WARNING - 4955

I'll post more details in a separate thread and won't be doing load refining or real accuracy testing for a while now.

But I can tell you this from four powders tried:


Superformance was entirely unsuitable for this application

H4831 was very useable but won't realize the velocity possible as it's still too slow a burn rate for this application - never thought I'd see 4831 being on the slow side for ANY .257 wby load.

H4350 hit the highest velocity before starting to show pressure signs - just heavy cratering, no stiff bolt or anything like that - nonetheless hit unacceptable pressure indicators at 4277 feet per second

H380 realized almost as high a velocity as 4350 and consistently at 2-3 grains lighter charges. But showed pressure at slightly lower velocities, still way over 4000 fps.

I am not going to proceed further until I also try rl17 as I have a sneaking suspicion it might be the king. However, it is not in my hands yet - I've already paid for it, but need to get to the city to pick it up haha.

If rl17 disappoints it's between h4350 and h380, whichever is most accurate I guess, the difference in velocity between the max of each was not enough to matter to me.

@ButterBean was right…again….

I never would have dared to put h380 in a 257 wby if it weren't for that menace! Oops, I mean, if it weren't for that man!
Thanks for that info. I didn't mean to derail the thread. I never thought RL17 would work. I was looking into RL26, VVN560, and IMR 7828. Can't wait to get the build in my hands to start playing around with it.
 
Thanks for that info. I didn't mean to derail the thread. I never thought RL17 would work. I was looking into RL26, VVN560, and IMR 7828. Can't wait to get the build in my hands to start playing around with it.
@ButterBean will attest that all those are waaaaaaaaaaay too slow burning for the 75 or 90 grain hammers in the 25-06 or .257 wby. I'll keep ya informed on how things go :)
 
My experience with 4955 is about the same......spikes very quick. Works just fine in the 30-06 & 6.5x55 but I used the crony to find top loads as the normal warning signs dont work out very well= blown primers aint cool!
 
ADDITIONAL DISCOVERY

not all these Barnes 75 x bullets are identical I just discovered.

I had got 6 boxes for a total of 300 bullets

They are very clearly (now) not from the same lot and they must have notably changed the tooling or something back in the day (as well, the projectile weights vary from74-76 grains over a sampling of 20 or so, certainly not as consistent as the more modern Barnes I've worked with.

I couldn't believe I hadn't noticed this earlier, great reminder to go ahead and be your crazy OCD overthinking overanalyzing selves and inspect everything. But there's two well defined projectile lengths in my batch that I all just dumped together when I was hbn treating them - by the way the hbn does seem to totally mitigate the copper fouling problem these bullets had a reputation for -

half of them are 0.932" inch long. And the other half are 0.913" inch long.

That's not nothing.

The longer bullets have a 0.439" bearing surface, a pointier nose, and a slightly but notably smaller hollow point.

The shorter bullets have an overall blunter profile, bigger HP, and a 0.420" bearing surface.

This could further explain what happened here. I can't prove it's what happened in hindsight but if you had been right on the edge of pressure to begin with and then like a bonehead jumped a whole grain in a .243 size case AND the next bullet happened to have 19 thousandths more bearing surface that would further amplify problems, for sure.

Or would it? What do y'all think? Does this matter at all?

Either way now I have bullets to sort into two piles 😑
 
Note the difference in HP size

I don't know if you can see the length difference in the pics but you'll see two different rings scratches into the bullet noses - one from a resized 243 case neck used to spin a ring onto the surface where it made contact with the bullet when I put the bullet nose into the case, and one from a 223 neck.

The shorter bullet has way more distance between those two rings, it has a shorter bearing surface and a more gradual tapering of the ogive up to that larger meplat.

Also, note the "HBN sheen" of the bullets 😁. Anyways, food for thought.
 

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I saw a thread a few weeks ago about pressure spikes due to really cold weather. I don't know if that affected your situation but something to think about
 
Had the same issue with Nosler BT 130 some time ago where the shape was different like you described. Reached out to Nosler with no response.
Definitely changed my pet load and had to start over.
 
I will not be touching this powder with a 10 foot pole from here on out. Thank God they've discontinued this particular enduron powder, imr 4955. This stuff is downright scary. Freaking dangerous. Just wanted to beat a dead horse ☠️ 🐎 for y'all.

Got to do some shooting to test a bunch of different loads for velocity data.

I was shooting with my beloved old savage 99 in 243 Winchester with the old school Barnes x (not tsx), 75 grain, hbn treated.

I have never seen a powder go from mild cratering to a siezed action AND TOTALLY BLOWN OUT PRIMER over an increase of one grain of powder. Except with 4955. I gave it another chance after this exact same thing happened in a 300 win mag about 7 years ago…

I was taking notes and chrono readings - Winchester headstamps, fed large rifle primers.

45 grains - nowhere near enough pressure, sooty looking, very rounded primers, only 3140 fps. Went up to 49.

49 grains - no pressure signs AT ALL. 3452 fps.

50 grains. Slight cratering, no pancaking of the primer, no shiny spots on headstamp. Easy extraction 3469 fps. Note - only 17 fps change from 49

51 grains - case failure - wouldn't extract, had to "manhandle" the lever violently to get it open. Primer COMPLETELY BLOWN OUT THE BACK OF THE CASE. SOOT EVERYWHERE. And the real shocker: 3631 fps!!!!! 😱😱😱

Went from very minor cratering to a failure to hang on to the primer over one grain increment. Increased 17 fps from 49 to 50 and increased 162 fps from 50 to 51.

WHAT THE HECK!!!!!

Any of you ever see anything like this ever?

Also again, fair warning, if you own this powder be so freaking careful. It's a disaster waiting to happen. I'm honestly shocked I haven't heard more about it.

Had nothing to do with the bullets, brass, gun…used the same bullets with 4 other powders and didn't see any funny business like this working up.

Just weird.

And scary.
So let me see if I understand your issue.You have clearly and up front admitted to the mistakes you made, like jumping up in too big increments etc, but you continue to maintain the 4955 is "CRAZY Spikey" and doesn't produce the traditional pressure signs before going over the top.

You loaded OLD Barnes 75 grain bullets, that were well known to hit peak pressure quite a ways BEFORE cup and core or the new Barnes with the Bands cut into them. The high pressure and heavy fouling is why Barnes changed the bullet designin the first place. On top of that you had two different lengths and two different bearing surfaces.

You then used a very slow powder, 4955, for which I cannot even find a published load by Hodgdon for 75 grain bullets. The 75 grain loads I did find generally top out around 3400*3500 FPS, with powder that is a lot faster than 4955 and also isn't compressed. They do publish a load for 90 grain Speer Spire Point Cup and Core bullets with 4955, which is min of 43.6 at 2926 and a max of 47.4 at 3153 out of a 24" barrel, and producing 58,500 PSI. You hit 3452 at 49 grains, you then ignored the velocity plateau at 50 grains, which is already 2.6 grains above the 90 grain published load and kept pushing, using a lever action as your test bed, that likely has a 2" shorter barrel than Hodgdon was testing with.

So all the data in the world from the Chronograph and published load data to tell you you were at max but somehow it is the spikey powder's fault that another full grain finally popped the primer? Things like falttened primers, rim and web expansion, ejector marks and sticky bolts means you are already WAY over pressure. Sticky bolt in a bolt action tells you that pressure is from 15,000 to 25,000 PSI too high already, and in some guns even more than that.

I think the powder is just fine. The issue is the current fascination with trying to push every load to the absolute max and not investing in the proper pressure gear to do that safely.
 
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So let me see if I understand your issue.You have clearly and up front admitted to the mistakes you made, like jumping up in too big increments etc, but you continue to maintain the 4955 is "CRAZY Spikey" and doesn't produce the traditional pressure signs before going over the top.

You loaded OLD Barnes 75 grain bullets, that were well known to hit peak pressure quite a ways BEFORE cup and core or the new Barnes with the Bands cut into them. The high pressure and heavy fouling is why Barnes changed the bullet designin the first place. On top of that you had two different lengths and two different bearing surfaces.

You then used a very slow powder, 4955, for which I cannot even find a published load by Hodgdon for 75 grain bullets. The 75 grain loads I did find generally top out around 3400*3500 FPS, with powder that is a lot faster than 4955 and also isn't compressed. They do publish a load for 90 grain Speer Spire Point Cup and Core bullets with 4955, which is min of 43.6 at 2926 and a max of 47.4 at 3153 out of a 24" barrel, and producing 58,500 PSI. You hit 3452 at 49 grains, you then ignored the velocity plateau at 50 grains, which is already 2.6 grains above the 90 grain published load and kept pushing, using a lever action as your test bed, that likely has a 2" shorter barrel than Hodgdon was testing with.

So all the data in the world from the Chronograph and published load data to tell you you were at max but somehow it is the spikey powder's fault that another full grain finally popped the primer? Things like falttened primers, rim and web expansion, ejector marks and sticky bolts means you are already WAY over pressure. Sticky bolt in a bolt action tells you that pressure is from 15,000 to 25,000 PSI too high already, and in some guns even more than that.

I think the powder is just fine. The issue is the current fascination with trying to push every load to the absolute max and not investing in the proper pressure gear to do that safely.
You're pretty late to this discussion. Nothing you've said here hasn't been said. Though you're right about one thing…I've been up front about my own mistakes. I legit hadn't seen this kind of variation in projectile dimensions before. That's new to me. Learning experience.

I know all about "old Barnes" or OLD Barnes - I'm happy to report that HBN treating them does in fact mitigate a lot of issues both regarding pressure spikes and also the horrendous copper fouling of barrels they were so notorious for - and my old savage 99 is an old and well shot barrel, she fouls! But hbn is awesome stuff.


I do still feel this powder is crazy spikey and no condescending lectures long after I've already acknowledged everything I did wrong and long after other concerned people already stated everything you've just said is going to change that fact as I see it BECAUSE…I was just as stupid with some other powders (full honestly) - this was a brain fart times ten, as I've stated all I've really loaded in the last two years has been larger belted magnums where one grain increments is perfectly normal - treated this tiny case the same way, thankful that I did not pay for my absent mindedness any more dearly than this - but the point is, no other powder in my 13 (I think?) years of handloading has ever come close to this rapid a spike.

I know about ejector swipe, primer flattening, cratering, incipient case head separation, I inspect cases with calipers to check post firing dimensional changes, look for neck splits, etc

I will say, I've had velocity plateaus waaaaaay below pressure in the past and maybe that was just a fluke but it gave me some reason to believe I wasn't hitting pressure yet IN CONJUNCTION WITH the fact that there was ZERO ejector swipe, ZERO primer cratering or even excessive flattening, ZERO reluctance to extract.

I ALWAYS practice my "one finger rule" when doing load ups - can I open the bolt or the lever with one finger easily? It allows me to feel even slight increases in resistance that ham fistedly manhandling the action might miss. There was, again, absolutley zero resistance to extract, and zero traditional pressure indicators on the brass or primer. Only thing warning was that velocity plateau which I do once again acknowledge

It went from nothing to a frozen action and a blown primer in one grain. Even from a 243 sized case I've NEVER seen that before ever. This also happened to me ONCE in my loading career in a .300 win mag. Again, no pressure signs on the brass, primer, or extraction…went up one grain in that big case and froze up the action so hard I needed a mallet. Primer was oddly still intact that time. 4955 again. If you wanna use it (provided you have it, it's discontinued) that's fine…just be careful is what I want to tell everyone. Be more careful even than usual with this one.

I've loaded thousands of rounds well over a decade now with about two dozen different powders in 10 cartridges of diverse case-to-bore ratios to learn from and have had this happen EXACTLY TWICE, and both times were with 4955. Moreover I haven't used it for anything else. Gave it a second chance, regretted it again. I tried making a 300 win load with it once and had this happen. I tried making a 243 load with it once and this is what happened again. Draw your own conclusions but don't tell me the powder is fine and it's 100 percent my error. I humbly acknowledge my errors in full, there was even multiple posts to that effect a while back that I suspect you must not have read before jumping in.

If you wanna tell me that it's coincidence, "the powder is fine", and ignore that unignorable real world comparative data (be interesting to do the math on what the odds are…) be my guest! Everyone is responsible for themselves but if I truly believe something is dangerous and I care about other people who use it I'm going to say something, even if it means revealing to the world my own stupidity about some things as well, which this thread has done and I won't try to hide.

I hope anyone who reads it heeds the warning both about the powder that's either crazy spikey or just hit 1/24+ (the number of other powders I've used with no such incident first time around) odds for me twice in a row haha (1/576 odds that's that's all there is to this that works out to - I'll admit my practices haven't been that much different with other powders in other cartridges - that variable remains the same)

And also the warning to be safe, be careful, and above all else DONT RUSH

I ONCE AGAIN HEREBY ACKNOWLEDGE THAT I TREATED THIS WHOLE THING IN AN IMPATIENT MANNER AND I THANK THE GOOD LORD THAT I DIDNT SUFFER ANY SERIOUS CONSEQUENCE FOR BEING FOOLISHLY HASTY

this is not an activity to ever do in a hurry and I was reminded of that. I do appreciate your concern if that's what this is. But everything you've attempted to chastise here has already been beaten to death in this conversation and I've fully acknowledged with all humility my own error!!!!! How many more times should I do that? I'm not going to withdraw my statement that, my error acknowledged, 4955 scares the **** out of me at this point and I care enough about everyone else on here to share my experience even if it makes me look like an idiot as well.

PS - superformance is definitely slower than 4955 (it appears one above the 4955 on the burn rate chart, but my experience in every cartridge I've used it in has shown it to be slower than they say it is - either way, if you don't think my experience indicates anything, they're immediate neighbours on the chart which I did consult before loading…and it did just awesome with that bullet.

this is kind of awkward now after multiple people have (in this case ignorantly) asserted in a somewhat condescending manner that 4955 is simply too slow and what was I thinking??? Thing is, again, it's very similar to superformance, as in nothing between them on the almighty burn rate chart

AND HODGDON HAS LOAD DATA FOR 75 GRAIN BULLETS IN A 243 ON THE SUPERFORMANCE CAN!!!! 🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣. It's one of the best for that class. And as you so aptly noted these Barnes pressure up harder than the 75 grain hornady from that on the can data. So if anything slower would be more forgiving than faster. Food for thought
 
I have followed this thread from the start. I intentionally did not post earlier. I was NOT trying to beat on you or be condescending when I made the comments I did. You have admitted the errors you made so there is no point in berating you and you owe no further mia culpas. My point was, pushing over published velocities for a 75 grain Cup and Core by a lot, and over published load weights for 4955 for an only slightly heavier projectile means you are over max pressure. You were at max at 49, over at 50 and way over at 51. How over pressure shows up varies greatly for many reasons, not the least of which is the gun used. There has been a ton written about primers and ejector marks NOT being reliable indicators of pressure. However, blown primer pockets are every time.

You are free to believe the powder is the problem but you are wrong. No matter how often you have gotten lucky using your specified loading practices, it is just luck, certainly not skill. The one fair conclusion you could draw from your experience with 4955 is the one you have already stated, learn and significantly change your loading practices, I think that is a great and fair take away.
 
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