Rubber O ring decreases runout? Basic die and theory question. Gauge suggestion?

[Danattherock]

I just got into reloading last year and while in its infancy, precision rifle reloading is of particular interest to me. Shot my first half inch group (0.501"), 7 shots of 223, Friday at 3:30 pm and I am motivated. Just put Krieger 20" in Barnes Precision AR15 with AR gold trigger and Burris Black Diamond 8-32. But loading long distance rounds for 300 Weatherby next, and buying a 260 Rem and Bushnell 3.5-21 for long range events in my area this coming year. Already bought 2000 Lapua Scenar 139's and H4350, ha ha, I'm ready to buy the gun and glass now. Cutting my teeth on the 223, but have longer range ambitions.

I've got Redding Deluxe dies I'm using on a rock chucker, weighing charges on a chargemaster. Weight sorted within a grain Lapua brass. 77 SMK moly. Don't know much about case prep yet, but have the rcbs case prep station and a Forster trimmer. Starting off on the bottom is an understatement. Point being, I might be getting ahead of myself here.

Read the below excerpt about a rubber O ring decreasing runout. I bought a Redding carbide sizer button and will be putting it in soon, should I try the O ring as well? If so, any idea what size or where to buy one? I am referring mainly to the one the article mentions going under the seating stem.

Also, if I'm not neck turning is it still worthwhile? I thought about buying a concentricity gauge, but wasn't sure if I had my cart in front of my horse. In the continuum, I'm not sure what aspects of reloading have the biggest impact on accuracy. Maybe this level of reloading isn't worthwhile if I'm only shooting half inch groups. I'm not certain that me or my equipment are capable of much better at this point. Hence, the horse and cart analogy earlier.

In either case, sounds like limiting runout is a good place to generate some energy. Just not sure what the route to take is. The normal sequence of priorities, to you guys, is a bit mythical to me still. Just learned of head space this past week for example. Seems limiting runout with die setup, parts upgrade, improved technique, etc is a start. Then I need to evaluate said runout with some type of gauge. Any suggestions on which gauge? And lastly, curious how essential neck turning is to this equation.


Thanks for any insights you may share.



Dan




This is what got me thinking....


"If you prefer other brands of sizing dies there are a few tricks that people use to minimize run-out as well. Many reloaders claim that the use of an O-ring at the base of the de-capping assembly lock nut will float the assembly and help self center during sizing. Another trick that has been used is to remove the retaining pin on the shell holder slot on the press ram, and use an O-ring in its place to hold the shell holder in place. This allows the shell holder to self center during sizing as well."


From....

http://www.accurateshooter.com/technical-articles/reloading/how-to-load-more-concentric-ammo/

 

[Lapua40X]

... I bought a Redding carbide sizer and will be putting it in soon, should I try the O ring as well? If so, any idea what size or where to buy one? I am referring mainly to the one the article mentions going under the seating stem.
his is what got me thinking....

I tried the "O" ring theory and, quite frankly, didn't find it any more effective than simply tightening the stem and backing it out about 1/8 turn to allow the bushing to float.
If you need an "O" ring you can find a good assortment at any ACE Hardware or other well stocked hardware store.

 

[SS427]

You try the O ring if you know your dies have a runout problem. If you don't have a way to measure runout, you don't know if your dies have a problem or if the O ring solved it.

 

[joshua43214]

You do have your cart in front of the horse so to speak.

I suggest you back up and take a deep breath and decide what exactly your objective is.

I get a bit stuck when I hear precision shooting and AR15 in the same sentence. No disrespect to the AR, it is a great platform and very fun to shoot, but it is not a "precision" platform.

You should not be thinking about run out, before you are thinking about neck turning. You should not be thinking about sorting brass before thinking about trimming. You should not be thinking about long range precision, and thinking about using anything but damn good dies rather than O-rings. Just bite the bullet and lay down on a Redding S-type competition die set or something equal. Learn to use your press properly, and you will not need to resort to O-rings to float the case. Seriously, are we trying to center the case on the decaping pin!?! Or are we using the expander ball!?! Toss the expander ball, the bushing should always be left a bit loose to float (read and understand the instructions...) I always start a case, pull it back a tad and give it a turn to make sure it is going up straight and clean.
I seriously doubt you will shoot enough 300 WBY to justify the cost of carbide dies, I like carbide dies for pistol cartridges that I crank out by the 100's. Carbide is nice when your cases are dirty, and it does not rust, but if you are not treating each case like it is your only child, just send all the fancy stuff back and buy Lee. Carbide is fashionable right now, and you got sucked into the trend.

Like I said, take a deep breath and decide what you are doing.

Remember, folks are making a boatload of money selling you stuff that you "absolutely must have" to shoot better. People buy expensive stuff and insist it is the best because the company is reputable, it cost a lot, and some guru thought it was good. My experience is that shooters are a gullible group that get sold a lot of junk products and do not stand up and demand better.

There is a story I read (I believe on this forum) about a precision shooter who was talking about bullets and accuracy. He put a tiny scratch on the base of a bullet and shot it into a 5 shot group, and it was a flyer. He could repeat this over and over again. Many thousands of dollars in riffle and equipment meant nothing if there was a barely visible scratch on the base of the bullet.

You have to decide what level of "precision" you want. I like a gun that I could take into the field if I want. All I do is make holes in paper, but I want to make sure I am always prepared for the zombie apocalypse. This means I use a Jewel sporting trigger rather than a target trigger. I use a "sporter" style synthetic stock rather than a wide wooden stock (wood is quieter, and feels nicer). I drill nice tiny one hole groups and really enjoy myself. I pay a great deal of attention to every little detail, but I do not obsess (not yet at least) like benchresters do.

It kinda sounds like we both have the same objectives, try to work inside your objective

-Josh

 

[37Lincoln1]

Get a concentricity gauge.

You will get one sooner or later.

 

[dkhunt14]

If you don't turn cases you will never get perfect runout because the bullet is off-center by variations in neck thickness. AR platforms can be very accurate. My buddy just bought one all tricked out and it really shoots. As far as the carbide expander button by Redding , they are very good. They float on the spindle and center themselves. It will even up neck tension especially on cases that are uneven thickness because they weren't neck turned. I know a lot of guys in 1000 yard BR that are using them in their dies. The ball has minimal contact in the neck because it is a ball. It is carbide so it expands much easier especially if you use a neck bushing that sizes the neck just enough that they all get expanded slightly.

 

['Freak]

With that floating carbide expander button installed in your Redding regular ol’ non-bushing full length size die there is no need for an o-ring since the expander ball already floats on its stem, but you do need to make sure everybody gets locked into position centered and square within their respective threads.

Using the press ram, apply light upwards pressure to the base of the die so squaring/centering the die in the press’s threads, and hold it there while you snug the locking ring about the die. Be rid of any locking rings that screw straight in against the die’s threads and are likely to shove it off centered, and replace them with the cross-bolted style of locking rings. If when setting up the die for a proper shoulder bump the die ends up adjusted out too high for the ram to reach it, use something like a machined/ground so dead flat, flat washer to make up the space between the top of the shell holder and the bottom of the die.

Lock down the de-cap/expander ball stem using pretty much the same method and for the same reasons. I’ll stop at ~ half way when pulling a sized neck back down over the expander ball. While the ball is stuck inside the neck, use ram pressure to lift the de-dap/expander stem upwards so the stem’s threads are topped out in the die’s threads. Holding the upwards tension, snug the stem’s locking nut while all slop is pushed out of the threads and the expander ball is captured centered within the case neck.

 

[Barlow]

I use O rings on a lot of dies. Barlow

 

[TimP]

Dannattherock

Joshua4321 make a lot of good points. Just don't throw out your expander ball when sizing for you AR or any other semi auto rifles you may be loading for. They are just too hard on brass. The floating carbide expander is what you want to use for those rifles with or without bushing dies. The expander is not needed if you are using a bushing die for a bolt action rifle.

OleFreak also makes some good points on die alignment and how to minimize it. I load for 6BR, 243 Win & .308 all with Redding competition dies. With typically run out under .002 with 70% closer to .001. I am going to try OleFreak's method of die set up and see if I get improvement.

This is a great site and it seems I learn something every time I sign on.

 

[Danattherock]

Agreed. My knowledge base doubles each week here lately. A compliment to the wealth of knowledge here, and a reminder to me just how little I know.

So first things first, I need a concentricity gauge. Would prefer not spending $300 on 21st century and such, but it's not out of the question. The wheel on that, and the other similar model, really looks nice.

How about the RCBS or Sinclair gauges? Worthwhile or not. Once I establish a baseline, I can then start tweaking die settings and identifying weaknesses in my reloading routine.

On the assumption that neck turning is required to get an acceptable (0.002") runout, any suggestions on a neck turning tool?

As always, thanks for any suggestions.


Dan

 

[Danattherock]

OleFreak also makes some good points on die alignment and how to minimize it. I load for 6BR, 243 Win & .308 all with Redding competition dies. With typically run out under .002 with 70% closer to .001. I am going to try OleFreak's method of die set up..

Same here man. Read his post several times. Exactly the kind of insight I was hoping for. Will take some coffee to garage soon and look over my die set up with his suggestions in mind.



Dan

 

[Danattherock]

I get a bit stuck when I hear precision shooting and AR15 in the same sentence. No disrespect to the AR, it is a great platform and very fun to shoot, but it is not a "precision" platform.

You should not be thinking about run out, before you are thinking about neck turning. You should not be thinking about sorting brass before thinking about trimming.

Just bite the bullet and lay down on a Redding S-type competition die set or something equal.

I always start a case, pull it back a tad and give it a turn to make sure it is going up straight and clean.


I seriously doubt you will shoot enough 300 WBY to justify the cost of carbide dies...


-Josh

Thanks man. I'm just reloading for 223 now, using it as a "teeth cutting" as I said. I have realistic goals for this gun. If it never does better than half inch I won't be upset. My main goal is leaning how to reload precision rounds, just happens to be for AR 15 at this moment.


I'm weight sorting Lapua brass, and trimming them all on Forster. Flash holes deburred, champher/debur mouths, brush necks, brushing primer pockets, etc on RCBS case prep center. Seems neck turning is a logical next step, or so I assume.

Regarding dies, is the Redding Deluxe die set not good enough? Should I buy something else? Was under the impression they were a good die set, but only recently heard about the bushing dies, not sure what I would gain by switching.

Read something about turning case while bullet seating. Is that what you are referring to above? If so, how does it help? Among many other things, that is a new one for me.

Regarding carbide, I just bought a carbide sizer button for 223, to go in my redding deluxe seating die. Got RCBS competition micrometer seating die for 300 Wby. Haven't bought 260 dies yet.




Dan

 

[Danattherock]

I tried the "O" ring theory and, quite frankly, didn't find it any more effective than simply tightening the stem and backing it out about 1/8 turn to allow the bushing to float.

Thanks man. Mine is locked down. Backing it out and allowing it to float seems very logical. Thanks for the suggestion.



Dan

 

[smoooth]

"Read something about turning case while bullet seating. Is that what you are referring to above? If so, how does it help? Among many other things, that is a new one for me. "

Many years ago I had read about turning the case while seating the bullet (VHA or FFG magazines), and it seems to help. The logic behind the process is that by seating a little, turn, seat a little more, turn, fully seat the bullet, helps to eliminate run-out by "centering" the bullet in the stem.

I don't own a concentricity gauge, so I cannot absolutely say if the process has merit, but I feel and find that it has worked for me, if only as a confidence builder. I'd like to hear of others experiences with this process.

Also, hand dies/ chamber type seaters, like Wilson, etc., quite often produce a better, more concentric round (no case turning during bullet seating). You may want to look into these as they are considerably less money than Redding Competition die sets.

There were many good points made in the posts above. Do your research, don't leap before you look. Joshua43214 made many excellent points in his post, re-read it a few times, very well written and the advice is spot on. I might just print that off and hang it on my bench.

Good shooting!

 

[MrMajestic]

The Neco measures runout and so much more!
http://www.neconos.com/details.htm

 

[TimP]

How about the RCBS or Sinclair gauges? Worthwhile or not. Once I establish a baseline, I can then start tweaking die settings and identifying weaknesses in my reloading routine.

The Sinclair concentricity gauge works very well and is the one I have used for years. Although I have had my eye on the Accuracy One wheel driven one for awhile but its not cheap.

On the assumption that neck turning is required to get an acceptable (0.002") runout, any suggestions on a neck turning tool?

There are a lot of good neck turners out there. Budget minded the K & M is hard to beat. PMA Tool, Sinclair's NT 4000 and the Pumpkin are a few that I would consider. All depends how much you want to spend.

 

[bigedp51]

Below is a RCBS full length .223/5.56 die I use for my AR15 rifles, it has a Lee lock ring with its rubber O-ring which I tighten finger tight. This allows the die to float slightly and self center in the press.

The RCBS die also has the Forster decapping assembly and expander button mounted high on the spindle. On the down stroke of the ram the neck of the case is still inside the neck of the die when the expander button enters the neck of the case. The assembly has a thick rubber washer below the lock nut and allows the spindle to float and self center in the die. This produces "LESS" runout when resizing your cases and I can get .001 or less runout "IF" your cases do not have excessive neck thickness variations.

On this setup I also use competition shell holders to get the proper shoulder bump.

I have a A2 HBAR and a standard carbine these rifles have a chamber .002 larger in diameter and longer headspace settings than standard SAMMI chambers. And you have more "wiggle" room for the bullet to self align with the bore. Meaning the body of the case never touches the over sized chamber walls with a full length resized case. The case will be supported in the base by the bolt face and by the bullet in the throat of the chamber. The military conceders anything under .003 runout as match grade ammunition and the "wiggle room" in the chamber reduces bore alignment problems from non concentric ammunition.

Bottom line with your AR15 rifle, get a neck thickness gauge and a runout gauge and you will be able to produce ammo with very little runout. And by using both these gauges during the reloading process you can find out at what stage your runout problems starts and fix the problem.

 

[BCoates]

I use rubber o rings under all of my sizing dies for a couple reasons. 1.) It helps the die self center, and 2.) It allows me to make slight adjustments to the headspace without having to loosen the lock ring on the die. This really helps as brass hardens and gets tougher to size. I even use an o ring under the die with my Lee collet neck die.

 

[Danattherock]

Really appreciate all the insights guys. The pictures are quite helpful as well, thanks Ed!

The Sinclair gauge is out of stock. Sounds like the next toy I 'need' is a concentricity gauge. Anyone able to compare the RCBS and Sinclair concentricity gauges? And perhaps how those two compare to the Accuracy One gauge with the wheel. Any suggestions on an easy to use neck turner for fairly low volume use? Thanks for any additional thoughts.

Tumbled 30 Lapua 223 cases today and will use all 30 to replicate my 0.501" seven shot group load from Friday, 23.8 Varget and 77 SMK moly. Shooting Saturday hoping to replicate my last effort. Secretly hoping it wasn't a fluke. I figure six 5 shot groups will tell the tale. Then will try to uniform the brass more and play with bullet seating depths in 0.010" increments. I'm near max COAL for my mags, but can go down.

Today I used case prep station to brush necks, primer pockets, mild champher/deburr, etc. I then measured about half the cases and saw about a 0.004" variance in OAL. Using Hornady headspace gauge I noticed resized cases varied by about 0.002". Is this acceptable?


Dan

 

[bigedp51]

I have the RCBS case mastering gauge pictured below and would not recommend it to anyone for measuring runout. In the background is the Hornady concentricity gauge for "bending" cheap 5.56 blasting ammo with extreme case wall variations in my carbine.

The problem with this unit is you have to mod the V-blocks and lock them down to keep them from moving up and down. Then after you start to get stable readings not effected by finger pressure the paint wears off the V-blocks and the cases will not spin without greasing the V-blocks.

Get the Sinclair concentricity gauge, the cases spin on solidly mounted ball bearings and it is a much better unit.

Between the runout gauge and a case neck thickness gauge you will be able to play detective and find your runout problem areas.

You can cut down on the varying headspace length by pausing at the top of the ram stroke for a few seconds and reduce the brass spring back. I rotated the case 180 and resize and pause again at the top of the ram stroke a second time and let the brass know who is the boss. And remember the amount and type of case lube, the dwell time at the top of the ram stroke plus the hardness of the brass effects the spring back of the case and its shoulder to base measurement.

Note, I prefer using Lake City brass because of its hardness in the base and higher quality standards. Meaning I have brass OCD and would never use Lapua brass in rifles that throw perfectly good brass away and makes you go looking for it. :'(