Finally tested my turned necks

[gamestalker]

I couldn't wait any longer and decided I would brave the extreme heat on Saturday for a couple hours. This was a Ruger American .270 win..

Before anyone jumps my case for not posting pics, I learned how to do it, but unfortunately I don't have the ways and means to do it right now. And I'm also not posting this report to boast about my shooting skills, this is only to provide my opinion as to how turning necks for a production barrel seems to have made a positive impact on accuracy.

I tried Winchester, Remington, and Hornady brass with several different, yet already previously developed loads that previously performed satisfactorily in this rifle, Ruger American .270 win..

Strapped down and shot off a lead sled.

Bullets were 130 gr. Speer Hot Core.
All were jammed about .010", same as the previous development.

Loads tested-
IMR-7828 / 60.5 grs. and 60.8 grs.
RL22 - 57.0 grs


I didn't get a lot of shooting time in, like I said the heat was brutal, but other than the heat, shooting conditions were very good, no wind at all, it was dead calm.

I also swapped the trigger out for a Timney, really good decision and well worth the money, the stock Ruger trigger was horrible. I had it adjusted at 1.5 lbs..

Anyway, it only took me 3 rounds to get it accurately zeroed at 100 yards, which took care of fouling the barrel and warming it up for the session. I allowed it to cool for about 5 minutes between shots, and 10 minutes or so between groups. I didn't want to go down range to change targets after the first 3 groups, so I just adjusted my elevation turret up 2 moa to separate the groups on the 3 targets, pretty nifty idea I thought.

I shot six groups, two of each load, all 5 round groups. the 7828 loads were from the Hornady brass.

Every single group was under an inch, two were in the mid .400" range, and the remaining 4 groups were all in the .700" range, and under 3/4". And to be perfectly honest, I was stressed by the heat and not really taking enough time to give it my best, I know I rushed some of the shots.

Right off the bat I noticed that the brass was sealing right at the mouths. There was very little, if any evidence of gases escaping down the necks. The only one's that had even minimal evidence of any gases getting past the mouths, was with the Hornady brass, which I had not been annealed yet.

So IMHO, replacing the trigger definitely made a difference. But I can't help but think that turning the necks improved accuracy. Neck tension was a lot more consistent, and was significantly lighter. Not so light that I could get any movement when chambering them, or by physically pulling on them with my fingers, but much, much lighter and much more consistent. And this rifle has never produced groups this consistent. I could get decent under an inch groups, but not back to back, and better than 1/2" was rare.

Next session will be 200 yards, and I'm going to borrow a remote trigger device, some fandangled hydraulic thing a friend made and uses to sight his rifles in with.

GS

 

[LiveLife]

Thanks for braving the heat!

There are many reasons why benchrest shooters turn necks.

Any opinions on turning necks on .300 BLK?

 

[Walkalong]

Benchresters turn necks to be a tight fit in tight necked chambers. Standard cases are unusable in them. Everything about case prep and sizing was about a very tight fit of the loaded case to the chamber. Both in body diameter, neck diameter (with a seated bullet), and head clearance.

For standard chambers just clean up the necks, some say 75% of the neck, some say more. Definitely not more than turning to the thinnest measurement of the neck walls using a proper micrometer.

I tried neck turning for a Sako in .222 Mag way back when, but couldn't really see a definitive difference.

If you don't have a very accurate rifle/load combo to start with, I don't believe neck turning will turn it into one.

 

[gamestalker]

I couldn't agree more Walkalong, you can't make an inaccurate barrel just suddenly start shooting accurately simply by focusing on the load, brass, trigger, or optics. But this American had potential right from the get go, so I felt like it would make a decent candidate to learn the skill of turning necks with.

But I don't think the necks being inconsistent was all that was going on. Like I said, the trigger was terrible.

I also swapped the glass out, same glass, but I sent it in to Vortex for service, which as it turned out, it had a couple problems that could have certainly contributed to sporadic accuracy. It wasn't having issues with holding zero, just not performing well at higher magnification. They determined the tube was bent, something I wasn't aware of, as it wasn't visually detectable. But considering my son admitted to dropping the rifle, I wasn't surprised. And apparently one of the lenses was defective, so it was producing a lot image shift, especially at higher magnifications. which was why I sent it in to begin with.

The necks certainly did need to be cleaned up, though none could be turned 100%, as it would have created excessive clearance for that chamber. So all I did was clean them up, the majority of which was from about mid neck and down to the shoulders. It's been a really fun and very educational experience, one that will certainly benefit me as I move into the custom barrel game.

And I certainly extend a big sincere thank you to everyone who has helped me to understand this aspect of reloading. Now I just need to get a good custom to work with, can't hardly wait.

GS

 

[Walkalong]

If you get to feeling really froggy, get a barrel from Shilen, Hart, Kreiger, etc, etc, have them cut a tight necked chamber in it, buy Lapua brass and turn the necks to fit, and have them make a full length bushing style sizer with the reamers they used, and go for it.

Or just get crazy, buy a full blown custom gun, some wind flags, and get ready to pull your hair out trying to shoot ones, twos, and threes (With an occasional rutro) all the time.

 

[Bart B.]

Hooray for your success.

But I think the main reason those bullets shot so well was the lesser neck grip on them in the loaded rounds. Most people have way too much neck grip which increases the release force (and its spread about the average) needed to push it out of the case.

For decades, some people have been getting the same benchrest accuracy at 100 yards with quarter inch 5- or 10-shot groups with SAAMI spec chambers (standard neck, not tight) thin walled unprepped full length sized cases. Some have .006" or more clearance all the way around the case neck to the chamber neck.

Loaded round neck diameter doesn't need to be almost that of the chamber neck it fits into; whatever their diameter is, it contributes nothing to where a rimless bottleneck case neck centers in the chamber when the round fires. The key to accuracy is how straight the bullet's held in the chamber when it fires. Doesn't matter if the case body has a lot of clearance to the chamber walls; their back ends are all pressed against the chamber wall by the extractor; their front end by the case shoulder centering in the chamber shoulder.

 

[witchhunter]

The trigger swap could get part of the credit. But that said, I turn necks for standard chambers too. Just enough to make them concentric.

 

[Walkalong]

Loaded round neck diameter doesn't need to be almost that of the chamber neck it fits into; whatever their diameter is, it contributes nothing to where a rimless bottleneck case neck centers in the chamber when the round fires.

A tight fit increases case life, just like you have talked about in other posts.

It also helps center the round, it has no choice with a fit that tight. Between the shoulder, the unsized portion of the neck, the tight fit of the rest of the neck, and being around .020 into the lands all contribute to getting the bullet started straight. As posted, lighter neck tension is better for more consistent neck tension % wise. .020 into the lands helps get the good starting burn we need. Something heavy neck tension does without help.

That is the way the Benchresters were doing it when I was competing. Long range shooters do it a bit differently.

FL sized cases in standard chambers can shoot very, very well, as proven by long range shooters and all the Match ammo out there that shoots great in good barrels. But they are not winning any Benchrest matches.

You give credit only to the cases shoulder centering against the chambers "shoulder", but a little help from other things is a good thing when it comes to shooting tiny aggregates. If things get too sloppy, the shoulder by its self isn't going to get it perfectly straight. You have mentioned getting custom full length sizers to make brass fit the chamber with almost no play. Same basic thing.

 

[Bart B.]

Walkalong,

Please explain why all these cartridges won't perfectly align their neck and bullet in the center of a SAAMI spec .308 Winchester chamber neck when in their firing position:

.243 Win
.260 Rem
7mm-08

All case dimensions are the same minimum SAAMI spec from the shoulder back, all necks are .0120" wall thickness and well centered on their case shoulders.

I have never mentioned getting custom full length sizers to make brass fit the chamber with almost no play. A few thousandths play is fine.

 

[gamestalker]

Walkalong, consistent reduced neck tension was what I was thinking actually also.

A long time ago, back in my early years of bottle neck loading, a good friend and locally known BR shooter, along with another fellow whom I had dated his daughter, also a well known BR shooter was talking had both been feeding me about what I could do to improve a standard production rifle in the 100 and 200 yard range. At the time much of what they were telling me exceeded my comprehension level. And they both attributed they're early beginnings with less than top end custom builds with several steps in the load and brass preparation process.

The number one step, was get neck tension as light as possible. In fact I recall both of them telling me that if I can get the bullet to stay in the neck, it had all the neck tension it needed, and this would help in getting a straight start during the pressure development process. Jam it .020" they would say, and if it won't jam .020", then increase neck tension just enough to prevent the bullet from seating deeper when you close the bolt. But I got conflicting views on this also, but mostly guys shooting the short necked 300 WM's back then. They would literally run neck tension so light the oal could be adjusted with your fingers, so they would just slide it out enough that closing the bolt would actually seat the bullet where it needed to be.

Some other tips were to work with the really slow burners, and work them up to as high as you could without piercing primers. This is something I find easy to accomplish with 7828 in the .270, as even published data produces nearly 100% case fill.

As for tuning the actions, make sure the barrels are completely floated, hand lap the lugs so they are getting full and even contact, but don't lap more than necessary, or you'll screw your head space up.

And a good trigger and good glass are a must.

But I'm all ears and really appreciate any current day advice you guys can offer. I'm not an idiot, but I'm very new to the advanced methods and would like to avoid as much trial and error as possible, so far so good, thank to the guidance. But I will have my custom Shilen BP 700 in the near future, I'm counting the days. In the mean time, I'm enjoying getting these production rifles to shoot these tiny groups, it's just so much fun, and satisfying. And there is a certain degree of satisfaction I get when I'm shooting these kind of groups next to a guy boasting about his $3500 build that's barely printing 1 inch groups, and then he see's my 1/2" groups.

GS

 

[Grumulkin]

There was a guy I shot bench rest with. He made his own dies. He reloaded the same 5 cases at the range during a match. The bullets were seated by his fingers. He did quite well.

There was a load I was working with and some of the bullets were so loose in the cases I could turn them by hand. I shot those and some where the bullets were firmly in place and the loose bullets did the best. Admittedly a small and not necessarily conclusive test.

 

[Walkalong]

I have never mentioned getting custom full length sizers to make brass fit the chamber with almost no play.

I guess I mis-read this:

http://www.thehighroad.org/showpost.php?p=9993035&postcount=6

Jug,

I'd have a custom full length sizing die made that sizes fired case body diameters down .001" with its neck .002" smaller than a loaded round's neck diameter. It'll resize cases with the straightest necks giving best accuracy and long case life when set to bump fired case shoulders back .002".

A few thousandths play is fine.

As posted, yes, that can shoot very very well.

That doesn't mean it is the only way, or that sizing to fit the chamber closely doesn't help align the cartridge. The straighter and more centered it starts the easier it is for it to be perfectly aligned when fired.

Please explain why all these cartridges won't perfectly align their neck and bullet in the center of a SAAMI spec .308 Winchester chamber neck when in their firing position:

I have never said they cannot, only that fitting the chamber closely is a good thing and helps. Is one better than the other? Dunno, I have never done extensive testing of both against each other, as perhaps you haven't either.

It is my opinion that for extreme accuracy (Defined by shooting tiny groups at Benchrest ranges) the tight fit is a good thing and it's the way most Benchrest competitors do it.

My .308 load is done the way you have suggested at times, a Redding FL bushing die. It shoots very very well, but is not going to beat my Bench gun, but the rifle isn't a full blown accuracy rifle, just a very good quality factory rifle.


So, to try to stay on topic, if one wants to turn case necks for standard chambers, don't over do it, just clean them up.

 

[243winxb]

Neck turning for factory chambers.

Gamestalker, I find that turning necks and using standard dies, does not produce the better accuracy, when compared to using a FL sizing bushing die. For me, sizing only 1/2 of the 243win neck produced better accuracy than sizing all of the neck in a factory Rem 40X chamber. The bushing die also helped my Rem 600 carbine by not over working the brass. Flyers were avoided by sorting Rem & Win brass by weight. Only way to know is do your own testing, as you are. Good job. Here are results of quick test in 223 rem.

[/URL][/IMG] If using the Lee collet neck sizing die-Half of the neck can be sized using Lees instructions. Maybe worth testing? I don't have one.

Knowledgebase





Partial neck sizing with collet die

Posted by on 20 October 2011 07:50 AM


If you want to resize just a part of the neck, find a washer at your local hardware store the has an inner diameter large enough to fit over the case, and an outer diameter large enough so that it contacts the collet sleeve that protrudes from the bottom of the die. Slide this washer over the case after the case has been inserted into the shell plate. Now when the ram is raised, you can still close the collet by applying force at the top of the stroke, but the case will not go up as far into the collet, and the neck will be sized less an amount equal to the thickness of the washer.

http://leeprecision.net/support/index.php?/Knowledgebase/Article/View/137/0/partial-neck-sizing-with-collet-die Takes about 3 firing* for the unsized neck area to expand to the factory chamber.

 

[Bart B.]

I've tried all sorts of neck only, neck and shoulder bump, standard FL dies, standard FL dies with honed out necks on several 30 caliber cases; some neck turned some amount and others left as is. So have others.

No die/neck-prep combination made resized cases with straighter necks than FL dies with honed out necks 1.5 to 2.0 thousandths smaller than loaded round neck diameter. Those put the case neck more centered in the chamber neck. That's easy to measure. Am I the only person who's actually measured case neck centering in a barrel's chamber? Measuring is better than assuming. Didn't matter how much clearance there was between case neck and chamber neck.

One-piece full length dies are the only ones that keep the case body and shoulder axis perfectly aligned with the case neck axis when sizing fired cases. Bushing dies let their neck bushing move sideways off the case body and shoulder axis; there's a couple thousandths or so clearance between them and the die cavity that holds them. Neck only dies do not support/align the case body at all because they don't touch those parts off the case.

Benchresters I've chatted with in the last few years tell me virtually all now use custom full length dies. Their smallest groups stay the same size but their largest ones are now reduced. Group agg's are smaller.

 

[gamestalker]

Wow, some really good stuff guys. I don't mind hearing the varying opinions either, bushing dies vs FL dies, partial sizing vs full length, all good stuff that I will test.

I have though, and for a good number of years partial sized off and on, but more for the purpose of minimizing over working the brass.

GS

 

[Bart B.]

Use the die and technique you want to. But judge the results by the size of the largest groups each method makes. Smallest groups made by any method happen when several variables cancel each other out or all's about minimum. How do you tell the difference? When a lot of those variables add up in all directions, groups are the largest. Forget those smaller groups. Make the biggest ones shrink. That's the easiest thing to do.

Ammo that always shoots under 1.5" produces 1/2" groups more often than stuff that shoots up to 2.5" groups. I understand the desire to shoot tiny groups. Reload ammo such a way to increase the odds of shooting them.

 

[murf]

only accurate ammo is interesting!

murf

 

[Walkalong]

Reload ammo such a way to increase the odds of shooting them.

That has always been the goal of Benchrest, shrinking Aggregates and Grand Aggregates. The only way to do this is to avoid the big groups, and the only way to do that is not make mistakes and have a gun/load that can shoot a tiny group every time, assuming we don't screw it up. The hardest thing to control is the nut behind the trigger.

 

[Bart B.]

...The only way to do shrink aggregates is to avoid the big groups, and the only way to do that is not make mistakes and have a gun/load that can shoot a tiny group every time, assuming we don't screw it up. ...

If that's reality, how come aggregate group records are 10 to 20 times the size of 5-shot group records?

 

[spitballer]

Light trigger pull is a big deal and worth having, trumps a lot of other issues. I was able to keep my x-pro working by simply slathering with rem oil, rather than putting a drop at each of our points as suggested in the manual. Have since switched to CLP for the trigger assembly: rem oil seems to be mostly carrier for the Teflon film and I felt that it dried out too quickly to use for the trigger assembly, although it seems to be ideally suited for the bore.

As for the aforementioned "other issues"... GS, got a question for you about breaking in a long barrel: when my .223 barrel was brand new I was getting tight groups at just over 3000 fps with around 26.6 gr of H414, but as the firing/cleaning regimen progressed, that same 26.6 gr charge sent the projectiles rattling down the barrel at a much faster velocity and started giving me split groups. However, just this last week I discovered that simply increasing the charge to accommodate the changing barrel may be the answer. But this seems to mean a velocity closer to 3200 fps and a charge of around 27.8 grains. Does this sound right to you? Is it normal for a barrel to pick up velocity this fast?

 

[Walkalong]

If that's reality, how come aggregate group records are 10 to 20 times the size of 5-shot group records?

Because it's far easier to shoot one good 5 shot group than several in a row, which is the whole idea of shooting aggregates, to get a better idea of who is shooting the best, just like you state all the time, you need more shots to prove accuracy? You confuse me.

 

[Bart B.]

Muzzle velocity drops as barrels have morel shots through them. The first inch of the rifling erodes away lowering start up resistance that lessens pressure. Not much difference the first two thirds of barrel life. Last third goes quicker with hotter powders and higher pressures.

If velocity is faster late in barrel life with the same lot of components, something else changed.

 

[spitballer]

Muzzle velocity drops as barrels have morel shots through them...

Perhaps I should have said "slightly higher" velocity. Bart B I have learned not to doubt your advice, yet it was something you said that got me started down an unproductive path. You had commented in an earlier post that top competitors only twist a projectile enough to stabilize it and no more, and when my rounds at 26.6 grains were no longer being held in check at 3000 fps by fouling, and group integrity started to break down at the same time, it occurred to me that I might try to restore some of the fouling in soft form (i.e. powder fouling) to maintain the lower velocity that I'd had such success with. Subsequent tests with a slower (and dirtier) 4350 produced mixed results, with 55 grain bullets stabilising at the lower 3000+ fps velocity at just over 27.5 carefully measured grains, but I decided to abandoned this approach after firing a small group charged with just under 27.5 grains of the H414 before leaving the range on Saturday. The 55 gr velocity for this last group was as follows:

3095
3188
3151
3149
3139

Don't have a photo but the first and second shots rolled left and right, fouling shot a little lower, while the last three came in centered and amazingly tight; in fact I believe that the second shot might not have rolled either, if the barrel had still been stone-cold (it was, however, clean). I'm speculating that the charge is just a little shy also because of the first two figures, and plan to raise the charge enough so that the third figure would more closely match the second. Is this the rational approach? It just seems like a lot of velocity when I consider what I started with, but is a faster propellant necessarily in order here? Anything you'd be doing different? thx

Thx also GS for bearing with me on this...

 

[gamestalker]

No problem Spitballer. But I think your question exceeds my pay grade.

A lot of folks don't think barrel break in doesn't do anything, especially for a production grade barrel, I'm not a lot of folks. I always do a what I consider to be a proper break in, I think it prevents copper fouling from piling up in that first 1/3 of the barrel.

I think it was a 300 WM, but anyway it was a Rem. 700, and within the first 200 rounds or so, and with periodic cleaning, accuracy was poor, and those groups that would come together would switch places. And the fellow who had bought it had recorded his chrony numbers, which helped a lot, as velocity had progressively increased.

So I decided to run a patch through the barrel, and I found that the first 6" or so of the barrel was heavily fouled with copper. I asked the guy if he cleaned the barrel since he bought it, and he said he had cleaned it after every shooting session, so obviously barrel break in wasn't performed. I stripped the copper fouling with some Hopes solvent and 0000 steel wool, I ran the steel wool through that section where the copper was piled up, it only took about 5 or 6 passes with the steel wool fitted tight in the bore for the first 6" or so to get it stripped out, but I only made one full pass to the muzzle with the 0000 steel wool.

Then using a bore brush, solvent, and patch, I cleaned the barrel after every shot for the first 20 rounds, focusing mostly on that area where it had piled up, then every 3rd shot for the next 40 rounds or so, then about every 5th shot after that, until we had run about 80 or 90 rounds total through it. I've used this method to break barrels in for a long time. A good friend and builder who knew his stuff about barrels got me doing this, he called it curing the barrel. I guess it works, cause I've never had problems with copper piling up in that first 1/3 of the barrel.

He later told me it was holding a consistent velocity, and printing very well, and in the same place.

I don't know squat about metallurgy of barrels, all I can say, is it seems to work well for me. Maybe someone more knowledgeable can explain how / why this helps stop copper fouling from piling up in that first 6" or 8" of barrel.

GS

 

[Bart B.]

Spitballer, that 93 fps velocity spread was probably caused by the rifle held by different pressures against your shoulder. I've seen an 80 fps spread in average velocity from the same load in one rifle shot from a bench across several people.

Another cause of poor accuracy with reloads is their case heads were flattened out of square against an out of square bolt face. Reloading those cases doesn't square them back. Shooting them again in the same rifle causes additional shot stringing at right angles to the bolt lug axis. It'll adds half MOA or more to what those cases did when new. It gets worse with cases having too much head clearance to the bolt face.