RCBS Case master. Now what? (new video)

[snowpro440]

Re: RCBS Case master. Now what?

I made my own high tech bullet straightener. First I mark the apex of the runout and then put in the hole and give it a bit of pressure. I repeat until I get it within .001 to .003.

How much runout before straightening?

I'd like to see a report on any accuracy improvement you find between straightened and un-straightened ones. Please update if you happen to do any such testing.

If the gun is not a tight neck with a benchrest chamber you probably won't see any differences. But if it is a tightneck chamber then the case would be more concentric to the bore but the bullet could be out of the ordinary too, so I don't see that it would matter because when fired the case will form to the chamber then the resizing die conforms it all over again. Tinkering can be fun.

 

[Grimstod]

Re: RCBS Case master. Now what?

I to would like to know how much it helped. I shoot jamed so in theory this will help me a lot.

 

[Joe R]

Re: RCBS Case master. Now what?

brians356 said:
How much runout before straightening?

I'd like to see a report on any accuracy improvement you find between straightened and un-straightened ones. Please update if you happen to do any such testing.

Obviously I can't give you a report on how the bullet would have behaved had I not straightened it. I do know that most of things we do to cases and case necks is to reduce runout. Yet about a third of my reloads end up having runout of .004 to .006. I have no idea why. With my rudimentary method I can reduce runout on most of that third to .001 to .002. Occasionally a stubborn one I let it go with .003. From what I've read most people consider less than .004 runout a success.

I am always looking for ways to improve my methodology, just today I received a Lee collet die (LCD) I've read that many people have great success with those, so next time I'll try a new method. Theoretically the collet method makes more sense than the bushings, because it seems to me that the mandrel supports the neck while forcing the neck and shoulder to align it self to the mandrel. Obviously getting the LCD properly lined up in the press is critical, but shouldn't be any more difficult than regular dies. But as Yogi Berra once said "In theory there is no difference between theory and practice. In practice there is,"

 

[KiowaDriver85]

Re: RCBS Case master. Now what?

Hadn't seen the RCBS tool before, I had made up my mind to buy 21st Century's Gauge, looks like it is more capable than either the RCBS or Sinclair and has a better gauge. I don't mind spending the money for quality. Thoughts?

 

[Joe R]

Re: RCBS Case master. Now what?

KiowaDriver85 said:
Hadn't seen the RCBS tool before, I had made up my mind to buy 21st Century's Gauge, looks like it is more capable than either the RCBS or Sinclair and has a better gauge. I don't mind spending the money for quality. Thoughts?

After some consideration last night I decided to buy this https://www.youtube.com/watch?v=h7PAeygRZAA . There may be some issues with it, but I think I'll try it out as a bullet straightener. It may be an improvement over my hole in a piece of wood.

Joe

 

[Brians356]

Re: RCBS Case master. Now what?

brians356 said:
How much runout before straightening?

I'd like to see a report on any accuracy improvement you find between straightened and un-straightened ones. Please update if you happen to do any such testing.

Obviously I can't give you a report on how the bullet would have behaved had I not straightened it. I do know that most of things we do to cases and case necks is to reduce runout. Yet about a third of my reloads end up having runout of .004 to .006. I have no idea why. With my rudimentary method I can reduce runout on most of that third to .001 to .002. Occasionally a stubborn one I let it go with .003. From what I've read most people consider less than .004 runout a success.

Fair enough. I wasn't being flippant, here's why I asked:

Reducing bullet runout is self-evidently desirable. But by bending the case neck to achieve that, you could well be introducing even worse effects. Uneven stress in the neck walls and uneven grip on the bullet come to mind. It's possible no such adverse effects are introduced, but without testing, who knows?

When I said "before / after" that was a poor description. How about "with / without correction"? You could sort rounds for bullet runout, then mark but set aside half of the ones needing correction, and correct the other half. If you had 30 rounds total, you could shoot five 3-shot groups from each half. It's not an exhaustive test, but if you saw no obvious difference in accuracy, or even worse accuracy from the "corrected" batch, then you might decide it's not worth the effort.

 

[Joe R]

Re: RCBS Case master. Now what?

brians356 said:
Reducing bullet runout is self-evidently desirable. But by bending the case neck to achieve that, you could well be introducing even worse effects.

Brian,
I'm not bending the neck, I'm just pivoting the bullet ever so slightly as it seated in the neck. I agree that bending the neck would result in a far more deleterious outcome. I'm just using the case body length as a lever to make the adjustment, If I were bending the neck in relation to the case body the concentricity would measure far worse. If my picture seemed to show that I apologize, I didn't mean to mislead anyone.

brians356 said:
You could sort rounds for bullet runout, then mark but set aside half of the ones needing correction, and correct the other half. If you had 30 rounds total, you could shoot five 3-shot groups from each half. It's not an exhaustive test, but if you saw no obvious difference in accuracy, or even worse accuracy from the "corrected" batch, then you might decide it's not worth the effort.

That is a good idea, I'm glad you thought of it. Next time I reload another batch I will do exactly that.

Joe

 

[Brians356]

Re: RCBS Case master. Now what?

brians356 said:
Reducing bullet runout is self-evidently desirable. But by bending the case neck to achieve that, you could well be introducing even worse effects.

Brian,
I'm not bending the neck, I'm just pivoting the bullet ever so slightly as it seated in the neck. I agree that bending the neck would result in a far more deleterious outcome. I'm just using the case body length as a lever to make the adjustment, If I were bending the neck in relation to the case body the concentricity would measure far worse. If my picture seemed to show that I apologize, I didn't mean to mislead anyone.

Wait, you are not just rotating the bullet about its intended spin axis, are you? That hole in the bench grips the bullet enough for you to spin it in the neck? Must not use much neck tension.

Or are you yawing the bullet by pushing sideways on the lower part of the case?

 

[bigedp51]

Re: RCBS Case master. Now what?

Grimstod

Do you have a neck thickness gauge?

I use the Redding neck thickness gauge and full length resize my cases, and there is a direct relation between uneven case neck thickness and runout. If you are using a bushing neck sizing die all your doing is pushing any irregularities in case neck thickness to the inside of the neck.


Tools for Measuring Case Necks
Consistent Necks Enhance Accuracy
http://www.6mmbr.com/casenecktools.html

I also use the Hornady Concentricity Gauge for "tweaking" brass with uneven case wall thickness, meaning cheaper low quality .223/5.56 "blasting ammo" cases and I have seen an improvement in accuracy.

Bottom line a quick twist on my Redding neck thickness gauge tells me a good deal on the quality and uniformity of the case.

Below when the case is fired it will expand more on the thin side of the case and force the case out of alignment with the bore. Then you will end up going nuts trying to reduce case runout with warped egg shaped cases with unequal case wall thickness.

 

[bsumoba]

Re: RCBS Case master. Now what?

i have a hornady concentricity gauge and it measures relative to the rim of the case. i seems that the other units measure off the body of the brass.

is there any difference? I would think that you want the bullet seated concentric to the base of the cartridge (assuming the rim is not badly chewed up or bent out of shape), which ultimately is against the bolt.

as a side note, i started measuring concentricity, and definitely noticed an increase in accuracy, enough that all my rounds go through the QC check now.

 

[bigedp51]

Re: RCBS Case master. Now what?

brians356 said:
Reducing bullet runout is self-evidently desirable. But by bending the case neck to achieve that, you could well be introducing even worse effects.

Brian,
I'm not bending the neck, I'm just pivoting the bullet ever so slightly as it seated in the neck. I agree that bending the neck would result in a far more deleterious outcome. I'm just using the case body length as a lever to make the adjustment, If I were bending the neck in relation to the case body the concentricity would measure far worse. If my picture seemed to show that I apologize, I didn't mean to mislead anyone.

Wait, you are not just rotating the bullet about its intended spin axis, are you? That hole in the bench grips the bullet enough for you to spin it in the neck? Must not use much neck tension.

Or are you yawing the bullet by pushing sideways on the lower part of the case?

The hole in his reloading bench and his method does exactly the same thing as the Hornady Concentricity Gauge does. In fact with some type cases the Hornady gauge does not exert enough force to "tweek" the case. This is especially true with poorly made cases with unequal case wall thickness fired in semi-auto rifles with larger diameter chambers. I use this same method with stubborn 30-06 cases fired in my M1 Garand "without" any ill effects. With quality made cases with equal case wall and neck thickness the majority of runout is caused by improper resizing and seating problems.

And bending and tweaking a case isn't a No-No.

H&H Concentricity Gauge
http://www.accurateshooter.com/gear-reviews/hh-concentricity-gauge-and-bullet-straightener/

 

[Joe R]

Re: RCBS Case master. Now what?

brians356 said:
Wait, you are not just rotating the bullet about its intended spin axis, are you?

You're misunderstanding me or maybe I'm not explaining it well. I put a little pressure to pivot the bullet along its length, so that it is straighter. One can also do it by simply grabbing the loaded round in your hand and using your thumb to nudge it the direction you want. See picture. The hole in the wood exposes the whole case and gives me more leverage for finer adjustments. The hand doesn't work very well for me.

Joe

 

[Brians356]

Re: RCBS Case master. Now what?

brians356 said:
Wait, you are not just rotating the bullet about its intended spin axis, are you?

You're misunderstanding me or maybe I'm not explaining it well. I put a little pressure to pivot the bullet along its length, so that it is straighter. One can also do it by simply grabbing the loaded round in your hand and using your thumb to nudge it the direction you want. See picture. The hole in the wood exposes the whole case and gives me more leverage for finer adjustments. The hand doesn't work very well for me.

Joe

No, I understood you Joe, but your choice of words left 1% of doubt, which is why I asked for a clarification.

You cannot change the direction the bullet points relative to the long axis of the case without bending the case somewhere. [Edit: I suppose if the bullet was barely seated into the neck you might.]

But in any event, if you chaps find this process is not only not detrimental, but is actually beneficial, that's good enough for me.

(The day I stop learning is the day they pat my face with a shovel.)

 

[bigedp51]

Re: RCBS Case master. Now what?

In the instructions for the Hornady Concentricity Gauge it states that .003 or less runout is considered military "match grade" ammunition. So I'm assuming this is for competition use with aperture sights with M14 and M16 military rifles. When looking into runout and how it affected accuracy the military did testing with rifles mounted in ridged fixtures to test runout and accuracy. When the ammunition runout was reduced to below .001 it only made the group size .030 to .040 smaller.

Right now with a set of Forster full length dies with the high mounted expander button and Lake City brass that has been neck turned, I can keep the cases to under .001 runout measured on the case neck after sizing. And this is where the neck thickness gauge and runout gauges can tell you the most about sizing and seating your bullets and the quality of your brass.

I have the cases sorted with the best brass being used for my Bolt action .223 and AR15 A2 HBAR and the "rejected" cases being used in my AR15 carbine as shorter range practice ammo. Bottom line, with quality made brass you can make high quality ammunition with minimum runout. And when it come to poorly made cases you can't make a silk purse from a sows ear no matter what you do.

 

[Steve Ladino]

Re: RCBS Case master. Now what?

Along with all the other techniques that contribute to less run out you might put a good uniform bevel on the inside of the neck rim, anneal the neck, set the bullet straight on top of the neck before seating. With a .001" nk. tension the correction should be very easy.

 

[mikecr]

Re: RCBS Case master. Now what?

There are two camps in the measuring;
-Neck benders (eccentricity)
-Straight ammo makers (runout)

Neck benders come about because sadly, they can't make straight ammo..

 

[bigedp51]

Re: RCBS Case master. Now what?

There are two camps in the measuring;
-Neck benders (eccentricity)
-Straight ammo makers (runout)

Neck benders come about because sadly, they can't make straight ammo..

Actually when you have cheaply made cases with .003 to .005+ variations in neck thickness you bend the ammo and cross your fingers. I had three five gallon buckets of once fired .223/5.56 cases given to me. They were 1/3 Remington, 1/3 mixed Federal and 1/3 Lake city, the Remington cases were the absolute worse cases I have ever seen for neck thickness variations and "WHY" I have the Hornady Concentricity Gauge.

These cases are not Lapua brass "BUT" the Lake City cases surprised me with there uniformity. The only downside is the rims and extractor groove get chewed up in AR15 rifles and this can effect runout on the down stroke of the ram and cause the cases to tilt.

You can remove the expander button and full length resize the case and it will have very little if any runout measured at the case neck. The real culprit is poorly made case with variations in neck thickness. And as long as you have a neck thickness gauge and a runout gauge the bad cases can be weeded out.

So instead of throwing these cases away that have poor case uniformity you become a "neck bender" and shoot them in your AR15 carbine with aperture sights and put these cases in 30 round magazines and work on your Zombie crowd control. (also called suppressive covering fire)

Then you use the good cases with minimum runout in your scoped AR15 and .223 bolt action rifles and only take head shots.

Neck benders come about because sadly, they can't make straight ammo..

So in reply to the comment above I have two words for you...............................

Get Bent!

And may the fleas of a thousand camels infest your crotch.

 

[Grimstod]

Re: RCBS Case master. Now what?

The RCBS case master does let me check for neck thickness however I don't think it will even come close to be accurate enough. It seams to have about .001 of variance without even a shell in it. I think I might have an ides on how to improve it though. Ill post photos if I can get it to work.

 

[amlevin]

Re: RCBS Case master. Now what?

The RCBS case master does let me check for neck thickness however I don't think it will even come close to be accurate enough. It seams to have about .001 of variance without even a shell in it. I think I might have an ides on how to improve it though. Ill post photos if I can get it to work.

"Index" the sleeve that the dial indicator point rides on and always take your readings with the sleeve in the same position. That helps a lot.

Another "help" is to trim cases first so the case mouth is square. This way, when the case mouth is firmly against the vertical post (top and bottom), the reading is accurate

 

[Grimstod]

Re: RCBS Case master. Now what?

Good Idea, I was going to see if some one could true it up in a lathe. Or I could get a spindle similar to the one in the Redding one posted above.