• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

Case neck thickness Uniformity

I'd like to hear from anyone who has uniformed case necks for their standard no-turn chamber, what they did, and if the results were worth the effort - with a bit of detail detail on cartridge, application and observed difference in results.

Specifically uniforming, not fully turning, so around 70% of the neck having material removed, not turning down necks to fit custom chambers.

I've made up my mind to test this for myself once I have the load ironed out for a couple of new target rifles with no-turn chambers, and I'd like to gauge opinion on it.

I want a consistent 1 MOA for ELR, and any improvement I can make past that will be bonus.
 
I'd like to hear from anyone who has uniformed case necks for their standard no-turn chamber, what they did, and if the results were worth the effort - with a bit of detail detail on cartridge, application and observed difference in results.

Specifically uniforming, not fully turning, so around 70% of the neck having material removed, not turning down necks to fit custom chambers.

I've made up my mind to test this for myself once I have the load ironed out for a couple of new target rifles with no-turn chambers, and I'd like to gauge opinion on it.

I want a consistent 1 MOA for ELR, and any improvement I can make past that will be bonus.
I turn my necks on a couple of rifles. one needs it to chamber and one that is a no turn. I turn them because the are not the same thickness in all parts of the neck. I also turn them down to .012" for neck tension to be the same at .002" without having to use a bushing die to worry about donuts because most of my bullets are seated with the bearing surface below the neck shoulder junction. I use the mandrel that I use to turn the necks after FL sizing. If you are already turning your necks, try both ways and see if it helps you. I don't think they can be to accurate, It's just how much effort do you what to put into it.
 
Last edited:
One of my 223 AI reamers is a touch tight for newer Lapua brass.

So I clean up about 50% of the neck for a bit more clearance. As an added bonus, groups and chrono data improved.
 
I'd like to hear from anyone who has uniformed case necks for their standard no-turn chamber, what they did, and if the results were worth the effort - with a bit of detail detail on cartridge, application and observed difference in results.

Specifically uniforming, not fully turning, so around 70% of the neck having material removed, not turning down necks to fit custom chambers.

I've made up my mind to test this for myself once I have the load ironed out for a couple of new target rifles with no-turn chambers, and I'd like to gauge opinion on it.

I want a consistent 1 MOA for ELR, and any improvement I can make past that will be bonus.
If you're not already getting much better than 1 MOA, I doubt very much that turning your necks will be of any help. :rolleyes:

I do turn ("uniform") all my case neck for use in my standard no-turn chambers. I've not run any actual testing to record data on the results of doing so. I just try to have as much uniformity from case to case as I can do and turning necks is just one aspect, which is really just a one time operation for the life of the cases I'm willing to do. I do "fully turn" my cases to take care of 100% of the neck surface as my goal is to have uniform interference on a seated bullet and uniform release of the bullet when being fired.

Though turning the necks is only one aspect of my prep, I think it's all that I do that's helped me get sub .5 MOA's consistently (typically between .35 and .45 and it's always fun to see the occasional .2's or the more rare .1's). Otherwise, I think my MOA's would be more like 3/4"+ or so.
 
I'd like to hear from anyone who has uniformed case necks for their standard no-turn chamber, what they did, and if the results were worth the effort - with a bit of detail detail on cartridge, application and observed difference in results.

Specifically uniforming, not fully turning, so around 70% of the neck having material removed, not turning down necks to fit custom chambers.

I've made up my mind to test this for myself once I have the load ironed out for a couple of new target rifles with no-turn chambers, and I'd like to gauge opinion on it.

I want a consistent 1 MOA for ELR, and any improvement I can make past that will be bonus.
Welcome to the ELR rabbit hole.

If that's 1 moa at 100 yards, as others have already indicated, there is something wrong if you just assemble ELR appropriate components and don't clear that easily. No turning, no sorting, drop the powder with something a little better than a progressive press.

1 moa at a mile is an entirely different matter. By a mile, the contributions of relatively small shot to shot variations in velocity and BC will open groups well beyond 1 moa even if the gun puts them all through the same hole at 100 yards. This is before "conditions" lift their leg on the group size. The contributions of those small differences just keep becoming larger faster and you head from 2000 to 3000 yards.

Velocity variations are minimized with judicious primer/powder pairings and brass prep well beyond what you're describing.

BC variations are managed with bullet choice, bullet sorting/culling, seating them in a manner that leaves them looking like they've never been handled by humans, bench rest level throat concentricity, and a fresh barrel. The BC variations will be dominated by throat wear for the second half of the barrel's life. A common mistake is spending too much barrel life searching for the ultimate 100 yard group. Another common mistake is using too much pressure thinking average velocity is everything. The BC variation is on the bullet that comes out of the muzzle and jacketed target bullets are relatively fragile. For a cost/benefit analysis, figure every additional 100 fps gained through case capacity, pressure, or double base powders costs 1/4 to 1/3 of the barrel's life. At 2000 yards, if you didn't screw anything else up getting there, that 100 fps has the same effect as moving the target 75 yards closer. Plan on shooting deep into transonic velocities. Staying supersonic is not a requirement with the right bullets and if the rest of your house is in order. If it's not, no amount of HP will cover that up. There are still some bad bullet designs being sold that won't shoot well deep into the transonic range, but ATips and Hybrids both will.

223 unturned LC brass. Top is my current 75 ELDm load, below is the 80ELDm, below that is 80AMax. Small cases are a pain. This test covered 2 powders and 3 bullets. I found 1200 of the AMax while organizing my reloading supplies, so they're going to be used. This was intended as a first test to generate data for further refining a load in QL. I'm just going to use that 80 grain AMax load as is. The point is, most of what's needed for hobby use long range loads can be done pretty simply once you have a solid brass prep routine and powders/primers matched to the application.



6XC, unturned Peterson brass, 108 ELDm seated into the neck, H4350, match primers.



300 Lapua, weight sorted Lapua brass turned for full cleanup/ID & OD/ into the shoulder, 250 ATip with the back of the bearing surface in the shoulder, Retumbo, weighed match primers.



The 223 and 6XC ammo is for shooting steel, generally inside 1000 yards. The loading process is simplified because I shoot so much of it and the error budget is completely different. The SDs on this ammo is about half what can reasonably be expected from commercial match ammo.

The 300 Lapua stats are more rigorous because there are a larger number of shots and groups and because they're shot in the wild at an actual match. The larger point is the differences are small on a chrono. I'll concede the point that I don't have the skills to find neck turning differences on target. Not conclusively and on demand anyway.

Because the bullet bearing surface extends past the neck/shoulder junction on the 300 Lapua, I uniform that part of the neck because it has such a large effect on the neck tension. My new reamer will move the bullet further out and should drop the velocity spreads some. I use the KM turner with a boring pilot. If you look into the neck after running a mandrel through it or pulling a bullet, you'll see lengthwise streaks. 2 thou of neck tension isn't enough to seal the joint if both surfaces are not perfectly round. The idea of the boring and setting the final neck tension with a mandrel is to manage the leakage around the bullet early in ignition. The larger lesson for ELR is to just give up on the magazine feeding early on. The 80% benefit 20% effort trick to velocity uniformity is throating the chamber so the bullet only engages 2/3-3/4 of a 1 caliber neck length. Yup, you'll probably have to give up on micro parsing jump to optimize one 5 shot group that won't repeat for the whole box of 50, but I've already pointed out ELR is not a precision game. That is, ELR has larger problems than 100 yard precision and after you've managed them the precision will be more than adequate.

For hobby ELR work, SDs below 10 and ES's below 30 are a pretty good effort. You should be able to do that with decent brass that was weight sorted when new and then forgotten about. That's for every 10 shot string in a box of 50. It probably won't happen at internet velocities for your combo....

If you can lower the SDs into mid single digits and the ES's below 20, the BC variation becomes the prominent problem beyond a mile. That's managed by keeping the barrel fresh. How fresh depends on how much you intend to shoot past 2000 yards.
 
It sounds like maybe you are over 1 MOA currently and looking to better? I'd probably look to tuning a good load before looking to the minute differences of turning necks. That said - I turn the necks on all of my target loads - as well as my varmint loads. The biggest improvements will come from "average" brass such as that made by most large manufacturers, such as Winchester, Remington, Hornady, Nosler, Lake City mil brass, etc., as well as brass that has been necked up/down. Because I fireform my .220 Russian into 6 PPC, I turn that too, even though Lapua out of the box in calibers not requiring necking up/down don't typically see too much benefit, especially in a no-turn chamber. I spent years shooting all my test loads over chronographs and when loading, I marked brass with an "X", using a sharpie on any piece that seated a bullet too easy or with extra force (XX), just to see what the chrono told me. I found the differences in velocity enough to make me want to neck turn everything, if for no other reason than to know I rid those discrepancies from my lot. Unless your rifle is REALLY dialed in and you are testing in great conditions, it is quite difficult to ascertain what measurable difference there is - but it IS there, in velocity uniformity, if not on target. Turning your necks won't make a 1 MOA load a 3/4" load with good brass - but there will be very slight improvement - which is why so many folks do it. Eliminating irregularities, however small. I see the biggest improvement when turning the necks on Federal and Lake City brass, whether it was necked up/down or not - to where it is measurable and easily recognized on paper. You can go crazy on cheap brass and make it shoot surprisingly well - even if it doesn't last as long.
 
I'd like to hear from anyone who has uniformed case necks for their standard no-turn chamber, what they did, and if the results were worth the effort - with a bit of detail detail on cartridge, application and observed difference in results.

Specifically uniforming, not fully turning, so around 70% of the neck having material removed, not turning down necks to fit custom chambers.

I've made up my mind to test this for myself once I have the load ironed out for a couple of new target rifles with no-turn chambers, and I'd like to gauge opinion on it.

I want a consistent 1 MOA for ELR, and any improvement I can make past that will be bonus.
I do a cleanup light cut. It's one of the few things I do to a case. Unless the rifle and your shooting ability is world class you shouldn't see the groups get smaller.
 
It sounds like maybe you are over 1 MOA currently and looking to better?
I'm still working on the load data for the new rifles with the bullets I've chosen to use.

I turned the necks on 375 RUM by necessity that were necked up from 7mm, and made donuts. I'm 600 rounds in on that one, it's a one mile practice gun , and the best I've done with it is 4 out of 5 on a 3/4 moa plate at 1000 meters.

This time I want to turn to uniform the necks for consistency, not to correct a problem.

If I never had the donuts, I would not have turned the necks and maybe not realised the same performance. If I remember correctly, I turned them to 12 thou.

This is what got me thinking to try the same on the other rifles once the load is right. From the experiences shared so far, my assumption might show benefits.
 
I'm still working on the load data for the new rifles with the bullets I've chosen to use.

I turned the necks on 375 RUM by necessity that were necked up from 7mm, and made donuts. I'm 600 rounds in on that one, it's a one mile practice gun , and the best I've done with it is 4 out of 5 on a 3/4 moa plate at 1000 meters.

This time I want to turn to uniform the necks for consistency, not to correct a problem.

If I never had the donuts, I would not have turned the necks and maybe not realised the same performance. If I remember correctly, I turned them to 12 thou.

This is what got me thinking to try the same on the other rifles once the load is right. From the experiences shared so far, my assumption might show benefits.
What bullets are you running, how fast, and what sort of SDs do you currently see?

I'd expect the barrel life of a 375 RUM to be quite good by ELR standards.

Usually, these discussions are with people that are thinking about tooling up to neck turn. You're already a little bit pregnant and it's not such a large step. I'd still suggest looking for turning effects on the chrono rather than in 100 yard groups.

As far as precision goes with ELR rifles, I've seen the most bang for the buck from setting the gun up to track. The brake reduces the perceived recoil, but the bullet doesn't see that because the brake action doesn't start until the bullet clears the barrel. The quarter inch or so the gun moves while the bullet is in the barrel needs to be managed well because when compared to BR setups, the recoil increases a lot more than the gun weight does. Solid tracking has an even larger benefit if you're self spotting.
 
With 6.5 Creedmoor and Lapua brass I found better groups with uniformed, and fully turned necks versus unturned.

Now with 6br and Lapua brass, I'm getting closer to saying that uniformed necks are not worth the effort. I have not tried full turning yet as there isn't much meat on the bones considering the chamber.

In both cases I'm seeing 1/2 MOA @ 300 yds; half the groups <= 0.75, the other half <= 0.5 MOA.

So, I guess it depends on things other than just neck turning by itself.

Hope that helps.
 
Welcome to the ELR rabbit hole.

If that's 1 moa at 100 yards, as others have already indicated, there is something wrong if you just assemble ELR appropriate components and don't clear that easily. No turning, no sorting, drop the powder with something a little better than a progressive press.

1 moa at a mile is an entirely different matter. By a mile, the contributions of relatively small shot to shot variations in velocity and BC will open groups well beyond 1 moa even if the gun puts them all through the same hole at 100 yards. This is before "conditions" lift their leg on the group size. The contributions of those small differences just keep becoming larger faster and you head from 2000 to 3000 yards.

Velocity variations are minimized with judicious primer/powder pairings and brass prep well beyond what you're describing.

BC variations are managed with bullet choice, bullet sorting/culling, seating them in a manner that leaves them looking like they've never been handled by humans, bench rest level throat concentricity, and a fresh barrel. The BC variations will be dominated by throat wear for the second half of the barrel's life. A common mistake is spending too much barrel life searching for the ultimate 100 yard group. Another common mistake is using too much pressure thinking average velocity is everything. The BC variation is on the bullet that comes out of the muzzle and jacketed target bullets are relatively fragile. For a cost/benefit analysis, figure every additional 100 fps gained through case capacity, pressure, or double base powders costs 1/4 to 1/3 of the barrel's life. At 2000 yards, if you didn't screw anything else up getting there, that 100 fps has the same effect as moving the target 75 yards closer. Plan on shooting deep into transonic velocities. Staying supersonic is not a requirement with the right bullets and if the rest of your house is in order. If it's not, no amount of HP will cover that up. There are still some bad bullet designs being sold that won't shoot well deep into the transonic range, but ATips and Hybrids both will.

223 unturned LC brass. Top is my current 75 ELDm load, below is the 80ELDm, below that is 80AMax. Small cases are a pain. This test covered 2 powders and 3 bullets. I found 1200 of the AMax while organizing my reloading supplies, so they're going to be used. This was intended as a first test to generate data for further refining a load in QL. I'm just going to use that 80 grain AMax load as is. The point is, most of what's needed for hobby use long range loads can be done pretty simply once you have a solid brass prep routine and powders/primers matched to the application.



6XC, unturned Peterson brass, 108 ELDm seated into the neck, H4350, match primers.



300 Lapua, weight sorted Lapua brass turned for full cleanup/ID & OD/ into the shoulder, 250 ATip with the back of the bearing surface in the shoulder, Retumbo, weighed match primers.



The 223 and 6XC ammo is for shooting steel, generally inside 1000 yards. The loading process is simplified because I shoot so much of it and the error budget is completely different. The SDs on this ammo is about half what can reasonably be expected from commercial match ammo.

The 300 Lapua stats are more rigorous because there are a larger number of shots and groups and because they're shot in the wild at an actual match. The larger point is the differences are small on a chrono. I'll concede the point that I don't have the skills to find neck turning differences on target. Not conclusively and on demand anyway.

Because the bullet bearing surface extends past the neck/shoulder junction on the 300 Lapua, I uniform that part of the neck because it has such a large effect on the neck tension. My new reamer will move the bullet further out and should drop the velocity spreads some. I use the KM turner with a boring pilot. If you look into the neck after running a mandrel through it or pulling a bullet, you'll see lengthwise streaks. 2 thou of neck tension isn't enough to seal the joint if both surfaces are not perfectly round. The idea of the boring and setting the final neck tension with a mandrel is to manage the leakage around the bullet early in ignition. The larger lesson for ELR is to just give up on the magazine feeding early on. The 80% benefit 20% effort trick to velocity uniformity is throating the chamber so the bullet only engages 2/3-3/4 of a 1 caliber neck length. Yup, you'll probably have to give up on micro parsing jump to optimize one 5 shot group that won't repeat for the whole box of 50, but I've already pointed out ELR is not a precision game. That is, ELR has larger problems than 100 yard precision and after you've managed them the precision will be more than adequate.

For hobby ELR work, SDs below 10 and ES's below 30 are a pretty good effort. You should be able to do that with decent brass that was weight sorted when new and then forgotten about. That's for every 10 shot string in a box of 50. It probably won't happen at internet velocities for your combo....

If you can lower the SDs into mid single digits and the ES's below 20, the BC variation becomes the prominent problem beyond a mile. That's managed by keeping the barrel fresh. How fresh depends on how much you intend to shoot past 2000 yards.
This would be one of the best replies I have read for a long while, really good info and a good understanding of the op's question. Well done on the effort to write this reply! And the one that followed later. I'm only a 1000 yd shooter but I picked a few nuggets from this as well.
 
What bullets are you running, how fast, and what sort of SDs do you currently see?
280 grain Peregrine monolithic at 2780 fps. 26" barrel. My data card shows 14fps spread over 5 shots from the load development. I've gone up to 2900 with a 300 grainer [ when the barrel was at 30 inches ] in load development without stressing the brass, this slower load shoots much better.

I really don't fuss over the numbers, I want as close as possible to a full case of powder, burn complete in the barrel, easy bolt opening and to shoot inside that one moa circle up to the range of the gun. I can see from the velocity numbers when the burn is right.

addendum : to clarify why the barrel length changed, I asked for the wrong twist limiting the bullet length to 300 grain monos, and those don't have the BC for ELR. The BC is good enough for 1 mile with the elevation in the scope and on the rail, so I re-used the ELR stock on another build, fitted a hunting style stock and shortened the barrel. i call it my training rifle, it taught me a lot.
 
Last edited:

Upgrades & Donations

This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.


Click Upgrade Membership Button ABOVE to get Gold or Silver Status.

You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.


To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.

Forum statistics

Threads
166,939
Messages
2,225,436
Members
80,060
Latest member
23sailfish
Back
Top