Different coals

davide montini

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Ok all you pro’s/masters of reloading ...I have a question so

I want to use temperature insensitive powder 4451 with 100g barns bullet tsx or ttsx barns doesn’t have any data ...but hornady has data on a 100 gr bullet ...I looked and found something similar....but!!!....
The coal is different from barns and hornady....
So my question is in Regards to seat depth would the 3.080 (barns )give me more pressure??
Or the hornady at 3.120 give me more pressure?....
In the way of jump to jam ..or being closer to the rifling
Not sure if 3.080 or 3.120 is better c.o.a.l
Rifle browning bar ....25-06
Any thoughts or opinions here please tell me
already started to test at 3.080 started to get some good results but more testing is needed
Thanks to all
 
Solid copper bullets will give higher pressure then lead core bullets, if you can't find data for similar construction bullets, use starting loads or even a couple grains less to begin with, and go up in smaller increments.
 
Start your Barnes DEEP!
I usually end up right around the top of the first driving band as opposed to cup and core bullets which are generally about .010 off the lans or so.....
Cat
 
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I’m just wondering if the cartridge over all length....coal makes a big difference

Other than for the purpose of fitting into a magazine, COAL is the most useless and worthless dimension. Ignor it, forget it exists, it means nothing. You absolutely should NOT be using COAL to be measuring seating depth and you should be measuring the distance to the lands.
 
If it will fit the magazine and feed, start .050" off of the lands with Barnes bullets, and go from there, the COL listed in a manual is meaningless for most rifles.
 
Who was it that always said a bullet should fit in a chamber as a turd fits in a toilet?????????????????????

I think it was some guy who (at one time) worked for Sierra Bullets, and the line was something like " a cartridge should fir the chamber like a rat turd in a violin case.".

I'm going by memory here, and I haven't OD'd on caffeine yet, so I could be mistaken.
 
I recently received the 2014 edition of Woodleigh Reloading manual - did not even know such a thing existed!! But it does describe how to measure for your rifle throat for cartridge length - if your rifle's magazine allows that - they recommend .020" to .040" "jump" for their bullets to the lands.
 
I'll slip a few words in here - between the men talking - and agree that it is good to stay away from the lands - because if there is a slight variation - let's say because of primer seating depth variation, or shoulders occasionally being squashed a bit, causing more force being held against the bolt face when chambering - if there is a few thousandths this way or that, it is much better that it be varying from 25 down to 15 clearance than it is to vary from 5 of clearance to 15 thousandths of stuck-in-the-bore. Being Stuck-in-the-bore sometimes, is hardly going to give a low standard deviation in pressure and velocity.

There are a lot of little things to make perfect before needing to reduce the "jump." Jump is hardly the right word for it because the bullet is sliding ahead, fully supported by the neck until it self-centers on the bore. I was just thinking about that ... there is a lot of bullet protruding far out into the cartridge, which is experiencing the pressure of the burn ... I wonder how the pressures affect the bullet ... a 30 cal bullet might have a square inch of area experiencing ... 40,000 psi? - I don't know how soon the pressure spikes, but even 20,000 lbs of force on a lead bullet with a thin copper jacket? There is only one small part which is not pressurized by the burn or contained by the bore and that is the part which is beyond the sealing affect of the bullet. ....

There is even more pressurized area ( just considering this), because when the case neck expands to release the bullet, that area also is pressurized. Hmm... so the only reason the bullet goes forward is because of the lower pressure on the front of the bullet - it is a wonder that the friction of the jacket does not keep it from moving forward, and those extreme pressures just blow the core of the bullet out the front. Lead bullets without jackets do best when pressures are high enough to upset them enough that they fully contact the rifling - but I wonder how much upset there is going on it a copper bullet as it experiences all these forces - and if a pure copper bullet upsets little or not at all, it may require a very good bore to keep it accurate..... maybe the back of the copper bullet should be fully annealed?

Here is an old memory - an article in Outdoor Life in the 70's - an older gentleman ( younger than I am now likely) who was shooting the relatively new 220 Swift, was occasionally experiencing a bullet disintegrating in the air before it arrived at it's intended prairie-dog. Hot weather, hot loads - and it occurs to me that if the centre of a bullet was damaged by excessive pressure, the centrifugal force may be able to explode the bullet.... maybe not - I donno.

Okay - I'll give up the mic now.
 
I'll slip a few words in here - between the men talking - and agree that it is good to stay away from the lands - because if there is a slight variation - let's say because of primer seating depth variation, or shoulders occasionally being squashed a bit, causing more force being held against the bolt face when chambering - if there is a few thousandths this way or that, it is much better that it be varying from 25 down to 15 clearance than it is to vary from 5 of clearance to 15 thousandths of stuck-in-the-bore. Being Stuck-in-the-bore sometimes, is hardly going to give a low standard deviation in pressure and velocity.

There are a lot of little things to make perfect before needing to reduce the "jump." Jump is hardly the right word for it because the bullet is sliding ahead, fully supported by the neck until it self-centers on the bore. I was just thinking about that ... there is a lot of bullet protruding far out into the cartridge, which is experiencing the pressure of the burn ... I wonder how the pressures affect the bullet ... a 30 cal bullet might have a square inch of area experiencing ... 40,000 psi? - I don't know how soon the pressure spikes, but even 20,000 lbs of force on a lead bullet with a thin copper jacket? There is only one small part which is not pressurized by the burn or contained by the bore and that is the part which is beyond the sealing affect of the bullet. ....

There is even more pressurized area ( just considering this), because when the case neck expands to release the bullet, that area also is pressurized. Hmm... so the only reason the bullet goes forward is because of the lower pressure on the front of the bullet - it is a wonder that the friction of the jacket does not keep it from moving forward, and those extreme pressures just blow the core of the bullet out the front. Lead bullets without jackets do best when pressures are high enough to upset them enough that they fully contact the rifling - but I wonder how much upset there is going on it a copper bullet as it experiences all these forces - and if a pure copper bullet upsets little or not at all, it may require a very good bore to keep it accurate..... maybe the back of the copper bullet should be fully annealed?

Here is an old memory - an article in Outdoor Life in the 70's - an older gentleman ( younger than I am now likely) who was shooting the relatively new 220 Swift, was occasionally experiencing a bullet disintegrating in the air before it arrived at it's intended prairie-dog. Hot weather, hot loads - and it occurs to me that if the centre of a bullet was damaged by excessive pressure, the centrifugal force may be able to explode the bullet.... maybe not - I donno.

Okay - I'll give up the mic now.

The last part has some merit as it is possible to push a cup/core bullet beyond it's rotational capacity.
Not so much today as most manufacturers are aware of this possibility so bullets are much better constructed, a bonded bullet or solid copper really doesn't have anything to worry about today even with the fastest shooting cartridges in the fastest twist rifles.
It definitely happened though back in the day and was something to pay attention to.
 
It seems like young reloaders (yes me too) are apt to try to get the bullet very close to the lands - and don't learn until there is a bullet jammed in the throat, and powder all through the action, and they are looking for a stiff rod to push the bullet free... but as far as I know, having this bullet jammed in tight never super-pressures the action, and wrecks the barrel - like a bit of fluffy snow in the end of the barrel does. I wonder if there is something different going on when there is something in the muzzle - why does it open up so violently? - when a bullet jammed in the throat does not? Is there a shock wave going forward which hits the snow, and ... I donno ...slows down and the bullet has to go through the shock wave and in doing so, develops extreme pressures? Is it ever the action that blows up, or does it always banana-peel? - wondering if it is an issue of pressure ahead of the bullet heading out, rather than an increase in pressure behind it. It has to be expending a huge amount of energy to do that amount of damage ahead of the bullet. I don't think that there is that much power remaining available in the powder combustion to do that much damage - but there would be plenty of power in the outgoing bullet by then.

A new theory: The ogive of the bullet is really a circular wedge which, if it encounters water or dirt etc. on it's way out, attempts to push the ice crystals to the outside, and if it is just a little, may just bulge the barrel until the bullet is past, losing some speed/energy...Time gathers to assault me i the dark ... I must go....
 
1. but as far as I know, having this bullet jammed in tight never super-pressures the action, and wrecks the barrel - like a bit of fluffy snow in the end of the barrel does.

2. I wonder if there is something different going on when there is something in the muzzle - why does it open up so violently? - when a bullet jammed in the throat does not? Is there a shock wave going forward which hits the snow, and ... I donno ...slows down and the bullet has to go through the shock wave and in doing so, develops extreme pressures?

3. Is it ever the action that blows up, or does it always banana-peel? - wondering if it is an issue of pressure ahead of the bullet heading out, rather than an increase in pressure behind it. It has to be expending a huge amount of energy to do that amount of damage ahead of the bullet. I don't think that there is that much power remaining available in the powder combustion to do that much damage - but there would be plenty of power in the outgoing bullet by then.

4. A new theory: The ogive of the bullet is really a circular wedge which, if it encounters water or dirt etc. on it's way out, attempts to push the ice crystals to the outside, and if it is just a little, may just bulge the barrel until the bullet is past, losing some speed/energy...Time gathers to assault me i the dark ... I must go....

Well that is quite the flow of consciousness and ........ stuff.

I have numbered your questions / suppositions so as to be able to answer them in a linear manner.

1. When a cartridge is fired, the bullet pushes an air column ahead of it and as well there is some blow-by of propellant gases. This high velocity air column will expel any light "blockage" in the barrel. I once intentionally tried to explode a LE barrel by jamming it into the snow and dirt as hard as I could, several times. The blockage was simply pushed out of the barrel with no damage done. A bit of fluffy snow is NOT going to result in a rifle barrel banana-peeling. The banana peeled barrels you see are pretty much all shotgun barrels, which are much thinner than a rifle barrel.

2. In the case of a heavy blockage, the air column being pushed ahead of the bullet, gets very hot from being compressed and when it hits the blockage, it turns 90 degrees and attacks the walls of the barrel like a gas cutting torch. Then the bullet impacts the blockage and flattens, spreading out 90 degrees to the bore axis. This combination cuts off a section of the barrel where the blockage began. I also experimented with this by pounding a bullet into the muzzle of the LE I was unable to damage in section 1. The result was the barrel lost a chunk off the end, which was cut surprisingly evenly right where the blockage began. There was no banana peel effect.

3. Sure actions blow up, just not from the same effect as a bore blockage. Actions blow up from cartridge over pressure. I managed to "blow up" the same LE from above by packing a 303 case to the top with Red Dot pistol powder and then seating a bullet on top of that. This caused a MASSIVE overpressure event which destroyed the action, without causing any damage to the barrel.

4. No. The air column pushed in front of the bullet and the gas blow-by are moving at nearly mach 3. That is more than enough to push water droplets, snow etc out of the barrel before the bullet hits them. Even if it didn't, water does not create an obstruction, even when the barrel is completely submerged in water. There are lots of YouTube vids showing guns being fired underwater.
 
The last part has some merit as it is possible to push a cup/core bullet beyond it's rotational capacity.
Not so much today as most manufacturers are aware of this possibility so bullets are much better constructed, a bonded bullet or solid copper really doesn't have anything to worry about today even with the fastest shooting cartridges in the fastest twist rifles.
It definitely happened though back in the day and was something to pay attention to.

I've had that happen, with Hornady 225 grain flat base bullets shot out of a Remington 338 Win mag, with a tight twist custom barrel, made up to shoot 275+grain bullets.

I noticed a "mist" which I ignored and shot three, nasty recoiling, rounds at a target 100yds out, to see if it was on paper after bore sighting.

Not one round impact was anywhere to be seen. There was a sand berm behind the target and no fresh impact dents.

I moved up to 50 yards and pretty much the same thing happened.

So I moved up to 20 yards and the target looked like it had been hit with multiple projectiles, some of which were stuck in the plywood the target was stapeled to. The bits were what was left of the metal jackets.

I haven't seen this happen with smaller bores, but I do believe it can happen.

I have had to remove jackets from the bores of several different milsurps. Back in the day, it wasn't unusual for a local nimrod to grind or file off the tips of surplus fmj bullets, which mostly had exposed lead bases, even those with boat tails, to make them ''legal'' for hunting big game.

The jackets would get stuck 2/3 of the way up the bore, sometimes a few inches after the leade and the lead cores would sail along on their merry way in whichever direction they wanted to go.

This was a dangerous practice and more than one very nice rifle was ruined through its use. I only saw one KABOOM, after the fellow shot the rifle a couple of times after the first jacket got stuck. Mostly it was just bulged barrels which was a testament to their makers.
 
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