I'm curious. If someone doesn't understand that 70,000 psi is an excessive level of peak chamber pressure, should they even be allowed to own or possess a firearm?
Close call with Nosler .243 load data
- Thread starter uncle-buck
- Start date
The load was over max in your barrel with your lot# of powder..
Undoubtedly their test equipment and lot# was different..
I suspect your Lapua brass is better than the Nosler..
Going forward, remember that book data is a starting point and it's up to you to proceed with caution..
I have been there and done exactly what occurred to you.. It happens..
Undoubtedly their test equipment and lot# was different..
I suspect your Lapua brass is better than the Nosler..
Going forward, remember that book data is a starting point and it's up to you to proceed with caution..
I have been there and done exactly what occurred to you.. It happens..
Did you actually read the QuickLoad data sheet (that I posted) for Nosler's published max load for that bullet?
shoot4fun
Gold $$ Contributor
OK, so you seem to keep pointing to your Quickload sheet as "the Bible" so it makes me curious as to why you would have ever used any reloading manual for reference since you obviously know that Quickload will, beyond any shadow of doubt, provide you with proper and safe data.
My take on QL has always been that there are millions of possible combinations available to us as reloaders. I don't think QL staff has physically tried each one and it is quite possible to assume that a bit of QL's data are predictions rather than facts.
Example, my 6 Creedmoor rifle has fired right at 1,000 rounds of a recipe using RL16. It does so very accurately and has never blown a primer, shown ejector marks or had anything close to stiff bolt open. It has also been fired in temps ranging from low 30's to high 90's with humidity levels in the low 90% range. I also have used a blade mic to measure case head expansion and found it within the .003" number Hodgdon uses as an indicator of over pressure. I have also reloaded the same Hornady brass at least 6 times with this load and primer pockets are still tight. Someone on this very forum has told me that QL says my load is way over pressure. Really? Without knowing anything about my barrel bore size (.237 or .236) twist rate, brass H2O capacity, COAL, etc. someone is able to tell me I am over pressure?
I may be reading between the lines and apologize up front for assuming but I get the impression you went to Nosler data, chose the top load they provide, loaded them and figured "well, it should be fine". I have never seen a manual that didn't caution to begin at a lower charge weight and work up.
It's time for you to lose the attitude! You are not the only experienced person in the room sir.
I have to say I find some things on the Nosler data sheet very strange. As Park Ranger said some posts back, the water capacity changes with the bullet, so is apparently not the fireformed 'overflow water capacity' that we input into QuickLOAD, rather Nosler's measured or calculated usable capacity under the bullet, ie as per the next QuickLOAD program automatic calculation taking the entire empty case capacity as input, the bullet form and subtracting that amount of space used up by the seated bullet to get the actual combustion chamber volume.
So I looked at Nosler's FAQs and this is confirmed
https://faq.nosler.com/index.php?action=artikel&cat=37&id=52&artlang=en
the relevant words being:
"Case capacity is measured by taking a piece of firedbrass, filling it up with water and then loading a bullet into the case neck at the tested OACL listed in Nosler’s Reloading Guide #7. The weight of water left in the brass after the bullet has been seated is the case capacity".
So far, so straightforward. However, use QuickLOAD's default case capacity without bullet of 54.0gn (a little pessimistic for Uncle Buck's Lapua brass IMO) and seat the 55gn Nosler Varmageddon into it at the stated 2.510" COAL (Very deep, two bullet calibres' worth at 0.484" of shank!) and QL calculates the usable capacity is reduced by 5.676gn water or 10.5% to give a combustion chamber volume of 48.322gn = 3.137 cc in volumetric terms.
Assuming that this bullet at this COAL reduces the starting water capacity of Nosler brass by a similar amount, 10.5%, and the actual usable capacity left over is as stated 53.9gn, that gives a starting case capacity of 59.6gn water. That is a LOT for the 243, more than I've seen in my brass and chambers.
Let's use that figure anyway in QuickLOAD with the other values as used by Nosler and we get:
48.5gn ............. 48,578 psi ......... 3,599 fps
52.5gn ............. 64,052 psi ......... 3,909 fps
So, stranger and stranger! Even with this abnormally high case capacity, that bullet at that COAL with Nosler's maximum charge of that powder is calculated as being 4,000 psi over-pressure!
The revised (59.6gn) case capacity isn't apparently that far out from what Nosler's data say - the loading set gives 52.5gn H414 a 101% fill-ratio; QuickLOAD calculates 99.9%, close enough to show nothing here is seriously awry. MVs though are a different matter, there being another significant discrepancy. QL calculates 3,909 fps from a 24-inch barrel despite being 4,000 psi over SAAMI maximum pressure; Nosler gets 3,982 fps from what should be a SAAMI compliant combination - and with some leeway at that to cover people using different capacity brass, primer model etc.
Unfortunately the online Barnes Bullets 243 data don't list this bullet, Hornady #10 has its 58gn VMax but not H414; Lyman #50 also has the 58gn VMax and this time H414 too, maximum charge 50.0gn in Remington brass (pretty well guaranteed higher capacity than Nosler therefore producing lower pressures and allowing slightly higher charges) for 3,776 fps. (Shown as a compressed load.)
Interestingly, my most recent copy of the Speer manual lists loads with Winchester brass and in its technical notes on the cartridge stresses that the 243 Win sees unusually large variations in case capacity between makes and that the following data is for that Winchester cases only and mustn't be used with other makes.
In summary, I'll also be interested to see what Nosler says in response to Uncle Buck's email as there are some very odd, I'd go further worrying, aspects to that load shown in the table. ....... and that's before we get a blown primer with the starting load as Uncle Buck did!
So I looked at Nosler's FAQs and this is confirmed
https://faq.nosler.com/index.php?action=artikel&cat=37&id=52&artlang=en
the relevant words being:
"Case capacity is measured by taking a piece of firedbrass, filling it up with water and then loading a bullet into the case neck at the tested OACL listed in Nosler’s Reloading Guide #7. The weight of water left in the brass after the bullet has been seated is the case capacity".
So far, so straightforward. However, use QuickLOAD's default case capacity without bullet of 54.0gn (a little pessimistic for Uncle Buck's Lapua brass IMO) and seat the 55gn Nosler Varmageddon into it at the stated 2.510" COAL (Very deep, two bullet calibres' worth at 0.484" of shank!) and QL calculates the usable capacity is reduced by 5.676gn water or 10.5% to give a combustion chamber volume of 48.322gn = 3.137 cc in volumetric terms.
Assuming that this bullet at this COAL reduces the starting water capacity of Nosler brass by a similar amount, 10.5%, and the actual usable capacity left over is as stated 53.9gn, that gives a starting case capacity of 59.6gn water. That is a LOT for the 243, more than I've seen in my brass and chambers.
Let's use that figure anyway in QuickLOAD with the other values as used by Nosler and we get:
48.5gn ............. 48,578 psi ......... 3,599 fps
52.5gn ............. 64,052 psi ......... 3,909 fps
So, stranger and stranger! Even with this abnormally high case capacity, that bullet at that COAL with Nosler's maximum charge of that powder is calculated as being 4,000 psi over-pressure!
The revised (59.6gn) case capacity isn't apparently that far out from what Nosler's data say - the loading set gives 52.5gn H414 a 101% fill-ratio; QuickLOAD calculates 99.9%, close enough to show nothing here is seriously awry. MVs though are a different matter, there being another significant discrepancy. QL calculates 3,909 fps from a 24-inch barrel despite being 4,000 psi over SAAMI maximum pressure; Nosler gets 3,982 fps from what should be a SAAMI compliant combination - and with some leeway at that to cover people using different capacity brass, primer model etc.
Unfortunately the online Barnes Bullets 243 data don't list this bullet, Hornady #10 has its 58gn VMax but not H414; Lyman #50 also has the 58gn VMax and this time H414 too, maximum charge 50.0gn in Remington brass (pretty well guaranteed higher capacity than Nosler therefore producing lower pressures and allowing slightly higher charges) for 3,776 fps. (Shown as a compressed load.)
Interestingly, my most recent copy of the Speer manual lists loads with Winchester brass and in its technical notes on the cartridge stresses that the 243 Win sees unusually large variations in case capacity between makes and that the following data is for that Winchester cases only and mustn't be used with other makes.
In summary, I'll also be interested to see what Nosler says in response to Uncle Buck's email as there are some very odd, I'd go further worrying, aspects to that load shown in the table. ....... and that's before we get a blown primer with the starting load as Uncle Buck did!
jimmymac
Jim McGregor
That's pretty harsh. All I did was ask a serious question and you come back and bust my balls. I really appreciate your thoughtful response. This is tough crowd.
My apologies. I thought you were being sarcastic.
The straightforward answer to that is 'No' if the QuickLOAD user relies on the program's default values. The two key ones that can change results very substantially indeed are the fireformed case's actual capacity as opposed to an average as held in QL and the actual freebore in the chamber. Just inputting your powder, charge weight and bullet may give a reasonably accurate result if various parameters match those that the program's compiler has put in as default values, but can equally be 'out' by several percent.
Note I say 'freebore', not COAL. A common misconception spread around and which basic use of QL has strengthened is that pressure is dependent on seating depth. It IS, but only at the COAL where the bullet is touching the rifling and that may not be what the bullet has been seated to.
Take two identical COAL scenarios where a cartridge is loaded to 2.800" COAL for a short action. In #1, it is a short FB chamber and the bullet ogive is almost on the lands. Once pressure gets up after ignition, the bullet hits the lands with just a few thou' of movement in the case-neck and as the case obturates in the chamber, the volume in the case underneath the bullet as loaded is that of the combustion chamber, or nearly so as there will be a very small increase from case expansion / obturation and the marginal amount of bullet movement.
In scenario #2, the round also starts at 2.800" as the shooter wants it to fit the rifle magazine, but the chamber freebore is such that if he is seating bullets for single-loading the revised COAL would now be say 2.950" or even 3.000" when the ogive is just off the lands. After ignition, a mere 3,000 or so psi pressure sees the bullet move out as far as the lands where it is checked. Let's say that's at an equivalent of 3.000" COAL. The combustion chamber size has now increased by the volume of 0.2-inches by the bullet calibre, enough to increase the working capacity to reduce pressures considerably. Experienced handloaders, especially those who loaded for the 308 Win back in the days when much ammunition ran at pressures that saw 5,000-7,000 round plus barrel lives (but allied to LOTS of nice smooth erosion) know that the mechanisms apparently go even further in that the bullet getting 'a run at the lands' appears to see it engraved and on its way down the barrel at a lower chamber pressure than one that sees a serious check or is stopped completely by the rifling until pressure rises enough behind it to force it into the rifling.
Vihtavuori's #1 reloading manual has a look at this in its technical description pages of what generates pressure. It takes a standard 7.62mm 145gn FMJ loading and seats the bullet progressively deeper in the case by a set amount, Three or four COAL reductions occur without affecting either chamber pressure or MV, then the final largest one shown, actually reduces both metrics in direct contravention of the common belief.
Dusty Stevens
Shiner
Yes he should. Something is wrong for sure the max loads are usually start loads
Sounded sarcastic to me too, and many of the responses you got to your question seem to be pulled right from someone's A$$. I don't shoot the 55 out of my 243 since it wan't accurate for me. I do however shoot the 70 B-tip and B-king over 45 grains of 414. I started there and worked up to 47 with the 55's and shot a few boxes but I still got better accuracy with the 70's. If I had seen 48.5 as a starting load for 414 I would have though Nosler was crazy.
There was a thread on here once about a certain powder in a 284 I think. It was the same powder I use in my 6.5x284. He quoted a load about 4 grains above what I shoot with that powder and my load with a drop tube comes to the bottom of the neck. I told him it couldn't be right because 4 more grains just would not fit.
Thanks for your response.
I tried the 55 gr. bullets because they were inexpensive. But they weren't accurate in my rifle, either.
Talked with a tech at Nosler today and did not get satisfactory responses to my concerns. He essentially said "We don't make mistakes. And I am an expert on internal ballistics and you don't understand."
From now on, I'm going to stick with Sierra, Berger, and Hodgdon loading data and check loads with QuickLoad.
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jimmymac
Jim McGregor
You can think what you want but you’d also be wrong about my intent. I don’t understand why you or the OP took it that way. It was a legitimate question. I don’t own that software. I know almost nothing about it. I certainly didn’t deserve the response I got questioning if I should even be allowed to own a firearm. That’s messed up.
Go back to the beginning of this thread. In post two I tried to help the OP by looking up some data in my book to cross reference his findings. I also complimented him on being smart enough to stop shooting. Does that sound to you like a guy who was being a butthole or trying to be friendly?
So many of these threads on this board devolve this way. I’ll blame it on grumpy old man syndrome. It’s as good as any explanation.
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Unless I'm mistaken, and I might be, Quickload is theoretical as are most of the external ballistic programs which provide drop, windage, etc..
Nosler's reloading data is based on actual reloading research.. I don't mean to imply that you were at fault either..
Be careful pitfalls can be costly regardless of fault.
Nosler's reloading data is based on actual reloading research.. I don't mean to imply that you were at fault either..
Be careful pitfalls can be costly regardless of fault.
OK, I have my flame retardant suit on.
How come NO ONE even mentioned the possibility of an over-charge?
It has been 2000 years since anyone infallible walked the earth--just saying.
I have screwed the pooch a time or two in my lifetime (and that includes 50+ years handloading)
Things happen.
Thank you for the opportunity to add my thoughts.
Gary
If the inputs are modified to suit actual values case capacity and COAL - easily enough done - it is often remarkably accurate. Bore dimensions aside (and I believe there is a way to adjust things for that too), there are two weaknesses IME - you cannot change primer brisance so there is no adjustment factor for 'mild' or 'hot' primers. This is a particular issue with some cartridges with a small primer / small flash-hole brass option. As a rule, QL will overstate pressures and velocities significantly for 308 Win 'Palma' brass combinations for example. (But don't take that as gospel and make assumptions based on it!) Secondly. some of the propellant metrics' values are 'out' IME (not just me, others say this too) so I trust calculations for some powders more than others.
The great thing about QL is that it allows desktop evaluations of combinations off the range as well as the modeling of combinations that aren't in reloading manuals. (This is a particular issue for us in Europe as with the majority of Hodgdon and IMR powders now banned by the EU, three quarters or more of some combinations in manuals other than Viht's and Norma's own online or printed data are now no good to us and we have some powders, mostly Nitrochemie products the US doesn't, so they're not included in any US publication.) It also allows a closer focused approach to starting loads. Some in manuals are ludicrously low - as much as 15-20% below maximum in Hornady's data - and you're at risk of burning the barrel out working up in 1% increments. (When I started reloading 30 odd years ago and Hodgdon powders, then made in Scotland, started to be sold here, Hodgdon didn't give starting loads, only maximum values with an instruction to reduce those by 6% to obtain a starting point, except for H110 and another few ball types where it was 2 or 3%. I've found that 6% or so very useful ever since on all makes of powder and QL becomes another tool to help here.) All of the bullet and powder companies use QL extensively for exactly the same reasons - to reduce testing time and costs by identifying possible winning combinations and looking for safe but not too low starting loads.
However, as others have said on this topic, it's an aid not Holy Gospel and loads / results should always be compared to published pressure-tested data where they are available. And as with data from any source, initial loads should be chosen with any possible error such that it sees too low pressures and then worked up very carefully on the range looking for pressure signs and comparing chronograph readings against QL predictions. I'd rather than have an additional trip to the range and an extra load development session to get 'a feel' for MVs and 2 or 3 round groups and MV spreads than grab data off the program and rush into what may turn out to be high-pressure and/or useless loads.
For QuickLoad users only (others please do not reply):
Using the the Nosler .243 Win. load data for the 55 gr. FBHP bullet, the published max load of 52.5 gr. of H414, OACL of 2.51", case capacity of 53.9 gr. of water (with the bullet seated in the case), and a 24" barrel, how do you not end up with an excessively high projected Pmax?
The only way I found was to reduce the weighing factor down below 0.25.
And how do you determine a correct value for the weighing factor?
Thanks
Using the the Nosler .243 Win. load data for the 55 gr. FBHP bullet, the published max load of 52.5 gr. of H414, OACL of 2.51", case capacity of 53.9 gr. of water (with the bullet seated in the case), and a 24" barrel, how do you not end up with an excessively high projected Pmax?
The only way I found was to reduce the weighing factor down below 0.25.
And how do you determine a correct value for the weighing factor?
Thanks
Sarcasm is often suspected but more often a figment of imagination, those who use it have a lot to learn .
Be glad you started at the lightest load.Was the rifle damaged,No ? Put the lid back on that powder container,put the Nosler manual back on the shelf .Try another powder load combo from a different manual .
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