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Run out ?

Posted: Tue Aug 05, 2014 3:47 pm
by Josh Cox
Last Saturday I had the great fortune of shooting at the Herberton OPM, I won a prize, which turns out to be one of Peter Smiths awesome run out / case thickness gauges.

Have been quite particular when seating my projectiles to half seat them, raise the handle a bit, twist the case and then fully seat, to try and reduce potential run out.

Now with my new run out gauge I am seeing about 2-4 thou run out in my loaded ammunition, what is the general consensus on what is acceptable ?

A big thanks to Pete Smith for such an awesome prize.

Posted: Tue Aug 05, 2014 6:29 pm
by AlanF
Josh,

While I would probably hope to get it better than that, I don't believe it would be a problem, unless you're running very little clearance around the neck (say less than 0.002). FL sizing also means you can get away with more runout (which is fortunate because it is often the cause of runout).

Alan

Posted: Tue Aug 05, 2014 10:39 pm
by KHGS
Josh,
Runout is something that we should try to avoid, having said that I think it's importance is somewhat overstated. What you are achieving is in my opinion within the acceptable range.
My .280HI is formed from necked down 30/06 brass & fireformed to Ackley configuration, the loaded cartridge prior to fireforming will have runout up to .010" & will regularly shoot 60's at the shorter ranges in 2 different barrels, neck clearance is .002" with Lapua brass. Makes you wonder doesn't it? As I have said before many times, the more you learn the less you know! :D
Keith H.

Posted: Wed Aug 06, 2014 7:17 am
by John23
I have been experiencing similar run out to Josh with my 308 (that I bought from Josh )


Is the simplest solution to run out a guided comp seating die?

I have been using a standard rcbs with this rifle and I am left wondering if this is where my problem is coming from as I never had this issue when using my forster ultraseater with another cartridge.

I am sizing with a redding neck bushing die

JH ;)

Posted: Wed Aug 06, 2014 8:00 am
by pjifl
I always aim for less than 0.002 inch runout and my loading reliably attained this or better.

About 1 year ago I changed something without thinking and assumed the runout remained low. In reality, there was the occasional cartridge with 0.010 runout and quite a few over 0.005.

When I noticed and corrected the problem, occasional flyers seemed to disappear and my shooting improved.

I do not know where to draw the line, and it may be that in TR shooting you have more allowable tolerance. But I do think that I was non competitive at a few major shoots because of this. You only need one or two flyers over a few days now to be out of the running.

I always now check a random selection for runout in EVERY box.

Peter Smith.

Posted: Wed Aug 06, 2014 1:36 pm
by ShaneG
Did a test on my equipment with Dave Mc a few weeks ago.
I have similar run out - around .003
We determined that the
Redding neck bushing die was the culprit!
Causing .0025 variation due to clearance on die body and same in bushing area.
My loads normally shoot quite well but I really would like to reduce same.
It is a matter of the lucky lottery with most factory dies.
Similar results from a Wilson die in arbor press.

Posted: Wed Aug 06, 2014 3:46 pm
by Brad Y
Try a redding body die to bump shoulders then a lee collet die for the neck. Wish they made them in the 284

Posted: Wed Aug 06, 2014 3:55 pm
by jcinsa
Id love to see a picture of one of Peter's runout gauge.

Please could someone post one.

Thanks in advance

John

Posted: Wed Aug 06, 2014 6:06 pm
by Josh Cox
Image

Image

Posted: Wed Aug 06, 2014 9:23 pm
by DannyS
Dave Mc and Peter Smith, can you guys move to Western Victorian, please. Need your advice locally

Cheers
Danny

Posted: Thu Aug 07, 2014 7:39 am
by Josh Cox
Stop brown nosing Danny, they're ours and we are not sharing :)

Posted: Thu Aug 07, 2014 9:07 am
by AlanF
The Yanks got a few rocket scientists out of Nazi Germany, so why not? However eastern Victoria is where its all happening :D .

Posted: Thu Aug 07, 2014 9:20 am
by Bindi2
For real innovation and progress the wild WEST is where you need to look. :P

Posted: Thu Aug 07, 2014 2:30 pm
by johnk
Don't know how any of you buggers can see with your heads where they are. :roll:

Posted: Thu Aug 07, 2014 3:10 pm
by Howard
I have a question about this runout you blokes are talking about.
Is it the "angle" that the bullet is sitting in the case, compared to the line of the bore? That is, the tip runs out, but the base does not.
Or, is it the "offset" of a bore aligned bullet, to the bore. That is, both tip and base run out in unison.
The latter may be caused by a case neck with differing thickness on each side?
A bullet that has runout of .010 or more, would surely align itself to the tolererances of the chamber? I would think it would come back to the tolererance or difference between the bullet diameter and the throat diameter, assuming that a pre-fired case is a snug fit in the chamber.
I can't see that diameter difference being .010, but just what it really is, I don't know.
I agree with Pete that the correction should be in the loading dies.
Howard.