I just found out I have fired off a about 40 reloads thru my 338 win which had the bullets seated too deep. It was the 1st batch I had done ever. The oal is supposed to be 3.34" but my reloads were 3.24". I realise I could of had a pressure spike issuebut I guess I lucked out. Do u guys think I could have damaged anything in the barrel?
338 pal too short
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No ! NOT at ALL ! Your Barrel - action are OK ! 
RJ
RJ
358Rooster
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OH, DEAR GOD! Okay, where are all the guys who like to claim that seating a bullet deep into a case will increase pressure? This idea is a complete fallacy.
OP, what you have likely read on the internet (no doubt) is that a bullet seated too deeply results in a decreased internal case volume, thusly, increased pressure - as though it took the guy running the press to apply 60,000 psi to seat that bullet. Think about it...
And no, you'll have suffered no damage to anything from your mistake. You would certainly know something was amiss if it was bad enough to damage your rifle. Good indicators are increased blood pressure.....or none at all.
Rooster
OP, what you have likely read on the internet (no doubt) is that a bullet seated too deeply results in a decreased internal case volume, thusly, increased pressure - as though it took the guy running the press to apply 60,000 psi to seat that bullet. Think about it...
And no, you'll have suffered no damage to anything from your mistake. You would certainly know something was amiss if it was bad enough to damage your rifle. Good indicators are increased blood pressure.....or none at all.
Rooster
redshooter
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Seating the bullet too deep will increase pressure. It just depends on how deep and how close you are to max. That said if you had pressure signs, sticky extraction, flattened/blown primers, smeared headstamp/ejector marks on case head, then you were over max. None of the above no problem, even if you did I wouldn't worry about it unless you had to hammer the action open.
As for the advise saying don't worry about it, it's not a fallacy. Pressure seating the bullet has nothing to do with pressure when the primer is struck. They go through the bother of crimping for a reason, why would ammo manufactures go through the bother if it wasn't necessary...think about it.
As for the advise saying don't worry about it, it's not a fallacy. Pressure seating the bullet has nothing to do with pressure when the primer is struck. They go through the bother of crimping for a reason, why would ammo manufactures go through the bother if it wasn't necessary...think about it.
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358Rooster
CGN Regular
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- Central Saskatchewan
That's fine to say, Redshooter, but cite one credible study or article that supports your theory. Your arguements are weak, at best without it. How many loading manuals warn the reloader against seating too deep? You'll note that every one of them concentrates on the effects of seating too close to the rifling. Why would they go through the bother of stating only one dangerous scenario if there was, indeed, another?
Go ahead, school the sh!t outta me....
Go ahead, school the sh!t outta me....
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Gosh man. Lowering the case capacity increases pressure, and if you need proof look at every loading manual ever published and note that the 308 gets more pressure than the 30-06 using the same bullet and powder charge.
Seating a bullet deeper may not make a big difference depending on how close to maximum pressure the load is already, airspace, how tight the chamber is, and how close the bullet is to the rifling, and a multitude of other variables. In some cases seating .1" deeper WILL raise pressure remarkably.
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358Rooster
CGN Regular
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Okay, I understand where the theory comes from but again, back it up. I'm more than happy to reconsider my position if someone would just provide credible, definitive studies to contradict it.
Consider this: how much force is required to get a bullet to move - even crimped - from its starting point in a case? If it is allowed to 'free wheel' with no forward impediment, not a great deal. On the other hand, getting a jammed bullet to move requires significantly more force, thus jacking pressure.
The point is, the case volume decrease by placing more bullet inside the case is almost completely negated by the fact that it takes a mere breath (by cartridge pressure comparison) to move that bullet. Once the bullet is moving, you're left with a pressure vessel of the same volume as you would at any other seating depth until it contacts the rifling. This is under the presumption, of course, that the same bullet type and weight are being compared. I have no doubt that yes, it does take some pressure to move that bullet, but enough to raise pressure remarkably? I have doubts. Unless we're talking low-pressure ammunition....maybe.
Yes, I do get crusty about such things but honestly, the supposition and conjecture I read are startling sometimes. This is exactly what has led this thread's originator to believe he may have F'd up his rifle.
Regurgitation of perceived fact is more dangerous than a bullet seated too deeply.
Rooster
Consider this: how much force is required to get a bullet to move - even crimped - from its starting point in a case? If it is allowed to 'free wheel' with no forward impediment, not a great deal. On the other hand, getting a jammed bullet to move requires significantly more force, thus jacking pressure.
The point is, the case volume decrease by placing more bullet inside the case is almost completely negated by the fact that it takes a mere breath (by cartridge pressure comparison) to move that bullet. Once the bullet is moving, you're left with a pressure vessel of the same volume as you would at any other seating depth until it contacts the rifling. This is under the presumption, of course, that the same bullet type and weight are being compared. I have no doubt that yes, it does take some pressure to move that bullet, but enough to raise pressure remarkably? I have doubts. Unless we're talking low-pressure ammunition....maybe.
Yes, I do get crusty about such things but honestly, the supposition and conjecture I read are startling sometimes. This is exactly what has led this thread's originator to believe he may have F'd up his rifle.
Regurgitation of perceived fact is more dangerous than a bullet seated too deeply.
Rooster
Where this increased pressure info comes from is in regards to Straight-walled pistol cartridges. Seating a bullet deeper in these can increase pressure.
As far as bottle-necked rifles chamberings...seating deeper seldom has any real effect. The way to increase pressure somewhat in these is by "jamming" the bullet into
the rifling. Dave.
As far as bottle-necked rifles chamberings...seating deeper seldom has any real effect. The way to increase pressure somewhat in these is by "jamming" the bullet into
the rifling. Dave.
redshooter
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- Central Ontario
I have a better idea. If you are so sure it's just a bunch of poop, get your fastest powder, stoke up a case to its max charge, now seat that bullet as deep as you can, and report back to us.
Did you ever study gas laws in high school chemistry or physics? If you did you might remember PVT - Pressure Volume Temperature. This is not a guess or a perception, it is a basic law of nature. There is no more proof necessary if you understand basic physics.
Reducing the volume without reducing mass = more pressure. Period.
Seating a bullet deeper reduces volume. Burning powder produces gas, which is the mass. The same mass in a reduced volume = more pressure.
Look at 45acp load data. Did you ever notice that sometimes different bullets of the same weight can have different start and max loads of the same powder? The reason is that a different profile bullet may be seated deeper in the case, which reduces volume and increases pressure. The load must be adjusted to compensate and prevent overpressure.
I would like to see your source that says seating a bullet deeper will have no effect on pressure.
About regurgitation - the worst is trying to spit out your own feet.
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358Rooster
CGN Regular
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Ugh, you're hopeless. Who said anything about a faster powder? And since when does changing critical variables such as what you're proposing hold any value in this argument? Once again comparing apples to oranges.
Did you ever study gas laws in high school chemistry or physics? If you did you might remember PVT - Pressure Volume Temperature. This is not a guess or a perception, it is a basic law of nature. There is no more proof necessary if you understand basic physics.
Reducing the volume without reducing mass = more pressure. Period.
Seating a bullet deeper reduces volume. Burning powder produces gas, which is the mass. The same mass in a reduced volume = more pressure.
Look at 45acp load data. Did you ever notice that sometimes different bullets of the same weight can have different start and max loads of the same powder? The reason is that a different profile bullet may be seated deeper in the case, which reduces volume and increases pressure. The load must be adjusted to compensate and prevent overpressure.
But I would be very interested to see your source that says seating a bullet deeper will have no effect on pressure. Please do share it.
About regurgitation - I hear that the worst part is trying to spit out both feet.
First, don't come off like an academic - what you've stated is only part of the physics / internal ballistics equation. You're missing a few other very critical factors. Yes, I've forgotten probably 90% of what I learned in high school physics. However, there are resources available if one cares to actually do the work. By the above, I'd hazard a guess that your retention of high school physics isn't a great deal better than mine.
I agree 100% that a reduced volume will give a higher pressure given the same quantity of propellant. What you're discounting (again) is that the volume changes as soon as that bullet starts to move. And early bullet movement is a function of primer ignition and forward solid propellant mass movement. And by the way, your gas is not the mass in this equation that you have to be concerned about, it's the bullet. Either bust out your books again or go slap your old physics teacher.
Your comment pertaining to 45 ACP data is invalid in this argument. We're talking about rifle cartridges here. Maybe you didn't catch Eagleye's post or my previous admission that this all may not be the case with low pressure ammunition (ie: pistol ammo). And for the record, never once did I say that a deeper bullet will have NO effect.
If you would care to engage, I have for you some very interesting reading. The first of which is a study of the effect of primer force on early bullet movement. To support my theory as expressed from the start, the study found that the force exerted from ONLY the primer ignition was sufficient to move the bullet, which then starts the increase in case volume. And what do you suppose happens when you increase volume in this instance? Yes, there is a pressure spike but nowhere near peak or maximum pressure. Oh, and so you don't have to bust out your Funk & Wagnalls for the following exerpt, ullage is the free volume in the case.
From the Conclusions section of this document from the U.S. Army Research lab (Google ARL-TR-7479 - link is much too long & clunky):
The primer is capable of producing enough force to debullet the projectile and begin the engraving process prior to any significant propellant burning. The timing of the projectile’s initial motion relative to primer output and propellant ignition is vital to IB models. These initial conditions set the stage for subsequent propellant gas generation and IB performance characteristics. From impulse and momentum measurements associated with the primer output, it was determined that the manner in which the primer force is transmitted through the propellant bed is dependent on the specific cartridge being investigated. It
appears that the amount of ullage is the driving mechanism that influences the primer force transmission mode. The ullage provides a certain amount of freedom
for the propellant bed to compress and move during the initial stages of the interior ballistic event. With minimal ullage available, the propellant merely transmits the primer force to the projectile, acting much like an incompressible fluid. Conversely, a cartridge with more ullage will create a situation where the initial motion of projectile and propellant act more in unison.
And another that contains pressure-time and time-distance graphs (among several others):
http:// www.arl.army.mil/arlreports/2007/ARL-TR-4181.pdf
All I asked was that anyone provide credible evidence to back up claims. That's all! Hell, I'm open to any theory providing there's evidence supporting its validity. But I guess it was too difficult to do the work to contradict my position and you'd hoped that someone would believe the unsubstantiated tripe.
Now, would you like to talk about that hairball....?
Rooster
The people who make Quickload are going to be disappointed to learn their software is unsubstantiated tripe.
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redshooter
CGN Ultra frequent flyer
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223, IMR 4198 vs IMR 4895, small Orange, medium sized Orange. I think you assume too much...
When referring to studies, where did you get the info? From the report, or from a web page? Before I draw any conclusions from that tidbit you posted I'd like to see a few things, mostly relating to the conditions present during the test, but also what they were trying to prove.
As for 45 ACP, physics doesn't change due to the shape of the case. I'll concede the difference may lie in the projectile being jammed into the case taper, but I also question that such a situation would be the outcome of a weak/no crimp, at least jammed hard enough to cause it to wedge in there. Perhaps it's possible from the use of fast powders with high density, I don't load for 45 ACP so I haven't given it much thought.
Many manuals warn of the situation of projectiles being driven back in the case by autoloaders, but none of mine expand on why. One thing is certain, you can seat the bullet further out, and can add more powder without spiking pressures. If this is the case I think it supports the idea that reducing the case volume will cause pressures to rise. Your assertion that jamming a bullet is dangerous isn't outright true, it can be done safely, and many precision shooters do it to improve accuracy. I use to do it with 208 A-Max bullets and Retumbo, over max recommended by the way with no problems, but I worked up that load.
I'm not even asserting that my argument is fact. Things happen quickly, especially when working at the limits. Caution is a must, your position seems to say don't worry about it, fine if you want to practice that yourself, irresponsible to suggest others follow in your footsteps.
358Rooster
CGN Regular
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- Central Saskatchewan
The people who make Quickload are going to be disappointed to learn their software is unsubstantiated tripe.
Okay, that's great. But take us through the scenarios that you've displayed. The seating depth changes are obvious but what parameters are you dealing with (distance to rifling, bullet position relative to time plotted, fill percentage of powder in the case, temperature, etc.)? And I am genuinely asking because I have no experience with Quickload and the finer points of its representations - other than the painfully obvious pressure-time and resulting velocities. All good stuff but I can't interpret it intelligently. For example, what does 'Z1' indicate? And the text boxes that you have beside the graph components; don't make sense to me and appear inconsistent. Take the text boxes beside Chamber Pressure: graph one has none, graph two shows a number unrelated to anything on the graph, graph three makes sense as the P-max, graph four again shows no direct relation.
The velocities are another thing that I have a hard time with. At what significant point in the velocity curve does that text box number represent? And I find it odd that despite very large max pressure differences throughout your series of graphs that the final velocities shown at the far right of the graph barely varies at all. I would have expected far more.
I'm not picking, I just can't make full sense of the representations. At least you're working to prove your theory with data now.
Rooster
358Rooster
CGN Regular
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- Central Saskatchewan
Oh, Red.....
Listen, neither one of us were ever top of our class. That much is clear. But you, sir, are sitting in the corner eating crayons. You're trying to speak at grade 10 but you're reading at grade 3.Until you trouble yourself to even view the studies that I have presented - which I have zero influence over (and your answers are there, BTW) - your perceptions are worthless and obviously without hard data of any sort. A child could see that. Experience is fantastic, but for God's sake, present some black & white data. Prove it! Should be easy enough, shouldn't it?
Insignificant tripe. Your contribution so far has only been to cut and paste links to somebody else's theories. You demand "data" but have offered nothing in return except insults and arrogance. It's not my problem you don't understand how Quickload works. Google it.
Have a nice day.
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redshooter
CGN Ultra frequent flyer
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- Central Ontario
Oh, Red.....
Until you trouble yourself to even view the studies that I have presented - which I have zero influence over (and your answers are there, BTW) - your perceptions are worthless and obviously without hard data of any sort. A child could see that. Experience is fantastic, but for God's sake, present some black & white data. Prove it! Should be easy enough, shouldn't it?
You're right, I wasn't top of my class, but I studied Physics, or even more fun topics like Organic Chemistry, and managed to get high enough grades to call myself an Engineering Technologist.
I've been too busy the last few day to read the study. I glossed over it last night, it appears to clearly show that under certain conditions the primer alone will drive the projectile into the lands. When I have time I'll finish it, but at the moment it looks like 5.56 and 7.62 Ball with one type of powder in a special test rig supports your position. If you were as brilliant as you appear to think you are you'd realize that all it proves is two cartridges with a specific set of conditions will drive the projectile into the lands. That's it! Your writing skills seem to be pretty good, critical thinking, not so good.
My final point before you insulted me. "I'm not even asserting that my argument is fact. Things happen quickly, especially when working at the limits. Caution is a must, your position seems to say don't worry about it, fine if you want to practice that yourself, irresponsible to suggest others follow in your footsteps. " It's pretty funny that my "perceptions" are worthless and more to the point your observations are unasailable after reading one study. It's pretty obvious you don't have the background to understand what you read, that, or you don't have enough respect for the rest of us to expand on your position. Instead you just cast stool at others who's whole point is exercise caution.
Did you notice the report you base your opinion on also shot a few holes in your statement about jamming the lands...
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