Conservative Data in Load Manuals

[Randy85]

Hey Savage shooters, first post here, long time reader. I was wondering what you guys do about the conservative load data given in todays manuals? Im working on a new 308 with Sierra load data and I am getting roughly 200 FPS less velocity than what is published for the given charge. My components and rifle are slightly different than they test but 200 FPS seems a bit much. I would like to take it out to 700 yds max and keep the bullet drop to a min so Im looking to move the bullet pretty fast for a long range whitetail rifle.

Im using the following

165 gr SBT
new winchester brass, FL resized
CCI LR primer
43.5 Gr of IMR 4064 (which is the published max)
COL of 2.8" ( slightly longer than their published of 2.75", which is why I felt safe to work up to max charge)
24" barrell (they test off of a 12FVSS with 26")

My chrono avg is 2562 FPS, they publish 2750 as what I should be seeing. I am not getting "bad" pressure signs at this charge but the primer is flat, not like cratering and filling the circle flat though. All of my groups working up to this have been around MOA but, Im not worried about grouping yet.

Do you guys work up past published max's to get the extra FPS you are looking for? Change powders to slower/faster? Thanks in advance.

[bearcatrp]

Each rifle is different. You can have 2 identical rifles and one will not like the others ammo it shoots. Whats published is conservative loads so they won't get taken to court from someone blowing there hand off from a heavy load. Thats why you work up loads, watching for pressure issues like primers flattening or blowing out, case swipes, etc.. Heck, my 308 load is about 2 grains above max load listed in the book. My pet load with Hornady 178 ELD-X is 43.9 gr of varget getting 2720 fps. Just be cautious when going above listed book amounts. Its your ass if something goes wrong.

[Rick_W]

Best grouping rarely happens at max velocity. Better to have consistent small grouping at a lower velocity than larger patterns at higher velocity. IMO

[Fotheringill]

I like my ugly face to stay the way it is.

For a chosen powder, i.e. Varget, I take the middle of the road load from at least three sources, average those and use that number as a starting point going up and down from that number and never going above the maximum load average of the same sources. So far, it has worked and I have not had to have reconstructive facial surgery.

[darkker]

1) I was wondering what you guys do about the conservative load data given in todays manuals?
2) Im working on a new 308 with Sierra load data and I am getting roughly 200 FPS less velocity than what is published for the given charge. My components and rifle are slightly different than they test but 200 FPS seems a bit much.
3) I would like to take it out to 700 yds max and keep the bullet drop to a min so Im looking to move the bullet pretty fast for a long range whitetail rifle.
4) Im using the following
43.5 Gr of IMR 4064 (which is the published max)
COL of 2.8" ( slightly longer than their published of 2.75", which is why I felt safe to work up to max charge)
5) My chrono avg is 2562 FPS, they publish 2750 as what I should be seeing.
6) I am not getting "bad" pressure signs at this charge but the primer is flat, not like cratering and filling the circle flat though.
7) Do you guys work up past published max's to get the extra FPS you are looking for? Change powders to slower/faster? Thanks in advance.

Sorry for crowding the reply here, spacebar is acting funny... Lots of very bad info here that keeps getting repeated online, so lets get you straightened out. 1) Especially with most data that is actually tested and not a re-print, why do you think the loads are conservative? Since every single bottle of powder sold has a big fat warning saying: "Drop loads 10% when switching lots". Some powder re-sellers actually list nominal lot variations, most powders have a allowable lot swings of 10%. Since data RARELY tells you WHEN the data was tested, and they NEVER list lot numbers tested.... Buying the same brand name on the bottle in no way means you have "The same" powder as was tested. There is a bit more to this, that gets covered in the following questions you asked. 2) So we know the powder you are using isn't the same, and you state what you are loading isn't the same. Well, when things are different, they are different. Some manuals shoot loads in a particular rifle for published velocities, but essentially all SAAMI cartridges are tested using standard protocols; meaning: Minimum-spec universal receivers, minimum bore/groove spec barrels, minimum spec chambers/throats. A mass produced rifle is none of those things. With mass produced tooling there are varying states of allowable wear, that is why drawings have tollerances. No mfgr. stamps a rifle with the final specs that a chamber, or barrel was built to. So again, things are different. 3) This is a preference deal, but from a 100 yard zero that is only 7 mils of "up", that is as easy as it gets. The greater issue is the velocity. That takes you near 1350 fps, which is dangerously slow, when it comes to operational velocity. 4) Again, they didn't list lot numbers tested; so don't assume you have the same burning rate in your powder. Having less jump to the lands is again a bit of an assumption, but will increase your pressure as there is less by-pass. 5) They didn't say that is what you "should" be seeing, they claim in minimum spec equipment, that is what they produced. Different equipment, different lots, different results. 6) "Signs" are as helpful as seeing Jesus in your toast.... They don't tell you ANYTHING resembling accuracy, they tell you whether or not your reached the yield strength of your equipment only! SAAMI originally used lead crushers, LUP. then pressures increased and they discovered that those units weren't accurate, so they moved to very carefully calibrated Copper Crushers, CUP. Again pressures in firearms increased and things went south. Long ago this was all over the gun rags of the day. SAAMI held some very carefully controlled reference lots of powder and sent it to the major players, such as Remington, Federal, et al. They all used their calibrated crushers in the same test equipment and found that when testing OVER approximately 45,000 psi, that copper crushers reported THE SAME load reporting differing results by 20-25,000 psi. That is why current testing is done with Conformal transducers, or some piezo equipment. Again as no one since Olin in the 1950's openly states what specs their alloy in cases are, a random reloader, using random powder, in a random case, with random primers, in a mass produced rifle; isn't mystically going to know if he is at SAAMI pressure for the cartridge he is firing. He only knows that his primers or cases reached their tensile strength and streched beyond the yield point. From the Pressure Trace work we've done, and some insider info from a few case makers; a reloader will "notice" some of the "usual signs" of pressure when you are around 70-75,000 psi. 7) Yes I have loaded beyond a books published max CHARGE, but it isn't because some limp-wristed lawyer backed off the loading data..... Book max velocity is SAAMI max pressure for that cartridge. Regardless of the charge weight(within reason now, sometimes powders run-away) if you reach book max velocity you have also reached book max pressure. I've posted some of my pressure testing of Superformance powder in the Creedmoor here. In those tests, my first 8# of Superformance was 12% SLOWER than what was tested in the 9th Hornady manual. My second 8# jug is very very slightly faster than that data. So did I go past book pressure? No I did not, I just went past book charge amount. Cheers, and happy loading!!

[Randy85]

Sorry for crowding the reply here, spacebar is acting funny... Lots of very bad info here that keeps getting repeated online, so lets get you straightened out. 1) Especially with most data that is actually tested and not a re-print, why do you think the loads are conservative? Since every single bottle of powder sold has a big fat warning saying: "Drop loads 10% when switching lots". Some powder re-sellers actually list nominal lot variations, most powders have a allowable lot swings of 10%. Since data RARELY tells you WHEN the data was tested, and they NEVER list lot numbers tested.... Buying the same brand name on the bottle in no way means you have "The same" powder as was tested. There is a bit more to this, that gets covered in the following questions you asked. 2) So we know the powder you are using isn't the same, and you state what you are loading isn't the same. Well, when things are different, they are different. Some manuals shoot loads in a particular rifle for published velocities, but essentially all SAAMI cartridges are tested using standard protocols; meaning: Minimum-spec universal receivers, minimum bore/groove spec barrels, minimum spec chambers/throats. A mass produced rifle is none of those things. With mass produced tooling there are varying states of allowable wear, that is why drawings have tollerances. No mfgr. stamps a rifle with the final specs that a chamber, or barrel was built to. So again, things are different. 3) This is a preference deal, but from a 100 yard zero that is only 7 mils of "up", that is as easy as it gets. The greater issue is the velocity. That takes you near 1350 fps, which is dangerously slow, when it comes to operational velocity. 4) Again, they didn't list lot numbers tested; so don't assume you have the same burning rate in your powder. Having less jump to the lands is again a bit of an assumption, but will increase your pressure as there is less by-pass. 5) They didn't say that is what you "should" be seeing, they claim in minimum spec equipment, that is what they produced. Different equipment, different lots, different results. 6) "Signs" are as helpful as seeing Jesus in your toast.... They don't tell you ANYTHING resembling accuracy, they tell you whether or not your reached the yield strength of your equipment only! SAAMI originally used lead crushers, LUP. then pressures increased and they discovered that those units weren't accurate, so they moved to very carefully calibrated Copper Crushers, CUP. Again pressures in firearms increased and things went south. Long ago this was all over the gun rags of the day. SAAMI held some very carefully controlled reference lots of powder and sent it to the major players, such as Remington, Federal, et al. They all used their calibrated crushers in the same test equipment and found that when testing OVER approximately 45,000 psi, that copper crushers reported THE SAME load reporting differing results by 20-25,000 psi. That is why current testing is done with Conformal transducers, or some piezo equipment. Again as no one since Olin in the 1950's openly states what specs their alloy in cases are, a random reloader, using random powder, in a random case, with random primers, in a mass produced rifle; isn't mystically going to know if he is at SAAMI pressure for the cartridge he is firing. He only knows that his primers or cases reached their tensile strength and streched beyond the yield point. From the Pressure Trace work we've done, and some insider info from a few case makers; a reloader will "notice" some of the "usual signs" of pressure when you are around 70-75,000 psi. 7) Yes I have loaded beyond a books published max CHARGE, but it isn't because some limp-wristed lawyer backed off the loading data..... Book max velocity is SAAMI max pressure for that cartridge. Regardless of the charge weight(within reason now, sometimes powders run-away) if you reach book max velocity you have also reached book max pressure. I've posted some of my pressure testing of Superformance powder in the Creedmoor here. In those tests, my first 8# of Superformance was 12% SLOWER than what was tested in the 9th Hornady manual. My second 8# jug is very very slightly faster than that data. So did I go past book pressure? No I did not, I just went past book charge amount. Cheers, and happy loading!!

Thanks for the information. What I am hearing is given my "Unique" situation is things could be different, and I understood that from the begining. I didnt realize you could expect a difference of 10.7% just based off of a few small differences.

What I am also hearing is that I can work these loads past the published max charge, albeit very carefully. My goal is to reach 2750 FPS, my calculated drop is 30" or 4 MOA less if I can get there. The less I dial up the more accurate I think I can be, its easy to dial up and shoot at paper all day, where I hunt you might get one shot per weekend. The hog that I took last weekend was 450 yds per a laser taken with the slower load that I took to the field anyway.

[darkker]

With IMR 4064 and a 165gr bullet. 2750fps will be over-pressure anyway you slice it, in a factory rifle. If that doesn't bother you, fine; but understand what you are doing.

You can in fact go beyond the book charge amount, while not going past SAAMI max pressure. Remember that that info isn't concrete, I'm not recomending that anyone does this; I'm saying it is very much possible to do. Sans pressure testing equipment, the most reasonable AND accurate way to know pressure, is to watch the velocity. Your barrel is shorter, that will hurt velocity; but there is no fixed amount per inch that you can calculate without pressure testing. You may also have a slow barrel which allows gas by-pass. So to know where your burning rate falls compared to the data, you REALLY need to start at the start, and chrono things working up to where you have been shooting. Preferably with a few different powders. That way you can reasonably approximate where your burning rate is, and if your barrel is slow, or just that powder.

So simply for an example:
If powder A shows you: That compared to the book charge, you are consistently 200 fps slower than book expectations.
Powder B shows the same, Powder C shows the same. THEN likely you have a slower barrel, whether that is due to length, diameter, etc is open for discussion, but it is slow none-the-less.
IF:
Powder A is slow, Powder B & C are not; THEN Powder A simply has a slower burning rate than the book.
You should never assume that you will ALWAYS match book velocity per amount of powder. Back to your mass produced barrel being looser than SAAMI test equipment.

[Randy85]

With IMR 4064 and a 165gr bullet. 2750fps will be over-pressure anyway you slice it, in a factory rifle. If that doesn't bother you, fine; but understand what you are doing.

You can in fact go beyond the book charge amount, while not going past SAAMI max pressure. Remember that that info isn't concrete, I'm not recomending that anyone does this; I'm saying it is very much possible to do. Sans pressure testing equipment, the most reasonable AND accurate way to know pressure, is to watch the velocity. Your barrel is shorter, that will hurt velocity; but there is no fixed amount per inch that you can calculate without pressure testing. You may also have a slow barrel which allows gas by-pass. So to know where your burning rate falls compared to the data, you REALLY need to start at the start, and chrono things working up to where you have been shooting. Preferably with a few different powders. That way you can reasonably approximate where your burning rate is, and if your barrel is slow, or just that powder.

So simply for an example:
If powder A shows you: That compared to the book charge, you are consistently 200 fps slower than book expectations.
Powder B shows the same, Powder C shows the same. THEN likely you have a slower barrel, whether that is due to length, diameter, etc is open for discussion, but it is slow none-the-less.
IF:
Powder A is slow, Powder B & C are not; THEN Powder A simply has a slower burning rate than the book.
You should never assume that you will ALWAYS match book velocity per amount of powder. Back to your mass produced barrel being looser than SAAMI test equipment.

I like your test here. I have a few powders that are acceptable for 308 and several manuals. I am going to load up some test rounds with mid weight charges and see where they chrono vs. the manuals. I didnt think about the barrel not being a .308 dia either. I do cast for a 30-30 and it likes a .311 bullet for that matter so I should have thought of that. I will also slug the barrell for a measurement there as well. Vacation days are coming so I will report back soon.

[darkker]

No sweat. There was an article written some years back by a gent on another board, have it bookmarked at home. But have Fire dept business tonight so not making it back before late and the storm hits us.
Anyway, the specifics escape me, so this is for a point, and not an exact. Point was that 308 bullets over a certain weight tended to shoot more accurately with a bore that was slightly tighter than a certain spec, whereas the lighter ones preferred a bit looser tollerances. Was a very good read, and will link to it when I can.

[m12lrs]

Well my experience has been that Reloading manuals are conservative. You can usually exceed their max safely if you are careful. Every barrel is different though.

But over the years I have found that your most accurate load is not likely to be at that max. Also why put all that wear and tear on your rifle and brass. Just back off and enjoy it.

Now if you want to develop a long range hunting load pushed to the max I can understand that. No reason to use it often after load development though.

[MZ5]

The best way to keep yourself in one piece when handloading is to stop adding powder when you reach book-max charge or book-max speed, whichever you reach FIRST. There are actually solid reasons why a rifle might be at SAAMI-max pressure but NOT reach the speed listed in the book. However, it basically will not happen the other way around.

Darkker has provided good info, particularly because he expressly said you may well be over-pressure if you keep going up, and that is a CHOICE you must make for yourself.

It'll be interesting to see what you get speed-wise from your alternate powders.

[darkker]

Here is the link i spoke of:
http://thefiringline.com/forums/showthread.php?t=558025
And since I'm home, here are some visuals on why "signs" are stupid.
This series had witnesses from members on this board. No off sound, no bolt lift issues, no primer or case growth issues; but was fixing to blow the end of the barrel off. Oh, and it was a charge from the MIDDLE of the book data for the weight class.


The load data from the side of a Creedmoor box. The worshippers of the Creedmoor, typically think this is "conservative" as well.

[adammiddagh]

I like to reference the books to get in the right neighborhood, but use quickload software to get the best estimates.

Quickload is very expensive, but worth it depending on how much you load.

If you have a chronograph and measure your case volume, you can get very close pressure estimates, burn %, and fill volume.

[darkker]

Be cautious with QuickLoad, it isn't the standard many think it to be.
As far as powders from Eurenco, Hartmut gets most any info he asks for, maybe Thales, prior to then asking for tech help from GD. I know he wasn't getting jack from Hodgdon, and really struggles to describe anything with newer tech coming out of GD's St. Marks plant. So his work is based off very limited bomb testing, which is inherently not terribly accurate. The progressive powders from GD seem to be a mystery to that program. The changing burning curve on Superformance in particular.

If possible, i'd like to test a somewhat progressive powder from Rhinemetal this Christmas. We'll see how the scheduling goes.

[MZ5]

Indeed, QuickLOAD is most emphatically NOT the "best estimate" compared with a pressure-tested load manual. I've owned a copy of QL for many years, and have used it extensively with old standards (30-06, 243, 308, etc.) with not-so-standards (6.5-284, 6.5 Creedmoor when it was new, etc.), and with wildcats (6.5-300 WSM aka 6.5 Leopard was the most interesting one). With some powders and cartridges, such as older manufactured IMR-4198 in the 223, it was absolutely dead on the money. With almost anything manufactured by General Dynamics these days, but particularly the sphericas (all Winchesters and all Hodgdon-labeled sphericals), it is sometimes pretty close and sometimes dangerously far off. I nearly blew up that 6.5 Leopard and my arm and face along with it when I listened to QL's suggestion for a charge of Win Supreme 780. OTOH, it gave reasonable estimates using H-1000 in that rifle.

Just be cautious, and mainly be _aware_ that going 'off-book' carries very real risk. I like to draw this analogy: Just because you haven't been killed in a car crash doesn't mean it can't happen next time.

[LongRange]

MZ5 when you say "I nearly blew up that 6.5 Leopard and my arm and face along with it when I listened to QL's suggestion for a charge of Win Supreme 780" did you actually blow up the action? or blow the head off a case? just curious what actually happened.

[JASmith]

The SAAMI pressure standard includes an allowance for a pressure standard deviation equal to 4% of the maximum pressure.

That means that a cartridge having a 60,000 psi maximum pressure has a 15% chance of actually producing pressures of less than 57,600 psi and a 15% chance of being greater than 62,400 psi.

Rifle and ammunition manufacturers are expected to keep these numbers in mind when designing and testing rifles and ammunition.

Should we believe such large deviations? Yes, i have tested about a dozen different handloads where pressure data is published using the RSI strain gage. The load to load variation is definitely consistent with the SAAMI standard even though the variation within a particular load is small.

Bottom line -- heed the manuals even though you might think the loads are too light. Precious little in trajectory can be obtained by adding a grain or so of powder and a lot can be lost if the statistics line up against you for your rifle and load.

[darkker]

JA,

That very Pressure Trace II system from RSI is where the graphs I posted, come from. Have you played with any of the progressive GD powders and traced them?
Really kinda fun to debunk the "magical" claims that some bullet producers spit out.

[psharon97]

About the most I can get out of my 308 shooting a 168gr Sierra TMK is around 2715 using a magnetospeed chronograph. Taking the rifle out to 1000 yards, the range estimates that the Vortex ballistic calculator produces are extremely accurate. Even at these velocities for my 308, shooting to 1000 yards still requires substantial elevation adjustment to reach the target. Furthermore, ~2700 is about what most reloading manuals say you'll be getting at MAX charges. As others have said here, work up your max charges extremely carefully.

Now, if you want to shoot to 700 yards that doesn't require AS MUCH adjustment to reach the target, you'll be looking at a cartridge like 7mm RSAUM, or necking a short magnum down to 6.5 if you want to stay on a short action platform. For example, if you wanted to shoot the Berger 168g hybrid, and achieve an aggregate of 2715fps, you're still going to need ~18.75MOA to get there. To put things into perspective, my velocity for my 7mm rem mag shooting a 180 berger hybrid is around ~2890fps. To shoot to 700 yards, I will still need ~14MOA.

[MZ5]

MZ5 when you say "I nearly blew up that 6.5 Leopard and my arm and face along with it when I listened to QL's suggestion for a charge of Win Supreme 780" did you actually blow up the action? or blow the head off a case? just curious what actually happened.

Blown extractor, primer blown and the cup flowed/swaged onto the firing pin, broken case, brass engraved into the shape of the bolt face & stuck there (once I got the bolt open), bolt stuck, lots of smoke and little bits flying my way, and WAY too high of speed. So no, the action was not destroyed. However, that was 'predicted' to have been quite a mild load. Good thing I started (at what _should have been_) low. ;-)

[LongRange]

gotcha...i had pretty much the same thing happen once or twice...but mine were not accidents...it was done to see how far things could be pushed before things started to fail...probable lucky im still around after some of the things ive done but ive always been one to push things right to the ragged edge...and past.

that said i had and played with quick load for a few months and stopped using it because i had to tweak the numbers to get it to match actual field velocities which i didnt care for...im old school when it comes to all of this...i load,shoot and watch for OBVIOUS/VISUAL pressure signs...and yes like darkker says all the time...when you see pressure your most likely over pressure...and i agree with that but for me personally and after pushing as far as i have im comfortable running over book max charges and velocities...but thats ME and MY equipment...for anyone else do your own testing and work up slowly...and when switching ANY OF YOUR COMPONENTS drop your charge weight and work up again...i learned the hard way about case capacity about 8yrs ago when i switched to a different brand of brass with a real hot load.

[barrel-nut]

Maybe try a different bullet/powder combination. I get a pretty consistent 2715 fps with 43.5 grs of Reloder 15 and a 168 gr. Hornady A-Max from a 24 in Savage barrel. This is also an accurate load in all of my rifles. I've gone up to 44 grs with it, but in our hot summer heat down here I start to get pressure signs.


Sent from my iPhone using Tapatalk

[bigedp51]

Case capacity with .223/5.56 cases can vary from 28.0 to 30.6 grains of H2O case capacity. This means the chamber pressure can vary 6,000 psi between these two case capacities. So your components used and your rifle can vary the pressure generated.

In the Lyman manuals they use universal receivers and pressure test barrels with chambers and bores cut to minimum SAAMI dimensions and this would generate the highest pressures. They also use data using strain gauges glued to the barrel when a specific firearm is listed in testing.

Quickload requires a chronograph to get semi-accurate guesstimates, and you adjust the burn rate in Quickload until the two velocities match.

Even reading primers or measuring the case above the extractor groove below is a guesstimate because of brass hardness.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/relo...-rifle-reloads

Bottom line your manuals also tell you to start low and make workup loads checking for signs of excess pressure. Meaning all loading data is a guesstimate for "YOUR" firearm and components being used. And measuring expansion just above the extractor groove is the best method for the brass you are loading.

Now ask yourself why the table below was created, and why you can't load a 30-06 to the same pressure as the .270 Win in a modern rifle like a Remington 700?
Answer, there are too many older 30-06 rifles still being used today, and published load data is for the weakest link in the chain.



When measuring just above the extractor groove you are measuring the unsupported base of the case. And when the diameter of the base increases by the limits above you have exceeded the elastic limits of the brass.



The same applies when brass flows into the ejector, meaning exceeding the strength and elastic limits of the brass.

[ttexastom]

the method that is explained by bigedp51 is the .one that I have been using for years. ken waters explained this method many years ago. funny to me that with (waters) method on the 263 express back in early 60's that his load data matches up with nosler today with imr 4064. this is data that did not have a computer to tell you that. when my chronograph starts to match book velocities for a cartridge. time to stop! adjust seating depth and tune for best accuracy.

[MZ5]

This article:
https://www.shootingsoftware.com/ftp...%2019%2004.pdf
shows, with solid data, why measuring case head expansion, pressure ring expansion, whatever you want to call it, is very very nearly useless. Yes, if you get that expansion, you should back off a fair amount. However, brass variation is such that it _may_ tell you something completely different, or next to nothing at all.