Experienced Re-loaders, please enter

[Short-bus]

I wanted to ask the thoughts of my fellow experienced reloaders just to make sure that my thoughts are safe, and perhaps doable.

I've been doing a lot of reading on precision reloading lately, and when it comes to benchrest accuracy, one thing that i'd like to try is setting the neck tension consistent from round to round at .002" tension on the bullet to help lower the ES of the rounds fired. Well, my biggest issue is that I don't have a neck sizer die, or an expander die. I only have RCBS competition dies, and I don't really have the funds available to run out and buy new dies whenever possible.

Here's my thinking of a cheap, however time consuming way around it until I can get the right equipment.

I just did this on 1 piece of brass while taking the required measurements to see if what I had done made a difference. When I load my rounds in my normal routine, I do feel differences in seating pressure from round to round, hence the reason I want to eliminate this factor, or at least reduce it. I measured the inside mouth diameter of a full length sized piece of my lapua brass. It measured out to .304(5), I have the '5' in brackets as the tool only measures to .001", however the dial was quite literally in the middle of 2 hash markings. I then seated a .308" diameter bullet (without powder and primer) into the brass, and upon removal, I pulled the bullet using an inertial bullet puller. After removing the bullet, I measured the brass with a mouth of .306", that will give me the required neck tension of .002" on the bullet.

Although time consuming, and rather primitive, is there any reason to suspect that I could be hurting accuracy in any way?

Just to review;

Brass mouth before .304(5)"
Brass mouth after .306"
Bullet diameter .308"

I just want to make sure that i'm not doing anything that's going to potentially cause a safety issue. I highly doubt it, but when there is any doubt, it's best to ask others their thoughts.

Branden

 

[918v]

Re: Experienced Re-loaders, please enter

The problem is you're assuming the neck is perfectly round and will remain so throughout the lifespan of the case. This is erroneous. Also, measuring the inside of a neck with a dial caliper will give you false readings because you are measuring a concave surface with a flat tool.

Second, brass tension varies from case to case, even if you turn necks to the same thickness.

The only way to sort them for bullet pull is to seat bullets using an arbor press with a strain gauge attached. Mark the cases for future reference.

 

[scaxeman]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 918v</div><div class="ubbcode-body">The problem is you're assuming the neck is perfectly round and will remain so throughout the lifespan of the case. This is erroneous. Also, measuring the inside of a neck with a dial caliper will give you false readings because you are measuring a concave surface with a flat tool.
</div></div>

+1 on this, get an inexpensive ball micrometer, you will get better measurements for wall thickness, then simply measure the neck OD with your calipers.

For the best repeatability, measure neck wall thickness, neck OD, loaded OD at a set distance down the neck from the case mouth .1" or whatever.

Darrell

 

[Short-bus]

Re: Experienced Re-loaders, please enter

I understand there is a more precise, and likely correct way of measuring the ID of the brass. On my calipers the backside of the tool is used for measuring ID of things, and it's not a flat surface, at least not a VERY flat surface, they are 'sharpened', but it gives me enough precision for what i'm doing. My main concern is not whether it's as precise as more common methods, only that it's not going to cause a safety issue.

Until I can get the funds together to buy the appropriate tools, this is what I have to work with to start experimenting now.

Branden

 

[ChrisGarrett]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body">I wanted to ask the thoughts of my fellow experienced reloaders just to make sure that my thoughts are safe, and perhaps doable.

I've been doing a lot of reading on precision reloading lately, and when it comes to benchrest accuracy, one thing that i'd like to try is setting the neck tension consistent from round to round at .002" tension on the bullet to help lower the ES of the rounds fired. Well, my biggest issue is that I don't have a neck sizer die, or an expander die. I only have RCBS competition dies, and I don't really have the funds available to run out and buy new dies whenever possible.

Here's my thinking of a cheap, however time consuming way around it until I can get the right equipment.

I just did this on 1 piece of brass while taking the required measurements to see if what I had done made a difference. When I load my rounds in my normal routine, I do feel differences in seating pressure from round to round, hence the reason I want to eliminate this factor, or at least reduce it. I measured the inside mouth diameter of a full length sized piece of my lapua brass. It measured out to .304(5), I have the '5' in brackets as the tool only measures to .001", however the dial was quite literally in the middle of 2 hash markings. I then seated a .308" diameter bullet (without powder and primer) into the brass, and upon removal, I pulled the bullet using an inertial bullet puller. After removing the bullet, I measured the brass with a mouth of .306", that will give me the required neck tension of .002" on the bullet.

Although time consuming, and rather primitive, is there any reason to suspect that I could be hurting accuracy in any way?

Just to review;

Brass mouth before .304(5)"
Brass mouth after .306"
Bullet diameter .308"

I just want to make sure that i'm not doing anything that's going to potentially cause a safety issue. I highly doubt it, but when there is any doubt, it's best to ask others their thoughts.

Branden </div></div>

First of all, let's back up a few steps.

What rifle are you shooting?

What distance are you shooting?

What ammo are you loading?

What size groups are you getting at X, Y and/or Z distances?

What extreme spreads and what standard deviations are you currently getting?

The way I see it, unless you're turning your necks, even when using a factory (read: sloppy) chamber and then reaming the insides of the necks, you're going to have inconsistencies.

This being said, at shorter (<600 yds) distances, you'll probably not realize any group size benefits if your extreme spreads and SDs (what matters) are reasonable for reloaded ammo.

If you want your neck tension to be consistent, turn your necks, get bushing dies with appropriate bushings, ream the inside of the necks so they're uniform and work on annealing them. Otherwise, all bets are off.

It's probably better to load reasonably consistent ammo and practice a lot vs. spending your life chasing the most consistent ammo you can manufacture.

Chris

 

[Short-bus]

Re: Experienced Re-loaders, please enter


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What rifle are you shooting?</div></div>

It's a Savage 10 .308 with mcgowen 1:10.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What distance are you shooting?</div></div>

Everywhere from 100-1100 yards. Only been to 800 recently, but the access goes out to 1100, maybe 1200, but I don't want to push it.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What size groups are you getting at X, Y and/or Z distances?</div></div>

Normally getting 3/4moa with 208 amax's at 100, however I recently shot 1.1" @ 300 and 4.75" @ 700 in a match. My most recent zero session with the amax's got me 2 3-shot groups of .5 and .4".


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What extreme spreads and what standard deviations are you currently getting?</div></div>

ES's around 25-30fps, SD's in the low 10's. I have perfectionism issues BTW.

I don't have the means (yet) of measuring the chamber to see if it's a tight, or loose chamber. I don't know how McGowen chambers their match barrels, if you have any insight on that, please inform me, i'd love to know.

This lot of brass that I have now is about done. I've been running some hot loads with the 208's, and my primer pockets are starting to get loose after 7-8 loads. I was reviewing old chrono data as well as the corresponding load data with target results and some of the chrono data is just bizarre. Es's of 80-110fps, and my (now formerly) pet load has shows SD's as low as 1.8fps (just once). I want to keep ES under 25fps, in the teens ideally.

I understand what you're saying about practice. I know that the practice is important. I need to settle the internal debate that never ends with me about whether I want to stay with the heavies (208amax, 210berger, ect...), or go down the 175-178gr class of bullets that have reduced recoil, and run them only in the 2700fps range where the pressures are still safe, but the wind deflection on them is much greater than the 200+gr class.

Bradnen

 

[918v]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body"> On my calipers the backside of the tool is used for measuring ID of things, and it's not a flat surface, at least not a VERY flat surface, they are 'sharpened', but it gives me enough precision for what i'm doing.</div></div>

No it does not. You might as well be using a ruler.

 

[ChrisGarrett]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body">
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What rifle are you shooting?</div></div>

It's a Savage 10 .308 with mcgowen 1:10.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What distance are you shooting?</div></div>

Everywhere from 100-1100 yards. Only been to 800 recently, but the access goes out to 1100, maybe 1200, but I don't want to push it.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What size groups are you getting at X, Y and/or Z distances?</div></div>

Normally getting 3/4moa with 208 amax's at 100, however I recently shot 1.1" @ 300 and 4.75" @ 700 in a match. My most recent zero session with the amax's got me 2 3-shot groups of .5 and .4".


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ChrisGarrett</div><div class="ubbcode-body">What extreme spreads and what standard deviations are you currently getting?</div></div>

ES's around 25-30fps, SD's in the low 10's. I have perfectionism issues BTW.

I don't have the means (yet) of measuring the chamber to see if it's a tight, or loose chamber. I don't know how McGowen chambers their match barrels, if you have any insight on that, please inform me, i'd love to know.

This lot of brass that I have now is about done. I've been running some hot loads with the 208's, and my primer pockets are starting to get loose after 7-8 loads. I was reviewing old chrono data as well as the corresponding load data with target results and some of the chrono data is just bizarre. Es's of 80-110fps, and my (now formerly) pet load has shows SD's as low as 1.8fps (just once). I want to keep ES under 25fps, in the teens ideally.

I understand what you're saying about practice. I know that the practice is important. I need to settle the internal debate that never ends with me about whether I want to stay with the heavies (208amax, 210berger, ect...), or go down the 175-178gr class of bullets that have reduced recoil, and run them only in the 2700fps range where the pressures are still safe, but the wind deflection on them is much greater than the 200+gr class.

Bradnen

</div></div>

Thanks for the quick reply.

I got my buddy to buy a Savage 10FCP in February and he shot it a few hundred rounds. He's kind of anal and decided he wanted a custom barrel instead of just toying with the Savage factory barrel for a few thousand rounds.

He ended buying a McGowen 26" tube and had a 'smith mount and bed it. Unfortuntely, the chamber was ballooned and he ended up sending that back. He's still waiting on it, so we'll see how she shoots.

I shoot a 10FP LE2b from '05 with factory 26" tube and 2700 rounds down the pipe and it's a decent .75 MOA gun, currently. My barrel took about 600-700 rounds to settle in, but it's not doing too badly:

You can pay big bucks for a guaranteed .5 MOA rifle, but most factory, or even second tiered barrels, you have to live with MOA or slightly better. They're just not benchrest grade.

Personally, I've never considered shooting the 208 AMAX, as that's at the upper end of the 308's capacity. My barrel shoots the 190 SMKs quite well, but there are better bullets, lighter bullets, with less recoil. My gun loves the 185 Lapua Scenars, but they still kick a lot and velocities for 1k are not quite as flat as the 175s or even the 168s and 155s.

I have a 26" tube, so I get a tad more velocity than shorter barrels, without loading too hot. I'm working up 155s right now, but honestly, I can get the 168 SMKs going up over 2725 and they're still supersonic at 1k.

Personally, try the 155s or the 175s SMKS, or even the 178 AMAX and ditch the 208s. Try Bergers, the lighter AMAX, the JLDs, the Lapua Scenars and even the new 155 SMKs.

Don't blow out your primer pockets if you don't have to.

Chris

 

[EddieNFL]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 918v</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body"> On my calipers the backside of the tool is used for measuring ID of things, and it's not a flat surface, at least not a VERY flat surface, they are 'sharpened', but it gives me enough precision for what i'm doing.</div></div>

No it does not. You might as well be using a ruler. </div></div>

Agreed. You really need a ball mic or a dedicated neck tool.

I may have missed it above, but ensure the neck (inside) is clean. Tumbler doesn't cut it.

 

[Short-bus]

Re: Experienced Re-loaders, please enter

What's the most efficient way to clean the inside of the necks?

Branden

 

[999yards]

Re: Experienced Re-loaders, please enter

I used to put some 0000 steel wool on an old worn out brush and chuck it in the drill press to clean inside necks. Brass also has an elastic quality about it, each piece will have a different memory thus a different "spring back" after sizing. To kill this spring back we anneal.

 

[lanwickum]

Re: Experienced Re-loaders, please enter

Correct me if am wrong here guys, but wouldn't DR be much further ahead by simply sorting brass by weight and maybe water capacity if he really wants to take up his time.

 

[918v]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body">What's the most efficient way to clean the inside of the necks?

Branden </div></div>

I chuck a bronze brush in a power drill, w/o any steel wool.

 

[918v]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: montana</div><div class="ubbcode-body">Correct me if am wrong here guys, but wouldn't DR be much further ahead by simply sorting brass by weight and maybe water capacity if he really wants to take up his time. </div></div>

Not much farther. Sorting by neck tension controls point of impact much better than sorting by case weight/water capacity.

 

[ZY100]

Re: Experienced Re-loaders, please enter

Re: Cleaning inside of necks...

A correct caliber (i.e 308 in this case) bronze cleaning brush in a small cordless drill works well for me. However, I feel a consistant technque is best--like most things in reloading. Goes w/o saying use a new brush that has never seen solvent or oil...

One pass, moderate rotation speed, fairly quickly in and out leaves a nice clean surface and cross-hatch pattern.

ZY

 

[Hummer]

Re: Experienced Re-loaders, please enter


Dust Remover, ALL these replys are very valid and useful.These guys that have been around the block a few thousand times and have all seen the elephant. The name of the game is uniform bullet pull tension and unless you have that all the other things (neck turning, case weighing, etc) are wasted efforts as variable neck tension cancels out what you are trying to achieve when you get to long range. Up close you won't see much difference and SD will start to kill you at long range.
What you are fighting:
1. case neck walls are not uniform and can vary in thickness to maybe .005".
2. when you turn necks the OD of the loaded round gets even more sloppy in the neck.
3. SAAMI chambers in the neck run .3442 to .3462. Bear in mind the industry folks want to get all the reamer life they can to cut down on production costs so they start making reamers on the max side so they can do a few hundred chambers, resharpen it and do a few hundred more so the odds of you getting a F------g (FB)big chamber is 50-50.
4. The ammo boys pretty well have their act together. About all the new commercial 308 brass I have seen unfired measure .465" on base as measured .200" up from rim. The new commercial factory ammo I measure runs .337-.339 on the neck dimension so worst case is you have neck expansion to hell and gone. LC Match necks run .339/.340. Obviously with such large necks the bullet having its base kicked one way or the other before it gets into the throat is very high. And this is before you turn necks which really throws things off. My personal chambers are cut with three reamers with neck dimensions .337", .339", .341" and SAAMI FB. If it is going to be a dedicated long range gun I use the .337 and neck turn cases so loaded rounds measure .336 on the neck or couple tenths on the high side.
5. The case body measurements are just as bad. Commercial brass I have measured runs .465" on base and LC cases measure .468. So I don't run into any problems my reamers cut .4685/.469 on base dimensions thusly I can turn LC case necks on down and it all goes in just fine. Commercial cases fire and spring back to about .466/.467 and it takes a close look to see any expansion where LC cases appear to be unfired. To take advantage of the expansion fit I have several sets of dies. One resizes base dimension to .466 and another to .468 thusly I don't "work" the brass any more than is needed to insure easy bolt closing and more importantly easy extraction. If you are fighting to open the bolt you are begging for a broken extractor. I also headspace as near to zero forward movement I can do them. Fired cases will still gage perfect in L.E. Wilson case gage.
6. Cleaning the inside of the necks is also critical as cases that are not cleaned have carbon deposits on inside which becomes hard fairly soon after firing. Evidence of this is seen on expander balls being scored by embedded carbon as evidenced by picket fence marks on inside of case necks from the scoring of the expander balls. There are several methods to do this as indicated by several posts on this forum.
Bottom line is if you want peak accuracy you have to have tight tolerances, excellent quality control and uniformity in cases/chamber/and barrel.
Larry Moore told me early on to get my own reamer so I always had all chambers cut with same reamer as well as many other things he and others passed on to me. This was repeated by Ray Steele who built all the Secret Service Rifles for many years which set several records and still holds the 1000 yard any sight record. Yep he had a custom 300 Win Mag reamer for this as well and I have one made to his drawing.
With the cost of brass these days a reamer will pay for itself in about a thousand rounds I figure.
I haven't touched on propellants/projectiles/primers because without the base foundation of a good barrel, chamber, bedding, trued action, heavy striker energy etc you are spinning your wheels so to speak.

 

[308sako]

Re: Experienced Re-loaders, please enter

Deleted in protest!

 

[Victor N TN]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 918v</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dust_Remover</div><div class="ubbcode-body">What's the most efficient way to clean the inside of the necks?

Branden </div></div>

I chuck a bronze brush in a power drill, w/o any steel wool. </div></div>

I use a bronze bore brush in a RCBS "screwdriver" handle. Twist while pushing in and twist while pulling it out.

 

[mdesign]

Re: Experienced Re-loaders, please enter

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 999yards</div><div class="ubbcode-body">I used to put some 0000 steel wool on an old worn out brush and chuck it in the drill press to clean inside necks. Brass also has an elastic quality about it, each piece will have a different memory thus a different "spring back" after sizing. To kill this spring back we anneal. </div></div>

Absolutely! This made a big difference on the long range accuracy of my 300wsm. 6mmbr has some good articles on annealing, I use 650deg F Tempilaq paint to control my heat range. This costs about $15 from McMaster Carr or welding supply store. I outlined my process in an article I wrote on my rifle for 6mmbr. Polishing the ID of the neck is the final step prior to reloading.

The combination of turning necks and annealing gave me almost zero run-out, more consistent resizing of my brass as well as more consistent bullet seating. All this adds up to better groups assuming the load, rifle and shooter are doing their part.

 

[Supersubes]

Re: Experienced Re-loaders, please enter

From what you have said about the guns performance, sounds like you are trying to solve a non-existent problem. Just shoot it.

Regarding the necks, you mentioned that your brass is reaching the end of it's life with 7-8 firings. Your neck tension issues are probably due to their hardness. Sounds like annealing would help.

FWIW, i don't clean the necks with anything abrasive like a brush or steel wool. I don't like the scratches they leave. I spin a nylon brush in the neck just to make sure they are all equally clean.

If one round here or there seats different than the others, i sort them. Usually they go all in the same zip lock bag, then get stuffed in my pack.

edited: The more of this field type shooting I do, the less anal reloading i do. It just doesn't seem to improve results on target. If your having good results on target, don't fret the SD's or any other detail that your OCD says you should.

 

[MitchAlsup]

Re: Experienced Re-loaders, please enter

It is my opinion that you have come to the end of your Full length die utilization. You are oversizing the neck by 0.002 downward, and then using the bullet to upsize the neck from 0.004 in tension to 0.002. This causes 3 work hardening steps to take place.

Instead you can get by with one work hardening step with a neck bushing die (or have the neck of your FL die machined to the required diameter). Adding an annealing step, and conversion to a bushing die will increase the precision and consistency of your neck tension.

Your ES and SD numbers are already on the "can't get much better" end of the scale.

 

[Short-bus]

Re: Experienced Re-loaders, please enter

I was out today with the rounds that I did this task with today, it was 25 degrees with a wind chill of 19 according to the Kestrel. I shot some 168 BTHP's, 178 amax's, and some 208amax's. It wasn't the most scientific approach today due to the cold, but I got the following data;

168BTHP SD-13.7 ES-42.3 (9 shot sample)
178Amax SD-19.4 ES-53.3
208Amax SD-11.4 ES-27.3 (48.0gr load)
208Amax SD-17.0 Es-34.0 (47.5gr load)

Everytime I shoot those 208's I get the best results, but they are also the hardest to shoot well, and they hurt the 'ol shoulder, lol.

I'm going to talk to the wife about getting bushing dies, and neck trimmer, as well as a concentricity guage. Bushing dies and neck trimmer will be first I suppose.

I'm going to write a full writeup later, I shot some video as well, groups weren't anything to write home about, but with the wind chill the way it was, I have a excuse.

Branden

 

[mdesign]

Re: Experienced Re-loaders, please enter

Branden - FWIW, I'm not a big fan of bushing dies because I have run out problems with them every time I use them.

I'll attempt to explain. When a 30 cal case is fired it expands to the dia of the chamber neck or to about .345 dia but a loaded round with a cleaned up neck measures about .336 dia. To have minimal neck tension your bushing will have to reduce the neck dia about .010 and I have had very poor luck doing this without having more runout than with a standard FL sizing die.

Some guys dual step this process by first sizing with a larger bushing and then the final bushing and they get great results. I think this work hardens brass faster but to each his own.

Something else I have learned. My runout and accuracy improved when I turned necks but the standard neck ID in a Redding FL sizing die is such that it will give you .001 - .0015 neck tension when sizing fired cases with turned necks and it is not uncommon to have .000 - .0005 runout in my loaded rounds. This meant I could have low neck tension without having to buy bushing dies, more bushings, etc, which saved me money.

If it were me, I would buy a simple concentricity gauge and see how good you currently are. Then I would invest in a simple neck turner and test to see if it made any difference for you. Maybe you gain nothing be at least you find out before you ask the wife to approve funding for something that does not give what you are looking for.

Also FWIW, perfect ammo does not make up for poor shooting or issues related to load development. It cost me the purchase of a lot of gadgets to learn that lesson.

 

[918v]

Re: Experienced Re-loaders, please enter

In my experience, with bushin and FL dies, the more you size the more runout you get. That's why Lee's collet neck die is such a brilliant design. Despite the large reduction of the case neck, total indicated runout is kept below .005"

 

[Greg Langelius *]

Re: Experienced Re-loaders, please enter

Interesting topic.

First thing I get is that blowing out primer pockets can and should be avoided. My approach to this is to control muzzle energy. For me, this means keeping bullet mass down, and keeping velocity where the amount of mayhem being perpetrated inside the engine room (read: "throat") to a minimum. Besides, high pressures and velocities increase obturation, which is good for neither fouling nor bullet deformation. IMHO, a 175SMK with around 45gr of Varget is running at a good energy level.

I believe that all bullets drop and drift, and that the key to limiting that is to limit Time Of Flight. Running the numbers on a calc, keeping pressure levels to a reasonable level, will tell you which load has a TOF edge.

I run SAAMI chambers and neither neck turn nor resize with bushings. I consider these efforts to be fruitful, but their fruitfulness to be limited by the fact that no matter what you do, once the case expands and is resized, it's now a different case, due to work hardening. Any effort to control neck tension is thus aiming at a moving target (unless, of course, you're annealing after each use, and even that's no guarantee of load-to-load uniformity).

My experiments with neck tension tell me that the best neck tension is the least amount that manages to deliver the bullet to its ideal distance relationship with the rifling each and every time. If it slips, it's too little. Beyond that, neck tension is just a headache, as far as I'm concerned.

My method of managing neck tension is to manage the amount of the neck's <span style="font-style: italic">length</span> which get resized.

The case neck expands on firing to conform to the chamber neck's expanded diameter, then both spring back to their 'at-rest' diameters. Typically, this results in a minimum clearance relationship between the case neck and chamber neck.

Incidentally, as long as the chamber dimensions are concentric, this results in a case neck which is rather nicely mechanically centered within that chamber neck. When we squeeze down that neck, we destroy that concentricity.

What I like to do is to back off my F/L resizing die so it only contacts the end half (or less) of the case neck. This retains the mechanical centering aspect of the blown out neck, while decreasing the actual resized contact area of the neck with the projectile. Neck tension and seating/pull force are thereby reduced. Work hardening is reduced to only the end portion of the neck.

In order to meet my criterion of minimal tension, I keep backing off the die until I can manually rotate a seated bullet with thumb and forefinger. That's where I know I've gone too far, and I return the die about a half turn toward where it was coming from.

This establishes a repeatable criterion for neck tension. Every time I reload a batch of ammo, I repeat this test with several cases, and reset the die to satisfy this criterion at this particular stage in the brass' lifespan.

This causes several other conditions to appear.

Because the die is not resizing the entire case length, the sidewalls, especially nearer the base, tend to get blown out, and not resized. The base diameters will reach a final expansion diameter and stay there.

Reloaders will note this expansion,and nearly universally panic. Now let's consider that. The cases still chamber; only now, they are not being work hardened at the lower end. Is this such a terrible thing? I find that it not only isn't, it might have the beneficial effect of reducing tendencies toward case head separation which is a consequence of excessive working of the brass in that area. In any instance, isn't this a lot like what's happening with a neck-only resizing die?

Shoulders are not getting bumped either. I tend to deal with these in the same way neck-only handloaders do, performing a F/L resize when fired and unresized cases drag too much upon bolt closure.

It's a completely different way to approach the issue. I think it has some logical points in its favor.

Greg

 

[Short-bus]

Re: Experienced Re-loaders, please enter

Greg, thank you for your post. I used to neck size only, however my accuracy was deteriorating for some reason, and the only thing that I changed that brought back the accuracy was to full length size my brass. I would prefer to neck size only, that'll allow my brass to have a longer life, but not at the expense of accuracy.

Anyone have any input as to why FL sized brass would shoot better in the rifle than neck sized brass?

Branden

 

[SPAK]

Re: Experienced Re-loaders, please enter

I would think that if your shoulders aren't getting bumped back enough than it's possible that the chamber would push back the shoulders upon chambering however many thousanths it needed to be bumped back. I found the same thing. I could get by neck sizing for 2-3 rounds of full power loads but eventually it would get harder to chamber and my accuracy fell off.