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Old October 7, 2013, 08:42 AM   #26
precision_shooter
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I want my bullet to have a running start, I do not want my bullet setting at and shoved into the lands, I want my bullet to hit the lands a=running, I do not want my bullet to hesitate.

I am the fan of 'the jump start', I know, it sounds cool "I seat my bullets to the lands" and I ask 'why?' and the answer is cause.

And now we have another new reloader hitting the road to reloading from a dead stop to a dead run.

F. Guffey
Why do you want your bullets to have a running start/Why are you a fan of the "jump start"?

There are advantages to having bullets seated touching the lands. Certain bullets, to get the best accuracy, have to be loaded at max OAL while others are more tolerant of a Jump to the lands.

Loading them touching the lands as a beginning load is probably not the best idea. I first find a powder charge that is the most consistant accuracy-wise. Then play with bullet seating depth to fine tune the accuracy for that bullet. First loads are always .020-.030 off the lands.
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Old October 7, 2013, 09:56 AM   #27
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To F Guffy

So then what do you recommend for this reckless reloader at a "dead run"?
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Old October 8, 2013, 10:52 AM   #28
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Quote:
This results in an Ogive for the VLD at 2.729
If the measurement from the case head to the ogive, when the projectile is seated touching the lands is 2.729, seat the projectile deeper.

I'd suggest loading up ogive lengths in the following:

2.719" (or .01" gap between ogive and rifling)
2.714" (or .015" gap between ogive and rifling)
2.709" (or .02" gap between ogive and rifling)
2.704" (or .025" gap between ogive and rifling)
2.669" (or .03" gap between ogive and rifling)

Once you determine what the jump into the lands needs to be to eliminate the overpressure issues, you can start making .002" or .001" or so adjustments up and down to fine tune the accuracy.

I don't seat that far off the lands, but it sounds like in a magnum type design like the .300 WM, you want a little more room between the lands and the ogive to alleviate pressure spikes.

You have to understand that each and every rifle and round is completely unique. Because I may find the best accuracy out of my .243 with a projectile sitting .003" off the lands does not mean the next guy will. He may need a greater jump, or may need to seat touching or even into the lands. You need to understand when a rifle doesn't like something, and discontinue doing that action. Continuing to shoot when you are popping primers and seeing extractor marks is a bad, bad, bad habit to get into. Simply because a book says X does not mean that it is 100% applicable across the spectrum of rifles in that caliber - and in this case, it is certainly not applicable to your rifle.

Your gunsmith would be a great source to help you out if you are continuing to have issues. I'm kind of surprised he didn't develop a load for your gun after putting the barrel on to be honest.
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Old October 8, 2013, 01:21 PM   #29
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schmellba99 Seems to have some good advice there . I'm new to reloading here but not knowing seating your bullet at the lands or in to them causes higher pressure spikes worries me . I'd go back and read your 123 reloading book or what ever you read before starting . I find it interesting how when I go back to my books I've already read looking for answers to issues I'm having now. I find the answer and at the same time remember reading that very thing before .The fact I was not reloading at the time of first reading the book/s . I don't think I grasped what was being said completely . I have a new perspective on the issue now that I have almost 1k rounds loaded and fired , almost all for the same rifle . When I go back and read some stuff now ( not all or much ) I think duh how did I miss or not remember that .

Anyways my point is maybe go back and read your reloading book again .

Let me add one other thing that I just ran into . I was seating my bullets very deep do to a very short throat . Well what I thought at the time was a short throat . It turns out My bore was heavily fouled and I was not getting the correct measurement when measuring to the lands . After cleaning my bore REALLY well I gained .035 in OAL and one bullet I gained .090 but I question If I had the original measurement correct with that bullet because that just seems HUGE to me .

Not sure that means anything to you but I thought I'd throw it out there .

Quote:
I want my bullet to hit the lands a=running, I do not want my bullet to hesitate.
Maybe I need to be corrected but I thought jumping your bullet is what causes the bullet to hesitate at the lands . The bullet jumps quick to the lands and because at that point the bullet is still fatter then the bore . The bullet slows down if not stops until it's squeezed down to the point it fits in the bore . If the bullet is at or in the lands the bullet only accelerates because there is no secondary force opposing it .
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Old October 8, 2013, 02:19 PM   #30
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Windfall, every bullet fired will hesitate, slow down, move slower or whatever terms you choose, when it engages the rifling. It's not an issue. And seating bullets too deep in the case can cause higher peak pressure than when closer to the rifling. But I don't think this is your problem

Does your powder look the same as another container of the same type? There have been instances of incorrect labeling/packaging of powders.
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Old October 8, 2013, 02:31 PM   #31
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“Why do you want your bullets to have a running start/Why are you a fan of the "jump start"?”

A friend called, he built 5 magnificent 7mm wildcats, one of the 5 was not accurate, it was a big disappointment. The last place he took rifle to was to a smith with a bore scope and nothing, the smith scoped-it-out, nothing. My friend called me, and I said “I do not know”, He wanted to know where I would start when troubleshooting. I said I would start with his fire formed cases, I indicated I would drill out the primer pocket/flash holes for modified cases. After making the modified cases I told him I would remove the bolt, seat a modified case with a seated bullet, then chamber the case and shove the bullet out to the lands to determine the length of the chamber from the beginning of the refines to the bolt face.

He went to the Internet and did a search, he found long dowels, pencil marks, bullets and bolt face measurements, and nothing made sense so he came over. I drilled out the flash hole/primer pockets and then seated a few bullets. And then? I started pushing the bullet out, toward the rifling, before hitting the rifling, the bullet came out of the case. And Then? The bullet continued to move forward while being pushed forward, until it reached the rifling .375”+ beyond the beginning of the throat. I then dug out some heavy 170 grain bullets and started over, no matter how long the bullet was, the bullet came out of the case before getting close to the rifling.

And the question was “How did this happen? and my answer “I do not know”.

We loaded cases to test fire, long, short, max powder, minimum powder etc.. No matter the extreme the best accuracy was in the middle. He has not decided what he is going to do with the rifle.

The running start, I do not want my bullet to hesitate, I do not use reduced loads, I do not use cereal as a filler. I use the perimeters set by reloading manuals and data from manufacturers.

I had a Winchester Model 70 chambered in 300 Win Mag. The rifle shot patterns like a shot gun, it did not shoot groups, (Start over) I am surrounded by a few reloaders that I have a lot of confidence in. First offer, went something like “We have to find something that rifles likes”, nothing but patterns, move the bullet out, move the bullet in to the tune of 120 rounds, I contacted Winchester and informed them the rifle had the ugliest chamber in the world, they did not believe me, so, they made arrangements to take the rifle to their local warranty shop. I took the rifle to the warranty shop and explained to him the problem, he informed me Winchester and their warranty man had it all planned out, they were going to polish, hone and ream the chamber. And I ask “ How is that going to fix a chamber that is too long and too large in diameter?”

I went back in two months only to find they sent the rifle back to Winchester and I ask “WHY” and they said the chamber was too long and too large in diameter , and I said “Longer, the chamber started out to long and too large in diameter, now it is longer and larger in diameter” , it was about that time they decided I was difficult, before I got the rifle back they decided I was impossible. I wanted a chamber that fit my dies or I wanted Winchester dies to fit their chamber. Before bringing the rifle to the warranty shop they wanted me to fire it more like it was going to heal itself.

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Old October 8, 2013, 02:32 PM   #32
F. Guffey
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Quote:
I want my bullet to hit the lands a=running, I do not want my bullet to hesitate.

Maybe I need to be corrected but I thought jumping your bullet is what causes the bullet to hesitate at the lands . The bullet jumps quick to the lands and because at that point the bullet is still fatter then the bore . The bullet slows down if not stops until it's squeezed down to the point it fits in the bore . If the bullet is at or in the lands the bullet only accelerates because there is no secondary force opposing it .

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

I am glad we are going to get that sorted out, I said I am the fan of the running start, I want my bullet to hit the rifling a-running. I understand that could make little sense, cute reduced loads causes the bullet to contact the lands, that is when the bullet stops and or hesitates or finds it self sitting against the rifling at a dead stop, all the while the power is building pressure and spiking out? And that is a bad time for the bullet to be setting still.

I want the bullet to hit the lands and be in the barrel before the bullet realizes it is getting squeezed down, because time is a factor.

There are fire arms that have been rendered scrap, the story always starts with “What happened?” “ ‘Musta’ been a double charge” “It makes no sense, all I have ever fed this magnum rifle is reduced loads”.

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Old October 8, 2013, 02:38 PM   #33
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See para 5
http://www.snipercountry.com/article...breakin_II.asp
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Old October 8, 2013, 03:07 PM   #34
Bart B.
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From that article in the above link:
Quote:
When the primer ignites there is enough pressure to move the bullet forward into the lands. The bullet then stops.
I've fired 20 rounds of 7.62 NATO ammo without powder in them and every single one's primer fired normally. Inside of each case and on the back of each bullet, it was jet black from primer residue. Not one single bullet left the case and stopped at the lands. Each round was extracted and ejected normally. All the bullets were at the same place in the case neck when they were seated in an empty primed case. All bullets were seated about .030" back from the lands; none had rifling marks on them.

Others have had the same experience.
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Old October 8, 2013, 03:32 PM   #35
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Bart would that be because you crimped or sealed the bullets or were they just seated with no crimp ? I would also think maybe the empty case had enough room in it for all the primer gases to expand and not create enough pressure to unseat the bullet . If the case is full of powder you might get higher pressures from the primer . This thought would be some what based on your last post stating seating a bullet deeper in the case creates more pressure then the bullet being closer to the lands . I'm assuming the bullet being seated deeper causes higher pressures because you have reduced case volume by doing so .
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Old October 8, 2013, 03:49 PM   #36
Bart B.
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All bullets were seated in new 7.62 NATO M118 cases with their bullets pulled and powder dumped out. New bullets were seated; none were crimped in.

There may be higher pressure with powder in the case. Maybe I'll put a bunch of BB's in primed case, seat a bullet and see what happens with less volume inside the case. I'll have a cleaning rod handy to push out the bullet if it jams into the rifling.
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Old October 8, 2013, 04:26 PM   #37
F. Guffey
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“When Mike worked at Aberdeen proving grounds, etc..” A boring conversation for me always starts with “Hatcher said”. and now I must add the second most boring conversation, that one starts with Aberdeen proving grounds.

“The bullet starts and stops as many as three times” and there is no one here that wonders how that is possible, how much time does it take the bullet to stop and start moving again, it is not the bullet that is doing its thing in milliseconds it is the speed of the burning gases. When my bullet takes off it does not have time to stop, it keeps-on-trucking. I am the fan of the running start, I want my bullets to do the jump, I do not want my bullets setting still at the rifling wondering. wondering if it is going to get out of the way before the expanding gas pressure gets dangerously high.

I said the shooter between us was doing everything he could do to pull the trigger, pull the hammer back, rotate the cylinder or swing the cylinder out on a Model S&W66, he did not have powder in the case, the primer forced the bullet out of the case and into the forcing cone, and that locked the pistol up. The case was empty.

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Old October 8, 2013, 04:34 PM   #38
F. Guffey
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Then there is that other thing, stopping and starting and with all that equipment used ease of Washington, it would seem the stopping and starting of the bullet would cause humps, instead of a spike, there would be spikes.

F. Guffey

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Old October 8, 2013, 04:48 PM   #39
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Quote:
Originally Posted by Bart B.
And seating bullets too deep in the case can cause higher peak pressure than when closer to the rifling. But I don't think this is your problem
I disagree. Seating deeper in a straight walled pistol round, OK, but in a bottle necked rifle round not so much.

Here is a chart posted before by our Moderator UncleNick. As you can see by this chart seating deeper continues to decrease pressure until the bullets is over .250 off the lands. Then it starts to increase, but never gets even close to the pressures generated up close and personal to the lands.



He is another graph from an old manuals, don't ask I do not know where I got it.

{Edit: please read board policy on posting copyrighted materials.}

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Old October 8, 2013, 06:09 PM   #40
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Steve, there are many variables. A huge one is load density. Seating deeper into an 80% load density may reduce pressure. Seating deeper into a compressed load will almost always raise pressure.

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Old October 8, 2013, 06:42 PM   #41
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Years ago I got a batch of primers from Federal that blew out with loads that not previously caused any problems. After reducing my powder charges further, and still getting blow outs, I tried another brand of primer -- no problem with the other brand. Months later I saw a small article in a gun magazine in which Federal confessed that they had released a bunch of rifle primers that had thinner metal intended for pistol primers. So I say, try another brand of primer before you make any other major changes.
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Old October 8, 2013, 06:45 PM   #42
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Quote:
Originally Posted by reynolds357
Seating deeper into a compressed load will almost always raise pressure.
Got and charts, graphs or test data to back this up?
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Old October 8, 2013, 06:57 PM   #43
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Read enough cases over the years to know it to be fact. 90% of what I load is compressed. I have blown case heads backing up bullets into compressed charges trying to find optimum accuracy. I work up loads according to an antiquated system the bench rest shooters of yesteryear used. It always involves starting in the lands and backing away from them. You will usually develop pressure signs by backing a max compressed load under tighter compression.
Due to freebore, WBY is an entirely different ball game, but having said that, load something compressed to the recommended COAL for the WBY chamber. Max it out at that coal. Back it up and see what happens. Might be more like feel what happens. Back it up and put a hard crimp on it if you really want to mess something up.
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Old October 8, 2013, 08:09 PM   #44
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Steve, "when closer to the rifling" doesn't always mean touching the rifling. Nor do all maximum loads have peak pressures at 64,500 psi.

In the chart posted before by our Moderator UncleNick, start with a load developing 61,000 psi with about .135" jump to the rifling; not against the lands as the chart shows. This is the basis for my comment you've disagreed with.

Seating deeper continues to decrease pressure until the bullets is over .250 off the lands. Then it starts to increase and goes higher than where it started from.
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Old October 8, 2013, 08:23 PM   #45
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Quote:
Seating deeper continues to decrease pressure until the bullets is over .250 off the lands. Then it starts to increase and goes higher than where it started from.
It started at over 64K and ended under 62K amost a 1/2 inch off the lands. Where do you see that it ended higher then 64K?
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Old October 8, 2013, 08:38 PM   #46
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Emphasized a few, deleted a few; to make it clearer....

Steve, "when closer to the rifling" doesn't always mean touching the rifling. Nor do all maximum loads have peak pressures at 64,500 psi.

In the chart posted before by our Moderator UncleNick, start with a load developing 61,000 psi with about .135" jump to the rifling, not against the lands as the chart shows. This is the basis for my comment you've disagreed with.

Seating deeper decreases pressure until the bullets is over .250 off the lands. Then it starts to increase and goes higher than where it started from.
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Old October 8, 2013, 09:43 PM   #47
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I am still trying to decipher what Mr. Guffey is trying to convey with his stories ans relevant to this thread.
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Old October 9, 2013, 12:37 AM   #48
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Update: I contacted Alliant and they say there is nothing wrong with the lot# of my R22 powder.

I have received the chamber print from my gunsmith and have forwarded it to Berger per their request. They are looking into it and promise me an answer. The head bullet technician at Berger told me to not shoot any rounds from the gun until he has a full review.
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Old October 9, 2013, 08:44 AM   #49
F. Guffey
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windfall, you sent the print? The print of the chamber is a print of the chamber, the chamber could be 'something else'.

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Old October 9, 2013, 09:04 AM   #50
F. Guffey
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Reynolds357, I had a weak moment, I reached over to "quote" Weatherby from one of his published articles, and then, I got over it.

It goes to making an attempt to protect one from ones self. There is OAL and MAXIMUM OAL, moving the bullet out to increase case capacity prevents the case from being feed from the magazine. His free bore allowed for the running start, the free bore gave the bullet 'jump'.

There were misguided attempts at increasing the length of the throat of rifles chambered to 300 Winchester Mag, it worked as long as the reloader understood the increase in free bore allowed for heavier/longer bullets or more powder. The argument was for more powder with the same bullet.

F. Guffey

Last edited by F. Guffey; October 9, 2013 at 09:07 AM. Reason: change e to a before moment
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