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Full Case Prep For Long Range Accuracy

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08 May 2011, 03:17
Hot Core
Full Case Prep For Long Range Accuracy
quote:
Originally posted by Ghubert:
Perhaps this is what HC is getting at?
Actually, it seems to me some of the things people shooting at Paper do to their Cases can be eliminated if they P-FLR and Seat Bullets 0.010" Into-the-Lands.

All the Concentricity gizmoes can be tossed. And they really only need to Turn Necks if they have a "Tight Neck" Chamber. It should be able to be seen by anyone who tries it if they have a regular Factory Rifle.

By P-FLRing, the Case CenterLine is "Forced" to be In-Line with the Chamber Centerline. And by Seating 0.010" Into-the-Lands, it Dead Centers the Bullet with the Lands. And it is also enough that it will cause the Bullet to "Slip Into the Case a bit more" which positions it exactly the same from Shot to Shot. Due to that all the variation in Neck Tension, variation in Neck Length, and variation in Concentricity are relegated to the Trash Pile.

But Big Grin..., people that want to fret over Neck Tension, Neck Length and Concentricity should do it if they want to, especially if we are shooting to see who buys the BBQ for Supper. tu2 BOOM
08 May 2011, 03:43
rcamuglia
All of these shells were loaded .010" INTO THE LANDS.



They also were sized identically. P-FL. The difference in accuracy IS because of case prep and neck tension. The cases that had no prep had much more neck tension (.004") as opposed to those that had full prep (.001") because of the neck turning relieving material from the case. (not from backing up the truck)

Loading into the lands DID NOT negate the affect of prep or neck tension.
knife
popcorn
08 May 2011, 18:20
Hot Core
You sure you weren't just Flinching them out??? rotflmo
09 May 2011, 13:47
Ghubert
quote:
Originally posted by rcamuglia:
I don't think it's in the BWDT Reloading Manual.

If you check upstairs here in my original post, I believe that neck tension has a lot to do with accuracy. Neck turning even for factory chambers aids consistent neck tension around the circumference of the neck


I agree that consistent neck tension is very important for accuracy, I like woods worship at the altar of the carefully adjusted Lee collet die but find that using good brass I get all the consistency I need/ can quantify the results of in my factory chambers and get longer case life as the neck isn't thinned and then over worked on each firing cycle.
09 May 2011, 14:00
Ghubert
quote:
Originally posted by Hot Core:
quote:
Originally posted by Ghubert:
Perhaps this is what HC is getting at?
Actually, it seems to me some of the things people shooting at Paper do to their Cases can be eliminated if they P-FLR and Seat Bullets 0.010" Into-the-Lands.

All the Concentricity gizmoes can be tossed. And they really only need to Turn Necks if they have a "Tight Neck" Chamber. It should be able to be seen by anyone who tries it if they have a regular Factory Rifle.

By P-FLRing, the Case CenterLine is "Forced" to be In-Line with the Chamber Centerline. And by Seating 0.010" Into-the-Lands, it Dead Centers the Bullet with the Lands. And it is also enough that it will cause the Bullet to "Slip Into the Case a bit more" which positions it exactly the same from Shot to Shot. Due to that all the variation in Neck Tension, variation in Neck Length, and variation in Concentricity are relegated to the Trash Pile.

But Big Grin..., people that want to fret over Neck Tension, Neck Length and Concentricity should do it if they want to, especially if we are shooting to see who buys the BBQ for Supper. tu2 BOOM


Thank you for your reply, I have not experimented much with P-FLPing being so far satisfied with the Lee Collet die as having the same self centring property as you describe above.

I'd be interested to know whether you think that's a reasonable proposition?

I don't however agree that seating a bullet into the lands eliminates run out issues, it is not always possible or even desirable even for target shooting and in my limited experiments only works for certain types of bullets.

In my Sako Varmint I did an experiment with a friend's immensely complicated run out gauge station thing ( It looks like a miniature Alien abduction examination table....) I batched 10 rounds that showed very little to no detectable run out of a jammed load with Berger bullets out of a 100 rounds and on a clam day shot a group so small at 600 yards that I won't admit it here for being challenged to repeat it! Big Grin

This load ordinarily hold half to 3/4 of a minute out to 1000 yards and is in all probability more consistent than my ability to shoot it.
09 May 2011, 18:04
Hot Core
quote:
Originally posted by Ghubert:
...I have not experimented much with P-FLPing being so far satisfied with the Lee Collet die as having the same self centring property as you describe above.

I'd be interested to know whether you think that's a reasonable proposition? ...
I believe we are talking about two separate things. It appears that you believe the Lee Collet(Thingy Big Grin) "Centers" the Case Neck, but my questions would be, "With what"? or "How is that possible?"

Since the Case Neck is Free Floating(not held rigidly) within the Collet, once the Collet Compression begins, the Case Neck will Reform(not really Resizing) wherever the weakest point on the Case Neck happens to be. Even with Case Neck Turning, there will still be a variation in which portion of the Case Neck begins and continues Reforming due to the Pressure of the Collet Fingers. Then the Reforming is stopped by the Mandrel and there is nothing I can see which causes it to Align properly with the Case CenterLine - for those folks chasing Concentricity. If it happens, it appears to be just Random Luck.

If using the Lee Collet Thingy caused the Cartridge to be held in Compression, between the Bolt Face and the Chamber Shoulder, then it would be the same. But, I do not see how it could do that.

It is my understanding(which could be WRONG), that the people who use the Lee Collet Thingy at some random point decide to "Bump the Case Shoulder Back" after it becomes difficult to close the Bolt on the Cartridge (due to normal Case Head to Case Shoulder lengthening). Just prior to the "Bumping", when the Bolt does close with a snug fit, is when the Case would be held in Compression within the Chamber. But, they allow this Dimension to change with each firing. (Random is bad.)

If that is True, and Bumping occurrs, then the Cartridge is no longer held in Compression and the two CenterLines(Chamber and Cartridge) can not possibly be in alignment. On a Push Feed rifle, the Cartridge will be held Skewed by the force of the Ejector within the Chamber and on a Controlled Feed, the Cartridge will lay on the bottom of the Chamber. Either way causes the Bullet to be out-of-alignment with the CenterLine of the Bore.
-----

That said, a lot of folks like the Lee Collet(Thingys) and really believe they somehow enhance accuracy. But, if they work well for you, you should use them. tu2
09 May 2011, 21:03
Antelope Sniper
So Hot Core. I you don't like the Lee Collet die, what sizing dies do you recommend for long range shooter?
09 May 2011, 23:36
rcamuglia
woods loves the Lee collets. I wish he would take a second away from trying to watch his Dinars give birth and give us a run down....

coffee
10 May 2011, 02:24
Hot Core
quote:
Originally posted by Antelope Sniper:
So Hot Core. I you don't like the Lee Collet die, what sizing dies do you recommend for long range shooter?
I've used Standard FL Dies by RCBS and Redding for many years, without any concerns. When I was messing with Wildcats many MANY years ago, they were always cut by the GunSmith(Morgan, Hale, etc., local folks who are all gone now).

I've never even tried the Lee Collet Thingy because the way it is designed, it just doesn't interest me. But..., as I said before, if anyone likes them, that is what they should use.
-----

I really believe having good Cases and long Case Life has a lot to do with how close the Dies and Chamber come to matching each other. Swap rifles often enough and eventually the right Chamber comes along. Then I dread the day it is time to replace that barrel, which is why I use Moly.

Best of luck to you all.
10 May 2011, 03:07
woods
quote:
Originally posted by Hot Core:
I believe we are talking about two separate things. It appears that you believe the Lee Collet(Thingy Big Grin) "Centers" the Case Neck, but my questions would be, "With what"? or "How is that possible?"



What can be said about the Lee Collet is that the mandrel self centers itself in the neck before you resize. IOW the mandrel is not fixed. After threading the die into the press you can reach up under the die and "toggle" the mandrel around.

This is ingenious and here's why; when you fire the case in your chamber the pressure expands the case neck to the chamber neck walls. This centers the case neck in perfect alignment with the case body unless you have a chamber that is reamed bad (and I have yet to see one of those and I reload for over 40 different rifles). So the free floating mandrel does not change the position of the neck to one side or the other. When you squeeze the collets in onto the neck brass and thus onto the mandrel, there is no pressure to move the neck out of concentricity with the case body.

Now the OD of the neck is sized smaller than the chamber (just like any other die) and you need something to then keep the neck in the center of the chamber neck. But at least you are starting out with the neck being aligned with the case body and very low runout.

The mechanism to keep the case body and neck centered in the chamber is up for dispute



If you have outside neck turned to keep the thickness variations to a minimum then this method will be even better since after fire forming a neck with even wall thickness will have a better alignment with the case body regarding the inside center of the neck.

In my experience and measurements the Lee Collet will solve almost all of any problems you might have with concentricity when measured on the bullet. If you outside neck turn then it will solve almost all of your concentricity problems period.

Now I am sure there are some benchresters and long range shooters who have much more detailed and even better tools and case preps. This is something any of us can do with readily available dies and thingys. Will it amount to a "hill of beans" on the target, who knows?


____________________________________
There are those who would misteach us that to stick in a rut is consistency - and a virtue, and that to climb out of the rut is inconsistency - and a vice.
- Mark Twain |

Chinese Proverb: When someone shares something of value with you and you benefit from it, you have a moral obligation to share it with others.

___________________________________
10 May 2011, 09:00
rcamuglia
Great Sig line addition and thanks for your living up to it every day here.

....Sensei!
tu2 tu2 tu2
11 May 2011, 02:27
Hot Core
quote:
Originally posted by woods:
[LIST]
  • PFLR - This is sizing the case body smaller than the chamber body and keeping a small amount of contact at the shoulder. Supposedly (and I'm not saying it is incorrect), the cone of the case shoulder will fit into the cone of the chamber and be held in stasis between that shoulder contact and the bolt face holding the case head.
  • Actually, when P-FLRing is done correctly, the Case will be in Compression from the Bolt Face against the Case Head and the Chamber Shoulder against the Case Shoulder. That "Forces" the Case Shoulder to center itself within the Chamber Shoulder. It can't be out of alignment if it is in Compression(aka a Snug Fit).
    quote:
    The thing is if you take 2 funnels of equal angle, one smaller than the other and with a smaller outlet tube, you can offset the smaller outlet tube and still have contact on all sides of the funnel. It takes just a little variable pressure. The natural tendency is to center on each other, but it can be done.
    I just do not see how that is possible when it is under Compression. Perhaps I'm missing something though. Anything else you can add to convince me?
    quote:
    Now when you fire the case there is considerable pressure from the primer and firing pin pushing the case forward and this should center the smaller funnel of the case down into the chamber funnel.
    The Case can't move Forward due to the Firing Pin if P-FLRing is done correctly, because it is fixed solidly in place by the Compression.

    It appears you believe P-FLRing leaves some kind of "Slack" for the Case to move within the Chamber and it does not do that - if done properly.

    However, "Bumping the Shoulder Back" as the Neck Sizers, and apparently the Lee Collet Users, does indeed cause the Case to be Slack within the Chamber. And as said in a previous post, on Push Feed rifles, that Slack Case will be Skewed in the Chamber by the Ejector, or on a Controlled Feed rifle it will just lay on the bottom of the Chamber. During that "Slack Case Fit" condition, the Force of the Primer could/would have an Impact( Big Grin) on the Case position, just as Mr. Woods described.

    quote:
    Even if the shoulder slopes have equal pressure on all sides upon firing, you would have a case body that was aligned with the chamber and have a case neck that was then out of alignement unless you have used a sizing method that aligns the case neck with the case body (I'm talking the center of the neck hole being in alignment, not centering the OD of the neck). The Lee Collet will do this as explained above. An expander ball with a fixed stem jerking the neck around is not likely to do it. ...
    And I can't see how that is any "more possible" with the Lee Collet than using a regular FL Die. As the Collets begin Squeezing, the "weakest" portion of the Case Neck with begin Reforming, not all around at one time. Same as cutting two pieces of Baling Wire(just for Mr. Woods Wink) a foot long, holding one piece at the ends and Bending it. Then take the second Wire and place a "Nick" in it 1" from the center and begin bending it. It will try it's best to bend at the Nick because there is less Restistance at that spot, just the same as the Collet works.

    I know some folks shoot good Groups with the Lee Collets(like Mr. Woods) and I'm real glad they work so well for you. tu2
    11 May 2011, 02:43
    rcamuglia
    quote:
    Originally posted by woods:



    and leaves a portion of the neck the thickness of the washer unsized, which in this case is .010"



    This method
    1. Uses the Lee Collet which leaves the neck in alignment as left by firing in the chamber
    2. Sizes the case body to alleviate any pressures from banana shaped cases or non-indexing of rounds to the chamber
    3. Leaves contact at the shoulder because of PFLR with a Redding Body Die
    4. Leaves a portion of the neck unsized to help center the neck in the chamber


    I've tried partial neck sizing like in your pic, but have never had good accuracy luck.
    11 May 2011, 09:04
    woods
    HC, from your post




    ____________________________________
    There are those who would misteach us that to stick in a rut is consistency - and a virtue, and that to climb out of the rut is inconsistency - and a vice.
    - Mark Twain |

    Chinese Proverb: When someone shares something of value with you and you benefit from it, you have a moral obligation to share it with others.

    ___________________________________
    11 May 2011, 18:25
    Hot Core
    quote:
    Originally posted by woods:
    I mentioned "small amount of contact at the shoulder" and you used words like "compression" and "snug fit". I would only say that I push the shoulder back ~.001" (which will still leave a slight crush fit) and prefer that for hunting situations but still call this PFLR because of the slight crush fit. ...
    That is where we differ. When the Case Neck Datum Line to the Case Head Distance is less than the Bolt Face to Chamber Shoulder Datum Line Distance, then it is not possible for any kind of Snug or Crush fit.

    The only way to have a Snug or Crush Fit is to have a "Negative( - ) Headspace Dimension", on a Bottle Neck Case of something in the range of " -0.001" to -0.002".

    What you are refering to as P-FLRing is not P-FLRing and is creating the confusion.
    -----

    quote:
    You have misread or please show me where I said there would be "slack" after PFLR
    OK, that would be in the sentence directly above
    quote:
    where you said:
    I push the shoulder back ~.001" ...but still call this PFLR ...
    But, old buddy, that is not a Snug nor a Crush fit. And it is not the definition of a proper P-FLR. It is the Definition of "Bumping Back the Shoulder" which always creates Slack between the Case and the Chamber.

    And yes, I agree that Bumping the Shoulder Back will allow the force of the Firing Pin to move the Case(because of the Slack, non-Snug Fit) - on a Controlled Feed Rifle, but I really doubt it will overcome the Ejector Force to reposition the Case from it's Skewed position on a Push Feed.
    -----

    I'm glad the Lee Collet Dies(aka Rube Goldberg Thingys Big Grin) work well for you. tu2