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Old January 5, 2015, 02:39 PM   #1
reynolds357
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Starting loads

*****Note********
*****I am not advocating anyone do anything, only proposing a question for thought******
I have been pondering something about the old advice of "begin with starting loads and carefully work up to maximum loads." Do not take my following question wrong. I am not advocating unsafe practices. I simply have begun to question this logic.
It is a given that back in the day when the loading data was worked up using brass voodoo and even in the day of the very imprecise "lup" and "cup" measuring devices it was a given that we must begin at starting and work up. The system of measurement was very imprecise. When I load using the old books, it is obvious that some of my rifles showed signs of pressure before maximum load.
It was also common in those times for the factory rounds to be loaded very conservative, coming nowhere near the velocity one could attain by reloading.
Jump forward to modern reloading. The test data is done in pressure transducer monitored barrels that are extremely precise. Lot to Lot consistency of primers, brass, and powder has become very good. Factory loads are being loaded to max Saami pressure (same pressures adhered to in modern reloading data).
I have personally observed that none of the modern data has shown signs of pressure in any of my rifles I have reloaded for over the past 10 or so years. I am estimating that is 60 rifles at the least.
The factories now run max Saami pressures.
The reoloading manuals now accurately obtain their pressures the same way the factories do.
If it is safe for factories to turn out 62,000 psi loads as their "starting load" for a rifle, why is it not safe to begin at the same point with a handload?
Is it still necessary to begin at "starting load"? I still begin under max and work up, but I am really beginning to question the old logic behind the practice. I definitely understand why we used to "work up," but I am seriously questioning the necessity of it with the modern data.
(I am also assuming everyone uses same brass, primer, and bullet of the load data they following) I am aware some brain surgeon will use Amax data with a full spitzer and create pressure problems, but I am just leaving those knuckleheads of of the discussion.

I will have to admit that many years of wildcatting have probably skewed my thought process. I am used to working with the unknown. I have also observed over the years just how much it actually takes to blow up a bolt action rifle. I have never done it, but back in the day, some others tried. The only way they could do it was using the wrong burn rate powder.

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Old January 5, 2015, 03:18 PM   #2
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I suppose that I'm inclined to agree WRT pressure (with everything else correct). But I (in my very short life as a handloader) am also interested in economy. I would personally like the load that does the job I want to do with the least amount of powder. If that is my approach, then the old logic would still apply (indirectly).

I have loaded some test loads without working up the load, just using a middle-of-the-road load. Those often are for purposes of just throw-aways for getting my scope on the paper without trying to work up a load at the same time, and for less expensive fouling shots that I don't care about before using more expensive factory loads (economy again).

Looking at the pressure side when all things are not correct, however, one could argue that the old-logic also has a built in safeguard for some oh crap cases, like when I transposed a couple of OAL digits and ended up with my bullet jammed into the lands a tiny bit. It wasn't a big deal at the starting load (fortunately, in my particular case) but could have been an issue if I started with the max. Even if it takes a lot to do real harm to the action, I still don't like to push it.

So there's my non-committal response, just to give me a reason to post today.
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Old January 5, 2015, 03:19 PM   #3
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"...when the loading data was worked up using..." When do you think that was?
"...Amax data with a full spritzer(sic)..." An A-Max is a 'full' spitzer. The type of bullet is irrelevant anyway. You load for the weight, not the maker or shape.
"...The factories now run max Saami pressures..." Who told you that? The manufacturers don't load for a specific pressure, SAAMI or CIP. They load, using powders reloaders can't get, to specific velocities.
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Old January 5, 2015, 03:26 PM   #4
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Sir I see your point and agree to a larger extent.

When I do a 'new load' for something that I already load for, I seldom 'start' at the 'starting load'. But then I do have a few years of experience.

However when I move into something totally new to me, after I check and compare as many listings as I can find, I will normally use an average 'starting load'.

Then comes the 'ain't listed or been done' loads. These pucker me for a long time before I will work out my 'starting load'. Sometimes they aren't all that much of a 'starting load'. I still have all of my fingers and haven't damaged anything.... so far.

I would council for the new loader to start with the listed 'starting load' and work from there. After they have a working understanding of the burn progressions of the powder/s they uses, maybe a little deviation from the listed start.

Safety first. When there is any question, don't.

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Old January 5, 2015, 04:09 PM   #5
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Two points.

Commercial loads don't use cannister grade powder.

Commercial ballistics labs know exactly what the final pressure, in their brass, with their primers, and with their bullet is from the final interaction with the non-cannister grade powder they've used for that lot.

Every time you crack open a new can of powder, or change a component, you need to work back up safely. If you could measure your starting pressures, in your rifle, you'll find they are not going to be consistent with the published data across every powder and load. Even the same load will have different pressures based on the condition of the barrel over the course of useable life.

I hope this puts things into perspective.

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Old January 5, 2015, 04:25 PM   #6
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Commercial ammo from Remington, Winchester, Federal, Hornady and all those others are typically loaded to SAAMI spec average pressure. The velocity each lot gets will vary a small amount about the average velocity they get across several lots of powders.

Some commercial ammo places use SAAMI spec pressure and velocity test barrels. The test data for a lot of reloading data is not done in pressure transducer monitored barrels that are extremely precise; Sierra Bullets uses visible indicators on primers and cases. Few commercial barrels have the same internal dimensional specs as the SAAMI test barrels; they're typically a bit bigger, but match grade barrels are often smaller; much smaller in bore and groove diameters. The velocity you get with the factory ammo in your barrel is usually a bit slower than what's advertised. Factory tests often used fixed mount barrels that don't move back in recoil; they shoot the same load out faster than what us humans get holding the rifle against our shoulders.

Did you ever compare the release force factory loaded ammo bullet's need to be pulled out of their cases compared to what your reloads have? You may be surprised. More neck grip means more pressure for a given recipie. There's about a .003" spread in SAAMI specs for bullet and groove diameters for a given caliber. Imagine a fat bullet in a skinny bore and its peak pressure and velocity compared to the reverse thereof. Rarely, does anyone get concerned, nor even know about such things causing varying pressure and velocities.

Few sources of loading data is derived from SAAMI spec test barrels with their transducer specs used to measure peak pressure. Most data's based on the developers impression of pressure signs on fired cases and primers with icing on that visual cake being muzzle velocity with a hand held rifle, not a fixed mount one. How many reloading data sources use the "SAAMI twist" loading ammo into their test barreled actions?

Bottom line; most reloading data's derived with a rubber ruler to measure stuff. At least they say you should start low on charge weight then work up in small steps. Ten people shooting any given lot of ammo in the same rifle will get chronograph readings for average muzzle velocity over a 90 to 100 fps spread; often and they'll probably be several fps different than what the factory gets in their test setups.

Last edited by Bart B.; January 5, 2015 at 05:05 PM.
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Old January 5, 2015, 04:26 PM   #7
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T'Oheir, bullet shape makes a tremendous difference. Bearing surface is a major factor on pressure. The A-max is by no means a spitzer. The box may or may not say Spitzer, (I have no idea without looking) but the A Max is a tear drop shaped bullet that has very little bearing surface. Run a mic down the bullet if you do not believe me. The shape of the bullet is the reason that it will only shoot in the best barrels.
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Old January 5, 2015, 04:36 PM   #8
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Bart, I agree that most factory ammo has a death grip on the bullet. I tried to pull down a box of Winchester .270 Win. ammo and it was impossible to pull using a kinetic bullet puller until I used a seating die to break the neck tension.

The thing I do not completely agree on is that the factories are running conservative on their loadings. Much of the premium factory hunting ammo sold today is screaming. Chronograph usually is higher than numbers on box. What strikes me as odd is that I consistently see pressure signs on factory ammo. I bought 4 boxes of 6.5 Creed just to play around with and get me some fire formed reloading brass in the process. The primers had definite pressure signs and all 80 pieces of brass wore a definite extractor mark after they were fired. I bought some factory .270WSM and had the same issues with the addition that I had to tap 4 out of 20 out of the chamber with a brass rod. Granted, my chamber is on the tight side, but the go gauge will just barely go.
None of the above Max loads I have loaded for the WSM have even begun to replicate the pressure signs of the factory ammo.
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Old January 5, 2015, 04:38 PM   #9
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Honestly, as long as you arent changing any of the components in the manual , and are using a modern gun in good condition, i dont see how you could screw up using any published data. I rarely start at the bottom, unless I am just looking for a light load...but thats just me
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Old January 5, 2015, 04:55 PM   #10
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I usually look at starting loads and velocity, and I find that usually the loads I have started with are either their most accurate loads tested, and work my BTO's first then work on velocity, and out of a few dozen different bullet, powder, rifle combos only one load with one bullet type and powder charge givin as a "starting load"gave me signs of too much pressure,ie hard bolt lift..

Mostly my handloading is for hunting bullets, other than the .243 bench rifle I got from Taylorce1 which I do use target style bullets, having said that some of the older loads that I have read about are way over what is now considered max loads, I guess back then the powders and bullets and rifles could be safely pushed to max with no detriment.
Take Bob Hagels book "Game Loads and Practical Ballistics for the American Hunter", super read....but wow check out his loads man!!
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Old January 5, 2015, 05:23 PM   #11
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The "maximum pressure load" is never my goal. Even when I'm working up defense rounds (I only load for handguns), I seek a round that shoots consistent in the gun for which I am designing it, and with a low Standard Deviation.

Cases in point with my Smith 686+ 3"bbl 357 Mag:

158gn Speer GDHP (#4215), using Power Pistol.
Speer #14 data: Minimum 7.5gn; Maximum 8.5gn.
My "set" round: 8.3gn; 1099 fps; SD = 13.03.

Same bullet, using HS-6
Speer #14 data: Minimum 8.7gn; Maximum 9.7gn.
My "set" round: 9.0gn; 1115 fps; SD = 7.93 (not a typo).
This round is plenty potent and shoots sweet as apple pie.

I have worked up these load combinations beyond my "set" round. But this is where these load combinations run best in my gun. And I have no doubt that I could work these load combinations beyond the Speer published data maximum - but why? I found what I'm looking for.

So to tie back to the OP's original (theoretical) question: If everything is equal, yes, you could start with max loadings. Heh, but everything is never completely equal.

Back to reality: Less often than not, I start with the minimum loading. A good example is if I'm creating a good 38+P round, but I know I'll be shooting them in an L-frame 357. I know I'm not going to be anywhere near the limitations of the firearm, so there's no point in starting at the bottom.
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Old January 5, 2015, 06:12 PM   #12
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jim8115, if you find load data for a 30 caliber cartridge that was developed in a maximum spec factory barrel with at least a .3087" groove diameter and your barrel's one of those from Great Britian with a .3065" groove diameter, plus your lot of powder's the hottest one made recently along with your case neck tension very high, you will probably see maximum pressure signs on cases and primers with that load's reduced starting out charge weight 10% or more below listed maximum.

I've seen such starting out loads do that with a .3092" diameter 30 caliber bullets shot in a barrel with a .3070" groove diameter. I had to back off 3 grains from that charge weight to stop having very flattened primers.
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Old January 5, 2015, 06:15 PM   #13
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Am I wrong in thinking that max pressure will vary from chamber to chamber? In other words, if my rifle's chamber is tighter than the chamber of Hornady's test rifle, won't the pressure in my rifle be greater than that shown in the Hornady manual for same bullet, same OAL and same charge?
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Old January 5, 2015, 06:22 PM   #14
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higgite, you're right. Any smaller dimension inside the barrel tends to increase pressure for a given load. There's less space for the powder gases to expand in.

One other thing most often left out of load data is how far the bullet has to jump to the rifling of the development barrel. The load's OAL number is meaningless; especially if it lets your bullet jump .001" to the rifling in your barrel and the development barrel let it jump .100"
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Old January 5, 2015, 06:30 PM   #15
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No need for speed. Reload for the distance & purpose. When shooting benchrest 200 yard paper targets, if on the low side of the load listing I find a accurate load, I stop there. Why over work your brass & rifle. No need to get the bullet there faster, stress the rifle just to get the same group. For hunting & long distanse, loads should be adjusted for that. Old school, I clean my rifle after every range trip, that's 25 rounds in 2 hours
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Old January 5, 2015, 07:16 PM   #16
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Pressure will vary from rifle to rifle. The point I am making is that the factory loads are now pushing the envelope on pressure and not selling loads that are at our "starting load" pressure. They are boxing pressures for sell that we say "must be worked up to."
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Old January 5, 2015, 09:02 PM   #17
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reynolds357,

It seems to me you are making assumptions that are not warranted. One is that the accuracy of measuring instrumentation is critical. It isn't. Good thing, too. Consider that the same lot of 5.56 NATO reference ammunition measured in the SAAMI standard and SCATP 5.56 standard conformal type piezo transducer measures 55,000 psi, but in the NATO EVPAT and CIP channel type piezo transducer measures 62,366 psi. This results in the two separate types of "super accurate" (to borrow your description) piezo transducer standards produces cross-compatible 5.56 NATO that produces the same gas port pressures and the same muzzle velocities from the same weight of ammunition so that interchanging the ammo source country in combat won't alter sight settings or range factors.

What is actually done is comparative. Below data from SAAMI shows copper crushers varying 23% in what absolute pressure they claim the same lot of reference ammunition us producing, and conformal Piezo transducers in the second test show 11% disagreement. We can get into the reasons for this rather unimpressive resolution of absolute pressure, but there's no need to worry about it because SAAMI figured out the way around that long ago.



The way the system works is there is one SAAMI member ammunition manufacturer assigned to be responsible for maintaining the standard for each SAAMI spec cartridge; to be the keeper of that cartridge, so to speak. That one company is responsible for producing both reference ammunition and proof load ammunition for the whole industry in that chambering. This insures that it is all produced by testing in one pressure gun operated by one technician (both sources of the variability) for everybody in the industry. Ammunition manufacturers other than the responsible company use the responsible company's reference loads to shoot a ten round test series. If the SAAMI MAP is, say 65,000 psi, and the "keeper" loaded it to meet that average, but the second manufacturer measures it to be 60,000 psi on his equipment, then he applies a correction factor of 65,000/60,000, or 1.083 to all the pressure readings he makes on his gear.

The same is done with copper crushers, and they use the same reference ammo, regardless of whether it was produced using a copper crusher or a piezo transducer. The fact the absolute readings don't agree well doesn't matter because they are all being calibrated to the reference ammunition, whatever reading they get. In other words, the manufacturer calibrating with reference ammunition is making a comparative measurement and not an absolute measurement. The company who is keeper of the standard is responsible for using their own reference ammunition to recalibrate new instrumentation or to break in new technicians when they have to. This way the absolute pressures stay constant, whatever they are.

CIP claims their channel pressure transducer system is accurate withing 2% of absolute. Big help. They drill cases and sample the high pressure gas. That's not what your gun sees. It sees pressure mitigated by the brass between the gas and the steel. That is why SAAMI uses the conformal transducer, even though it sometimes brings unexpected results, like the 5.56 number earlier, and lower psi numbers for .357 Magnum and .44 Magnum than a copper crusher using drilled cases does. This fools many people into believing the industry changed the pressure standards for those two cartridges at some point, but they did not. The CUP standard remains valid for those companies still using copper crushers. The disagreement in unit magnitude is mostly a matter of drilled vs. undrilled cases again.

And that brings up the next problem, which is that even though manufacturers are steadily phasing out the copper crushers, there is no peizo transducer pressure standard for some of the older cartridges. They still only have a copper crusher standard. Also, some smaller outfits can't afford to drop $5K on a piezo barrel for every chambering they test, so they just keep using a copper crusher that will fit onto any barrel made for drilled cases. Look at the mix of CUP and psi readings in Hodgdon's or Lyman's load data sometime, and they can't even afford to update all the old CUP data even after buying a piezo transducer barrel for it. And because the measurements are comparative, the crusher isn't necessarily less able to replicate peak pressure values in the reference ammunition.

You suggested commercial manufacturers are all loading to SAAMI MAP. I can give you a lot of examples from personal experience were that hasn't been true. I've bought both Remington 405 grain 45-40 ammo and Winchester 350 grain 45-70 ammo and, despite the greater bullet weight, the Remington had substantially softer recoil. No way the pressures are the same. Moreover, try firing some military 7.62 or 5.56 and compare it to same weight bullets in commercial loads. In 7.62/.308 in particular, even though the maximum peak pressures specs match and use the same military reference ammunition pressures, the 7.62 almost always recoils noticeably harder, especially in a light gun like my Steyr JC Scout. The reason is the military ammo, unlike SAAMI standard ammo, doesn't just have a peak pressure and a velocity window. It also has a gas port pressure window it has to meet. Loaded down to a lower pressure with a slower powder, as some commercial ammo does to reach the SAAMI velocity spec, won't necessarily achieve the required gas port pressure. So the military is married to a narrower selection of powder burn rates than commercial manufacturers can use. As a result, it is almost always at near the required MAP, where commercial need not be to reach the velocity spec range.

There are other complications. Since SAAMI is a manufacturing standards organization and not a handloader's standards organization or a laboratory standards type organization, its specifications are for manufacturing purposes and expedience. They have not one, but six different pressure specs for each chambering. The one you see published in load manuals is Maximum Average Pressure (MAP). It is a peak pressure average for only one a sample of 10 rounds from a newly manufactured lot of cartridges. This spec allows for a standard error (the standard error is the standard deviation of the average value you would find from firing several 10 shot averages), two times which may be added to the MAP to allow for the fact the next 10 round sample could give an average that is higher. This higher number is called the Maximum Probable Lot mean (MPLM). The same lot could produce the MAP with one sample, and the MPLM with the next and something lower than either with the next.

Which one are you actually producing to your load data? I don't know. Maybe the MAP met by 10 rounds by the load data developer was on the low side or the high side of the difference between MAP and MPLM. Then there's the Maximum Probable Sample Mean (MPSM), which is how high a future 10 round sample from the same lot might measure later in the lot's shelf life when the bullets tend to stick harder to the brass, raising start pressure. Then there is the Maximum Extreme Variation (MEV). This is how much individual cartridge pressure may vary while taking an average of ten rounds. It works out to be about 18% higher than MAP in the worst case, and approaching minimum proof pressure. Then there is minimum proof pressure, and then there is maximum proof pressure.

Example: .308 Winchester

MAP: 52,000 CUP or 62,000 psi
MPLM:53,300 CUP or 63,600 psi
MPSM: 55,300 CUP or 66,000 psi
MEV: 10,700 CUP or 12,800 psi
Proof Min: 69,500 CUP or 83,000 psi
Proof Max: 77,000 CUP or 89,000 psi

But, with all that room for variation, let's get to the nitty gritty: We had on the board about two years ago a fellow with a Handi Rifle in .243 Winchester. A full grain below the maximum load in the Speer Manual #14, his action was popping open every time he fired, despite his checking to be sure the latch was clean and engaging properly and that it never popped open with commercial loads. His velocity was nearly 200 fps above what the manual said it should be, even after allowing for his longer barrel. I used QuickLOAD to estimate he was at about 72,000 to 77,000 psi, depending on differing assumptions. Not quite to proof. He called Speer, and they stood by their data because they'd contracted Alliant to pressure test their loads, and that test came back OK. I don't know that it wasn't OK in some other gun. Or did Speer happen to buy a lot of powder that was on the low side of the burn rate range and the board member got one on the high side? Maybe. Did the member have a bore on the tight side of spec? Maybe. Could brass hardness or primer choice have been responsible for part of it? Maybe. I just don't know, but what happened, happened. His was a case where the safe maximum load for his gun was about 8% below the maximum listed by Speer. Speer had done their CYA documentation with Alliant, and changing their data would have been like an admission of culpability, so their lawyers won't let them do that, perversely for liability reasons.

So with all the modern measuring gear and whatnot, "stuff" still happens. The pressure standards are for manufacturing and are complicated and have variability in the results they produce, as all the layers of SAAMI pressures reveal. The bottom line is, it is your eyes and fingers and thumbs at risk, and you can do as you choose. But I always start at the bottom of the load range because with all the equipment and expertise and cross-checking, it remains the case that only God is perfect; human beings still make mistakes. Even load manual authors are not God.
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Old January 5, 2015, 11:17 PM   #18
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Start at 10% below max load and work up carefully

Something like this is in virtually every load manual I have read. Lyman recommends shooting 10 rounds for each powder charge as you work up a few tenths of a grain at a time.

I called bs on that tactic a few years ago. I may be in for a glass eye or missing fingers, but here is my thought process:

I do start low and work up carefully. But not 10 rounds at each powder charge. One round at each powder charge for the lowest 3-5 loads is enough for me. I am careful about brass preparation, I check multiple data sources and individually weigh each powder charge. The OAL is determined by me on my rifles. (I did use a Speer bullet for my 270 that the data recommendation would have had the bullet jammed into the lands so I was lucky for determining the max col in my gun.) After firing each round, I examine the brass. As of yet, I have never had excess pressure indicators on the brass or primers. I do NOT exceed load data recommendations. As the powder charges approach the max listed in the data sources, then 5 or more rounds are loaded at each charge wt. and I work up to max in 0.3 gr increments. That way accuracy of the loads will be evident.

Just me, but shooting 100 bullets to work up and test load data trying to find an accurate load range is just not for me. On a varmint rifle, if you try several combinations of powder and bullet, you could use up 25% of the barrel life.
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Old January 6, 2015, 11:50 AM   #19
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25% barrel life used up? Closer to 100% used up.
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Old January 6, 2015, 01:33 PM   #20
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The reason for the ten rounds per load thing likely has to do with the inconsistencies in brass and powder dispensing and ignition. If you look at pressure trace data, such as this, from RSI's site with kind permission from Jim Ristow, you see one load varying 10% in peak pressure:



I expect that sort of variation is what Lyman is allowing for. On the other hand, to get a 10% change in peak pressure, if that's what they are allowing for, usually requires about 3% or more in charge weight change in a rifle. That's over a grain for a typical .308 load. So I think Richard Lee's method of using steps that are 2% of the expected maximum charge are small enough. You don't need to use just a few tenths of a grain per step. I have used as few as 1 round for each step, but I do figure the velocity to expect for my barrel length, and use a chronograph to be sure I don't exceed it. That's a sort of double-check.

The other strategy I use, and this is most often the case, is smaller steps of 0.7%, but only three shots per load. This lets me shoot an accuracy ladder at the same time as I watch for pressure signs, so that I've killed two birds with one stone. Very often I pre-dispense charges and cork the case mouths with Neoprene stoppers at home and do my bullet seating at the range with a Redding Competition Seater Die in my Lee Hand Press. It seems to work fine. If I get a pressure sign, I just never seat bullets into the cases with higher charges.
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Old January 6, 2015, 03:58 PM   #21
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That is good idea--seating the bullets at the range.
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Old January 6, 2015, 04:06 PM   #22
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