Home Forums Hunting & Shooting Ask The Gunwriters Full Length vs Neck Sizing

drop point , thank you much i will order Neolude #2 , i always thought i had a problem with the inside of a case neck and this should solve the problem. thanks again, Pete53

Now ask him how many varmint rifles he's blown up due to high pressure neck sizing.

On inner case necks, they should never be squeaky clean. Certain tumbling methods and cleaners are particularly bad in that respect.

On fired cases, the powder residue left in the case neck is all they need for seating. If you feel like you have to do something, a quick pass with a nylon brush and you're done.

For lubing the inner necks for sizing when using an expander... lots of stuff works well. You want to reduce the friction as much as possible so the expander doesn't pull the neck out of alignment with case as it passes up through the neck and expands it.

With a standard F.L or N.S. die, the best approach is to not excessively reduce the neck diameter in the first place.

Good shootin' -Al

Al, earlier I had some questions about your post on the 6mm jet brass you made. It may have got lost in the shuffle. If you don't mind:


Thanks!

not sure ? but i thought there was mention he liked and used a 17 Hornet or something similar, so if that`s true i think that case takes 12 grs. of powder , you might wanna think about that a little ????????

drop point , i have now ordered some Neolube #2 after i have watched a couple of videos on how to use Neolube #2 ,i will see a approvement in my handloading using this Neolube #2 . thanks again ,Pete53

You ordered last night, received shipment and have used it in reloading operations this morning?

You rent an apartment next door to a UPS Hub?

I believe he meant "foresee an improvement".

Al, that's been my experience as well.


Some more general comments on this thread:
Have found that bullet run-out matters far more in some circumstances than others. In my 6mm PPC benchrest rifle I've found run-out of more than .001 results in 5-shot groups at 100-200 yards doubling in diameter, but that's with bullets with flat bases (or very minimal boattails), which tend to result in more consistent gas blow-by at the muzzle than "full boattail" bullets--which is of course why short-range bench shooters tend to use flat-based bullets.

Boattails tend to de-stabilize slightly at the muzzle due to powder gas blasting along the rear half of the bullet. But at ranges longer than about 250-300 yards, boattails tend to group better, despite often not tending to group as well at 100-200 yards, because they resist wind-drift better--which is also why bullet run-out isn't as critical at longer ranges. (The effects of wind on group size also grow larger, one reason many hunters think bullets tend to de-stabilize at longer as their velocity drops--when bullets actually become more stable, unless of course they approach subsonic velocities.)

When I acquired my first bullet-runout gauge over 30 years ago, an RCBS Casemaster, the directions suggested that .005 bullet run-out got about as much accuracy as possible out of typical big game rifles, and .003 in varmint rifles. I found this to be generally true, but also depends on the quality of the rifle, brass, bullets, loading techniques--and of course the shooter.

>>> i guess i forgot a word ? > i " will " see an improvement in my hand loading using Neolube #2. > thanks for pointing out my very small mistake i feel so much better now !

>drop point you can see how some on the campfire are critical and foolish , so don`t forget a word ,cross a t ,dot an eye > some of these little boys are always trying to make themselves feel superior by being critical , but the campfire does have some very good people on here too. thanks again,Pete53

I agree. What is the rifle/shooter "system" able to resolve? The same question applies to thrown vs weighed charges.

The first step was checking the necks for thickness variation. Close to 50% showed in excess of .002 with half of those being closer to .003. My normal cutoff is .0015 but I relaxed a bit on these cases as I knew I'd be touching up the necks with the neck turner.

When deburring the flash holes and lightly chamfering the flash hole from the inside, it became apparent that my chamfering tool (it uses an internal collar inside the case neck to pilot it) was only touching about half of the floor of the case. Long story short...the floor of these cases was 'tipped', for lack of a better term. My solution to that was to open the necks with a .338 expander and with the cases in a holder in the mill vise, I went in with a .312 end mill and squared up the 'floor' of the cases. The worse case took .016 to clean it completely so that's what I cut all of them to.

To neck them down to 6, they first went through a 308W seating die, then through a succession of Redding Body Dies: 308W, 7-08, 260 Rem and 243W. I knew what the chamber neck length was from doing a CerroSafe cast and verified the end of the neck wasn't going to 'stack up' against the end of the neck area of the chamber, so I pushed the shoulders back with a standard 243W full length die (that I had shortened .075 based on the chamber cast). I just used a single case at that point and kept pushing the shoulder back in .005 increments until the action would j-u-s-t close with a skosh of resistance and set the die to that point.

They all then went through the shortened 243W full length die, the cases were trimmed to the same length, the necks were expanded over a .241 expander and the inside of the necks were cut with a .242 reamer to make them round and straight. Then they were neck turned with the .241 expander, neck/shoulder area was stress relieved at 450 for 15 seconds, washed in acetone, left to dry. Finally, they were full length sized again with a shortened 243W Type 'S' F.L. Bushing Die.

They were ready to rock at that point. After firing them all the first time to f-form them, the primer pockets were then uniformed.

Target was the first 3 shot group @ 100 yds. when fire forming. The shot at 11:30 is the fouler. I gave the scope two down and two right shot the little three shot 'weather report' .420 group....it actually measures quite a bit bigger than it looks. It shows a 9:00 pick up I missed on the flags. With f-formed cases, 5 shot groups at 100 are well under 1/2". Pretty decent for a falling block rifle with an oddball case, I think.

Hope this helps. -Al

You read things into what you heard, but were never said. The shooter (Lou Murdica, was it?) only said that pressure differences show up when firing neck-sized only brass. Obviously, this would be because of gradual case volume increases with each firing if the case volume is not controlled precisely. He did NOT say you'll experience dangerous pressure. He is saying that if you keep the shoulder in one single place, consistency improves.

I have watched that video a number of times and listened carefully. I think that Cortina means "neck sizing only" is not the way to go. He emphasizes bumping the shoulder back two or three thousandths each time is important. I think he would agree that using a body die to bump the shoulder and then sizing the neck in another step is essentially FL sizing...just not all in one die in one single step.

I'd be very, very surprised if any of those guys are using any off-the-shelf FL die set, and I mean the run of the mill RCBS, Lyman, Hornady, or even Redding or Forster (wouldn't be the first time I was surprised, though). I've never spoken to Cortina so I don't know, but I'll bet he's using a die set custom made and paid a lot more than $100 for them.

you would be surprised how many good bench shooters use a Redding bushing full length sizing die.

I'd be surprised if you really knew a damned thing about it. I've read your posts.

Wow, that was a lot of work. Thanks for the details.

common on up this winter let`s see how well you can shoot against me ? so bring it on or is it all keyboard mouth ? my old rifle is ready. and yes you will be surprised . so bring your neck sized brass up against my full length sized brass. > you were right about one thing his name is Lou Murdica .

You got me shakin in mah boots, yes indeed.

I wouldn't drive around the block to prove anything to you any more than I'd seek out your "expertise" in these fora. No one who knows jackshidt would.

As a competitor in 100-300 sanctioned tournaments (NBRSA and IBS), I can tell you that the main thing a competitor looks for in a die is one that works with his chamber and brass at the pressure ranges he loads to. You need to be aggressive enough with the sizing so you can effortlessly open the bolt after firing a 70,000+ psi load without disturbing the gun in the bags. We beat the dog snot out of cases so F.L. sizing and bumping the shoulders is what you need to do. When the clock is running, the wind flags are dancing around and there's guns going off on both sides of you...no Interweb nonsense or ridiculous Urban Legends surrounding accuracy is going to save you.

So there's more to the equation that non-competitors think there is.

The most commonly used full length bushing die is the Harrell's. They offer a range of die sizes that size in .0005 increments that will accomodate almost any scenario. I have them for my 30BR in #2, #2.5, #3 and #3.5. I also have and use the Redding Type S F.L. Bushing die (which sizes like the Harrels #2 or 2.5). A few others here have been converted from Redding Body Dies into bushing style dies. The stainless Wilson F.L. bushing dies are excellent, too....couple of those here.

Other dies I've seen on the Win-Place-Show are Redding Competition Series sliding chamber dies, Forsters (with tweaks and work) and the mentioned Wilson F.L. bushing dies. There are quite a few using Bullet Central dies and a fair number that use custom dies done with a sizing reamer that works with the chambering reamer.

At this level of competition, you don't see any Lee Collet dies or Lee dies of any sort. I've never seen anyone sizing necks against a fixed dimension mandrel inside the case neck either. The use of a bushing to adjust neck tension is critical to tuning these guns, especially at the chamber pressures we run them at.

The bottom line is: in real Benchrest competition (where people see the results and your name and score/placing is posted) you use a dies that works for your program to combine accuracy, ease of extraction, repeatability and acceptable case life. What one guy does may not be the other guys approach. But both can win and shoot well when their approach is part of the entire combination.

Good shootin' -Al

How did this thread turn into a discussion of what benchresters do? A lot of guys shooting benchrest with 30-06? In a sporter-weight rifle? Using Federal Brass?

Weird sort of pissing match going on here.