Too much bullet runout with a Forster Ultra seater?

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Rmeju

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I bought a Forster Ultra seating die with the mic adjuster to help me with bullet runout issues (previously around .006"). The Forster improved that (now I'm getting about .0015" to .0035", but honestly, I thought it would be better than that; more like .0015" or better on most rounds. Am I being too picky, or is something wrong?

For reference, all necks have been turned to about a half thousandth of concentricity, and runout measured just above the shoulder for all cases was at .0015" or less. Sized using a Redding FL bushing die. Bullet is a 7mm 162gr A-Max.

I'm trying to improve my group sizes. I'm not a match shooter, but I'm looking to clean up my reloading game, since I'm thinking about getting started down that road.

Any help would be appreciated!
 
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Are you using a FL sizing die with the expander ball? I've never really noticed, but several precision long range shooters I know say that when the expander ball pulls out of the case neck that it will pull the neck that causes runout.

Solution: would be to FL size with the expander removed and then use a seperate Neck sizing die or a bushing die to size the neck and set bullet tension.
 
So you've already reduced runout but you feel as though 0.0035" is still too much? Before you start trying to reduce it further, what exactly is your acceptance criteria? Why do you want to reduce runout? Is it because your groupings are too large? Are you seeing a noticeable effect on long range shots (>= 1,000m)? If you're not concerned with the aforementioned then you'll probably be wasting your time to further reduce your runout.
 
In the 50 BMG my run-out cutoff point was .006" and anything over was set aside for rocks and fun while those under that were used on paper at long range. Wouldn't surprise me if the really good 1000yd shooters were using under .001" runout ammo because ANY is too much for the ultimate precision. There are little fixtures built so you can tweak the ammo into perfection which might not be attainable with just the dies.

If you're spinning the cases with the body resting on one V-block and neck on another, then the case body thickness variations could be affecting your readings even if the neck/bullet relationship were perfect. Would this affect the grouping? I don't know, but I believe the Precison Rifle Game is one of eliminating EVERY variable that you can.

One thing to ponder: there is no such thing as 'perfect'. Once you get the runout down to your gauge showing .000" if you would go to a more sensitive instrument you'd very likely find it wobbling around a LOT!:) Like the air quality sensors that used to measure in ppm...and once it got so clean that they were showing 000's, switching to ppb and look at the terrible pollution we've got!

If you can set up a test with ammo that measures under .0015" to see if you notice a tighter grouping then it might be worth tweaking them to that level. At least then you'd see what the runout is really doing to/for you. If the 'perfect' rounds DO shoot better groups, then getting or building a fixture so you can tweak them into perfection might be the easier way out rather than trying to make them perfect straight out of the dies.
 
To answer a couple of questions above, I'm not using an expander ball. Also, my goal is to shrink my group size and eliminate "unexplained flyers," which have been causing me a headache. Ideally, I would like to not monkey with runout after seating, as I understand that can cause neck tension problems that would create more issues than it solves.

I also did see and read the accurate shooter article, but it didn't quite answer my question, and I was doing the things it suggested. I simply thought that after doing those things, I would be getting smaller runout numbers.

In any case, thank you for the replies so far.
 
my goal is to shrink my group size and eliminate "unexplained flyers,"
Click to expand...
My flyers went away with full benchrest prep of the brass and sorting by weight. If your shooting that 7mm Rem mag, going to a lighter recoiling rifle would help.
 
Having shot 30 caliber ammo into sub MOA with 15 to 20 shot test groups with ammo having .0035" bullet runout, I don't think your accuracy problem is bullet runout.

What cartridge are you shooting those 7mm bullets out of? If it's big one, the recoil's probably enough to cause a lot of unwanted barrel movement off the desired bullet release point while the bullet's going through the barrel.

Most people shoot heavy recoiling rifles more accurate slung up in prone with the stock fore end on a bag and the stock toe on another one. Even benchrest folks know that holding onto their mild recoiling rifles shoot less accurate when they're hand held against their shoulder, so they're fired in free recoil untouched by humans except for a finger on a few-ouce trigger.

No runout gage measures the actual bullet runout on bottleneck cases headspacing on their shoulder as it will be positioned in the chamber. The rear rest is typically on the case body at the pressure ring; about 1/4 inch forward of the case head and pushed there by the extractor against the extractor groove. The front rest is on the case body behind the shoulder, on the case neck or on the bullet. None of those front points on the loaded round touch anything in the chamber when the round fires so they do nothing to center the bullet in the bore. It's the case shoulder centering in the chamber shoulder that centers the front of the round in the chamber because the case body is smaller in diameters than the chamber body area it fits in.
 
Fliers are always a bitch. But it sounds like runout is not the cause. Just because you can measure it, does not mean it is a problem on target.

How bout neck tension? Operator error? Wind? Do you trim the meplats? Do you true the case heads? Polish inside the necks? A never ending battle ...
 
Dave, my front reference is mid point on the case shoulder. The dial indicator's on the bullet about 1/10th inch back from the tip. I don't want the out of round case body behind the shoulder messing up the runout numbers.

Truing case heads is a waste of time. Each firing of a squared up case head with the bolt face not squared up with the chamber axis flattens it out of square again. Square up the bolt face and forget about squaring up case heads; they square up on the first firing. New cases have pretty square case heads to start with.

One think that keeps case heads squared up is minimal head clearance to the bolt face when the round's fired. .001" to .002" is perfect. Minimal stretching of the back half of the case and with the normal wall thickness spread of cases, the thin side of the case stretching the most won't cause problems. This also lets the bolt close into battery very repeatable from shot to shot; no binding at all.
 
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Ok, to answer some more questions, in no particular order:

On caliber, it is the 7mm Rem Mag. For reference, on a good day, I can hold 1/4 MOA with the rifle (5 shot groups). My goal is to be able to do that consistently.

As for prep, I have just started doing things like annealing, neck turning, weight sorting, and using better equipment like bushing dies, premium seaters, co-ax presses, and concentricity gauges. This is actually my first time going through this process... I just happen to be at the seating step now. I can't honestly say if I'll have flyers at .0035" bullet runout, since I haven't tried them yet. It may very well be that they shoot just fine. I only know that before I started doing "real" brass prep, I was getting some unexplained flyers, and one of the measurements I saw in my "old" rounds was .006" bullet runout. When I only reduced that to about the .002" to .003" range, I expected better, but maybe my expectations were too high. My original question (i.e. are these numbers too high for a Forster seater?) was aimed at avoiding a situation where I had loaded up a bunch of rounds only to find out I did it wrong. I get (and appreciate) the advice saying that "it isn't a big deal, just shoot it." But to me, I'm always looking to tighten things up, and if I should be seeing lower numbers, I want to know that, so I can make sure I'm getting all the mileage out of my equipment that I should be. If my numbers are about what people expect from my seater, then I'll know to move on and not worry about it.

As for how I'm measuring, I have the Forster gauge, rolling the case head side of the round in the v-block just ahead of the belt, and the tip of the round sitting in the front notch, riding just behind the meplat. I set the dial just in front of the case mouth, but also took some measurements on the ogive, and didn't see much difference (the instructions said either spot would be ok).

On recoil, I've been shooting prone, on grass, off a bipod with a rear squeeze bag. Also, I'm just about to add a silencer (almost 6 months into my form 4), which should tame the recoil a little bit. I don't mind the recoil personally, but I understand it can interfere with the shot, spotting, etc., so I'm giving that a try.
 
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If you use the Sinclair runout gauge that gets .003" readings on a round of ammo, switch to Hornady’s runout gage and get readings about half that much.

Sinclair’s gage that uses the body right behind the shoulder as the front reference and case body in near the extractor groove as the rear one:
http://www.sinclairintl.com/reloadi...s/sinclair-concentricity-gauge-prod37479.aspx

Hornady’s gage that uses the bullet tip as the front reference and case head as the rear reference:

http://www.hornady.com/store/Ammunition-Concentricity-Tool/

Why is explained in the following:

http://s854.photobucket.com/user/unclenickmod/media/RunoutAngleandGaugeTypes_zpsdd0038a3.gif.html

Regarding the addition of something to reduce recoil to improve accuracy, the recoil that degrades accuracy happens before the bullet exits the muzzle. By the time a device redirects gas to lessen felt recoil, the bullet's a few inches past the device. Why do double rifle's bore axes cross 10 to 20 yards down range toeing in several MOA?
 
You can also correct runout with the Hornady gauge that Bart references

I've been correcting runout with mine and have noticed a reduction in flyers. I'm also trying to eliminate the causes of variation in the process that lead to runout and I'm getting close to not needing to check every round (.0015 or less is my goal).

I'm using the redding comp seater. Looking at bushing dies but haven't pulled the trigger yet.
 
Being a belted magnum cartridge, are you headspacing on the shoulder or belt? I believe that you should be trying to keep the shoulder in contact (or real close) for best consistency and if it's headspacing on the belt the shoulder blowing forward could easily cause some inaccuracy.
 
I am never infatuated with the smallest groups I shoot. They happen when one of two things takes place. All the variables in different directions cancel each other out. Or, everything is perfect. There's no way to prove one or the other. The largest groups show what you can count on all the time; not 5% or less. Think about it.

Your load accuracy is what the largest groups are. How big are they?

When 30 and 28 caliber belted magnums were popular in long range prone matches, the best scores were shot with new, often unprepped, cases. Or full length sized ones fired in rifles with their bolt face squared up that had the body sized down all the way to the belt. In both, shoulders were set back a couple thousandths.

Why do you think new belted cases could shoot so well? They center the bullet pretty straight in the bore when fired and their shoulder is a few thousandths back from the chamber shoulder; it gets blown forward at peak pressure after the bullet's several inches down the bore.
 
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put a piece of plastic, or something flat and smooth, under those bipod legs.

agree with benchrest prep your cases.

try to shoot a modified free-recoil by keeping your shoulder back off the buttplate a bit and your cheek off the stock. you can squeeze the trigger with your index finger and the back of the trigger guard with your thumb (not the greatest setup, but sure beats pulling backward on the rifle with whatever trigger letoff weight you have).

luck,

murf

p.s. don't forget to adjust your parallax every time you shoot. that has to be spot on for small, consistent groups.
 
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Bart B wrote: "The largest groups show what you can count on all the time; not 5% or less. Think about it." ... Truer words were never typed.

As to your die question - I use the Forster Benchrest Seat Die on 3 different cartridges - 7mm RM, 25-06 and 223 Rem. If set up properly you should not induce additional runout in your ammo by seating a bullet with the die.

I have the Forster Runout Gage in addition to the Forster Seat Die. I like it, it could be better, but it helped me minimize runout in my brass processing which benefited me in bullet seating.
 
actually, you haven't shot your largest group yet. at a 95% confidence level you have 5% more to go.

murf
 
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