neck turning

[bob64]

whats the advantage with neck turning and is it likely to tighten up the groups, or is it awaste of time in factory chambered rifle regarding accuracy with the neck a uniform thickness. thought about giving it a

go for a while now.

bob

[Elwood]

whats the advantage with neck turning and is it likely to tighten up the groups, or is it awaste of time in factory chambered rifle regarding accuracy with the neck a uniform thickness. thought about giving it a

go for a while now.

bob

 

Bob I will have a stab at this one, as I'm led to believe a small clean up around the neck (about a 75-80%) can be beneficial to remove any high spots, but in a sporting rifle I'm not sure you would notice the difference ( it doesn't stop me doing it) but if I remember correctly from Target sports magazine a full clean up of the neck can be detrimental to accuracy when used in a standard chamber.

 

If you're shooting paper competitively then I would say go for it, if you're shooting for blood I honestly can't say if it's worth it or not. I quite enjoy neck turning (sad but true) so I guess I get a feel good factor from doing it.

 

I would like to think that the likes of Foxing Tonight or one of the other guru's can add more or correct my comments.

[foxing2night]

Hi mate,,

A little bit of info as to what i do to my cases!!! 6mm ppc

1= 6mm exspander is run through the case,,This will iron out any dimples or dents in the case mouth??? Use plenty of lube???

 

2= square the case of at the correct lenth,,, measure case thickness!! and then set my k&m case neck turning tool to take a nice clean cut ,,, Useing lube on the case to stop any case chatter and give a nice shinny case neck

 

The idea is to give better consistacy and improve runout,,, To be honest if you use lapua cases the consistancy is very good,,

 

In a hunting rifle it is not necessary,, But if it makes you feel good than it can only help??

With your rifle i would first fire a round measure it!!! Then see what the differance is?? As that case does not want to be to sloopy in the chamber

 

The cost to have these tools, would not be far off 100 pounds???? So this is not a cheap job to do,,,

 

Benchrest rifles are set up with very tight tolerances??? Most 6mm ppc have got a .262 neck so if you bought a case it would not chamber!!! so you would have to take the neck down a tad,, Thus you would leave 2thou for the round to go off,,,,

 

My neck on my ppc is a .272 so after a case has been turned, prepped and so on,, when it is loaded it will measure .268,,,, this then gives me 4thou clearance for the round to go bang??

 

Is it worth all the efort ,,, Yes cos it makes me feel good and i know that all my ammo is the best that i can possibly make??? Other things that are realy worth doing is flash hole debering,, primer pocket uniforming and using the best bullets that i can get my hands on????

 

Any probs just give me a shoot and i will help as best i can,,,, Darrel

[Alycidon]

Is that not a bit too much clearance ?, how many reloads are you getting to a case ?. My PPC runs a 270 neck and I load to 0.2684, I have been told to expect at least 30 reloads per case. Not had a failure yet but only 7 or 8 per case so far.

 

The smith building my 20BR recons on less clearance than that !!. He gets over 80 reloads from a standard 22.250 case so he has prooved his point but I do accept that these sort of tollerences are not needed for sporting rifles and are possably unwise for people begining neck turning.

 

A

[bob64]

thanks for the info lads i was thinking about turning the case necks for my rem action 308 boarder

barrel in AICS STOCK , TO SEE IF I COULD TIGHTEN THE GROUPS UP EVEN FURTHER.

SMALL GROUPS ANY WAY ,BUT THEN I,AM ALWAYS LOOKING TO BETTER, USING THE BEST DYES +

CASES +155 SCENAR AND CCI PRIMERS .cheers

bob

[Ronin]

If your having a rifle built, having a tight or fitted neck is the cheapest accuracy gain there is, as the reamer costs no more to purchase with or without fitted neck.

 

 

The idea is to keep the bullet totally concentric with the boreline and allow a controlled and repeateable neck tension / release when the trigger is pulled.

 

I have both tight and standard neck chambers in various rifles. The standard necked rifles shoot well, but the tight necks shoot better.

 

For the standard necked chambers I turn my cases to a 75% clean up to equalise neck wall thickness and remove the expander ball on my resize dies.

 

For the fitted necked chambers, I turn so that a loaded round is - .003" of the neck diameter for my "field" guns and - .002" for the target rifle - again my dies have had the expander ball removed.

 

The single most important thing when turning is go into the base of the neck where it meets the shoulder by about .030" otherwise you wil end up with an internal dohnut preventing you seating your bullet deeper than the dohnut.

 

Second thing is take light cuts and measure often once you have set the trimming tool how you want it do all your cases - it is a one time only proceedure.

 

 

 

Other thing - get a K&M trimmer and expanderiron - they are about the best neck trimmers you can buy, or use a lathe.....

[Vermincinerator]

Andy,

Running your neck turner 030" into the neck/shoulder junction will almost certainly nearly cut through the case!!!!!

I have also found that do-nuts are not a problem when neck turning standard cases but are a lot more prevalent when fireforming for an improved chamber or blowing out 220 russian cases.

 

Ian.

[Ronin]

Ian

 

I think you misunderstood the context I meant.

 

I didnt mean deep as in cutting deeper into the case neck wall, I meant downwards into the shoulder union with the neck - my turning tool is equipped with a shamfered shoulder at the inside edge of the cut that allows a cut to run "into" the shoulder ;

 

Old pics but should display what I mean

 

 

[Vermincinerator]

Didn't misunderstand anything Andy, i knew exactly what i was saying

 

Ian

[shootingbags]

I know what you meant Andy

[Redfox]

Bearing in mind the average case wall thickness in this area is .0125-.0135" so it is only the fact the cutter has a rounded corner ( I have 4 of these) that it isnt going through. I only just clean up the end where the contour changes when new and only a whisker then about .002" if that.

There are reamers (including K&M make a mandrel with cutter)to remove the doughnut if it is an issue from the inside, which is slightly safer, but still iffy as you are not measuring the actual wall thickness..

However not many of my loads have the bullet down into the neck, particularly if you are seating near the lands and to be honest, cases in most cals are very expendable and I have some that only realistically get 3 -5 reloads before I re-cycle them, some do a lot more, like the 222 which is very easy on cases.

I only clean up the necks when new to about 50% of the circumference as I have no tight neck chambers. It is really only to get the bullet as reasonably concentric to the bore as is possible. Due to the way cases are formed, even the best are not exactly the same wall thickness all the way round so a little clean up is ok, any more and you are ruining the cases and changing the neck tension and spring back which is counter productive.

A tight neck chamber in a custom barrel is a different ball game altogether and does benefit from neck turning and fitting to the actual barrel, factory rifles are made to SAAMI dimensions and as above will not show any real benefit from this.

Consistent reloading techniques using the loads that peform best in your rifle will give far more benefit, as your loads will perform the same each time and of course shooting practice to get your technique the same each time you squeeze the trigger is absolutely vital to accuracy.

Redfox

[Ronin]

Fitted neck 6.5x47 Lapua case (.290" nk)

 

You can see the "shiny ring" at the junction of the neck and shoulder.

 

This measures .030" "deep" - measurement taken in the orientaion from top to bottom of case

 

 

Same case sectioned;

 

 

I tried to make a image with all the measurements on in a simple diagram form, but my image server wont accept the original file format, so please bear with me.

 

 

The measurements below were taken with the aid of dial calipers and a magnifying glass at the junction of the neck / shoulder so I am pretty sure its correct.

 

All are thickness of material:

 

Neck wall - .012"

 

Neck / Shoulder junction - .020"

 

Shoulder wall - .017"

 

Side of case at junction of web - .047"

 

Web (primer pocket to to inside of case) - .055"

 

Depth of cut into shoulder from neck - .030"

 

 

 

I dont think that my method of preventing dohnuts causes any noticable weakness in the case - it is the same method that benchresters use and it works for me.

 

My own cutter is chamfered at an angle specifically to assist with this type of cut....

 

 

Most if not all my bullets are seated so that the shank is slightly deeper than the base of the neck, in some cases (pardon the pun) its quite alot deeper.

 

I have never had an issues with dohnuts forming and turn or partial turn ALL my brass to suit whatever chamber I have in my rifles - even the non fitted neck chambers get a partial clean up.

[Redfox]

Andy

If you read my post carefully, I said that custom barrels/chambers are a different thing altogether, we are talking about a std factory rifle in this instance.

From your measurements your thickness agrees with what I said and you obviously could not cut .030 deep as it would cut the case in two. You are making a subjective length measurement and cutting further along by your stated amount which eventually cuts into the taper of the neck shoulder but only by a small amount as it is by now a compound angle cut anyway. So no danger at this stage of the case parting.

However if you think of why and how the doughnut forms, cutting on the outside may provide temporary releif for the brass to go somewhere but ss the brass flows forward the ridge forms on the inside not the outside, therefore exterior cutting is really not the answer ( whatever some people think and do), as K&M and others who have really thought about this shows they have come up with internal neck reamers to remove the excess brass driven into that internal area by firing and resizing.

 

So in answer to the original question, clean the neck up as I said and concentrate on the consistency of loads and shooting technique, it will do most for your accuracy with a standard rifle.

Redfox

[Ronin]

Redfox

 

 

quite correct regarding standard chambers.

 

 

I posted the sectioned case as I wanted to demonstrate the fact that cutting into the neck / shoulder junction using the method I use didnt impact on case integrity.

 

 

I have some 25-06 brass that I turned partally when I first had this rifle rebarreled, they are now on maybe their 20th reload.

 

I will sacrifice one of these fine pieces of brass tomorrow and post a photo of the sectioned case, just to see if the dohnut has formed - the rifle is only used with 100grainers and seated to .005" of the lands, so they dont seeat deeper than the base of the neck anyway.

 

 

WIll be interested to see if any internal dohnut has formed..

[Redfox]

I will be interested to see what that case is like. The biggest culprit I have is the 22-250, which I will section a well used case shortly, I do turn these necks back to the shoulder and they last about 10-12 reloads before they get beyond using due to wall thinning near the web.

Which camera were the pics taken with?

I am thinking of taking that out to the AI version, do yo have reamer?

Redfox

[Guest northernchris]

Red

 

How often are you trimming your .22-250 cases,with the .22-250,s body taper and hard loads i ended up trimming alot that is one of the main reasons of going to an Ack chamber.

 

On another note i have 7mm Boo Boo cases here that where neck turned from new and have been fired 3 times (inc fire forming) only and do-nut is evident

 

Cheers Chris

[Ronin]

Hi RF

 

 

the first two pics were taken with a 1MP camcorder, the two latest pics were taken with a Nikon compact (forget the model but its 6 MP) I usually take images on my Nikon D2X, but the flash is still away being repaired and as ive no lightbox set up, the smaller compact does an excellent stand in.

 

 

 

Funny really when a £400 (2007) camera does the same job as £4000 worth of digital SLR and high end lenses (in 2005) - strange how technology catches up..........

 

Although I havent a macro lens for the D2X the image size allows wuite harsh cropping and blow ups - some thing that the smaller compact does not let you do without obvious "noise"

 

 

(sorry, my other "passion" is photography )

 

 

 

Sorry, I havent the 22-250 AI reamer (I have the 243 AI reamer though) and as ive just spent well over a grand with PTG only hours ago, I wont be ordering any more "tools" before the new year.....

[Redfox]

I understand fully on the tooling, it is not ready yet for the mod anyway so we can talk nearer the time next year. As for cameras your not kidding, I have a Panasonic like Stag 1933s and a Canon digital, 8mp and 6 mp respectively and they are so good compared to the canon I had before which cost more. However the 3 mp olympus I had pinched took better pics than the 8mp Olympus compact I have now,explain that? but it does have lot more bells and whistles in the menu ( which I dont use! )so progress isnt always forward and the number of Mps doesnt guarantee better pics just the ability to print them larger.

 

Chris I run the 22-250 fairly hot so I need to trim nearly every time and yes the doughnut forms very quickly, luckily the 55gr Vmax is just above it at my seating depth, but I will send for the K&M reamer in .22 after xmas. Appreciate your comments on the AI version, I am sure I will go that way in the new year, as it will extend the life of the barrel as well instead of just cutting the tenon and thread off to re do it.

Thanks lads interesting subjects and may help others.

Redfox