I'm just wondering how many of you will shoot loads that show some signs of high pressure if that's where you also find better accuracy? Or will you cut back to safe levels and take a cut in accuracy? Or will you drop right down to find your node at even lower charges?
Who likes to play with high pressure?
- Thread starter fuzzynuts54
- Start date
It depends on what and how many signs. I don't worry too much about flat primers unless it is in conjunction with something else like hard extraction, ejector marks on the case head, or cratering. I would definitely drop charges if I saw any of the latter signs.
I have seen factory ammo that will produce pretty flat primers when fired, which tells me that primer flattening isn't really a good pressure sign in and of itself.
I have seen factory ammo that will produce pretty flat primers when fired, which tells me that primer flattening isn't really a good pressure sign in and of itself.
I completely understand high pressure does not mean accuracy, but I also do understand every rifle has a number of nodes where barrel harmonics give higher accuracy. Sometimes the next node is in the higher limits of pressure and you can also bet there is another node waiting to be found in the dangerous overload range. I'm not going there, it's just that I have 2 nodes for one of my .300 with 150gr sst's, one of which is one grain over max at 79 gr of imr 4831 and it shows slight ejector extrusion and some primer flattening, the other node is 74grains.
I'm about to work up another for some matchkings. I'm comfortable with some
pressure signs if I also get tight groups there. Maybe I'm just an idiot disaster bound... Anyhow I'm just wondering who else is too.
I'm about to work up another for some matchkings. I'm comfortable with some
pressure signs if I also get tight groups there. Maybe I'm just an idiot disaster bound... Anyhow I'm just wondering who else is too.
My Ruger M77mkII 338win is most accurate at 69.1 and 70.4 grains of IMR4350 and a 250gr SGK. However, the pressure signs are starting to show up by the 70.4gr charge so I use the 69.1gr load which is a nice safe charge and makes the brass last longer.
I will not worry too much about flattened primers in a modern action. As noted, older milsurp actions should be treated a bit more gently. At what temp does your 79gr load show signs? In summer heat or even in colder hunting weather? If it only shows signs in summer weather and you shoot mostly in fall, I wouldn't worry about it.
Mark
fuzzynuts54, If you take your favorite vehicle out for a ride, put it in first gear and run it at hi way speeds all of the time, how long do you think it will last?
The more you hot rod your loads, the more damage you are doing. Instead of getting 5000 - 7000 rounds of acceptable accuracy, with trouble free, reliable operation, you can cut that in half or maybe even less. Depending on your degree of hot rodding.
If you load past maximum, it may be perfectly safe in your rifle. Bench Rest shooters rifles, are often loaded to what would be considered extreme pressures for several thousand rounds. Throat erosion will advance, depending on case capacity.
The reason bench rest shooters can get away with this, is because the tolerances of the chambers, bolt fit etc are a lot tighter and concentric. Most off the shelf rifles, are set up to take any factory round available and therefore the chambers are quite generous. It is also common for a factory rifle to have uneven bolt lug contact, while locked in battery. This is just the tip of the iceberg.
Without proper testing equipment, once you are out of the listed loading ranges, anything is possible. Pressures don't rise incrementally. Because a load is listed at 50,000 cup, with 50 grains of XYZ powder, does not mean you will only get a 2% pressure rise when you add 1 more grain of powder. It may not do anything but on the other hand, it can also increase pressures by 50%. There is no firm and fast rule.
There is a good reason, why the engineers at White Labs, get grey hair, when they endorse a batch of powder. The coatings on each lot are slightly different and burn rates will vary because of it.
Now, for a bit of disclosure. I have blown up more than one perfectly good rifle. 40 years ago, when you could buy Lee Enfields and Mausers etc, new in grease for $10, it wasn't a big deal. 4831 powder, could be had in a 50 lb keg, for $20 or $1/lb by the bag. There were other surplus powders available as well. BL-C for instance, 3031, and several others as well. All plentiful and cheap. FMJ bullets, ran a penny apiece. Primers, were about a penny a piece as well.
We could afford to play. We copied some of P.O. Ackley's experiments. He was a fine gentleman by the way. We blew up a P17 one afternoon, to see if we could. Loaded up a case full of 2400 under a 220 grain bullet in a milsurp case and let her go. Nothing happened, other than a great roar and bang. The bolt lift, was admittedly a bit snug but nothing serious. The case of course was a different matter. It didn't want to extract an we tore off the rim, with the extractor. Jammed a 1/4 in steel rod down the barrel and hammered it out. The primer, was gone, evaporated, no sign of it at all. Other than that, no other damage. The lugs and recesses weren't set back and we were a bit disappointed to say the least.
Next, we loaded up another case, with "Bullseye". Everything else was the same. This time, the results were totally different. The rifle, had a catastrophic failure. The receiver was split in half, the extractor was gone, the barrel was bulged and the bolt wouldn't budge. Understandable. By the way, the rifle was picked from the lower grades that were being sold to amatuer gunsmiths to Bubba, $10 each. The bore in this specimen was mint. Pitted bores, went for $7. This was in the basement shop at the "Bay" in Vernon BC.
Second rifle was from the same place, in the same condition and was an Eddystone P14. We shot a couple of rounds of milsurp out of it and a few handloads, all was well.
Loaded up a milsurp case with 4831, under a 220grn round nose FMJ and fired it off, all was well. Now for a bit of information. 303 British, was loaded with different components during WWII. The 220 grain FMJ, came out of machine gun belts. The original cases, were loaded with what appeared to be a ball powder, maybe BL-C? Much of it was still loaded with cordite sticks and other powders like 3031, were also used, depending on the country that loaded it.
Next, we loaded it with 3031, as much as we could stuff in the case and tap down, under the 220 grain bullet. We loaded the round with a bit of difficulty as the bullet wouldn't compress the powder enough to seat deeply enough, not to engage the lands. When we set this rifle off, it had a Kaboom with the first hot load. Every bit as catastrophic as the P17. The damage was almost identical though. One thing we did notice, was how thin the receivers are on the P series rifles. The barrel tenons are massive though and I surmise that they felt that was where the strength was needed.
Above maximum loads, just aren't necessary. The more powder you add, the more the returns drop.
You just can't trust the metalurgy or components enough to take the chance. I will say, it goes to show how well firearms are made and the quality of the materials they are made from, because a lot of people, are willing to take the risks.
We destroyed several rifles. Mausers, Springfields, Lee Enfields, Carcanos and a Remington 721, that one was not intentional, nor was the M1 Carbine. The only rifles we couldn't destroy, were Model 38 and 99 Arisakas. The M38, was rechambered to 30-06 in the original 6.5 barrel (burned out) and so was the 99, in it's 7.7 barrel. This was a copy of Ackley's experiment and had similar results. The M38 action, is still in use today, as a 257 Roberts and the 99 is also still in use in Saskatchewan as a 30-06, loaded with .312 bullets. They were magnafluxed to check them out but not much else. The 99, was a very rough, late war rifle. Today, it would be a sought after collectable. Such is life.
You just don't know what will happen, it isn't worth it and the game on the receiving end won't be able to tell the difference. Neither will the target.
The more you hot rod your loads, the more damage you are doing. Instead of getting 5000 - 7000 rounds of acceptable accuracy, with trouble free, reliable operation, you can cut that in half or maybe even less. Depending on your degree of hot rodding.
If you load past maximum, it may be perfectly safe in your rifle. Bench Rest shooters rifles, are often loaded to what would be considered extreme pressures for several thousand rounds. Throat erosion will advance, depending on case capacity.
The reason bench rest shooters can get away with this, is because the tolerances of the chambers, bolt fit etc are a lot tighter and concentric. Most off the shelf rifles, are set up to take any factory round available and therefore the chambers are quite generous. It is also common for a factory rifle to have uneven bolt lug contact, while locked in battery. This is just the tip of the iceberg.
Without proper testing equipment, once you are out of the listed loading ranges, anything is possible. Pressures don't rise incrementally. Because a load is listed at 50,000 cup, with 50 grains of XYZ powder, does not mean you will only get a 2% pressure rise when you add 1 more grain of powder. It may not do anything but on the other hand, it can also increase pressures by 50%. There is no firm and fast rule.
There is a good reason, why the engineers at White Labs, get grey hair, when they endorse a batch of powder. The coatings on each lot are slightly different and burn rates will vary because of it.
Now, for a bit of disclosure. I have blown up more than one perfectly good rifle. 40 years ago, when you could buy Lee Enfields and Mausers etc, new in grease for $10, it wasn't a big deal. 4831 powder, could be had in a 50 lb keg, for $20 or $1/lb by the bag. There were other surplus powders available as well. BL-C for instance, 3031, and several others as well. All plentiful and cheap. FMJ bullets, ran a penny apiece. Primers, were about a penny a piece as well.
We could afford to play. We copied some of P.O. Ackley's experiments. He was a fine gentleman by the way. We blew up a P17 one afternoon, to see if we could. Loaded up a case full of 2400 under a 220 grain bullet in a milsurp case and let her go. Nothing happened, other than a great roar and bang. The bolt lift, was admittedly a bit snug but nothing serious. The case of course was a different matter. It didn't want to extract an we tore off the rim, with the extractor. Jammed a 1/4 in steel rod down the barrel and hammered it out. The primer, was gone, evaporated, no sign of it at all. Other than that, no other damage. The lugs and recesses weren't set back and we were a bit disappointed to say the least.
Next, we loaded up another case, with "Bullseye". Everything else was the same. This time, the results were totally different. The rifle, had a catastrophic failure. The receiver was split in half, the extractor was gone, the barrel was bulged and the bolt wouldn't budge. Understandable. By the way, the rifle was picked from the lower grades that were being sold to amatuer gunsmiths to Bubba, $10 each. The bore in this specimen was mint. Pitted bores, went for $7. This was in the basement shop at the "Bay" in Vernon BC.
Second rifle was from the same place, in the same condition and was an Eddystone P14. We shot a couple of rounds of milsurp out of it and a few handloads, all was well.
Loaded up a milsurp case with 4831, under a 220grn round nose FMJ and fired it off, all was well. Now for a bit of information. 303 British, was loaded with different components during WWII. The 220 grain FMJ, came out of machine gun belts. The original cases, were loaded with what appeared to be a ball powder, maybe BL-C? Much of it was still loaded with cordite sticks and other powders like 3031, were also used, depending on the country that loaded it.
Next, we loaded it with 3031, as much as we could stuff in the case and tap down, under the 220 grain bullet. We loaded the round with a bit of difficulty as the bullet wouldn't compress the powder enough to seat deeply enough, not to engage the lands. When we set this rifle off, it had a Kaboom with the first hot load. Every bit as catastrophic as the P17. The damage was almost identical though. One thing we did notice, was how thin the receivers are on the P series rifles. The barrel tenons are massive though and I surmise that they felt that was where the strength was needed.
Above maximum loads, just aren't necessary. The more powder you add, the more the returns drop.
You just can't trust the metalurgy or components enough to take the chance. I will say, it goes to show how well firearms are made and the quality of the materials they are made from, because a lot of people, are willing to take the risks.
We destroyed several rifles. Mausers, Springfields, Lee Enfields, Carcanos and a Remington 721, that one was not intentional, nor was the M1 Carbine. The only rifles we couldn't destroy, were Model 38 and 99 Arisakas. The M38, was rechambered to 30-06 in the original 6.5 barrel (burned out) and so was the 99, in it's 7.7 barrel. This was a copy of Ackley's experiment and had similar results. The M38 action, is still in use today, as a 257 Roberts and the 99 is also still in use in Saskatchewan as a 30-06, loaded with .312 bullets. They were magnafluxed to check them out but not much else. The 99, was a very rough, late war rifle. Today, it would be a sought after collectable. Such is life.
You just don't know what will happen, it isn't worth it and the game on the receiving end won't be able to tell the difference. Neither will the target.
I'm not worried about barrel life, I need a good excuse for an aftermarket. The pressure signs were showing in winter. I know the effects of temperature, i have summer and winter loads. I'm not working into the danger zone, I
just so happen to have a load that shows some pressure signs, I am not going deeper into the over load range to find a node. I'm happy where I'm at.
just so happen to have a load that shows some pressure signs, I am not going deeper into the over load range to find a node. I'm happy where I'm at.
WOW Great post! So much change in attitude towards "safe loads" over the years. I have talked to a bench rest competitor and have been told the primer is always smeared after extraction. I would NEVER want to see that in a sporting rifle. In their world "the faster the bullet gets to the target the better". Word for word from an active competitor......
Many so called mild or ineffective cartridges work just swell in the real world. Why do people think an extra 100-200 fps will kill anything better? Dead is dead. The 7x57 has been wonderful for over a century. Ditto the '06, 8x57, 9.3x92, 6.5x55, 30/30 and so many more when they are used within normal hunting range loaded with appropriate bullets for the game. The painful truth is that you don't need to exceed the maximum loads in any cartridge, EVER. Use them the way they, and the rifles that fire them, were intended and designed. Metal fatigue is insidious in that it does not immediately show up. You may fire hundreds of "safe" overloads in your rifle only to have it dome undone in your hands one day. Why take that chance?
Sure, some pressure sign, In my opinion you are going too far, I don't tolerate any pressure sign. What exactly are you trying to accomplish?
If its more velocity so you could become better hunter may I suggest the new 300 Ultra Supper Duper Pooper Magnumaxium. s**t you don't even have to aim.
The bullet knocks the moose off it's feet if it passes within 10 feet of the critter.
drummerboy73
Regular
I have a load i shoot in my .280 that is over max from the published data. It doesn't show any pressure signs in my rifle and is very accurate. On the other hand it took me a while to find an accurate load in a 30-06 till i went to a much lesser powder charge...then the groups just shrunk. I generally start with a middle of the road load and increase till i find the most accurate load without pressure signs. When i was younger "HOT" was king and trying to wring out every fps i could was a little scary a few times. Now i'm older and a lot more meticulous in my loading practice and go for accuracy first and foremost. Once i find an accurate load i call it quits.
- Location
- The Conservative part of Ontario
My suggestion is to back off, before experience bites you in the face.
Yes, I was a velocity hound too. I didn't blow up any rifles, but I did do a lot of stupid stuff in my early reloading, and I did permanently damage some rifles. I consider myself lucky.
I walked the line, always hunting for a faster load, always pushing the edge.
I've seized bolts shut so they have to be hammered open, broken internal parts on leverguns apparently from recoil alone. Bulged several barrels, and damned near lost my sight from gas blowing back in my face.
Then one day it all seemed to click. WTF do I need that kind of power for?
And I started work on lower power loads. Soon I found that barrel harmonics would also permit the right low power load to be accurate. In fact, usually more accurate that the fast loads for me.
The high power loads, are too fussy, weigh each charge so you don't blow up, temperature sensitivity increasing pressure, bullet type, brand, and composition each affecting pressure. Primers, case differences...just nuts, not worth it.
I no longer use the loads that I used to. Sure, I read about that kind of stuff, but let some one else blow his face off. You see, if you walk the line, sooner or later, some unseen variable will reach out and grab you, and your rifle will be history. If you're lucky, as I was, you won't go with it.
The .300s tend to shoot better on the high end of the range. I was getting a little peeved when the best loads always seemed to show up at the same time as the pressure signs and short case life due to primer pockets. I want a lot more than 3 loadings out of a case.
Getting a pile of Norma cases solved my issue. No doubt the pressure is there, but if I can't see it, the primers stay tight, and the groups shrink so I'm happy.
Getting a pile of Norma cases solved my issue. No doubt the pressure is there, but if I can't see it, the primers stay tight, and the groups shrink so I'm happy.
Long ago, I was pushing a Rem. 600 .308 carbine hard with 748. Somehow a D.A. case got in with the Imperials. Thirty odd years later the bolt handle remains broken off from the 2x4 hammering needed to (unsuccessfully) open the bolt. The B.A. has sat in the back of the safe ever since as a reminder of my stupidity.
Nowadays; a half thou. case head expansion, or, ejector marks, or, heavily cratered/flattened primers, or, stiff bolt lift, and I'm going back to the lower node.
Over the years some rifles have shot their best with over the top loads, and yes its hard to say no when she's begging for it.
Nowadays; a half thou. case head expansion, or, ejector marks, or, heavily cratered/flattened primers, or, stiff bolt lift, and I'm going back to the lower node.
Over the years some rifles have shot their best with over the top loads, and yes its hard to say no when she's begging for it.
just having some fun
CGN Ultra frequent flyer
I did a test last year
Looking for a load in 308 using brass fired in the same rifle as the test (a semi)
Full length resized and trimmed to the same length same brand and brass weight within +- 1 g
Loaded brass 50 rounds in .2g increments -10% to max
My results after firing
Brass length varied by .007 low to high (longer)
Base dia varied by .0015 low to high (larger)
Shoulder dia varied by .0015 low to high (larger)
Just fired them off at targets for groups (made 5 of each)
Top loads brass ejected in a different direction than lower loads 3-4
After neck sizing brass would stick in the chamber when checked so I had to full length resized and re trim brass (after 1 firing unusual for this load / rifle combo)
10 PCs of brass (top loads) had primer pockets loose after next loading and were scraped
So as I see it
Loading to max velocity was not worth it
Best groups were in the middle powder charge
Low brass life
Extra working of brass (and me extra time)
Max charge changed ejecting
Extra wear & tear on rifle
NOT WORTH IT for me
but I Realize every rifle/ load combination is different and not every one gets the same results
Looking for a load in 308 using brass fired in the same rifle as the test (a semi)
Full length resized and trimmed to the same length same brand and brass weight within +- 1 g
Loaded brass 50 rounds in .2g increments -10% to max
My results after firing
Brass length varied by .007 low to high (longer)
Base dia varied by .0015 low to high (larger)
Shoulder dia varied by .0015 low to high (larger)
Just fired them off at targets for groups (made 5 of each)
Top loads brass ejected in a different direction than lower loads 3-4
After neck sizing brass would stick in the chamber when checked so I had to full length resized and re trim brass (after 1 firing unusual for this load / rifle combo)
10 PCs of brass (top loads) had primer pockets loose after next loading and were scraped
So as I see it
Loading to max velocity was not worth it
Best groups were in the middle powder charge
Low brass life
Extra working of brass (and me extra time)
Max charge changed ejecting
Extra wear & tear on rifle
NOT WORTH IT for me
but I Realize every rifle/ load combination is different and not every one gets the same results
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