neck or full length sizing ?

[Bc'z]

@Bc'z
Basically no 2nd firing brass is in need of full-sizing yet (a bad example to compare from - IME).
Even 3rd firing is to soon to compare from.

What indifference do you see in case measurements at the expansion line, shoulder, and case headspace from say 4th, 5th, 6th, and 7th firing brass?
Or from a same cycle, but a long string, where the chamber was subjected to wide range of temperature variation?

On your targets, the fly'ers you blame on yourself. How do you know they were you, and not the load?
IME - any time you have variance in brass specifications, fly'ers like those in your targets can be expected and/or to blame.
IME - anytime a bolt closes harder on one round more then another, again fly'ers can be expected, and a product of neck sizing only.

Also, why do you look so hard at 100yd results for high BC VLD's like your using. Distance is what there designed for and what will tell you the true tales of the loads (100yd results tell me very little what to expect down range with long, heavy bullets).

At one time I also neck sized only (like many people have at one time or another). But soon after learned better and seen the light and advantages to F/L sizing every time.

Ok a lot to look at here.
I get that 2 firings are not in need of full length sizing. As for the RP brass with multiple firings, that I never measured base to datum.
Lapua brass has grown .002-.0025 after 3 firings.
I have since started keeping track of case growth and times fired.
Still not weight sorting or checking volume.
As for long strings of firing I've never shot more than 5 rounds in a string, being a factory sporter and all, even I'm not that dumb.
Flyers I know for a fact I pulled the 3rd shot on the right hand group of 4.
Have shot this same load at 300 into an inch group.
Flyers could also be contributed to not all the same lot of brass as it was derived from factory ammo, and never sorted by weight.
So is a 30 06 case with a fair amount of body taper fully supported when die is backed out 3/4 turn?

 

[JFrank]

I wonder how many guys shoot a 3006 better than BC?
Probably not too many.
J

 

[Straightshooter1]

Below German Salazar answering a question about "partial full length resizing, and the benefits of full length resizing.

"a full-length sized case in which the neck is also fully sized. There is clearance at the neck and in the body of the case, the closest fit anywhere is the bullet in the throat. If the neck to bullet concentricity is good (although it needn't be perfect), then the bullet will find good alignment in the throat and the case body and neck will have minimal influence. Let's not forget that the base of the case is supported by the bolt face or the extractor to a certain degree as well; this is yet another influence on alignment. As you can see, there are several points from base to bullet that can have an effect. My procedure is to minimize the influence of those that I can control, namely the case body and neck, and let the alignment be dictated by the fit of the bullet in the throat and to some extent by the bolt's support of the base. Barring a seriously out of square case head, I don't think the bolt can have a negative effect on alignment, only a slightly positive effect from minimizing "case droop" in the chamber. Given that a resized case will usually have a maximum of 0.001" diametrical clearance at the web, this isn't much of a factor anyway.

In conclusion, I believe that allowing the bullet to find a relatively stress-free alignment in the throat by full length sizing (including the neck) and turning necks to enhance concentricity gives the bullet the best probability of a well-aligned start into the rifling."

The Rifleman's Journal
Germán A. Salazar

Have read some about "partial neck sizing", which is supposed to align the bullet best (addressing that point I've highlighted in red above) as the unsized part of the case neck fits firmly in chamber's neck. I've just started to experiment with this to see if I can find any noticeable difference with my factory gun. Curiosity often gets the best of me. For sure, it does make for a little firmness in locking the bolt down.

 

[Uncle Ed]

Have read some about "partial neck sizing", which is supposed to align the bullet best (addressing that point I've highlighted in red above) as the unsized part of the case neck fits firmly in chamber's neck. I've just started to experiment with this to see if I can find any noticeable difference with my factory gun. Curiosity often gets the best of me. For sure, it does make for a little firmness in locking the bolt down.

One point you are missing about neck or partial neck sizing, is if the case has unequal wall thickness it warps and becomes egg shaped. Meaning a completely full length resized case will reduce the body diameter more and give the body more clearance and reduce the chance of the warped case steering the bullet out of alignment with the bore. (the rat turd in the violin case)

And if the case does warp the base of the neck sized case will no longer be 90 degrees to the axis of the bore. And this will cause the rear of the case contacting the bolt face to be tilted or tipped and out of alignment with the bore.

The full length resized case with shoulder bump will have head clearance or air space between the rear of the case and bolt face. Meaning a warped full length resized case will have less effect on bullet alignment. This is what German Salazar was trying to get across, meaning the base of the case and the case body has no steering effect on the bullet.

 

[Homerange]

One point you are missing about neck or partial neck sizing, is if the case has unequal wall thickness it warps and becomes egg shaped.

And in reality how much of an issue is this really ?
First I've ever heard this mentioned.

After multiple firings when the case has fully expanded to chamber dimensions, how can it still be egg shaped so badly to effect runout more than spring back ?

 

[cw308]

I've tried it all , with partial neck sizing by the time you get to the range your runout you could see by rolling the round across a table . Full or neck sizing , all the rest is something to try you won't stay there .

 

[klamathsteel]

Remington 700 cdl w/j lock, 4x16 vortex viper.
Smallest group was with lapua brass 2nd firing., 3 shots factory sporter, 2# trigger,
Target confirmed by gunsmith. 185 vld
Same rifle umpteen loadings RP brass
Never annealed. 5 shots under .25", followed by 4 shots under .25". 185 vld hunter.
Rifle is at gunsmith now installing a 4 groove 1-11 Krieger, timney 510, and bedding in a McMillan edge fill.
Wonder how small I can shoot with it now?
Not being argumentative with you Donovan,
But I've learned alot from you, Toby Dusty, Ned, Ed, Boyd and theist goes on in crafting the very best ammo I can, and proper shooting techniques.
All because they say it cant be done.....
Dont tell me what I cant do is my response.
Shot during seating depth test. View attachment 1116096
Using up the last of my vld hunters
How many x's?View attachment 1116097
Looks like yes it is repeatable.
Thanks for the lessons everyone, after this rifle is put back together I'm thinking about putting together a f class rig.

Does that mean we'll be seeing you at White City ??

 

[Bc'z]

Does that mean we'll be seeing you at White City ??

Very possible!
Mark is really giving me push into the rabbit hole.
I've already contacted Xringstocks about the cost of a laminated stock, and I'm digging on this sitman I'm working on.

 

[klamathsteel]

Very possible!
Mark is really giving me push into the rabbit hole.
I've already contacted Xringstocks about the cost of a laminated stock, and I'm digging on this sitman I'm working on.

Well cool ! I look forward to meeting you. I haven't shot there in 4 or 5 weeks. This is my really busy time at work and the wife and I just got a new grandbaby 2 weeks ago so it's been a little hectic. Gonna try to make it next wednesday.

 

[Steve Donlon]

Ok a lot to look at here.
I get that 2 firings are not in need of full length sizing. As for the RP brass with multiple firings, that I never measured base to datum.
Lapua brass has grown .002-.0025 after 3 firings.
I have since started keeping track of case growth and times fired.
Still not weight sorting or checking volume.
As for long strings of firing I've never shot more than 5 rounds in a string, being a factory sporter and all, even I'm not that dumb.
Flyers I know for a fact I pulled the 3rd shot on the right hand group of 4.
Have shot this same load at 300 into an inch group.
Flyers could also be contributed to not all the same lot of brass as it was derived from factory ammo, and never sorted by weight.
So is a 30 06 case with a fair amount of body taper fully supported when die is backed out 3/4 turn?

If that will shot like that at 100, you should be able to put 5 in under an inch at 500 yards. My 210 Sierra bullets will all day long if I do my part. Of course it takes longer for my barrel to heat up. If I have a flyer, I know it's me, no doubt about it.

 

[SGK]

Below German Salazar answering a question about "partial full length resizing, and the benefits of full length resizing.

"a full-length sized case in which the neck is also fully sized. There is clearance at the neck and in the body of the case, the closest fit anywhere is the bullet in the throat. If the neck to bullet concentricity is good (although it needn't be perfect), then the bullet will find good alignment in the throat and the case body and neck will have minimal influence. Let's not forget that the base of the case is supported by the bolt face or the extractor to a certain degree as well; this is yet another influence on alignment. As you can see, there are several points from base to bullet that can have an effect. My procedure is to minimize the influence of those that I can control, namely the case body and neck, and let the alignment be dictated by the fit of the bullet in the throat and to some extent by the bolt's support of the base. Barring a seriously out of square case head, I don't think the bolt can have a negative effect on alignment, only a slightly positive effect from minimizing "case droop" in the chamber. Given that a resized case will usually have a maximum of 0.001" diametrical clearance at the web, this isn't much of a factor anyway.

In conclusion, I believe that allowing the bullet to find a relatively stress-free alignment in the throat by full length sizing (including the neck) and turning necks to enhance concentricity gives the bullet the best probability of a well-aligned start into the rifling."

The Rifleman's Journal
Germán A. Salazar

I still don't get this when the bullet isn't seated at touch/jam. In that case there's slop/droop in the bullet/throat. And if you have a bolt with 'mechanical extractor' (e.g. Defiance Elite) there's no extractor pin pushing on the head of the case. In that case the rat turd is rattling around in the violin case and highly unlikely to be aligned.

 

[47WillysGuy]

I still don't get this when the bullet isn't seated at touch/jam. In that case there's slop/droop in the bullet/throat. And if you have a bolt with 'mechanical extractor' (e.g. Defiance Elite) there's no extractor pin pushing on the head of the case. In that case the rat turd is rattling around in the violin case and highly unlikely to be aligned.

I have also wondered of that same misalignment of the round to chamber effect. And I have rationalized for myself, if head space and runout are the same for every load, the bullet should hit the same hole every time.

I have removed the ejector mechanisms from the bolts.

So If case head space is 0.001” less than chamber dimension and the bullet runout is 0.000”, the bullet to bore alignment is going to be very close. The case shoulder should be in contact with the chamber and holding the round parallel to the bore. The case neck should not even be resting on the chamber neck section. But it should be very close to center of the bore, not perfect but very close.

A friend was shooting a FTR 1000 yd match and noticed upon bolt closing some tight cases and when fired had hit low out the expected area of score. So raising his cross hairs on the next tight cases he hit where he wanted. A fluke, maybe, but consistent loads gives results.

So many elements to precision shooting. When they are right, yes!!!

 

[cw308]

Am I missing something , I shoot a Rem.700 308 caliber , it started out as a LTR 20" barrel 1/12 twist after 4000+ rounds changed the barrel to a Rock Creek M24 5R 1/ 11:27 twist full size 700P stock bedded completely blueprinted with a Jewell trigger set at 10 ounces, it's my one and only for 10+ years , just love shooting it . Gives me a consistent half inch 10 shot group at 200 yards . Bc-z is shooting a .25 four shot group with a 30 caliber bullet , how could that be when the bullet is .30 What am I missing?

 

[Dusty Stevens]

Am I missing something , I shoot a Rem.700 308 caliber , it started out as a LTR 20" barrel 1/12 twist after 4000+ rounds changed the barrel to a Rock Creek M24 5R 1/ 11:27 twist full size 700P stock bedded completely blueprinted with a Jewell trigger set at 10 ounces, it's my one and only for 10+ years , just love shooting it . Gives me a consistent half inch 10 shot group at 200 yards . Bc-z is shooting a .25 four shot group with a 30 caliber bullet , how could that be when the bullet is .30 What am I missing?

You must be missing that we measure groups center to center. You could shoot a .110 with a .416 if you wanted to

 

[JFrank]

Am I missing something , I shoot a Rem.700 308 caliber , it started out as a LTR 20" barrel 1/12 twist after 4000+ rounds changed the barrel to a Rock Creek M24 5R 1/ 11:27 twist full size 700P stock bedded completely blueprinted with a Jewell trigger set at 10 ounces, it's my one and only for 10+ years , just love shooting it . Gives me a consistent half inch 10 shot group at 200 yards . Bc-z is shooting a .25 four shot group with a 30 caliber bullet , how could that be when the bullet is .30 What am I missing?

Deduct the width of the Bullets

 

[INTJ]

Very possible!
Mark is really giving me push into the rabbit hole.
I've already contacted Xringstocks about the cost of a laminated stock, and I'm digging on this sitman I'm working on.

Next NBRSA 600 yd Match is Sunday Sep 1, 0700 show. Tuning in Saturday starts at 0900. Just don’t neck-only size.......

 

[INTJ]

Forgot to say it’s its at White City

 

[Bc'z]

Next NBRSA 600 yd Match is Sunday Sep 1, 0700 show. Tuning in Saturday starts at 0900. Just don’t neck-only size.......

Being labor day weekend I'm hoping to be bow hunting elk over in Tioga unit with my brother.
Besides I need a lot more scope to play with you guys. I'm thinking at least a T36.

 

[JFrank]

Forgot to say it’s its at White City

Nice to have a day for tuning.

 

[Bc'z]

Nice to have a day for tuning.

A day?
White city is 30 miles from me, I'd spend at least a week over there so as I didn't get my ass handed to me to bad!