DoneNOut
Well-Known Member
My first blown primer/seized bolt in 25yrs was with my .243 AI. I've had powders spike quick. Even with a slow Retumbo burn rate powder N570. I think it is the big case, small neck design.
WARNING - 4955
- Thread starter Calvin45
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In smaller case sizes, I move up .5 grns per increase. 1 grain seems like a lot.
choprzrul
Well-Known Member
After hearing they were discontinued, I am using whatever Enduron powder I have to fire form new brass at starting charge weights. Seems to work fine in that capacity.
Never could get the stuff to give me good velocities when doing load development
Never could get the stuff to give me good velocities when doing load development
DoneNOut
Well-Known Member
.5 is what I do on everything. One grain is a jump, but in 30 cal cartridges I get warning signs before cataclysm. Lol
Doing a ladder test with 1gr steps?.5gr steps as big as I'll go, and that's only where I'm pretty confident that the load is too low, but test it anyways. .2 or .3gr steps when I start getting up there.
4955 sure seems slower for that bullet weight. And hbn on top of that. Can't say I'm surprised looking at all of your variables.
4955 sure seems slower for that bullet weight. And hbn on top of that. Can't say I'm surprised looking at all of your variables.
QuietTexan
Well-Known Member
I did read your post. You obviously didn't consult enough load data to see that 3140 FPS is very much so inline with starting load data and 75gn bullets. You made an assumption on signs, and didn't work up. You skipped max, and over-pressured a case. There is a point where traditional pressure signs of primer, head swipe, etc, go away due to the pressure spike holding the case against the chamber wall, and it stays that way right up until the weakest link fails. Which is usually the primer.
That's an assumption based on kernel size and shape. It's not always true. Load density isn't something that can be reduced to something like "is the case full". The ability of the kernels to pack, how far you drop them, how compressed you actually are in the case. Going to 105% is not hard if you load longer than standard COL, even 110% without a crunch in possible based on seating. You need to take a step back and evaluate your assumptions, because you blew up a case after making a huge jump in propellant weight.
Let's look at some QL data:
You shot a 75000 psi load and blew a primer. End of story. Do the work up, man, it's your face to keep unrearranged. I'm 1000% in favor of pushing limits, but please do it smartly.
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ResearchinStuff
Well-Known Member
1 gr powder change is 2% in that size case. No reloading manual will suggest changes that large, because it's unsafe, as you found out. You also did it in an older rifle than probably can't handle pressure like a new bolt action might. You're lucky it wasn't worse. Either change your loading practices or up your disability and life insurance policies.
Calvin45
Well-Known Member
Fair points. And much obliged for the QL data. Of course it doesn't tell you everything for every individual rifle. I do realize it was silly to be impatient and jump from 45 to 49. I did have 46 47 48 loaded up even.
However this really is getting derailed here. It seems a few of you refuse to acknowledge what I've voluntarily shared: I've NEVER had this happen with any other powder in any cartridge with other bullets in any conditions etc…. I've already listed them earlier but while I'm not as old and wise as many many folks on this fine forum and am learning things every day, I have been handloading for 13-ish years now, thousands of rounds loaded and tested in 10 (I think) different rifle cartridges, using over 2 dozen different kinds of powder over that time. I have a lot to learn, always will, but this isn't my first rodeo haha. It's happened like that twice with this powder. Exactly 0 times with 24+ other kinds of powder. That's all I really made this thread to say, because I care about others and just wanted people to know that it's EXTREMELY fast-spiking with no traditional signs on the way there
My real world experience has been that velocity plateaus are certainly not always a sign of pressure. And I've heard a few people put forth the idea that at truly high pressure the signs go away because the case is somehow part of the load bearing system now…there's so many issues with that theory and so many holes that can be poked in it im not going to get into it now but it's besides the point anyway.
I have experience.
I acknowledge I was in a hurry and stupid things happen then.
This doesn't change that 4955 is crazy spikey and doesn't give much of a warning, at least not compared to
Rl25
Rl22
Rl23
Rl17
Rl19
Imr 4350
H4350
Imr 7828
Imr7828 ssc
H 4831
H4831 ssc
H1000
Superformance
Leverevolution
Im4064
Imr 4451
Imr 7977
Imr8133
H50bmg
H870
H380
Imr 4895
Imr8208xbr.
H110
And a couple others I can't remember off the top of my head.
Absolutley I was reminded of the fact that 1 grain increments may not be wise in such a small casing - I will admit that over the last year all I've really been loading and shooting has been 257 wby, 300 win, and 358 Norma - 1 grain increments make sense with those at least for me
Been a while since I played with the 243 and again, on that note I shall be changing my ways haha, no more 1 grain steps.
BUT IM NOT TAKING IT BACK!!
4955 is different I'm telling you! DIFFERENT!!!!
Calvin45
Well-Known Member
I'll change me ways I swear!
. No i do realize you guys are all right about that - as I just replied to Quiet Texan, I guess all I've been loading for the last two years has been 257 bee, 300 win, and 358 Norma. Much bigger cases, and for them 1 grain ladders are no big deal.
I do still maintain that 4955 is the only powder I've ever worked with that has done this and without pressure signs leading up to the primer fail (and no the case doesn't somehow hide pressure over a certain point - MAYBE somehow the brass could hide it but the primer sure won't)
But going forward I have re-learned my lesson and will work with cartridges of this capacity in .5 grain increments
Calvin45
Well-Known Member
@QuietTexan I will say thanks again for
Sharing your quickload data…
However what a reminder of why I'm not gonna buy it. Those mathematically calculated guess numbers don't even roughly compare with my in the real world data.
My 43 grain load was already going about 200 fps faster than your program suggests it would. And that's with an hbn coated bullet and bore. If anything it should have been slower at a given charge weight.
Yeah…I'm thankful but not really sure I have much to learn from computer generated numbers that my real world chrono data says are wrong by an awful lot.
Sharing your quickload data…
However what a reminder of why I'm not gonna buy it. Those mathematically calculated guess numbers don't even roughly compare with my in the real world data.
My 43 grain load was already going about 200 fps faster than your program suggests it would. And that's with an hbn coated bullet and bore. If anything it should have been slower at a given charge weight.
Yeah…I'm thankful but not really sure I have much to learn from computer generated numbers that my real world chrono data says are wrong by an awful lot.
Calvin45
Well-Known Member
I'm kinda slow today…who's a legend? Me for blowing a primer? Or Quiet Texan for making a legendary post?
Again, just one of those days, maybe I need more coffee…
Calvin45
Well-Known Member
You're right (and thanks for not being condescending about it!) - haven't worked with small cases for a while and did indeed do a silly thing. But I guess I'm lucky…4955 is the only powder I've ever not "got away" with doing something silly like this with, and so I do still beleive that it is fundamentally more abrupt to spike and unforgiving of error compared to most other propellants. Just trying to share my experience in the hopes that some others might read it and be doubly cautious if working with this powder. I've also been reminded to be more meticulous and patient myself, which I appreciate.
milo-2
Well-Known Member
I bought a fair share of 4955 when it first appeared, drawing a blank on what cartridge I wanted to use it in, think 6 Comp Match. There is nothing linear in loading, but my first thoughts were this powder is way faster than what it was advertised at. I shelved it and sold it to a guy with advice.
Then 2 yrs later I revisited 4955 and this time i found it way slower for my application than anticipated and of course did not have the case capacity to make it work, fire sale again.
Both times, the buyers loved it.
Losing 4166, 4451 and 7977 hurt, and heard good about 8133 too!
Then 2 yrs later I revisited 4955 and this time i found it way slower for my application than anticipated and of course did not have the case capacity to make it work, fire sale again.
Both times, the buyers loved it.
Losing 4166, 4451 and 7977 hurt, and heard good about 8133 too!
