I've seen a few people mention they do not believe there are Fast Barrels and Slow Barrels. I disagree with them and have no doubt there are Fast Barrels and Slow Barrels.

When you have multiple rifles, chambered for the same Cartridge, with the same Barrel Length, shooting the same exact ammo, they shoot at different Velocities. Some shoot at a Higher Velocity and some at a Lower Velocity.
-----

Apparently it has something to do with the meaning(s) of the words we are using, because it does not make sense to me that anyone would not know there are Fast Barrels and Slow Barrels. And yet, I have yet to find ANYONE who can explain "WHY" they think the way they do.

I spoke with a buddy in Califony last night to see if I could determine where the "words" mean something different and had no luck at all. Here is a brief of the discussion:
1. He does not believe there are Fast Barrels and Slow Barrels.
2. With the same ammo and Barrel Lengths he believes some rifles will shoot at a Higher Velocity than other rifles, and also, some will shoot Slower than others.
3. When pushed for "What do you call the Velocity difference?", he had no answer.

What am I missing???
-----

By the way, if Dave or Larry happen onto this thread and can include a flick out of their M43 Owner's Manual, or a flick from the screen, of a "Pressure Curve", I believe it would help this discussion.

Question:
Do you believe there are some Fast Barrels and some Slow Barrels?

Choices:
1. Yes.
2. No.
3. Other???

 

I`ve gave my thoughts on this before

Fast & slow barrels? No!
Can one barrel produce more pressure with the same ammo and show a increase in velocity due to it? yep!

Now if we`er talkin` fast & slow women.....

quote:

Originally posted by Ol` Joe:
Fast & slow barrels? No!
Can one barrel produce more pressure with the same ammo and show a increase in velocity due to it? yep!
..

Seems to me that an increase in velocity equates to a fast barrel. Can you explain why this would not be true?
Regards, Joe

If we had to use more energy to overcome the friction force presented in a rough barrel as apposed to a mirror finished lapped barrel, all else being equal, than the laws of physics dictate that a bullet out of one will be faster or slower than the bullet from the other. There are numerous other possibilities. roger

Hot Core ----- From my experience, there certainly are FAST and SLOW barrels. I have had multiple rifles of the same chambering and have never had them shoot the same speeds. Some are not much, but still they differ. Let me make a point here, unless you use a good chronograph extensively, you will never know this. I will usually shoot 3000 plus rounds per year through my many rifles and those of my hunting buddies. I reload all my own rounds, usually through others rifles I shoot factory, unless they ask me to develope a load for them, then reloads for them also. I chronograph 99% of all my shots with an Oehler 35-P chronograph, after having worn out two different Chrony models. ----- Case in point. I own and shoot extensively two .358 STA's, both custom rifles. One has a Lilja barrel, the other a custom Winchester barrel. The Lilja shoot all weight bullets from 50 to 150 fps faster than the Winchester barrel, normally in the 100 fps range. While I can shoot through the Lilja barrel, resize and then shoot the next round through both rifles, sometimes when I shoot through the Winchester barrel, resize, I cannot chamber properly in the Lilja. (I now keep all cases shot from both rifles seperate).This tells me the Lilja chamber is a smidgeon smaller than the Winchester chamber. I attribute this for the difference in speeds. Am I right or wrong. ----- Second case in point. I have two .270 WSM's, both Winchesters. One is a stainless Ultimate Shadow that came from New Haven plant. The second is a Featherweight Deluxe from the South Caroline plant, with chrome moly barrel. These two rifles are from 50 to 100 fps different in speeds of all weight bullets. When I clean the barrels the Featherweight Deluxe barrel offers just a smidgeon less friction to the same wire brush. Is that the reason for the different speeds, in my opinion it is. Am I right or wrong. ------ In the STA case the chamber is a part of the barrel, IMO the Lilja has a faster barrel than the Winchester. In the .270 WSM case the 1,000th or so difference in barrel size makes the Featherweight Deluxe barrel slower than the Ultimate Shadow. Those are my opinions until someone proves otherwise. Just a country shooters observations. Good shooting.

Yep, All I have are slow barrels. I know this because all of my handloads are slower than everyone else's on the internet.

The variation in manufacturing tolerances is probably why. Sounds like a great idea for a comprehensive study.

Well there will be a definate difference between length of barrel and speed. Longer ones generally shoot the same load faster. Not what you are asking but a variable that always comes into play.

Buckeye
HC has already heard this one, and if you think about it it will go a long way towards explaining the Fast/slow difference
Same barrel, same lot of ammo, same receiver
A was at 26" and averaged 2725fps
B is at 25" and averages 2995fps

A had a sloppy chamber, with the throat at .0035 over bullet diameter
B has a tight chamber, with the throat at .0010 over bullet diameter.

Now, as most guys don't/won't have a chamber cast done, they don't see the internal clearances (or all the powder gas that can leak by before the bullet seals the bore)

One of my best shooting buddies was a well known Benchrest barrel maker. He's gone now but I know you'd recognize his name immediately.

We'd often sit around after a match and talk about all kinds of stuff, mostly coyote shooting because that was his favorite pastime. I'd take every chance I could to ask him about making barrels and his answers were always the same.

What makes one barrel more accurate than another? Ans: I have no idea.

Does one barrel shoot faster or slower than another? Ans: Yes. But I have no idea why.

Why do you make both 4 groove and 6 groove barrels? Ans: Because that's what my customers want.

Why do you make both right-hand and left-hand twist? Ans: Because that's what my customers want.

Why do you make 6mm barrels in both .236 and .237 bore diameter? Ans: Because that's what my customers want.

You get the idea?

Ray

quote:

I've seen a few people mention they do not believe there are Fast Barrels and Slow Barrels.

I count myself among them. There is a reason for the phenomina but for the life of me I don't know what it is.

The term "fast barrel and slow barrel" are used to describe the result as no one else knows either. And yes, there's a lot of guessing going on!

I'm not buying the chambering differences either but it's on the right track to explain the issue. There are many variances that may be adding up to cause the velocity differences. Rifling depth is one not mentioned.

To merely explain away the differences in velocity by simply calling the barrel "fast" or "slow" is an evasion of the truth. Yet it's as good as we have right now.

Fjold
I must get my barrels from the same maker.

muck

For lack of a better term, certainly. How else can you expain identical rifles or psitols FTM, getting diff. vel. w/ the same ammo? SLightly tighter or looser tolerances, smoother bores, etc. Even rifling twist & the number of grooves probably has some affect on velocity.

?

quote:

Originally posted by J.D.Steele:

quote:

Originally posted by Ol` Joe:
Fast & slow barrels? No!
Can one barrel produce more pressure with the same ammo and show a increase in velocity due to it? yep!
..

Seems to me that an increase in velocity equates to a fast barrel. Can you explain why this would not be true?
Regards, Joe

JD I get the impression most when they talk about a barrel being fast or slow are trying to say their rifle is shooting faster or slower then it should due to some "vodoo", and that the pressures, bullet, ect are all the same except for the speed.
Example; my 708 gives 2700 fps with a 140 gr Sierra over 43gr of Varget but my buddies is faster and gives 2775 with the same load.
I don`t agree, I am of the opinion there are variations in pressure due to something different in the bores that causes one rifle to toss a given load faster then the next.
The claim should be instead of fast or slow, that one is producing lower or higher pressure.

Yes there are, and I have seen and proved it. The very best example I can use is my own double rifle. The upper tube is 30 ft/secs slower than my lower. Everytime.

Also having had an Oehler chronograph since the Model 33 days, I have witnessed this phenomenon many times where rifles of the same caliber and barrel length were shot against their peers and consistent results showed the fast vs slow barrel result you speak of.

yes, there are .. its not a huge difference, just a difference .. a single load will not tell you, ..perhaps 10 different loads, compared to a standard will give you a good notion.

any other answer is just head in the sand denial

quote:

Originally posted by Ol` Joe:

The claim should be instead of fast or slow, that one is producing lower or higher pressure.

Joe PRESSURE, itself, has NOTHING to do with velocity . don't believe me? that's okay ..

EVERY reloading book on the market PROVES it, so agreement or not doesn't mean anything.

You see, every load in that book (unless listed as a reduced load) is loaded to the SAME average pressure .. Yes, really ..

What makes velocity is WORK, which, in this realm, is the area under the curve of pressure over time.

MAX pressure is a safety constraint .. and a darn good one.

Minimum pressure .. gets the bullet our of the barrel

the amount of TIME of the amount of pressure tells you.

FRICTION, bore diamater, smoothness, lots and lots of other things, lead to a faster or slower barrel

quote:

Originally posted by jeffeosso:

Joe PRESSURE, itself, has NOTHING to do with velocity . don't believe me? that's okay ..

It's Okay that I don't beleive you because you are dead wrong. Increase pressure in the same barrel and you will increase velocity, not linerally and the curve flat spots but higher pressure does mean higher velocity.

And the manuals don't all load to the same pressures, they should but they don't.

Slower barrels exist, but in general the only way to exceed normal velocities with the SAME COMPONENTS is to exceed normal pressures.

Hot Core, I remember your justifications for believing in fast barrels but until you hook those rifles up to a pressure guage you can't prove your point.

This arguement really isn't going to be settled until someone starts doing pressure testing, chamber castings etc. to eliminate the variables that slow bullets down and/or increase pressures to make barrels seem faster..................................DJ

DJ

which is faster, 62kpsi of rl22 in a 180gr/30-06 or 62kpsi of bluedot in the same?

The 22, of course

Dead wrong? well, you CAN feel that way

I'll be happy to send you a quickload readout of "load X to 62,800 psi" and you can see that PRESSURE has nothing directly to do with velocity

but, you are free to disagree with me, and I'll still think you are a great guy

quote:

Originally posted by jeffeosso:
DJ

which is faster, 62kpsi of rl22 in a 180gr/30-06 or 62kpsi of bluedot in the same?

The 22, of course

Dead wrong? well, you CAN feel that way

I'll be happy to send you a quickload readout of "load X to 62,800 psi" and you can see that PRESSURE has nothing directly to do with velocity

but, you are free to disagree with me, and I'll still think you are a great guy

Everytime velocity and pressure are spoke the subject changes from the pressures of the SAME load to pressure from powder "A" in relation to powder "B" as having different velocity but equal pressure. Actually it is as you noted, only the peak that is similar.
You`ll notice I stated the same load in different barrels give different pressure. Nothing was mentioned of R22, Blue Dot or even a bullet or primer brand change....

Load 50 gr of 4064 with a Speer 150 gr SP in a Remington case with a WLR primer and shoot it in two rifles of the same make, BBL lgt, and style. One will give faster velocity, but I doubt very much the "peak" "rise" or "curve" is the same as in the other rifle. They may be very close but there will be a difference.

?

quote:

which is faster, 62kpsi of rl22 in a 180gr/30-06 or 62kpsi of bluedot in the same?

The 22, of course

Absolutely correct.

Pressure increases don't necessarily mean an increase in velocity.

The determining factor is how long the pressure is held against the bullet!

?

I KNOW there are fast and slow barrels.

When you chrono 15 to 20 rifles of the same manufacture, with the same lot of ammo,on the same day, and have done this 10 times or so, [with a different set of rifles each chrono session] then you too will know, there IS a fairly wide difference in velocities between "identical" rifles.

It is a fact that you can (I have!) chamber 2 supposedly identical barrels with the same reamer, same headspace, same bbl length, same maker, same maker specs, same bore & outside dimensions, same action make & model, same-same everything you can imagine, and the 2 bbls will STILL give different velocities!

Now, I don't know the details of the actual mechanism of this seeming anomaly in any particular specific case, and I don't really care at this point. The FACT is that the 2 barrels give different velocity results and the results are measurable, predictable and repeatable.

So, I repeat my original question: if one barrel consistently gives a higher velocity when all other factors appear to be identical, how can you say that that barrel is not a 'fast' one?

Guess it would depend upon what your definition of what 'fast' is. Kinda like our ex-president questioning the definition of 'is', in his impeachment trial...

I'm pretty sure of one thing, however. The deer doesn't care about a couple hundred FPS extra.
Regards, Joe

of COURSE if you increase weight of ONE powder it goes faster ... and the pressure goes up.

Not the point ..
If you have 10 powders, at a given average peak pressure, and the loads are not IDENTICAL in velocity in the same gun, then QED, pressure doesn't CAUSE velocity, as a single factor.

And, since they sell lots of 'different speed" powder, and lots of reloading books, and we ALL don't get exactly the same velocities, again, QED, not all barrels are the "Same" speed ...

this is an OBVIOUS apriori discussion.

I have a J.P. Sauer 8X60RS double rifle that has a faster and a slower barrel. Shooting the same handload in the right and left barrel over the chronograph shows one barrel consistently about 100 FPS faster than the other. What better proof is there?

quote:

Originally posted by ALF:
.

If E =1/2 Mv^2 the graph looks to be in error. roger

jeffeosso I understand where you`re going with the peak pressure not relating to velocity. There are more stages in the burn then that, and I should have acknowadged them. I am not argueing that point.

The point I`m trying to make is even if you have two indentical barrels chambered with the same reamer and shot useing the same ammo there will be a difference in the pressures. The rise time may vary, which will be like speeding the powder burn, or the peak pressure will vary, the curve (time under pressure) will not be the same.

Play with your Quick Load, try adding 0.010" to the leade.

Maybe the bullet isn`t the most consistant and one sets 0.003" deeper in the case or closer to the leade.

We have all seen case capacity vary by a few grains water even of the same lot. Add or subtract a little case volume from your set up.

Then concider, the barrel could be old and have a eroded throat that offers more resistance or possibly the reamer chattered in a small area or a burr exists.

When the throat was reamed and polished did the angle change slightly from one to the other?

The bore might have a small tight tight spot in it. BTW, Just for kicks if you have a good 0.0001 accurate/0.00005" resolution capable mic try measuring a barrel at say 65F then hold the spot in your hand for a couple minutes to warm and remeasure. Does the barrel measure the same? Do you think a possible tight or loose spot in the bore may exist there?

Any of this, and likely other conditions I missed will either raise/lower peak pressure, alter the rise time, or change the area under the curve. Velocity will rise or drop true, but there will be a pressure related cause somewhere.

We always tell newbies to work up. The books are just guides and every barrel is a law onto its self, what is safe in your barrel may not be in mine. Then you say pressure has no bearing on whether a barrel shows a better velocity then the next? A load that gives XX psi in one barrel gives more fps with the same XX psi in another?

You can`t have velocity and not pressure, something is either pushing or applying the skids to the bullet. Put a bullet in a bore and remove the pressure and it will not have any velocity, not today, not next year, or ever.
Come on...We`re way past demons rideing on our bullets wreaking accuracy and I really doubt the "force" is stronger in some bbl`s either .

quote:

Originally posted by El Deguello:
I have a J.P. Sauer 8X60RS double rifle that has a faster and a slower barrel. Shooting the same handload in the right and left barrel over the chronograph shows one barrel consistently about 100 FPS faster than the other. What better proof is there?

Put a strain gage on both barrels and see what the same loads give for overall pressures with your load.

Joe,
Let's not mix tenses and definations.. . and don't demonize the other if you don't understand .. that quickly errodes to name calling, which results in me abandoning the discussion, and certainly NOT in agreement

This is why there's reloading manuals, with tons of powder. They ARE loaded to a benchmark. That benchmark is then used for all loads as a max .. and the velocity differences are thusly recorded. There's no arguing, escaping, or denying it. This is why the 30-06 SCREAMS on rel22, and not win 760 or 748 .. same peak pressure limit, higher velocity .. go figure

I didn't say pressure has nothing to do with safety. Don't try to put words in my mouth,.. this is just bad form. I am saying max PEAK pressure has nothing to do with velocity, in and of itself.



We aren't talking about loads so hot "if you add .01gr to the load it will blow up the gun" we are talking about reasonable loads.. most folks actually do load reasonable .. and persons that have loaded as long as either of us HAVE to have loaded reaonablely .. otherwise we'd be known on sight.. or lack of sight.

However, fast or slow bore .. is WAY less difference than lot to lot of powder ... heck, TWIST has more to do with pressure than 50 fps.

If one assumes a box of ABC caliber, from XYZ maker is "safe" in all guns, and one fires 100 rounds FROM the SAME gun, one WILL have deviation. Why? it doesn't matter, but we can kibitz around a glass of beer about it...

Is that angels and elves, or just the fact that powder doesn't always burn perfectly even?

Its the same powder, the same expansion ration, the same primer, and the same GUN .. and all of us have seen it happen.

Don't play the "ooowwww... jeffe says don't be safe" silliness. Peak pressure is critical for SAFETY not for VELOCITY.

oh well, i guess i was a little juvenile on that comment, but it does strike me as funny

My appologies for the little bratty "ooowww" thing.
jeffe

quote:

Originally posted by jeffeosso:
This is why there's reloading manuals, with tons of powder. They ARE loaded to a benchmark. That benchmark is then used for all loads as a max ..

jeffe

All the manuals don't load to the same benchmark especially older ones. The newer pressure tested ones should be loading to the same SAAMI limits but they don't. Some powders can't be loaded to max pressures within case capacity limits but are included because they are close enough to consider. Some manuals offer different pressure levels of loadings for different firearms such as 45-70 being loaded for trap-door springfields and modern lever actions, or 45 Long Colt being loaded for as many as 3 different pressure levels in some manuals but not others.

The only time you can be sure exactly what pressure levels the manuals have loaded to is when they actually PRINT them in the manual. Many don't..............................DJ

?

DJ,
pick ONE manual .. just one .. open the page to the 30-06, and note that there are probably 20 powders, delivering a velocity. That threshold is explained by Alf before .. Please, you wouldn't use the starting load from book A and the top load of book B and think they are the same load data. How many questions in this forum start out with "one reloading manual says X grains max, and another says X-y, which is right?"
You aren't correcting me, rather further proving my POINT, otherwise you are stating that you firmly believe all reloading manuals are willinilly and have no value,.

Let's take the 45/70, as a "3 load values" to PERFECTLY prove my point

Let's say that the trapdoor load is 28Kpsi/cupp (this is the only time they are the same). .. and the ruger #1 as, oh, 55kCUP (it doesn't matter)...

There are NO high pressure loads in the load pressure loading section .. NONE.

Why?
There is a benchmark that they are loading to, and they classify them.

We agree, and you have stated it perfectly. I do thank you for that example .. You have CLEANLY stated, in the case of the 45/70, that there are OBVIOUS pressure levels, and aren't intermixed.

We are now in violent agreeement.

Alf even states this to be true - that modern reloading books don't just guess at that pressure level, they use lab gauges to read the pressure.

Gentlemen, its inescapable.

alf stating the older reloading manuals are loaded to a mathmatically derived level, and then to an actually tested with gauges level, and not willynilly

quote:

Originally posted by ALF:
Load manual data for the most were not actually pressure tested, nor velocity tested, all those hundreds of loads and data points were mathematically derived, using over time a variation of mathematical models and solutions much like the graphs in previous posts.

The mathematical solutions commonly used for this purpose have built in error based on the assumptions from which they are derived and consistantly overesitmated velocity and underestimated or overestimated peak chamber pressure, hence the commonly observed tendency for frustrated handloaders not understanding why their loads consistantly shoot at lower velocities lower than the manuals values.

More recent editions of these manuals have been corrected with values based on actual pressure gauging and chrono values, hence the noted differences to older editions of the same manual.

With the advent of the use of strain gauging the classic mathematical solutions used also needed some corrections made because they are important in calibrating the gauge to reflect the true nature of the event.

this MAY not make any sense to you. Quickload is able to take a given bullet, OAL, cartidge, barrel, etc.. and predict what charges will result in a PEAK pressure, definable by the user. In this case, if have taken out all but the high and low velocities to show you, without a doubt, that PEAK pressure, alone, doesn't drive velocity

Some of you are doubters of quickload.. that's cool .. its a tool, and is the SAME error for all loads, so comparative data is at LEAST trending to the same results

here's loads, at pressure, for a well know cartridge, and a well known bullet combo .. this is NOT loading data, and I have done my best to mask the CHARGE .. this is NOT reloading data, and should not be used as such. you COULD injure yourself trying to back into it


it is CLEARLY seen (i cut out about 50 powders between these) that PRESSURE isn't what you might assume it is

This whole thread seems to have deviated away from a fairly simple conceptual question into a masterpiece of "How Many Angels Can Dance On The Head Of a Pin?"

Of course there are barrels that deliver bullets loaded with the same amount of the same components at different speeds than do other barrels of the same chambering and length under the same conditions. We are talking different "AVERAGE" velocities here.

It is also true that there are logical explanations why that occurs; it isn't magic.

But the truth is that one barrel will still ON AVERAGE deliver its bullets faster or slower than other barrels fired with the same loads.

I have been chronographing loads for 50+ years. At one time I had 9 .30-06 military Springfields of my own. The difference between the AVERAGE velocities of them was over 70 fps between the "slowest" and the "fastest", with the same loads. And we are not talking 5-shot chrono averages...we are talking averages covering more than 50 shots per rifle.

I would not try to explain to anyone WHY each varied somewhat from the others in the average velocity of its bullets. It was much easier just to say that some were "faster" than others. Otherwise conversations about them could rapidly just become rather painful bores.

quote:

that quickly errodes to name calling, which results in me abandoning the discussion, and certainly NOT in agreement

Definatly not where I`m trying to put either of us.

quote:

This is why there's reloading manuals, with tons of powder. They ARE loaded to a benchmark. That benchmark is then used for all loads as a max .. and the velocity differences are thusly recorded.

True, they normally are expected to be loaded to either SAAMI or CIP max avg pressure. This can`t always be done though.
There are a couple of pressures that the labs keep tabs on. Useing your 30-06 as example, the SAAMI max avgerage pressure is 60,000 psi. The load though, to be an average has a certain number of shots that are at the high side of it and a number on the lower side. All SAAMI cartridges also have a "max probable lot mean" "MPLM" which is a figure that should represent the midpoint of the upper pressures recorded. This is 63,800 psi in the `06.
If a lab has a load for the 30-06 that gives 60K psi, but a MPLM of 64K psi, they will drop the load down until both figures are within the accepted range. That`s why you often see pressure figures in books under the SAAMI max avg allowed. There are also low pressures due to the powder being too slow for the cartridge and not enought fitting in the case to get pressure where it should be.
The exact bullet used also dictates the load. Nosler as example might find they can load XX gr of ABC powder under their 180 gr Partition and be within the SAAMI standard limits. The same load but with their 180 gr Ballistic Tip may be showing a rise in max average pressure of 2,000 psi. Now if Nosler wants to list thier loads by bullet wgt, they have to drop the max book load to reflect the Ballisitic Tips max charge level. I don`t know which bullets velocity they use when this happens but, I suspect they list the higher one they recorded. All the bullet companies do this where they have more then one bullet of a given wgt.

quote:

I didn't say pressure has nothing to do with safety. Don't try to put words in my mouth,.. this is just bad form. I am saying max PEAK pressure has nothing to do with velocity, in and of itself

I don`t believe I said you believed pressure pressure has nothing to do with safety. If so, I did a very poor job of expressing myself.
I tried to say we, meaning the both of us and most others here on the forum, accept that every barrel varies in pressure with the same load. That the load in the books is not cut in stone as to the pressures produced in every rifle, so why presume that a barrel that gives a faster velocity is giving the same pressure.

quote:

This is why the 30-06 SCREAMS on rel22, and not win 760 or 748 .. same peak pressure limit, higher velocity .. go figure

I agree you`ll get more vel with R22 then W760 or 748. What I keep trying to get across is that even though they have the same peak pressure, the rest of the pressure picture is not the same. The faster powder rises to peak faster then drops lower just as quick. The R22 rises to the same peak (in theory)a little slower but stays at a higher pressure for a longer time. This results in a longer push at higher pressure on the bullet. I think we both agree here too.
The fast/slow barrel difference though is claimed with the same powder at a claimed same peak pressure, not 2 different powders. I believe there is something in the faster barrel that either drives the pressure up higher, then lets it drop down at about the same rate, or it hits the same high but something causes it to remain at a higher level longer. Or maybe it doesn`t reach or drops to a lower pressure for the rest of the bullets travel in the bore and that produces the slower barrel. That was the reasoning behind offering conditions that will vary pressure you could easily see with QL.

quote:

If one assumes a box of ABC caliber, from XYZ maker is "safe" in all guns, and one fires 100 rounds FROM the SAME gun, one WILL have deviation. Why? it doesn't matter, but we can kibitz around a glass of beer about it...

Is that angels and elves, or just the fact that powder doesn't always burn perfectly even?

Its the same powder, the same expansion ration, the same primer, and the same GUN .. and all of us have seen it happen.

That is what i`ve been saying all along. There are no "angles or elves" just something causing the powder to burn differently and vary pressure (velocity). It might not be that the pressure rises above SAAMI max but that it drops below it in one. What it is I don`t know. I don`t know that anyone truely does. In my mind a pressure change due to some unexplained event makes more sense though then then saying a barrel is simply faster then another.
Something is making that burn deviate.

If I`m wrong about pressure being the culprit I can accept it. Tell me what your reasoning for the jump in velocity is though instead of simply saying I`m wrong and pressure isn`t it. What is it that is the cause in your opinion? I`m honestly trying to figure where you are headed with this.


BTW, where`s HotCore?
I`m getting the feeling he tossed this out and then sat back just to see if someone would take the bait and provide him some intertainment.....