Firearm damage from high pressure rounds
- Thread starter Alpheus
- Start date
Big JD-From the hills
CGN Ultra frequent flyer
- Location
- Saskatchewan.
A chronograph is an extremely useful tool for checking your loads.
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Some adventurous individual decided to load his 223 Ruger No.1 a bit on the warm side. Known to be a strong action. Apparently he was getting 4000 fps muzzle speeds and his particular rifle was none the worse for having done that. However the brass didn't fare as well. Not recommended of course.
I love the .223 R case on the far right! LOL
Signs of over-pressure are primers backing out; ruptured primers; breech face printing on the case; cases hard to extract; or unable to extract.
I bought some cheep Maxxtech steel cased 9mm ammo a while back. in the first two boxes, I had two instances where the gun jammed shut (Norinco NZ85); in both cases I had to drive the cases out to get the gun open. Primers were backing out, case head heavily imprinted, and case expanded tight in the chamber. Even though there was more recoil, it did not overcome the gripping pressure of the case on the chamber. After sending photos of the cases and showing the cases to the dealer, he promptly gave me a store credit with which I bought dies, bullets and primers and powder, and am again back reloading. I have full control over quality now.
Note; Lessons Learned:
Reloading data is only as good as the reloads themselves. Maintain good quality control....
Every 100-150 rounds check your powder charge. I have had a locking screw back out on my powder measure, and got heavier charges. I discovered this by weight a couple of charges after reloading over 400 rounds. I am in the process of pulling all of those bullets, and reloading those shells; a lot of work that could have been avoided.
While I have a lot of work to do, weighing did help me avoid firing any of these rounds (2.75 gr. over max in the manual) in my firearm.
I bought some cheep Maxxtech steel cased 9mm ammo a while back. in the first two boxes, I had two instances where the gun jammed shut (Norinco NZ85); in both cases I had to drive the cases out to get the gun open. Primers were backing out, case head heavily imprinted, and case expanded tight in the chamber. Even though there was more recoil, it did not overcome the gripping pressure of the case on the chamber. After sending photos of the cases and showing the cases to the dealer, he promptly gave me a store credit with which I bought dies, bullets and primers and powder, and am again back reloading. I have full control over quality now.
Note; Lessons Learned:
Reloading data is only as good as the reloads themselves. Maintain good quality control....
Every 100-150 rounds check your powder charge. I have had a locking screw back out on my powder measure, and got heavier charges. I discovered this by weight a couple of charges after reloading over 400 rounds. I am in the process of pulling all of those bullets, and reloading those shells; a lot of work that could have been avoided.
While I have a lot of work to do, weighing did help me avoid firing any of these rounds (2.75 gr. over max in the manual) in my firearm.
X2 on that. This isn't rocket science or alchemy.
Here's something to consider when it comes to 98 Mauser Actions. Several European commercial firearms companies built some very impressive high pressure magnum chambered rifles on those actions. NO they didn't X ray them and maybe didn't even magnaflux them before milling or grinding off the tops of their receiver rings for scope mounting and to clean up unwanted roll stamps which designated military use.
Just as an example, many were converted to 338Win Mag, 7mm Rem Mag and a myriad of others. The Brazilians used to and maybe still load their 7x57 Mod 1908 Mausers with 140 grain SPBT to 2900 fps with relatively fast powders for use in equatorial heat. That's a pretty stiff load and a duplicate velocity load is mentioned in the Lyman manual that is safe in the 93 Mauser it was tested in.
It boils down to this. If you are looking to get your brass to last for many reloads then load to moderate pressures. If you need a handload to hunt with then load for the ranges you are willing to shoot so that the velocity and trajectory are manageable. Once your brass starts to flow, you've reached close to 70K CUP. That's when as guntech mentions it's definitely time to back off your powder charge by 5-10%.
As for modern commercially produced rifles, they are stronger than ever before. The heat treatment and metallurgy is also better than its ever been.
Late war, rifles can be tricky and if you want to load them hot there are a couple of things you should consider before doing so. A Brinnell Hardness test for instance. At the very least, check the locking shoulders for set back, which can occur if the receiver hasn't been properly heat treated. Many of the old shops that specialized in building custom sporters commonly re heat treated these old actions.
The safety margins are HIGH on modern rifles and just about every firearm that was built for military service all the way back to black powder days. Troopies didn't respond well to firearms that could cause them serious injury.
Bench Rest shooters commonly load their cartridges way over the listed specs in our manuals. Most of them develop their own manuals. I do. So does Ganderite.
Just use some common sense and you will be fine.
I have a lovely Swede M38 Husqvarna with a 42 dated receiver. I can't get anywhere even close to maximum pressures with any powder/bullet/primer/brass combination before the bolt lift gets sticky. Even with Swede surplus ammo the bolt lift is sticky. So I hand load it accordingly. It has a very tight bore with what I would call a sloppy chamber but it is incredibly accurate. It shouldn't be but it is. Also, it doesn't shoot well with normal pressure loads. Anyway it gets a couple of grains over minimum specs in my Lyman manual and both of us are happy.
If the high pressures of a magnum cartridge are acceptable in your receiver, IMHO those same pressures should be acceptable with standard cartridges. Your brass will be the indicator every time.
- Location
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Doesn't seem to be a correlation between accuracy and muzzle speed. Sometimes the lower muzzle speeds produce better accuracy as in this example. For the 9 out of 10 loads listed it's the starting load that's most accurate.
Doesn't seem to be a correlation between accuracy and muzzle speed. Sometimes the lower muzzle speeds produce better accuracy as in this example. For the 9 out of 10 loads listed it's the starting load that's most accurate.
Well that’s been my experience too, so it makes me wonder why some folks go to such lengths (like making 223 brass look like 303 brass) to get such speed.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
If you can find it, White Laboratories published a study for a test done for a commercial receiver certification.... years back.
In short, what they demonstrated was the metal "degraded" very rapidly when exposed to repeated pressures in the "proof pressure range". When run at standard pressures, it exceeded the trial rd count by a lot. Magnum pressures put it at the desired limit... going higher and things could break down in a fraction of the test goals.
With alot of modern custom actions AND reinforced brass, the typical bolt lift and pressure signs can be masked. I have seen brass that flicked out of an action with 1 finger that was well into "stupid".
The only way is to compare muzzle velocities vs PRINTED LAB TESTED LOAD DATA. Every load manual will list pressures with their velocities so you can see where you are. No one is interested in down loaded data.... but they are not interested in blowing up customers either.
In this age of "information", shooters and "business" are free to share info that they deem safe but that has not been properly vetted. With so many using custom rifles, that data can be repeated with decent results leading them to believe they are immune to the laws of physics and have found performance that all the strain gauges and engineers around the world are blind to see.
QC and tolerances have improved dramatically but the steel, dimensions and manufacturing styles really haven't changed over the last 25yrs.
pressure is pressure, steel is steel... stuff breaks down at proof pressures. Many of the current mid case performance levels are WAY beyond SAAMI pressure limits. There is no free lunch.
Enough of the doom and gloom... this is the more practical reason to not bother. For those who have read my load tuning articles over the years, I describe 2 accuracy nodes and to use the higher. Well, there are actually 3 and current "cool kids" want to reach this 3rd node.
What I found years back was that 3rds node was a royal B!TCH to keep in tune. It was like balancing on a razors edge... one day, unbelieveable.... next day, horrid. Depending on the ambient conditions, you could also see the change during a match day which was no good for your scores. Great fun to see other competitors go in and out of tune during the day and pull their hair trying to hit where they want.
They usually talk about "hidden" conditions and weird vertical.... sound familiar????
So the vast majority of shooters I know that want to win, moved back to the 2nd node. Here, the tuning is usually stable... some set ups capable of match winning accuracy from -5C to +30C using the same load... nice.
Besides having no brainer consistency, brass, barrels all lasted much longer which was great for the wallet.
How hot is the 2nd node? SAAMI Spec pressures.... yep, them there grey haired white coats might just know a thing or twelve.
YMMV
Jerry
- Location
- In the shadows of the Rockies
Runs deep. Could be that it symbolizes individuality and belief in personal freedom...
Runs deep. Could be that it symbolizes individuality and belief in personal freedom...
[video=youtube;6UocVDjpCJA]https://www.youtub.com/watch?v=6UocVDjpCJA[/video]
Lol
From a practical user's standpoint, yep. But I do no believe that was what the conversation was about. Further to that, different case manufacturers' brass will deform at different pressures. So, yet another variable!
Meh. This conversation amounts to mental masturbation, fun enough, though not productive, really. Not tobe taken too seriously as far as decrying the general concept, methinks. The ones dumb enough to do such things are already pretty close to licking bare electrical wires already, and won't be missed.
There were some pretty interesting experiments published years back, where guys took rifles and just kept loading them up higher and higher until they blew up. Not representative of anything in particular other than as examples of practical, hands-on experimentation to see if what was the common 'knowledge' was anywhere near what would actually happen. One such experiment was done with a none too fresh Win High Wall rifle, loaded with ever increasing amounts of rifle, then pistol powders, ad the results were brass extrusion and failure long before the action was damaged beyond use.
Another such experiment I recall reading of, was with a Japanese Arisaka where they reamed the chamber larger and larger, and fired cartridges loaded with bullets far larger than the bore diameter to see how it would end up. Surprisingly, the rifle endured rather a lot more of that than anyone would have thought too.
Sometimes the hot loads are the most accurate, sometimes they are not. Once in a while I like to make jackrabbits disappear with a 270.
I have a 7x57 that won't shoot anything other than near max loads well but on the other hand a 6.5x55 that definitely prefers loads a couple of grains off minimum specs.
It's like all the rest of the girls we go with or went with, some do, some don't.
It's like all the rest of the girls we go with or went with, some do, some don't.
I can only speak to what I have seen and what I have seen is rifle actions which have deformed lugs and set back locking lug seats. This is not on old 98 Mausers and Springfields but on modern bolt action (and one lever action) rifles. These rifles were not damaged by the firing of a badly over-loaded round but by the continued use of load which were just a little too hot. Most were magnum cartridges though some were .473 diameter. Actions which were damaged in this way included Browning A-bolt, Browning BLR, Sako AV, Winchester Model 70 (post-64), FN Mauser, and Weatherby MKV. In all cases, the owners loaded them too hot and ignored warnings from people who knew better.
