No neck turn 6PPC

jackie schmidt

jackie schmidt

New member
One thing I have been experimenting with as of late is using a .274 neck chamber and not turning necks.

I got the idea when I bought 600 Lapua Cases about two years ago, and noticed how even the case wall thickness was, certainly less than .001 inch on any of them.

I made a little fixture that allowed me to simply ream out my existing .269 neck chamber to .274. The loaded round measures about .272 at the gas ring.

I did a barrel for my Rail Gun, and one for my LV. Both were proven barrels in competition.

At the two times I have been able to get to the range, I cannot tell the difference. Both barrels shot at the same level as before.

This is something I am going to continue playing with, I know it goes against our conventional thinking, but if the brass is that good, why turn.

Here is a picture of a round, the case has been fired about five times in my Rail Gun.

http://benchrest.com/attachment.php?attachmentid=15652&stc=1&d=1418918628
 
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Here is the fixture I made that allows me to ream the neck straight with the existing chamber. The little pilot is machined on the same taper as a case. You insert it and the reamer, and the pilot and the existing neck guides it right in. I ream them by hand, taking the reamer right to the original neck ending.

If this proves to work to my satisfaction, I will have a .274 reamer ground.

http://benchrest.com/attachment.php?attachmentid=15653&stc=1&d=1418919080
 
ReedG said:
Jackie, do you use a different neck tension on the unturned necks?
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I'm using a .271 bushing, I just made one up out of StressProof for the time being. That is about the same neck tension as I use in my .269 chambers.

I have never went overboard on neck tension, I play with the seating depth, charge, and my barrel tuner.
 
Alright!

Jackie, I'm glad to see you trying the no-turn neck chamber for the 6PPC. My no-turn 6 Beggs chamber also uses a .274 neck.

My experiences mirror yours. With the Lapua 220 Russian case being such good quality, I can tell no difference in accuracy with no-turn vs., tight neck. It sure is nice to be able to pluck new cases from the box, load 'em and shoot 'em! :D I know this is not going to set well with those who make neck turning equipment but we are just telling it like we see it; huh? :confused:

When someone asks me if they should go with a no-turn neck or tight neck, I tell them that if they are seeking the ultimate in accuracy and will be shooting in sanctioned tournaments they would probably have more faith in the tight neck.

Glad to see you posting more on the forum. Drive out sometime and we'll do some shooting in the tunnel. :D

Later,

Gene Beggs
 
Gene Beggs said:
Jackie, I'm glad to see you trying the no-turn neck chamber for the 6PPC. My no-turn 6 Beggs chamber also uses a .274 neck.

My experiences mirror yours. With the Lapua 220 Russian case being such good quality, I can tell no difference in accuracy with no-turn vs., tight neck. It sure is nice to be able to pluck new cases from the box, load 'em and shoot 'em! :D I know this is not going to set well with those who make neck turning equipment but we are just telling it like we see it; huh? :confused:

When someone asks me if they should go with a no-turn neck or tight neck, I tell them that if they are seeking the ultimate in accuracy and will be shooting in sanctioned tournaments they would probably have more faith in the tight neck.

Glad to see you posting more on the forum. Drive out sometime and we'll do some shooting in the tunnel. :D

Later,

Gene Beggs
Click to expand...

Gene, I shot these two Sundays ago, I personally think that the two 10 shot groups are about what that barrel has in it as I took my time and tried to hit the condition as close as I could. the left group was fired in a quartering right to left, the second in a quartering left to right. It's one of those barrels that will stick 5 in a "zero", but by the time you get to 10, it's going to wallow out.

The LV group was shot with a set-back Krieger from around 2005. I think I will leave it on the Rifle.

The first 10 shot was with 30.2 grns 133, the second with 30.5. The LV was shot with the 30.5 load. The bullets are the originol 65 grn Barts Boat Tail on .790 jackets. I still have about 10,000 of those, I suppose they are what I will shoot.


http://benchrest.com/attachment.php?attachmentid=15655&stc=1&d=1418939873
 
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It is good to see you back Jackie, I always enjoyed your experiments and write ups!
 
Dusty Stevens said:
What really happens if you have excess clearance?
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Dunno. Excess of probably 0.005" or more. maybe nothing but it wouldn't be in my rack if it were supposed to be a benchrest rifle.

There has always, in benchrest, been followers of tight necks, fitted necks and then the 0.004" crowd (loose to win as Krupa put it). Tightening neck clearances in some instances may help accuracy, in some instances may hurt? Proof? Not many books written on that subject.

Too many variables in powders wanting high neck tension and too many powders wanting very little neck tension.

I remember one time at Rockingham CCBW and Tommy10gun both just dropping the bullet on the powder and they
whipped a bunch of us.

I think yo' bro' and his bullet buddy would probably suggest 0.0015"??

I'll betcha' most benchrest shooters, even though they try to keep neck wall thicknesses to 0.0001", don't know
what their chamber neck diameter actually measures. They know what they spec and what the reamer says but most 0.262" called for necks are closer to 0.263".

SAAMMI spec between max chamber and minimum cartridge on some drawings go to about 0.009" clearance.
 
Just wondering since i have shot many matches with 262 brass in a 268 chamber and found no ill effects on the target or the brass after a weekend. How much room does say a factory 300 win mag have over the thinnest brand of brass?
 
The whole point in neck turning from day one was to get consistant case neck thickness not to see how close you could get em fit to the chamber neck dia. Now that brass is better folks still just turn it all off not really knowing why and then theyre not able to get proper neck tension over the life of the brass without annealing. Its a never ending cycle not knowing where it even started. I can remember the days of having to turn to a 262 neck because the brass was that bad. I also remember using 7.63x39 brass because you couldnt get 220 russian. Now that brass was bad.
 
JerrySharrett said:
Ok, but how about if the next batch of Lapua turned out to be 0.003 smaller? You're stuck with those oversized barrels.
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Honestly, I haven't seen a Lapua 220 Russian Case vary hardly any at all during the going on 20 years I have been doing this. But anything can happen.

When I went to the .269 neck back years ago and did write ups right here on Benchrest.com, many people said it would not work. How many are using it now?

I'm going to try the no neck turn, if it looks good, fine. If not, I will just go back to the .269.
 
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Dusty Stevens said:
Just wondering since i have shot many matches with 262 brass in a 268 chamber and found no ill effects on the target or the brass after a weekend. How much room does say a factory 300 win mag have over the thinnest brand of brass?
Click to expand...


Kinda' like if it ain't broke don't fix it, if it shoots ok keep doing what works for you. The only detriment I could foresee with that much brass movement, it WILL shorten your brass life. Its called "work hardening" a predictable event. Annealing occasionally would help that some, probably but moving that type metal that far, 0.006", is not the best idea in the hat.
 
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