Case filled past base of shoulder a no no?

[stagpanther]

I've been reloading for some time now; and I never really paused to think about this one but occasionally I run across some cartridges which by virtue of being able to load them to a longer COL than their normal specs I gain extra case capacity for more powder. In some cases, especially when using flat based type bullets, I can run charge weights up that stay within pressure limits forecasted by QL--and are not compressed--but do fill into the area of the shoulder itself. could this potentially result in pressure spike that is maybe not captured in QL (since I guess it does not take into consideration the taper area of the shoulder in the powder column)? Ignorant minds want to know.

[RC20]

I doubt it.

I run some pretty low loads that do the same with (usually with H4895)

If you look at the range of low loads from one book to another I would guess its a lot wider than wheat you are doing.

[T. O'Heir]

"...charge weights up that stay within pressure limits..." Unless you're using pressure test equipment you have no idea what the pressures are. QL uses a mathematical guess. Pressure limits are set by SAAMI, not a computer program.
However, lots of loads using lots of powders with lots of cartridges fill the case to the shoulder. Compressed or not depends more on the powder's bulk than anything else. And just because there's space, doesn't mean you should stuff more powder in.

[Unclenick]

Stagpanther,

No. There's nothing special about doing that. If you look at QuickLOAD's various inputs, you'll see one called the Weighting Factor. That is the portion of the charge pushed forward with the bullet. Powder ignites near the flash hole first, so it builds pressure and starts pushing on the powder column before the flame front has propagated fully through the powder mass. If you use a stick powder and recover an exposed base rifle bullet from your backstop, you clearly see the outlines of the grain sticks impressed into the lead. So forcing powder to funnel out of the case mouth happens anyway. You're not introducing a special issue.

The only thing with QuickLOAD you have to watch out for is that it doesn't directly tell you the effect of the bullet shoulder being close to the throat of your bore. If you hover the cursor over the start pressure, the instructions tell you to add 7200 psi to the usual value to allow for actual contact with the throat (a jammed bullet). In my experience, that extra start pressure's effect on typical tangent ogive bullets has disappeared by the time you are about 0.030" off the lands. The effect is not linear, but I figure a linear interpolation is probably close enough, so I add about 2400 psi for 0.020" off the lands and 4800 psi for 0.010" off the lands until I can test it with a Pressure Trace. Anyway, if you are seating your bullet out further to get more powder space, that it something to consider.

QuickLOAD's pressure calculation is an estimate based on measured powder properties. SAAMI uses measurements to determine load values, but the data below, which came from SAAMI's 1992 and 1993 centerfire rifle and handgun cartridge standards, respectively, show that the absolute measurements made by different labs using the same calibration method have pretty wide variation, so any one measurement of the average of ten rounds (SAAMI's standard approach) doesn't actually do any better than QuickLOAD does.

[gwpercle]

I've been reloading , reading and studying ballistics 50+ years now and have never heard of powder in the sloped shoulder area being of any concern , problem or hazard whatsoever !
Lets not go and get some rumors started...you know how people like to get the story messed up and start a big internet reloading panic !

It's Not a Problem !

Gary

[stagpanther]

Great responses and thanks especially unclenick (Tim, well, you're just being yourself)--excellent point in regards to the start pressure in relation to the base of ogive in the throat. In the particular cases I'm talking about I'm not especially worried about that since I'm still a long way off from engaging the lands--far more than .03--with the flat base style bullets I'm talking about it. I usually keep my weighting factor at a "neutral" .5 but might do some fooling with it.

[stagpanther]

Went out and shot a ladder of 338 fed and labradar recorded average velocities which were almost dead on the forecasted values by QL. Using RL15 I really couldn't get added benefit from the extra powder in the case without running up the compression.

[stagpanther]

I've been reloading , reading and studying ballistics 50+ years now and have never heard of powder in the sloped shoulder area being of any concern , problem or hazard whatsoever !
Lets not go and get some rumors started...you know how people like to get the story messed up and start a big internet reloading panic !

It's Not a Problem !

Gary

Good point--my question was one of genuine curiosity but would be more than happy to have the thread deleted if the admins think there's a risk of "net spin" getting out of control.

[44 AMP]

with certain cartridge, bullet and powder combinations some charges listed in the books can fill the case to the neck, or even part way up the neck. Some loads are compressed by the bullet base, some aren't, or aren't as much.

All of that has been shooting ok for people for the past century plus. Powder level in the case into the shoulder area? Not a concern.

[std7mag]

Stag,
When i'm using QL, i usually give myself a 2-3 kpsi buffer as a max load. Most accurate is usually 1-2kpsi below that.

So if i have 60,000 psi SAAMI, i load to max of 57,000-58,000 psi.
My accuracy node usually ends up in the 56,000-57,000 psi range.

So far QL has usually been pretty close in prediction with actual readings on chrono.

Where it really shines is the old cartridges in modern bolt guns, with more modern powders.
Aka my Stevens 200 with 24"barrel in 250 Savage shooting a 115gr Berger VLD with RL17.

[stagpanther]

Stag,
When i'm using QL, i usually give myself a 2-3 kpsi buffer as a max load. Most accurate is usually 1-2kpsi below that.

So if i have 60,000 psi SAAMI, i load to max of 57,000-58,000 psi.
My accuracy node usually ends up in the 56,000-57,000 psi range.

So far QL has usually been pretty close in prediction with actual readings on chrono.

Where it really shines is the old cartridges in modern bolt guns, with more modern powders.
Aka my Stevens 200 with 24"barrel in 250 Savage shooting a 115gr Berger VLD with RL17.

That's what I've usually found--about 95% of the time there are two "sweet spot harmonics" loads for most loads I've developed--they seem to occur at 10% or so from the bottom and top end of the min/max pressure ranges. Once in a while one pops up in the middle--but that is rare. Incidentally--the loads I tested above I was about 9,000 psi below SAAMI max according to QL even at my maximum load which was around 4% compressed. I simply had no option at that point other than jam more powder into the case which I wasn't comfortable doing with the bullet already seated pretty far out. I generally don't do heavily compressed loads in an autoloader, I'm a bit paranoid about bullets getting set-back in the event of a "problematic" chambering.

[Don Fischer]

When I load, I wouldn't care for powder to go into the shoulder to the base of the neck. I like to use the base of the neck as the max seating depth for the bullet. Has always seemed to me a case full of powder, as in any compression at all, meant the powder was simply to slow!

[44 AMP]

I simply had no option at that point other than jam more powder into the case ...

Not quite sure what you meant, but the way you say this....scares me...

[stagpanther]

What I meant was having to go 5 to 10% compression.

[FrankenMauser]

Looks like I'm late to the party, but I'll add my opinion that it's a non-issue. Just a larger powder charge, or even a compressed load.

I used to avoid compressed loads, having been taught that they "do weird things". After experimentation on my own, however, I came to really appreciate cartridge/bullet/powder combinations that resulted in compressed loads - usually somewhere between 102% to 105% case fill.
Performance with compressed loads is, at least in my experience (and that of some writers that have expounded on the topic), far more predictable and consistent than loads with an air space - particularly loads that are under about 80% case fill.

I generally don't do heavily compressed loads in an autoloader, I'm a bit paranoid about bullets getting set-back in the event of a "problematic" chambering.

If there's enough compression, the bullet can't be set back.

[stagpanther]

I said I generally don't venture past the 5% compression range.

If there's enough compression, the bullet can't be set back.

If a press can do it--I suspect an AR carrier slamming the bullet can too.

[F. Guffey]

Case filled past base of shoulder a no no?

There is no 'one' answer. In the ole days reloaders had cute little sayings similar to the sayings of today., One of the old sayings: "All you got to do is dip this case into the powder to fill it up and then you seat a bullet" The logic had to do with slow powders. I have never gotten into the bad habit of dipping cases when filling with powder.

F. Guffey

[stagpanther]

The loading of 338 Fed is pretty tricky. Yesterday I tried the Woodleigh bullets for the first time--so far, they seem to be one of the best bullets I've tried optimally configured for the 338 fed cartridge.

[Roadkill2228]

I’ve often found (with many others) that lightly compressed loads or loads where the case is filled so that there is little or no wiggle room (can’t hear powder shaking in the case) give the best accuracy and consistency. I’ve run loads in my 270 that have had powder going partway up the neck before seating, very compressed. When they’re that compressed you need to crimp the bullet or it can start creeping back out over time, not good.

[cw308]

I use IMR 4064 for my 308 using a light load of 40.8 with a Sierra 168 MK , the powder is at the base of the case neck and that's with a very light load . My brass is on the thick side which works well with my light loads . I'm sure if I loaded to the high end of the scale it would be compressed . Or I could switch to a thinner brass like Remington or Winchester.

[Stats Shooter]

I have dealt with compressed loads a lot. I like the case to be full enough that its orientation has little or no impact on primer to powder gap, but not compressed enough bullet seating becomes a problem. I have tried up to 10 % compressed and I get inconsistent seating depths. Even with a drop tube it can be an issue.

I have never seen the bullet get pushed back out, but that doesn't mean it doesn't happen. As a rule I try and stay at or below 105%, but it depends on the powder. Ball powders like H335 doesn't compress well, while H1000 or 4831 does.

4064 probably would compress, but I use 41 gr behind a 175 gr match king and find no compression.

[Roadkill2228]

That’s very true about ball powder not compressing as well. One thing I’ll add is that while I’ve never personally had issues with standard primers in the past, I’ve switched to magnum primers whenever I’m loading compressed, and especially with ball powder, to ensure consistent and clean ignition, especially relevant where I live and hunt as it’s in winter and often below -20 Celsius. Again, I’ve had no bad experiences with standard primers, but with very compressed loads the magnum primers actually lower extreme spreads and you can’t be too careful.