Tips on getting cartridge runout under .002"?

[McCrazy]

Uncle,
I think we're trying to take this stuff way to far. Read the 6.5x47 Lapua brass thread, one guys states he uniforms flash holes on new brass, that's been drilled out, not punched.
I spend alot of time reloading, but there comes a time!

Don't know if you were referring to me or not, but I uniform the flash holes on my 6.5x47 and .308 Lapua brass. Maybe I am wasting my time but it probably takes me less than 10 minutes to do 100 and lasts the lifetime of the brass. Believe it or not that drill bit has hung up on burrs a few times so I don't consider it a waste even if the burr would have had no real effect. Besides, I would rather know flash holes are not a problem rather than hope they aren't.

I spend too much time, money, and effort on this hobby to cop out on something so quick and easy to do. Do as you wish.

 

[ChrisGarrett]

Don't know if you were referring to me or not, but I uniform the flash holes on my 6.5x47 and .308 Lapua brass. Maybe I am wasting my time but it probably takes me less than 10 minutes to do 100 and lasts the lifetime of the brass. Believe it or not that drill bit has hung up on burrs a few times so I don't consider it a waste even if the burr would have had no real effect. Besides, I would rather know flash holes are not a problem rather than hope they aren't.

I spend too much time, money, and effort on this hobby to cop out on something so quick and easy to do. Do as you wish.

I agree with you. I processed 200 Lapua 308 cases from '08/'09ish and did the flash holes. While most were free of burrs, there were many that had some stuff hanging.

It's easy to do and doesn't take much time.

Whether it matters, or not, I still take the limited time and perform the task.

Chris

 

[Unknown]

I uniform flash holes on Lapua cases for 6.5 Grendel because I noticed they weren't consistent. I found the issue when I was poking some tumbling media out of some cases, and my tool would not pass through many flash holes.

I actually haven't tested whether this makes a difference or not, to it may be a waste of time...but it does give me more confidence in the uniformity of my ammo.

My reasoning was that the various sizes of flash holes would give various levels of ignition to the powder because the flash holes would sometimes restrict the amount of flame coming from primer ignition. Hence, various rates of powder burn, and accompanying velocity, or deviation.

 

[milo 2.0]

Don't know if you were referring to me or not, but I uniform the flash holes on my 6.5x47 and .308 Lapua brass. Maybe I am wasting my time but it probably takes me less than 10 minutes to do 100 and lasts the lifetime of the brass. Believe it or not that drill bit has hung up on burrs a few times so I don't consider it a waste even if the burr would have had no real effect. Besides, I would rather know flash holes are not a problem rather than hope they aren't.

I spend too much time, money, and effort on this hobby to cop out on something so quick and easy to do. Do as you wish.

Yes, it was your comment I was referring to, I just stated some people go to extremes. Was I saying you're wrong for doing it, NO, I wasn't. I've just never visually seen a burr folded over the flashole that I thought would impede the primers job. I've went so far as to fire cases with media stuck in the flashole and it didn't effect anything.

There's a ton of myths here in this game, and X-fan's referral to Bruce Baer and his shooting is just one rebuttal, and one I buy into.

I guess if I was shooting a factory Remington gun, or one with needless mods, I won't go there now, I'd be looking for any advantage I could also. But I'm not, if my guns won't group 1/4" with new brass, with little prep, they don't stick around for long.
When one considers powder burn rates, and how even the slowest powders seem to propel a bullet out of your rifle faster than you can blink your eye, I fail to see how a burr, one that you can't see inside your case will interfere with the process.

I hope you don't consider me picking an argument here.

 

[Deadshot2]

Correct set-up for the bushing die is to screw the seater down to where it contacts the bushing, then loosen it 1/16th of a turn. This gives the bushing the space it needs to float.

I overlooked this step with my Forster neck size/shoulder bump die. Didn't take long to figure out that it was an important step. Case runout fell to under .002" with some cases even showing <.0005".

 

[Sargesniper]

I do not think a CDL carrier is permitted to carry any type of firearm in the vehicle at any time. Best to check out the law first or you may run afoul with it. I carried a CDL for more than 38years and know that you cannot carry firearms in the vehicle at any time in my state. You are travelling across state lines and that could be very serious indeed. Good luck. ..... Sargesniper ..... SEMPER FI!

 

[Sniper Uncle]

One problem I see contributing to runout is copper shaving off the bullet jacket, even after chamfering the inside of the case neck.
I can eliminate it entirely if I use an Exacto knife to "chamfer the chamfer", removing the burr that the chamfering tool pushed into the case neck.

I am thinking about making tools specific to bullet/neck diameters that radius instead of chamfer the inside edge of the case neck.
I need to buy some O1 tool steel, which is fairly easy to heat treat properly with a torch and some peanut oil.

Joe

Joe,

I suspect the burr you are referring to (or pieces of the burr/nicks in the bullet base) accounts for many fliers.
Something tells me I read something about what you are suggesting being tried before...IIRC it made the bullet harder to start straight? I can't remember for sure.
Either way I would be interested to hear how your tooling works out.
Cheers,

Yeah Joe, me too! BTW, sounds like we are almost neighbors, being from the Filtha-Effin-Delphia burbs.....

 

[BuzzBoss915]

I used to turn my cartridges 180 degrees as I was seating. That was before I began using bushing dies without an expander button. I also started using Wilson chamber type seating dies and an arbor press. Run out is a thing of the past, I could probably sell my concentricity gauge since I hardly ever bother to check run out any more. A good barrel will compensate for run out, (somewhat) if you continue to use conventional seater dies. BB

 

[scudzuki]

Yeah Joe, me too! BTW, sounds like we are almost neighbors, being from the Filtha-Effin-Delphia burbs.....

I'm in Malvern.
You?

I'll make a couple of tools while I'm at it... by the time I setup to make one, I can make 5 with another 10% time invested.
If it works out, I'll have a few for others to try out.

As for not being able to start the bullet straight in the case as a result of adding a nice blend radius to the case mouth, I have a hard time visualizing why that would happen. We shall see.

Joe

 

[X-fan]

I agree with you. I processed 200 Lapua 308 cases from '08/'09ish and did the flash holes. While most were free of burrs, there were many that had some stuff hanging.

It's easy to do and doesn't take much time.

Whether it matters, or not, I still take the limited time and perform the task.

Chris

I do the same and to be honest I leave no stone unturned in my OCD quest for accuracy.
Hell...I enjoy the process!

As a counter point I though I would share the results of what happened when I loaded my gopher load for my new bolt 223.
52gr Speer / 25.5grs Win 748 (tossed not weighed), Win brass (unprepped and unsorted), BR4s....nothing special..at all. Normally a 3/4 minute load.
I shot 5-5 shot groups none larger that 5/8" at 200 yards!

As I cleaned the brass I was a little surprised to see the flash holes were so badly burred most looked D shape! When I tried to ream out the holes I had troubles getting the reamer to go in without becoming stuck. I finally resorted to power equipment and a case vice. The CHUNKS of brass coming out of the uniformer had to be seen to be believed!
Neck thickness was all over the map!

Hell yes I am blueprinting the brass!
Will it shoot better?
You will be the first to know if it does.

 

[McCrazy]

Yes, it was your comment I was referring to, I just stated some people go to extremes. Was I saying you're wrong for doing it, NO, I wasn't. I've just never visually seen a burr folded over the flashole that I thought would impede the primers job. I've went so far as to fire cases with media stuck in the flashole and it didn't effect anything.

There's a ton of myths here in this game, and X-fan's referral to Bruce Baer and his shooting is just one rebuttal, and one I buy into.

I guess if I was shooting a factory Remington gun, or one with needless mods, I won't go there now, I'd be looking for any advantage I could also. But I'm not, if my guns won't group 1/4" with new brass, with little prep, they don't stick around for long.
When one considers powder burn rates, and how even the slowest powders seem to propel a bullet out of your rifle faster than you can blink your eye, I fail to see how a burr, one that you can't see inside your case will interfere with the process.

I hope you don't consider me picking an argument here.

No perception of picking an argument at all. You are not calling me an idiot (openly anyways) for prepping my brass. Nor am I calling you one for not prepping it all the way. I am not dead set on flash hole deburring being a necessity and would not insist on it to a new reloader. I do it for the peace of mind knowing it won't be an issue even though I doubt I would ever quantify the resultant increase in accuracy/consistency. The thread asked what people do to prep Lapua brass and I just realized this is actually another thread this spilled over into, so I will stop the highjack.

 

[Sniper Uncle]

I'm in Malvern.
You?

I'll make a couple of tools while I'm at it... by the time I setup to make one, I can make 5 with another 10% time invested.
If it works out, I'll have a few for others to try out.

As for not being able to start the bullet straight in the case as a result of adding a nice blend radius to the case mouth, I have a hard time visualizing why that would happen. We shall see.

Joe

I know where that is. I reside in Lansdowne--the Upper Darby area. If it works well, I'd be interested in buying one from you....

 

[scudzuki]

I lived in Drexel Hill when I was separated from my wife a while back.
Work all over DelCo.
I'll keep you posted on the tool.

Joe