262 or 268 necks for 6mm PPC

Alright !

Wilbur said:
I don't see how a .243 bullet could "wobble" in a .236 bore...but like I said, I ain't no Ferris Pindell. Further, I don't know as much as Jerry does either!
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Wilbur, glad to hear you've been thinking about this issue and have come to the same conclusion that I did some time ago.

My experience with the no-turn 220 and 6mm Beggs cartridges has proven to me that there is nothing gained from laborious neck turning as long as you have high quality cases to begin with. I can see how neck turning would be necessary with wildcat cartridges made from other caliber cases but with the fine cases we have today from Lapua, Norma and others I see no reason to bother with it.

This also brings to mind the old myth that says bullets must be seated in contact with the lands to prevent inbore yaw. I'm with you; how could a .2430 diameter bullet wobble or start out crooked in a .2360 or .2370 bore? For years I've had best results with bullets seated 'just off the lands.'

Later,

Gene Beggs
 
Gene Beggs said:
Wilbur, glad to hear you've been thinking about this issue and have come to the same conclusion that I did some time ago.

My experience with the no-turn 220 and 6mm Beggs cartridges has proven to me that there is nothing gained from laborious neck turning as long as you have high quality cases to begin with. I can see how neck turning would be necessary with wildcat cartridges made from other caliber cases but with the fine cases we have today from Lapua, Norma and others I see no reason to bother with it.

This also brings to mind the old myth that says bullets must be seated in contact with the lands to prevent inbore yaw. I'm with you; how could a .2430 diameter bullet wobble or start out crooked in a .2360 or .2370 bore? For years I've had best results with bullets seated 'just off the lands.'

Later,

Gene Beggs
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That maybe true at short range but long range I believe uniform neck tension is needed to stop vertical. turning necks and annealing help this..... jim
 
guys Guys GUYS!!!!!


Inbore yaw is real. And it has absolutely NOTHING TO DO WITH bore size! :) The 'wobble' referred to has everything to do with neck size. The more clearance in the neck, the further over the butt of the bullet will be offset as it swages into the lands..... IT WILL BE OVER against one side or t'nuther, it shore ain't gonna' hang there in thin air while 600lb of swirling airhammer cram it in the hole.
 
Well...whatever the bullet does when it enters the barrel it completely fills the bore. It may be distorted quite a bit but it swages to the bore. I can't see how it "yaws" in the barrel but if anybody has a different story I'd like to hear it.
 
Wilbur said:
Well...whatever the bullet does when it enters the barrel it completely fills the bore. It may be distorted quite a bit but it swages to the bore. I can't see how it "yaws" in the barrel but if anybody has a different story I'd like to hear it.
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The bullet doesn't yaw or wobble while it is in the barrel. If the bullet is at a slight, even very slight, angle as it enters the bore it will remain at that offset as it exits the bore. If it is offset, especially in a flat base bullet, the gas of ignition exits one side of the base rather than being evenly exhausted. This is where the expression of "the bullet going to sleep" comes from.

Notice that the top shooters closely examine their targets to see if the bullets bade round holes or oblong homes.


.
 
JerrySharrett said:
The bullet doesn't yaw or wobble while it is in the barrel. If the bullet is at a slight, even very slight, angle as it enters the bore it will remain at that offset as it exits the bore. If it is offset, especially in a flat base bullet, the gas of ignition exits one side of the base rather than being evenly exhausted. This is where the expression of "the bullet going to sleep" comes from.

Notice that the top shooters closely examine their targets to see if the bullets bade round holes or oblong homes.


.
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Compressed loads will do this, uneven pressure on the base..... jim
 
Ol' Beggs again.

Wilbur said:
Well...whatever the bullet does when it enters the barrel it completely fills the bore. It may be distorted quite a bit but it swages to the bore. I can't see how it "yaws" in the barrel but if anybody has a different story I'd like to hear it.
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Wilbur, again, I'm with you on this.

Many years ago during a discussion among the Midland Shooter gurus, I remember Harold Broughton stating,
"The barrel is the final bullet swage." And you know what? I think there is a lot of wisdom in that statement.

Sorry Alinwa, but in my opinion, there is just no way the ass end of a bullet could be slammed over against one side or the other as it moves from the case neck into the barrel's throat.

FWIW

Gene Beggs
 
Gene,
I will have to respectfully disagree. I have tested loaded round runout back to back with perfectly straight and others loaded with a predetermined amount of runout. There is a small difference. Think of center of form versus center of mass. It's not a huge difference but as close as the aggs are these days I don't want to give up anything.

Richard
 
Richard said:
Gene,
I will have to respectfully disagree. I have tested loaded round runout back to back with perfectly straight and others loaded with a predetermined amount of runout. There is a small difference. Think of center of form versus center of mass. It's not a huge difference but as close as the aggs are these days I don't want to give up anything.

Richard
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Richard, most benchresters will agree with you and Alinwa on this tight-neck vs., no-turn issue. If one is after every last little bit of accuracy for competition purposes, most will have more confidence in a tight-neck chamber setup where loaded round measurements are within .0001. Me? I just enjoy experimenting and proving things out for myself. I'm sure I earned my last hall of fame point fifteen years ago and don't mind risking leaving a tiny bit on the table in order to enjoy the convenience of no-turn chambers. But, I'm not yet convinced there is any compromise at all in using a no-turn setup. Like Jackie Schmidt said recently, "Wish I was twenty years younger." :rolleyes:

Later and with best regards. :cool:

Gene Beggs
 
Gene,

I am using a no-turn setup. It works great with the Norma brass. The wall thickness variance on that brass is really good, better than the Lapua. When using Lapua I still turn necks. The jury is still out on the Norma and will have to see how it lasts. So far the butt of the case is staying where it needs to be and the primer pockets still tight.

You have to remember I shoot so poorly the gun has to carry me through an agg.:p

Richard
 
Neck Clearance

JerrySharrett said:
The bullet doesn't yaw or wobble while it is in the barrel. If the bullet is at a slight, even very slight, angle as it enters the bore it will remain at that offset as it exits the bore. If it is offset, especially in a flat base bullet, the gas of ignition exits one side of the base rather than being evenly exhausted. This is where the expression of "the bullet going to sleep" comes from.

Notice that the top shooters closely examine their targets to see if the bullets bade round holes or oblong homes.


.
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I got my last batch of bullets from Misfit Island, and they shoot square holes. I don't think tight or loose neck clearance is the answer as much as a square reamer is, really.
 
Anschuter2013 said:
I got my last batch of bullets from Misfit Island, and they shoot square holes. I don't think tight or loose neck clearance is the answer as much as a square reamer is, really.
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In the chamber neck is a conical mergerance of the straight section to conical. Usually 1.5-2 degree taper according to which chamber is used. The downbore end of that cone where it merges with the cylindrical bore must, must, make a symmetric circle for the bullet tp truly start on-axis and thus eliminating in-bore yaw.

Misfit Island????



.
 
JerrySharrett said:
In the chamber neck is a conical mergerance of the straight section to conical. Usually 1.5-2 degree taper according to which chamber is used. The downbore end of that cone where it merges with the cylindrical bore must, must, make a symmetric circle for the bullet tp truly start on-axis and thus eliminating in-bore yaw.



Misfit Island????



.
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Misfit Island is from Rudolph where the train with square wheels was sent because nobody wanted it, kinda like my bullets.
 
6ppc .262 or .268 necks

I shoot a .269 neck. Mike Conry shoots a 0.268 and he cleans up in most matches.
 
I'm really late to this discussion and am anything but expert in this area, but am considering having a 6 PPC varmint rifle built. I plan to use Norma 6 PPC brass. I've mic'd a couple of Norma 6 PPC cases with a Starrett neck micrometer, and the brass thickness appears to be about .011". Therefore, to clean the necks completely, I'm thinking that .010" would be about right. This would give me a loaded round outside neck diameter of about .263". So my question to all of you experts is this: Would a neck diameter on the reamer of, say, .265" be ideal? I plan to order up a reamer from Pacific Tool & Gauge and need to know what neck diameter to specify.

One other question that you guys can undoubtedly answer. I've been shooting a Sako 6 PPC (using Norma brass) with a longer-than-desirable throat. To load the rounds to have slight land contact on chambering, the bullets I've been shooting (68 grainers) only reach down about half the depth of the neck. I'd much prefer to have the neck contact closer to all of the neck. So here's my question: How do I specify this to PT&G? Can this be articulated as freebore?

Thanks in advance for any assistance you guys can provide to a benchrest illiterate!:eek:

Edit. I might add that the Sako 6 PPC chamber appears to have a neck diameter of something like .272". I turned the Norma brass down to .009" (so probably over-turned it, but was just learning how to use the neck-turning tool). This gave me a loaded round neck diameter of about .261". So tons of space around the round in the chamber, along with the undesirable long throat. This rifle (sporter weight repeater) has not shot as well as I'd like, and this is the reason for building a better 6 PPC.
 
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Need one of your experts advise on reamer neck size if you plan to use Norma brass exclusively. 6ppc that is! I've ordered a bunch of brass an in the process of getting a reamer. .268 or .269? I forgot to mention I do not intend to turn necks. I apologize if missed the answere earlier in this thread.
 
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