond max are in 9mm, because my Glock can swallow OAL much longer than published minimum, and because even standard pressure 9mm brass is so strong. And because there are so many recommended loads I see repeated that are beyond manufacturer data. (E.g. 6 gr Unique behind a 124 gr jacketed bullet seems to be fairly popular, and that is beyond Alliant's max by a couple tenths). These hotter loads, I worked up gradually.

The only reason I'm skipping around, now, is because my new powder doesn't play well with my powder measure, so I'm stuck with scoops. And because I'm loading for maximum pumpkin terminal ballistics, rather than accuracy, I'm not concerned with finding the best group, ATM. Even though I'm sticking to max charge weights and min OAL's, I know better. I just can't help myself. So I guess I wanted to hear some horror stories to put myself in check. These loads are for .45 ACP, btw, which is also supposed to be fairly forgiving. It's another caliber where I see oft repeated recommendations that go as much as half a grain above manufacturer rec's.

I don't expect anyone to come along and say that starting loads are optional. What I'm curious about is what I stated in the title of the thread. Especially in .40 SW, which I also load (more cautiously), has anyone had a kB when following manufacturer published recipes, fired from an appropriate platform with good chamber support?

 

[LiveLife]

The only reason I'm skipping around, now, is because my new powder doesn't play well with my powder measure, so I'm stuck with scoops.

I sure hope you are weighing your "scoop" charges or thinking about switching to powder that meters better.

Be safe.

 

[ArchAngelCD]

Originally Posted By: Walkalong
That is certainly one way to get into trouble.

Start low, work up, watch for signs of trouble along the way. No shortcuts. As you gain experience you can start in the middle sometimes. Not before.

Certainly words to live by. You really shouldn't take shortcuts until you have more time under you belt and even then, well, you know...

I am relatively new to this hobby, and I find myself sometimes skipping the published starting loads and even going straight to max - depending on the nearest sized dipper I have on hand.....

.....The only reason I'm skipping around, now, is because my new powder doesn't play well with my powder measure, so I'm stuck with scoops.

In that case either buy the whole set of Lee dippers so you have the correct one available, buy a new powder measure that plays well with the powder you're now using or change powders so it works well with your current powder measure.

You didn't say what powder you're using but in my experiance W231/HP-38 works well in most powder measures because it's a flattened Ball Powder which also works well in the 9mm.

 

[GLOOB]

I sure hope you are weighing your "scoop" charges or thinking about switching to powder that meters better.

Triple checked with 2 scales by weighing 10 scoops 3 times.

You didn't say what powder you're using but in my experiance W231/HP-38 works well in most powder measures because it's a flattened Ball Powder which also works well in the 9mm.

My Lee measure is an anomaly. Unique is the only powder that it likes. With HP-38, it gets "grindy" and leaks out the side on every pull. With my new powder, W Auto Comp, it's even worse. The balls are much smaller and denser. By the seventh pull, the arm is very difficult to move, and a whole new, even smaller and finer powder, is being created and dispensed out the side. On the upside, scoops are very consistent.

 

[don]

A few years ago, I had numerous case head separations with my .243W. I was forming .243 brass from 7.62 NATO brass by running it through a .243 die. After about 3 or 4 reloadings I would get case head separations and my loads were not hot. As I recall, my loads were 43.5gr. IMR 4350. I was using a full length resizing die. The rifle was built on a Remington 700 action and I was never hurt in the least. The most I ever felt was a puff of gas on my cheek.

 

[ArchAngelCD]

GLOOB,
Are you using a Lee Auto-Disk Powder Measure or a Pro Auto-Disk Powder Measure? I was using the none Pro for a while and changed over to the Pro and had no more leakage problems.

 

[GLOOB]

Don: Interesting. I'd a thought you'd get shoulder separations in this scenario!

ArchAngel: I think I'm using the Lee Perfect Something-or-other. You adjust the charge weight with a screw. It came with my Breechlock Challenger kit. I suppose I'll buy a real dispenser some day, and I'll keep your experience in mind. I rather like using scoops, once I've found the right charge. It's the workup that's a pain. Even with Unique, which works quite well in my thrower, I find I prefer using a scoop once I find the load I want.

Umm, I just thought of the solution. I made 5 rounds of max charge with a scoop. Now I can stuff some paper into the bottom of the scoop, and do five more. Then add some more crap to the scoop, and continue on in that fashion until I have 5 at the starting load!

 

[jpwilly]

GLOOB, Frankly your post is scary. There are a lot of variables when reloading and if your keep pushing it I think you'll have a story to share with us not the other way around. Hopefully you'll still have all your digits and be willing to post pictures of your Kaboom.

Work up loads safely, your rifle isn't the same as the test rifle. Powders can vary by lot. Seating depth can cause pressure early even before a max published load would. Yada Yada Yada...it's your butt not mine.

 

[Funshooter45]

In my opinion, the techniques employed by the original poster are idiotic at best.

But... hey. It's not my gun and not my fingers. It appears he has a counter to every piece of advice offered, so in that case, good luck.

 

[GLOOB]

Well, I don't take offense. As I stated, I'm not looking for someone to tell me it's ok to do what I do. I wasn't even asking for advice. And yet, if you read my last post, you'll see that I have taken advice into consideration and am working on an easier way to do a conventional load workup using standardized scoops.

Perhaps I should start a new thread. My reloading technique aside, I'm still wondering about the original question.

What with Lee specifically warning that the Bulge Buster is NOT to be used on brass fired from a Glock (as if you can tell in which guns your purchased range brass has been fired in, anyway), and with the Lyman manual specifically warning against reloading .40 in barrels without full chamber support (which, depending on the definition of "full" could mean any autoloader), I still wish to hear others' kB experiences to see how often they occur with "normal" loads, due to other factors besides hotrodding, double charges, or bore obstructions. Are kB's happening because of various stupid mistakes, or simply because in some calibers brass is destined to fail in a violent fashion?

 

[cfullgraf]

Gloob,

First, I have never heard of a case head separation in straight walled handgun cases. Doesn't mean they don't happen but in 30 years of reloading I have never heard of it. My experiences with straight walled cases have shown the wall splits when the brass desides it has had enough.

There are plenty of pictures floating around from folks who overcharged their handgun reloads and blew the gun up. Generally, the cause was some kind of human error. Small charges of fast burning powders in large cases make some kind of mistake all too easy without the appropriate viligance.

The only case head separation I have ever experienced was with my 22 Hornet. The shallow taper of the case aggravates the situation. Neck sizing helps greatly as I do not disturb the body of the case when resizing and the cases do not stretch..

I don't even know a case head has separated until I open the action and a very short case is extracted. It is a royal pain to get the remainder of the case out. Rarely does the case show any signs of incipient case head separation prior to failure.

Others will disagree, but I feel the Lee powder measures and scales are problematic at best. Get a good measure and follow recommended loads.

The dippers are great for working up test loads. I use a dipper to pour powder on the scale pan for measuring each test charge.

Starting at the published maximum is a recipe for disaster.

 

[Crashbox]

I've never had a KB with a factory round but if I shoot some of those original .405 Winchesters I have in stock, maybe... they are ANCIENT.

I wholeheartedly agree with the other posters WRT load development- start at the low end of what is published and work up from there- anything else is an invitation for picking rutabagas from a step ladder.

 

[Slamfire]

I was wondering if anyone has had a case head separation while following a reputable recipe, published in a manufacturer's reloading guide or in a published loading manual.

The classic case head separation is caused by excessive case stretching. Gaging and tolerance stack up is safety critical for firearms. Chamber headspace is made within tolerances, “GO” and “No Go”, and cartridge manufacture keep their cartridges within these limits.

The typical design limit for cartridge expansion is .006”. Beyond that the cartridge case ruptures. Brass can only stretch so much you know.



To prevent case overstretching everyone sizing centerfire rifle bottleneck cases should use cartridge head space gages in setting up their rifle dies. I use Wilson gages because they are simple and inexpensive.

Set your case shoulders back .003" from fired cases in your rifle and you should never have case head separations.



Now if you are talking about overpressure events, well I don’t trust Accurate Arms reloading data. Too many times I have used the minimum load and had leaking and blown primers. I have also used their data and created loads that were underpressure and slow.

As an example, I used a 1998 Accurate Arms reloading handbook to develop loads with AA#5 in the 44 Spl. The maximum load in the handbook was 6.8 grains with a 245 Lead at 860 fps.

I started off at 6.1 grains with a 240 and got 523 fps. This was so low and so under pressure that I had lots of unburnt power. I tested their maximum load of 6.7 grains and got 571 fps. There was absolutely no relationship between their printed data and what I received over the chronograph screens.

In my data analysis of that day, I performed load extrapolation and two weeks later I came back and was able to develop loads that made sense with this powder.

[SIZE="3"]

4" M624   	44 Special 		
					
240 LSWC Valiant 6.1 grs AA#5  thrown,  Lot 35 590,  Mixed Brass WLP
T = 62 °F	25-Feb-07				
		 			
Ave Vel =	523.1				
Std Dev =	31.1		 		
ES =	121.9		 		
Low = 	585.1				
High = 	463.1				
N =	28				
		Accurate, light recoil, lots of unburnt powder
					
240 LSWC Valiant 6.7 grs AA#5  Lot 35 590 Mixed Brass WLP	
T = 62 °F	25-Feb-07				
					
Ave Vel =	571.1				
Std Dev =	34.46		 		
ES =	142.6		 		
Low = 	645.4				
High = 	503.4				
N =	32				
		accurate, light recoil, lots of unburnt powder
					
240 LSWC Valiant 8.5 grs AA#5 Lot 35 590  Mixed Brass WLP	
T = 64 °F	3-Mar-07				
Ave Vel =	790.4				
Std Dev =	30.69				
ES =	134				
High = 	845.7				
Low = 	711.6				
N =	32				
		Accurate			
					
240 LSWC Valiant 9.0 grs AA#5 Lot 35 590  Mixed Brass WLP	
T = 64 °F	3-Mar-07				
Ave Vel =	845.5				
Std Dev =	17.43				
ES =	51.74				
High = 	869.9				
Low = 	818.1				
N =	10				
		Very Accurate[/SIZE]

 

[don]

Cfullgraf, removing cases that have had head separations from the barrel are no problem assuming you can clean from the breech. Simply insert an oversize bore brush far enough to get to the neck of the case and pull it out. For example in my .243 I would use a .270 bronze bore brush. When you push it in the bristles bend one way. When you pull it out they grip the case and out the case comes.

 

[Walkalong]

As an example, I used a 1998 Accurate Arms reloading handbook to develop loads with AA#5 in the 44 Spl. The maximum load in the handbook was 6.8 grains with a 245 Lead at 860 fps.

I started off at 6.1 grains with a 240 and got 523 fps. This was so low and so under pressure that I had lots of unburnt power.

I had the same problem with some AA #9 in .357. Unburned powder and low velocity compared to the data. The AA #9 data worked fine in .44 Mag though. Go figure. It doesn't breed confidence.

 

[243winxb]

I feel most KABOOMS happen from double charges, or bridging of the powder, when one case gets 3/4 of the charge and the next case get a 1 1/4 charge. More of a problem in the 40 high pressure round than the 45acp. IMO. Watch out for the plastic guns with the 40 S&W Photo link below.

 

[Walkalong]

Hot loaded (Over pressure) rifle rounds just keep stressing the action until one day something lets loose.

 

[Peter_S]

Gloob

I've been using the Lee measure for about two years now and don't have that problem. I use both W231 and HS-6; both powders measure well.

There is a screw on the right side (handle side) that can be adjusted. Too tight or too loose can cause problems. If it's too loose it will allow powder to escape and start grinding in the mechanism. Too tight...lol...well eventually you can't move it. Try cleaning the measure out and adjust the screw setting.

 

[918v]

I have never KB'd anything. FWIW, a published load from a manual will not blow up a gun in good working order. Also, if a case is defective, it will let go no matter what load you use, starting or maximum. Firearms are inherently dangerous. Our goal is to make our hobby reasonably safe, but it can never be 100% safe. Therefore, protect your ASSets by following all safety rules. Work your load from min to max. Inspect your brass for defects. Inspect your firearm. Check each powder charge. Check your bullets. Be safe.

 

[rcmodel]

First, an over-pressure load does not cause a case-head separation.
Excess head-space or excess stretching for whatever reason is what causes case-head separations.

Over-pressure loads first cause pierced or blown primers, followed by expanded primer pockets, and resulting gas leakage.
Finally, at extreme over-pressure, the case completely fails due to escaping gas melting the head like a cutting torch.
Once that happens, the gun comes apart in your face.

and even going straight to max

That may work indefinately in low pressure handgun calibers.

But do it with a centerfire rifle and you are on the road to disaster!!

I have more then one rifle that will simply not handle many published max loads without showing sticky bolt lift, bolt face impressions on the case head, expanded primer pockets, etc.

rc