Neck sizing vs full length

[Mr.Snerdly]

Mr. Snerdly this is my take on the subject, when the round is fired the brass expands to close off the chamber. Then the brass is full length resized back down again To SAMMI specs, repeating this process will work harden the brass resulting is reduced brass life. Neck sizing reduces this stress on the brass case.


That's kind of what I think but I hesitate to share my opinion because I am a green amateur compared to most here. So far I have just been neck sizing the 223 brass and it chambers well. The 243 brass seems to push the shoulder out much faster and after about 3 or four firings I try to full length resize but if I use the die according to instructions by the manufacturer it really puts the shoulder back I believe farther than necessary. I try what I guess you call bump sizing. One thing I noticed though, there can be a variation in the dimensions with the exact same setting on the die. I don't know if this is a difference in the hardness of the brass or what but that has been my experience.

[Robinhood]

Do yo have a SAAMI chamber or a custom Bisley or 1995 Palma? Sometimes the chamber dictates what type of die works best. Consistency will give you the best results for development of your process. Consistency in neck tension is a bigger step forward and the right tension is a big part of that. Whatever your process is get the best out of it. If that does not get you there, try something different and make that the best you can.

I have witnessed Erik Cortina's results on target and it is hard to not follow his methods when all top F class shooters do the same thing.... Down to the extreme accuracy of powder weight.

[Fuj']

Just to muddy the water a bit....

Most of the 'accuracy nuts' out there are not using standard full length sizing dies. They go to someone like Forster and have custom dies made to match their rifle chamber. They do not resize to SAAMI spec like you do if you have a standard reloading die.

So, that makes 4 choices here.
1. Standard full length resize.
2. Neck size only (bushings or collet).
3. Custom fit full length resize.
4. Custom fit full length resize with neck size bushing.

And there is a #5, the small base full length resize, if you have a stubborn semi or full auto rifle :)

"BINGO".....Give the Man a Cigar !! :cool:

I fall into category 3. I do most of my own dies favoring Lee's for bodies
and tweaks. And don't forget the staggered length shell holders for bumping.

[FiveInADime]

I like simple. I think Forster BR full-length and seater dies are more than good enough for me and I've had good luck controlling the shoulder bump with a little math and knowing how much to turn the die in to get the bump I want. I get straight ammo and I usually bump the shoulder .003".



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[Iowa Fox]

I gave up on neck sizing in about 1971. That's long before there was any internet for help. I found it gave me hard bolt close, hard bolt open and other issues. The next thing I did was to quit using the expander ball in my resizing dies. It was all trial and error in the old days.

[Ted_Feasel]

"BINGO".....Give the Man a Cigar !! :cool:

I fall into category 3. I do most of my own dies favoring Lee's for bodies
and tweaks. And don't forget the staggered length shell holders for bumping.Neck size with about .002 bump on bolt rifles, on AR308 FL forster BR. I do anneal every time, sometimes every 2 loads, seat with LE Wilson and arbor press.. thats just on those particular rifles , pretty much exact process on bolt and AR 6.5 creedmoor. I used to get neck failure(cracks) until I started annealing. I used to think annealing was overblown but once I tried it and doubled my brass life and got extremely consistent sizing more easily, im a firm advocate, especially on harder brass like lapua and lake city

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[Stumpkiller]

The next thing I did was to quit using the expander ball in my resizing dies. It was all trial and error in the old days.


Good point. Some years back I picked up a K&N Precision neck-expansion adapter/riser sleeve and an assortment of mandrels. Much easier to feel the process and keep it smooth. I also deprime everything in a separate step with a Lee universal deprimer. Again - I can fell the pocket tension much better.

[Texas10]

Mr. Snerdly this is my take on the subject, when the round is fired the brass expands to close off the chamber. Then the brass is full length resized back down again To SAMMI specs, repeating this process will work harden the brass resulting is reduced brass life. Neck sizing reduces this stress on the brass case.

Not picking on your response, but just to expand upon it to provide a bit more revealing detail. When the round is fired, it expands to seal the chamber, but then springs back a little therefore making extraction easier. When neck sizing only, the case is being expanded during repeated firing cycles and exhibits less and less spring back until eventually this leads to what's described as "bolt click" upon primary extraction. This occurs when the case does not spring back from the chamber walls, the bolt is raised but stops just before complete opening requiring additional force placed upon the bolt to obtain primary extraction. The "snap" or "click" sound is made by the bolt as it slams into it's stops and the case is loosened from the chamber walls, then extracted.

This is a primary reason for FL sizing, to eliminate this variability in extraction effort. Some dies will size the case walls and bump back the shoulder, but use a bushing to size the neck. This has the benefit of keeping the neck centered and in the same axis as the case walls, and also sizes the neck in one step, instead of two as when using a die with a sizing ball that is drawn back through the neck after being undersized. This reduces work hardening of the brass, neck splits and makes for better neck tension consistency, extends brass life, and requires less frequent annealing.

The advantages of neck sizing only are also of value. Less work hardening of the brass, better neck concentricity, as well as reducing the variability of brass expansion upon firing as there is no bumping back shoulders, or resizing cartridge bases. This can help lower ES and SD as less energy is lost to case expansion.

Some chambers/loads will reveal themselves to be friendly towards neck sizing only, some will not. I find the best performance is obtained by performing the least amount of brass reformation as possible for a given chamber and load. In the end that may be FL sizing with a neck bushing, or neck only sizing. Sometimes the only choice is a FL sizer with expander ball. You have to decide what is best for your particular chamber and shooting style.

[Ted_Feasel]

Not picking on your response, but just to expand upon it to provide a bit more revealing detail. When the round is fired, it expands to seal the chamber, but then springs back a little therefore making extraction easier. When neck sizing only, the case is being expanded during repeated firing cycles and exhibits less and less spring back until eventually this leads to what's described as "bolt click" upon primary extraction. This occurs when the case does not spring back from the chamber walls, the bolt is raised but stops just before complete opening requiring additional force placed upon the bolt to obtain primary extraction. The "snap" or "click" sound is made by the bolt as it slams into it's stops and the case is loosened from the chamber walls, then extracted.

This is a primary reason for FL sizing, to eliminate this variability in extraction effort. Some dies will size the case walls and bump back the shoulder, but use a bushing to size the neck. This has the benefit of keeping the neck centered and in the same axis as the case walls, and also sizes the neck in one step, instead of two as when using a die with a sizing ball that is drawn back through the neck after being undersized. This reduces work hardening of the brass, neck splits and makes for better neck tension consistency, extends brass life, and requires less frequent annealing.

The advantages of neck sizing only are also of value. Less work hardening of the brass, better neck concentricity, as well as reducing the variability of brass expansion upon firing as there is no bumping back shoulders, or resizing cartridge bases. This can help lower ES and SD as less energy is lost to case expansion.

Some chambers/loads will reveal themselves to be friendly towards neck sizing only, some will not. I find the best performance is obtained by performing the least amount of brass reformation as possible for a given chamber and load. In the end that may be FL sizing with a neck bushing, or neck only sizing. Sometimes the only choice is a FL sizer with expander ball. You have to decide what is best for your particular chamber and shooting style.I have to agree with what your saying. I neck size only and anneal after every firing on certain harder brass like lake city, lapua, IMI but every 5th reload I do a FL resize and that seems to maintain the best of both worlds including not having doughnutting since starting that. I picked 5th reload for FL resize because it seemed to average out to 6 or 7th load necksize only I would start getting the bolt click you were referring to. I dont use lapua much but I do have to boxes of it. I uses IMI for my AR308s, atlas for my AR 6.5 creedmoor, starline for AR Grendel, 5.56 and starline for my bolt 308 and 6.5 creedmoor.. ill also use lake city.. ive had several people tell me it crazy to develope loads with different component sets but my thinking is to have equal performing options should one or more component become not obtainable or pixidust status.. alot more work but I enjoy it:)

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[mikeinco]

both work, but it aint that simple.
what rifle, what caliber, what is it used for ??
most of my loading is done on brass that has just been annealed, cause most of my rifles are serious target rifles...as in not savages*.
bulk rifle loading may be a mix, again based on rifle and use.
i am currently loading lc93 match (308) brass with pull down 223 powder and old out of spec m80 ball bullets. dillon 550...prime powder drop seat bullet. brass was all sized and cleaned in a prior life. dl with a neck bushing for the under sized bullets.
DO WHAT YOU ARE COMFORTABLE WITH AND WORKS IN YOUR RIFLE.

[Texas10]

I think you brought up a very important point that adds relevance to the discussion. You mention you shoot serious competition rifles, i.e. not Savages. So just to clarify the difference, in your opinion, what is the likely reduction in group size or precision between a well built Savage target rifle and a full custom?

When the OP asks whether to FL size or Neck size, are we talking about a technique or procedure that increases precision by 1/8 moa, 1/4 moa, or little to no change in a less than full custom build? And how much of any change is the result of better loading procedures vs better wind reading, and how do you separate the two since it's rare to have a perfectly still day to shoot?

I ask this from the perspective of someone interested in knowing what techniques apply to a particular style of shooting. Are we discussing a full on competition level loading procedure, or will the average hunter, plinker, occasional target shooter also benefit from learning when to FL size and when to neck size?

[Stumpkiller]

I don't own any "serious target rifles" (mine are all kind of practical joker rifles that I use to shoot at targets for practice) but back when I did shoot sportsman benchrest it was generally thought that the pursuit of accuracy was an accumulation of techniques that each made tiny reductions in group size. That was the path to first place.

[mikeinco]

neither
both will work well up to a point. so the basic process will not limit the gun.

i have pointed out before that an f class target has SEVEN TIMES THE AREA of a benchrest target( 10 ring at 600 yards)
savage builds rifles that do well in f class, but that is the end of their limit, they do not do well in 600 yard benchrest.
loading technique nor wind reading will over come that short coming.
savage has a 6br which would allow one to participate in 600 yd benchrest, it is not likely to be a winner.

i use to shoot stock savage rifles in true stock rifle classes at 100 club benchrest. those rifles and the game are long gone.
savage does not make a short range benchrest capable rifle. my custom 6ppc has shot as small as 0.040 at 100. i bought it used for less than $1800 and added a scope.
i fl size with a bushing, no button pulling, load from a chargemaster lite. anneal after every days shooting.



I think you brought up a very important point that adds relevance to the discussion. You mention you shoot serious competition rifles, i.e. not Savages. So just to clarify the difference, in your opinion, what is the likely reduction in group size or precision between a well built Savage target rifle and a full custom?

When the OP asks whether to FL size or Neck size, are we talking about a technique or procedure that increases precision by 1/8 moa, 1/4 moa, or little to no change in a less than full custom build? And how much of any change is the result of better loading procedures vs better wind reading, and how do you separate the two since it's rare to have a perfectly still day to shoot?

I ask this from the perspective of someone interested in knowing what techniques apply to a particular style of shooting. Are we discussing a full on competition level loading procedure, or will the average hunter, plinker, occasional target shooter also benefit from learning when to FL size and when to neck size?

[charlie b]

.......I ask this from the perspective of someone interested in knowing what techniques apply to a particular style of shooting. Are we discussing a full on competition level loading procedure, or will the average hunter, plinker, occasional target shooter also benefit from learning when to FL size and when to neck size?

For the average plinker or hunter it makes little difference in accuracy. I have done both and noticed no change in accuracy, BUT, I am a 0.5MOA kind of shooter. No competition, just targets for fun.

Other than for accuracy, neck sizing can create a case that is difficult to chamber after many reloads. Sizing the neck too much, as in std full length reloading dies, can cause 'early' failure. Early may be after 5 reloads or 10 or 15 depending on the brass and loads. Again, the average hunter, plinker won't really notice since they don't shoot that much.

[mikeinco]

bs on the poorly worded statement

Sizing the neck too much, as in std full length reloading dies, can cause 'early' failure. Early may be after 5 reloads or 10 or 15 depending on the brass and loads. .

[Ted_Feasel]

I've done the experiments.. annealing is important to brass life.. on lake city ill get neck splits after 2 or 3 fl resizes, with anneal lake city of same lot went to 10 reloads before primer pockets were to loose to reload

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[Fuj']

It was generally thought that the pursuit of accuracy was an accumulation of techniques that each made tiny reductions in group size. That was the path to first place.

Yes Sir !!

[Ted_Feasel]

Definitely the general idea is remove as many variables as possible in ammo and in the rifle and shooter

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[charlie b]

bs on the poorly worded statement

Only if you anneal regularly. Poorly worded? LOL

[Ted_Feasel]

Only if you anneal regularly. Poorly worded? LOLI do anneal every load on lake city, imi and lapua. Starline every 3 reloads , it seems to be a good bit softer than the 1st 3 I mentioned. I've also noticed much more consistent shoulders on annealed brass

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