Bullet runout????

[bobinpa]

Say for example that you have a rifle that shoots consistent 2.5" groups at 600 yards. Just for conversation, we'll say it is a 6.5x47L. Now lets say that you feed that rifle 10 rounds of it's favorite load and that ammo has consistent bullet run out of .002 or better and as expected you get a 2.5" group. Then you feed that same rifle 10 rounds of it's favorite load and this batch has consistent bullet run out of .005.

What can you expect the group to look like?

 

[Dans40X]

At mid range(600yd) distances-
Mother Nature,The Moon,The Tides are throwing more your way than .002"-.005" runout will produce.

 

[Curious]

Another 2.5" group

Now, I would consider .005" enough to try and find the cause however.

Tom

What do you consider an acceptable amount of runout Tom for your 1000yd benchrest ammo?

 

[Richard Coody]

Say for example that you have a rifle that shoots consistent 2.5" groups at 600 yards. Just for conversation, we'll say it is a 6.5x47L. Now lets say that you feed that rifle 10 rounds of it's favorite load and that ammo has consistent bullet run out of .002 or better and as expected you get a 2.5" group. Then you feed that same rifle 10 rounds of it's favorite load and this batch has consistent bullet run out of .005.

What can you expect the group to look like?

your favorite load is shooting less than half a MOA at 600. if that is consistent then you are a really good shooter. unless you are willing to go through all the sorting of brass and bullets, neck turning, annealing, measuring powder to. 02 and all the other stuff that goes with improving your group size another 0.1" i would ignore your runnout and be happy with what you have.

Consistent is the key word here.

 

[marchboom]

Say for example that you have a rifle that shoots consistent 2.5" groups at 600 yards. Just for conversation, we'll say it is a 6.5x47L. Now lets say that you feed that rifle 10 rounds of it's favorite load and that ammo has consistent bullet run out of .002 or better and as expected you get a 2.5" group. Then you feed that same rifle 10 rounds of it's favorite load and this batch has consistent bullet run out of .005.

What can you expect the group to look like?

I think you should do a test with loads that have .005" runout and post the results. I would like to see the difference.

 

[seymour fish]

I don't check it very often, say if I'm switching out fl dies I might check a couple. If my bullets have really distinct pressure rings(picture a ball and socket), you might see up as bad as .003". But the sized brass measures next to nothing, I will not worry about it. If the bullets are more normal, I will see bad ones as much as .0015". Once again, I don't sweat it. I've colored the extremes, and they are right in the middle of the group so often I've quit worrying about it.

Tom

Agree, have shot a lot of 308 at 1 K and found no difference between .000 to .003 runout showing on paper, with caveat seated .010 into the lands.
.005 will start to go south even so

 

[dmoran]

My experience is when jumping the bullets runout can be more critical and effect accuracy. When seating into the lands and/or jamming, don't believe it effects accuracy much at all.

With that said, for me I use runout to judge my own skills as a reloader to how well I can make my ammo, setup dies, and maintenance my equipment.
My 2-Cents
Donovan

 

[Shynloco]

Another 2.5" group

Now, I would consider .005" enough to try and find the cause however.

Tom

I'd start (trying to find the problem) with the Decapping rod in the die you are using. Remove the current Decapping Rod completely and resize that same case and see if the runout improves. Redding just replaced my Decapping Rod (free of charge) in a Die of mine where the runout was .006. Took the Tech's advice and removed the Decapping Rod and resized that same casing in that die and the runout improved to .0015.

Alex

 

[T-shooter]

There are a lot of different ways to measure runout and each one will give you different readings. With a Sinclair tool, I could measure in these ways. I measure my resized cases that are neck turned as in #1 and want them under .001". I measure loaded rounds as shown in #3 and want .002" or less. I also tried to be able to measure more like the Hornady runout tool and made a spacer as in #5 and #6 to put under the left support to level the round. The reading of #6 will be half the reading of #3 with the case round.