How important is bullet run out?

[mphfreak]

Ive never checked runout on any of my reloads. I tumble, sort brass by headstamp and weight, clean flash hole, neck turn, brush inside of necks and clean primer pockets on all my brass. I use berger bullets mostly. I clean the copper from my rifles every 60 rounds or so and run a dry patch every 15 on avg. Rifles twists are all matched to my bullets. My goal is to keep a consistent group. Im having flyers. Mostly 2 within .5 moa the ill get one that brings the group to an Inch. The odd group ill get one in 5 shots. I always allow the barrel to cool to skin temp before making the next shot. All my rifles are bedded.

Would checking and truing my cartridges possible help eliminate these annoying flyers?

Thanks all

 

[Shooter ----/]

It is one of the steps to eliminate flyers.

With no run out, try turning necks. After that, start annealing.

 

[bearhunter]

Run out happens from a combination of issues. The first culprit to check would be your press. Is the ram true to the threaded die holder? Then, is the threaded hole in the top of the frame square to the machined area on top that you run your lock nut onto. Is your die square to its axis?

I went through several presses until I found one that was true to its axis and have passed on some supposedly very good quality dies that were supposed to be square as well. Bonanza dies are about the only ones I haven't had to return. Thankfully RCBS/Redding/Hornady will honor their guarantees. As often as not the dies are within spec but right on the outer limits. Usually a quick phone call to them gets very quick and positive results.

Turning the necks is only necessary when you are loading for match chambers with smaller than SAAMI spec necks. Then you need Wilson dies with interchangeable neck sizing inserts and an arbor press.

If you are running more than .002 inches of run out consistently, chances are pretty good one of your loading tools isn't square to the axis of the ram. If you are running .002 or less and shooting a big game hunting rifle all should be well.

 

[Splatter]

Yes, reducing run-out will reduce flyers.

If your flyers are caused by run-out.

Do you have run-out? See if you can borrow a buddy's concentricity gauge and find out.

 

[bigedp51]

More neck runout is caused by locking the expander and spindle assembly down off center than any other reason.

I use my runout gauge when installing and setting up my dies in the press to get the least amount of runout.

Forster bench rest full length dies have a high mounted expander that floats and self centers with the neck of the die. The neck of the case is still inside the neck of the die when the floating expander enters the case neck. I ordered Forster expander and spindle assemblies and installed them on my RCBS dies and getting reduced runout. And with the Forster dies I'm getting .001 or less runout on the neck after sizing. And the American military considers .003 or less runout to be match grade ammo.

A neck thickness gauge and a runout gauge will tell you a great deal about your brass.

 

[Dogleg]

Most fliers aren't really fliers. They are just a way of disregarding shots we don't like. There arent many three shot groups that don't have 2 closer together than the total group size and not many 5 shot groups that can't be improved by selectively picking one bullet hole to throw away.

 

[Northman999]

Most fliers aren't really fliers. They are just a way of disregarding shots we don't like. There arent many three shot groups that don't have 2 closer together than the total group size and not many 5 shot groups that can't be improved by selectively picking one bullet hole to throw away.

Have to strongly agree with this.

I actually think lots of guys use the term "flier" to describe any single shot in a group that makes the group substantially larger, even if they know they flinched the shot.

 

[Dogleg]

Oddly, some will too quickly take the blame for any shot they don't like, perfecting to believe the equipment is perfect and everything else is human error.

Ever notice that the worst 3 shot groups measure about the same as the average 5 shot group? Or that 5 shot groups don't vary as much from group to group? Or that 5 shot groups tend to be almost twice the size as the best 3 shots? Every group will look better when you only look at half of it. 10s don't grow as much from 5s.

 

[Chinbullco]

Try culling the brass that creates the flyers. Brass that's thin on one side will never give good results.

 

[H4831]

Some interesting comments on causes of group sizes. There are lots more reasons why the bullets don't all go into the same hole.
Going from a standard military type trigger to a good custom trigger, where the release occurs within the trigger itself, will, without doubt, cut down group size.
Lighter recoiling rifles will make better groups than heavier recoiling rifles, with all other factors remaining the same. OH, I can hear the voices out there screaming, "Not Me, I never flinch with a big boomer!"
OK, let's give you the benefit of the doubt, for now, you don't flinch, but your rifle moves, even with remote release of the trigger. Years ago the British military were great for figuring out every thing and finding reasons for what happens. They discovered that with the standard full wood Lee Enfield 303 rifle, shot by an average weight soldier lying prone and wrapped up in his military sling, moved back a tenth of an inch, before the bullet left the barrel!
So if your big boomer is resting on sand bags, or commercial rests, is it not reasonable to assume the barrel is going to rise before the bullet gets out the barrel? Or if it just moves backward before the bullet gets out the barrel, the movement will not be the same with every shot. And since the distance to the 100 hard range is about 100 lengths of your rifle, any upward movement of the barrel would be multiplied 100 times in the distance to the target. This means if the barrel rose 1/10 of an inch before the bullet got out of the barrel, it would hit ten inches high at 100 yards!
And even if the barrel rose only .01", about the thickness of one sheet of writing paper, before the bullet got out the barrel, it would hit the target one inch high.
One other thing about recoil. After the 308 Winchester came out it soon became very popular in bench rest shooting and people assumed it was more accurate than the 30-06. But world class bench rest shooters soon corrected that theory, stating the reason they shot better with the 308 than they did with the 30-06 was because of less recoil with the 308.
In short, there are a great many reasons why we don't make one shot holes with our rifles, if we shoot more than one shot!

 

[spatrick]

Which runout gauge (make, model) is worth buying?

 

[mphfreak]

Thanks all for the comments. Could very well be the operator of the trigger. I just want to eliminate as best I can any mechanical means. I do shoot about 2000 rounds a year in all different calibres and yes my 22-250 and my .243 are easier to group by far. My 30-378 accumark, .257 accumark and my 35 whelen tend to have the one hole thats not where I want it too be. I shoot off a lead sled with my non dominate hand under my chin against the top of the stock. Any suggestions of a better position to hold to try to keep the gun more steady as it fires? Im thinking about purchasing the hornady lock and load concentricty gauge to check and reset my loads. Keep the comments coming. Thanks again.

 

[maynard]

Ive never checked runout on any of my reloads. I tumble, sort brass by headstamp and weight, clean flash hole, neck turn, brush inside of necks and clean primer pockets on all my brass. I use berger bullets mostly. I clean the copper from my rifles every 60 rounds or so and run a dry patch every 15 on avg. Rifles twists are all matched to my bullets. My goal is to keep a consistent group. Im having flyers. Mostly 2 within .5 moa the ill get one that brings the group to an Inch. The odd group ill get one in 5 shots. I always allow the barrel to cool to skin temp before making the next shot. All my rifles are bedded.

Would checking and truing my cartridges possible help eliminate these annoying flyers?

Thanks all

I use Lapua brass, sorted by weight into 1 gr batches. Resize and trim to length. Depending on how dirty the brass is it either goes into the ultrasonic cleaner then the tumbler, or straight into the tumbler. If the primer pockets get cleaned in the process then they are clean. If I just throw them into the tumbler, that's all they get as far as cleaning primer pocket. In other words, I believe cleaning primer pockets to be a total waste of time.
All my target rifles have match chambers, these are cut with a reamer that requires no neck turning of the brass. If you are shooting a factory rifle with a factory chamber, neck turning is a waste of time. If you are using different brands and lot numbers of brass, throw it out and start with a fresh batch of brass from the same lot number. Just my 5 cents.