The Creedmoor Forum

I chatted with a fellow shooter and range member yesterday while I was on RSO duty. I've known him for years, and served RSO duty with him many times. This guy is very intelligent, a commercial international pilot by trade, and a serious competitive shooter.

I think because he knows I shoot with a brake, he dove into the risks of brain damage caused by the repeated concussive blast from muzzle brakes. He no longer will use a brake, nor flash hider; it's either no muzzle device or a suppressor. It didn't seem to matter when I explained that the shooter, myself in this case, doesn't feel the concussive blast, it's the folks on the sides, or standing behind the shooter that feel the blast, I say this because I've been the guy standing behind braked shooters.

In any event, this fellow shooter urged me to reconsider using a brake, I have no reason to believe his advice is anything but genuine, and given because he cares about me as friend.

I did an internet search on the matter and found several articles that appear to confirm what my friend told me. That said, I don't shoot 100s or 1000s of rounds on a regular basis, like military members may be required to do. Anyway, below is a link to one person's viewpoint on this which appears in-sync with what my friend stated.

Brain Drain

What do you guys think?

Life has twists that keep me from shooting, but, I'm persistent darn it 

I shot the brass I'd posted about previously; necks outside and inside turned to 12.5 thou wall thickness. These necks look pretty clean which isn't too far off from how the last batch of outside turned necks looked when they were first fired; they were turned to the same wall thickness, 12.5 thou-ish.

The reason I'm posting this is I'm measuring the now-retired, 14x fired brass necks, they are averaging 11.7 to 12.0 or so neck wall thickness.

Do neck walls shrink in thickness as they're shot?

We are taking off at the end of the month for some campground time  .

I've taken care of the security/deterrence basics like hitch, tire and wheel, propane tank and battery locks.

I imagine folks here who travel around with the kind of personal valuables I have in mind, have given some thought to ensuring these items don't change hands on their own.

Just looking for ideas 

I've always found virgin Lapua 6.5 Creedmoor brass to be kind of wild when seating bullets, with or without lube. The pull stroke on the arbor press always feels choppy, and the force required is all over the place.

I primed and charged these OD/ID turned and Neolubed cases today. Frankly, I was expecting a tighter set of curves but, it is what it is. It's much tighter than I've experienced with unturned virgin brass, so there's that.

Here's a picture, warts and all:



Filtered to 1 Standard Deviation of Work required to seat, 21 pieces survive, 13 don't:



We'll see how it goes tomorrow, range time 

I decided to jump in the deep end of the pool today, just get it over and done with, for better or for worse  .

Here's a picture of my super-premium, ultra-precision brass guide rod:



Ok, I exaggerated a bit; it's a 1/4" diameter piece of wood dowel from Home Depot. The picture shows where it's inserted into the brass holder.

Here's where it emerges:



The tool I showed in a earlier post is then used to seat and lock the brass into the holder. It's probably overkill but, I used my Wheeler torque wrench set to 10 inch-lbs to lock the brass in; that amount of torque is more than ample to prevent the brass from spinning in the holder without distorting the piece.



Alright, lets get to turnin', but first, let's review some important metrology. I apologize in advance for the lathe metrology console in the picture, it's as messy as my mind, but the key numbers are there.



X-Axis shows the depth of cut into the neck wall.

Z-Axis cutter axial position shows how far into the neck bore we are.

Spindle RPM is self-evident.

Cut quality (my terminology) is a ratio of spindle RPM to how fast we feed the cutter into the work.

These are what I keep an eye on so I'm not just wondering around like an idiot.

Here's a turn video, yes it takes time but, make it work, then make it fast. Check out the slow leftward turn on the 3 face screws, I'll bet that's the 612 or so spindle turn blended with the 60 frame per second video frame rate, fascinating  .

Inside Turn

Results are really what matters; every one of these 34 pieces indicates 12.5 thou neck wall thickness. I have not verified inside runout but I will, just for completeness. As for my pet peeve, surface finish, the Teslong borescope doesn't lie. What I show in this video is an inside turn, followed by a Teslong view of the outside turn. Everything looks different under magnification, while there's no incentive to look at outside neck turns under magnification, because we can see them; there's no other way to look at inside necks turns, because we can't see them.

Surface Finish In and Out

Finally, here's a quick video showing the unavoidable element of inside neck turning; the mouth may show scars. I guess that means no 100% cleanup for me  , lol.

Crapadoodeldoo

Next steps: Loading, and Shooting!





 

Got to the point of no return today, tomorrow will be inside turning for real 

I changed the single-use neck holder preparation; the center bore was omitted, only the 3 bolt holes are drilled. Why I thought I could drill a hole on one machine, then bore the hole to final I.D. on another machine is beyond me , I know better.

Here's a picture of the permanent holder with the single-use neck holder mounted in the lathe chuck, ready to drill and bore. The neck holder is about 0.3195" thick.



First step is using a 1/8" spotting drill to mark the center of the chucked assembly. The bit is allowed to wonder; it always wonders to dead center  .





1/4" hole drilled, ready for boring.



Here's a video of the hole being drilled, have to tall ya though; it's boring 

0.25: Hole Drilling

The last step is to bore the hole to neck O.D. which is 0.2900". I did not video this part because, for me at least, it requires undivided attention. The idea is to keep checking work with gage pins, then make the final pass to size. Here's the finished piece with a .290- gage, and an outside turned neck. The fit is superb which is the only adjective I can think of, I'm sure there's a technical term for the feel of a good slip-fit.





Here's a snapshot of the finished holder with a dial test indicator made live on the inside diameter, and set to zero for reference, this will come in handy later.



Here's a video which aims to quantify the axial and radial excellence achievable by making a holding part on the lathe. Radial runout is in the low 10 thousands of an inch, axial runout likewise as seen when the indicator tip traverses the length of the bore. At the very end of the video the lathe spindle is placed in neutral and motor turned on, that's the noise floor of the machine. Anyway, I think this one's worth watching for those interested in the subject, music courtesy Blake Shelton  .

https://drive.google.com/file/d/1LOqhXOXmzMVDqI8OyWNPqplcpPW6Q49C/view?usp=drive_link

Here's a picture showing the brass ready to inside neck turn. It takes just seconds to insert the piece into the holder and secure it for turning.



Finally, recall the picture showing the dial test indicator (DTI) zeroed on the holder I.D., here's one showing the same DTI touching the inside of the outside-turned neck. I'd estimated taking 0.0009" off the wall, this picture indicates it's 0.0008"  . The wall thickness here is 0.0133", always nice when the math adds up 

As postulated in my last post concerning neck turning, holding brass by it's neck is the most sure way to turn the neck since the neck is obviously concentric with itself, and less obviously, it's eccentric with it's body.

Holding the neck by itself for outside turning lends itself well to a mandrel approach, as previously beaten to death by myself, and perhaps others.

Holding the neck by itself for inside turning is ripe for conjecture, frustration, abuse and crazy ideas, I'm not sure where this one lands, but it's in the groove  .

The brass holder shown below is not unlike a rifle chamber; the brass is inserted into the chamber, the bolt is closed, a boring bar makes it's way from the muzzle end and turns the neck inside to tolerance. The key difference is the chamber is optimized to hold the neck's outside with a tight fit.

Since the neck is going to have it's inside bore turned, and tolerances are in the ten thousands of an inch, radial and axial runout must be minimized. The most practical way to do that using a lathe is to turn the neck holder's bore in-place.

Enough talk, show me the money!



This is a parts and pieces layout showing the permanent holder, the single-use neck holder, fasteners, and an item of levity  .

The next picture illustrates how the holder plans on keeping the brass from spinning while while it's teeth are being drilled on, from a proctological perspective  .



The next picture shows how the brass is oriented in the permanent holder; the single-use neck holder has not been prepared for use, it awaits it's fate.



This last picture shows the neck turning assembly ready to be placed in the lathe chuck and bored to the outside diameter of the necks. Once that's done, it's a matter of feeding a piece in from the back end of the lathe spindle thru-hole, into the holder, lock the bolt down to secure the piece, then run the machine to turn the inside of the neck.

The trick of course, is to turn the neck to diameter tolerance, and leave a surface finish which is no worse than it's congenital, extruded surface finish. BTW, single-use as applied to the neck holder means single-session use, not single piece of brass use; the only rule is once the brass holder is removed from the lathe chuck, the neck holder is used up and should be recycled. The neck holders may be made from just about any suitable material; brass, aluminum (as shown), plastic, etc, as long as it's amenable to machining, and preferably as soft, or softer than brass.



Next up is a where the rubber meets the road, for better or worse.

In my effort to illuminate a subject that's probably had more search lights focused on it than a bombing run over Europe in WWII, I've discovered a few things I wanted to share with those interested in the subject.

The problem with turning necks, outside, inside or both, is necks are not coaxial with the body of the brass, at least not for Lapua 6.5 Creedmoor brass, IMO. The result is any turning operation which depends on holding the brass by the body will have to deal with the shortage of coaxiality, traditional outside neck turners deal with this by spinning the brass on it's neck axis.

I'd posted before about turning the outside of the neck using a lathe and a mandrel, and it's been discussed on AS as well as other relevant sites, what I'm sharing here is a refinement of this approach.

Two problems: The mandrel, and the cutter.

Using a gage pin as a mandrel, as I did, exhibits both radial and axial runout; my workaround addressed only radial runout. Axial runout is the same kiss-of-death that afflicts brass necks and bodies. The solution, which was pointed out to me by a skilled machinist long ago on AS, and which I foolishly ignored, is to turn the mandrel on the lathe; both radial and axial mandrel runout solved!

Here's a link to a short video (02:02) showing the turned mandrel as indicated with a precision drop indicator. I start by rotating the lathe spindle by hand, the radial runout is for practical purposes zero. Next I turned the lathe on, in neutral, and there's "runout"  , nope, that's just vibratory noise caused by the motor. The spindle is engaged, and we still have very low radial runout at the indication point. It's worthwhile noting the 120 rpm spindle flicker is keeping perfect time with Mark Knopfler's guitar licks  . Then I address axial runout by moving the carriage in and out within the bounds of a neck's length, again, very low axial runout.

Mandrel 02:02 minutes

OK then, now for the cutter. I have yet to find any tool that cuts brass necks better than a conventional cutter like those offered by 21st Century, PMA, K&M et al; they just plain work. So, if ya can't beat 'em, join 'em I say. I made a holder for a 21st Century 30° shoulder angle cutter which adapts it for use in a lathe tool post, here's a picture of the assembly.



Because the tool is designed for right-hand cutting, and it's seriously directional, it's deployed upside down in the lathe, and the spindle runs backwards, not a big deal, and well worth the excellent cuts.

Alright, now for the fun part  , let's turn some necks!

I made seven videos of differing time lengths, with different music to suit individual tastes, lol. I crossed international borders for our good neighbors up north, particularly those in, ahem, Saskatoon, with two selections from Rush .

Outside Turning Duran Duran (01:43)

Outside Turning Rush Limelight (04:19)

Otside Turning Rush Camera Eye (8:18)

Outside Turning Earth Wind Fire Fantasy (4:41)

Outside Turning 3 Doors Down (03-59)

Outside Turning Great White (7:07)

Outside Turning Sting (3:39)

These brass pieces ended up with neck walls at 13.3 thou, they started at 14 thou, that leaves me with another 7 thou for the inside. Suffice it to say at this time, I've developed a neck holder which is designed to confer the same radial and axial runout tolerances to inside neck turning as this simple turned mandrel confers to outside turning, that's for part 2.

Additionally, the outside turning procedure I shared here has much room for improvement, particularly with respect to time per piece but, as my old computer science teacher told me, over and over again, make it work, then make it work fast  .

After reading a lot about the subject online, I'm left feeling that the best we can hope for is a FL sizing die, particularly a FL bushing die, doesn't make concentricity worse.

If a FL sizing die can make concentricity worse, why can't a FL sizing die make concentricity better?

Let's say a die used on a perfectly concentric piece of brass, zero runout, results in the piece having 0.001" runout, why can't some other die reverse that?

I'm sure this is really simple and I just can't see it 

I'd given up on inside neck turning for so many reasons I've lost track but, here we go again  .

I got to thinking about how good a job conventional neck turners do with respect to surface finish; bright, shiny and almost devoid of evidence they've been turned. I casted a wide net to see what common lathe turning tools, specifically inside boring tools, might be similar in geometry.

The picture below illustrates a good match.



Please ignore the glitter on the face of the O-ring cutter, it's a cellphone camera artifact. The important dimension, IMO, is the width of the cutting edge. The two are quite similar, both are as far from the typical single-point cutting tools used for lathe turning as possible. The 21st Century cutter is proven, it will work as expected. The O-ring cutting tool loses all advantage because it's presented parallel to the work versus perpendicular, think tool deflection, this is where feed and speed come into play.

The result on virgin Lapua 6.5 Creedmoor brass is quite good, the seating feel is excellent.

I'm working on having both inside and outside cutters applied in one pass. While that may be an elegant solution to zero net force, and net deflection issues, it has it's own set of issues, geometry management among them.

As the lead dead horse beater here, I feel the need to proceed 😁. 

I read this article recently and, as a reloader, found it interesting, and worth a share.

Some of the equipment and processes are familiar to everyone here, some may be novel, some even disputed.

Credit to Shooting Times Magazine. Sorry I could not for the life of me figure out how to get the scanner to make one document instead of one per page  .

Worth a share, I learned a few things...

https://mdttac.com/watch/how-to-clean-your-rifle-like-a-pro/?utm_source=klaviyo&utm_medium=email&utm_campaign=Expert%20Tips%20for%20Proper%20Rifle%20Cleaning&_kx=OQbuMR56TzYgPUlMwsO30tVdDcf5wxn12hsDy3J2g1E%3D.M2GHgi

I took the piece of brass from my last live seating which showed the greatest amount of donut interference fit, piece #8, and examined it in some detail, shared below.

First thing I did was bore scope the piece; just like the last time I did this, I can't see a donut. Below is a short video, in all videos the 4 o'clock position is the neck.

Brass#8 Fired Borescope

Next, I chucked the piece in lathe, minimized runout (as indicated off the OD), and positioned a boring bar cutter so it barely kissed the inside of the neck about half way in. I ran the cutter inwards past the donut area, the video below shows some of the donut area was trimmed off. Indicating runout off the OD, then turning the ID is not a precise operation, I think that explains why the turn is one-sided.

Donut removal try #1

I went ahead and Neolubed the case, and seated a bullet, more on that later.

I pulled the bullet and ran it back through the lathe taking a bit more off, it took off a bit more than I'd hoped for but it is what it is.

Donut removal try #2

I pulled together into one chart the seating curves for all three seatings as shown below:



I think if a person wanted a donut detector, 0.0005" increment pins would be required, it really doesn't take a fat-boy donut for it to be felt, or seen, whether it matters on the target is anyone's guess.

I fashioned a target carrier which seemed worth sharing:

2" drain pipe secured to the cart with ratchet-style Oatey straps. All available at any decent hardware store.

As our sunlight wains, I've noticed it's more difficult to see my target dots. I realized yesterday that my safety glasses are tinted a smoke color, without them, the target dots looked just fine.

Anyway, I need some new ones that are not tinted. Before ordering something unknown from Amazon, figured I'd ask if you guys have suggestions for good quality, clear safety glasses? Not looking to save money here, my eyes are worth way more to me than any savings  .

Thanks

I noticed something different with several brass pieces in a batch of 32 Lapua 6.5 Creedmoor cases, neck OD turned to 12.5 thou wall thickness. The puzzle came to light on the 13th reloading of the brass, these are well-worn. A few pieces seated normally to start with, then I could feel the strokes harden up towards the end of the stroke. My Force Gage showed the hiccups very clearly as we'll see in the charts below. 

Below is a chart showing the last unremarkable seating force session, #12 on 8/30/2023, this is what I'm accustomed to seeing.



The next chart shows seating #13 on 9/20/2023, I've marked the spot in inches where I felt, and observed the resistance; each x-axis distance tick represents 10 µm, that's 0.291" measured from the case mouth.



This chart shows seating #14 on 10/12/2023, notice the resistance increasing in magnitude.



Now for seating #15 on 10/18/2023, there's a fight brewing.



Now I'm getting concerned so, in desperation, I pin tumbled the batch figuring that maybe carbon buildup was the culprit. The necks looked tumble-clean, and I doubled down on Neolube. Here's the result for seating #16 on 11/13/2023:



My optimistic view is that while pin tumbling didn't fix anything, it held the line; nothing seems worse.

Let me say this for completeness: I cannot prove the pieces of brass demonstrating this resistance are the same every session since I have not permanently marked the case heads. I know they are the same pieces purely by inference, and experience with the equipment.

Here's where 0.291" from the mouth is on a finished piece:



At this point, I think these pieces of brass have been spending lunch hour at Dunkin Donuts  , what do you guys think?

Thanks.

I recently familiarized myself FreeCAD and figured I'd try to print my own range targets. Crunching the numbers, I can make a 6-target page, with adhesive fluorescent red dots for about 4 cents each, and just print when needed instead of having to find another place to keep my "stuff"  .

The one shown below has a 1" grid with 3", 2" and 1" circles, the red dots would be centered on the 1" circles. It's printed on legal size paper, 8.5" tall by 14" wide.

Since my goal, ahem, is to stay within 1-MOA at 300 yards, I figure this is a good start. Questions though: You guys think 1" target dots are too small at 300 yards? I'm used to 1.5" dots now. And, are there too many targets on the paper for that distance? Thanks.

Spotted this on AS: https://www.garmin.com/en-US/p/771164

The riflescope in question linked here: https://sightron.com/products/siii-long-range-10-50x60?variant=39278115258526

Considering the side focus knob, I've always been able dial an ultra-crisp image at 200 yards or less, now at 300 yards, the dial hits the end stop, which I assume is the infinity position, where the target is clear, but not crisp. Magnification is set at 25x or so. The side focus knob has no distance hash marks like I've seen on other scopes.

I guess my question is, what distance is considered infinity? 

I'm considering buying Eric Cortina's NextGen Tuner Brake, link: https://www.shootsmallgroups.com/product/next-gen-ec-tuner-brake/

Since I know close to zero about tuners, figured I'd ask a few questions.

1) Is there a "better" tuner-brake I should consider? I'm not looking to save money nor waste money, I just don't want to buy something that is wasteful of time and components.

2) Is a tuner effective at 300 yards, that's the range maximum for now?. When I say effective, I'm thinking tighter, more consistent group sizes, making the rifle the best it can be if I do my part.

Any other thoughts and suggestions welcomed. Thanks.