Is This Possible

[Willie]

I've been having accuracy problems on a 280 Ackley, lately. So, to find the problem, today I tracked 5 pieces of fired brass thru my loading process. All had .0005" run out to start.

All five pieces kept that runout thru .0015" bump with body die, thru bushing neck sizing, and thru opening neck to .282 with a mandrel die. The seater die produced no run out either.

I then pulled the ejector and firing pin. All rounds chambered with bolt falling free. Perfect rounds with .0005" run out. Installed firing pin & ejector and I could feel a drag on each round, as I chambered each round. There was a distinct rub mark on each bullet @ the ogive/bearing junction. Checked runout again and it jumped to .006" on each round.

Is it possible for the ejector spring to be strong enough to induce that much run out ?????? I scoped everything else, no burr, no carbon ring and lands look even and clean.

What could I be missing? The ejector seems to be only culprit, to me.

 

[David Christian]

Why don’t you permanently remove your ejector pin? What does it do for you? Almost all of the guys I shoot with, whom are High Masters do not have ejector pins, including myself.

 

[Sniper338]

I would say it could... some are pretty damn stiff. and depending on the speed at which you eject it could knock the bullet to the side against the chamber

 

[rardoin]

Yes...I have experienced that also. I shortened the ejector spring a coil or so only to reduce the throw of the brass on ejection but it also greatly reduced the 'rub' of the bullet on extraction.

 

[Willie]

I would say it could... some are pretty damn stiff. and depending on the speed at which you eject it could knock the bullet to the side against the chamber

What I believe is happening is I'm getting the run out from chambering the round. I'm sizing about .275" of the neck @ .002" under caliber and find it hard to believe the spring could induce that much run out.

The spring is stouter than most and I'm gonna start trimming it in steps. On chambered, but unfired rounds, the rub is pronounced. I can feed a round into the chamber by hand and it will shoot in the .2-.3s @ 100, so it has to be the spring wt. Right?

 

[Sniper338]

What I believe is happening is I'm getting the run out from chambering the round. I'm sizing about .275" of the neck @ .002" under caliber and find it hard to believe the spring could induce that much run out.

The spring is stouter than most and I'm gonna start trimming it in steps. On chambered, but unfired rounds, the rub is pronounced. I can feed a round into the chamber by hand and it will shoot in the .2-.3s @ 100, so it has to be the spring wt. Right?

why not try taking it out completely and firing a round to see if theres a difference at all before you start trimming

 

[jonbearman]

What are you using to check your runout on your loaded rounds?

 

[Willie]

That's one thing I did not try.

 

[Willie]

What are you using to check your runout on your loaded rounds?

Used 21stCentury and double checked on Sinclair. Confident on readings.

 

[carlsbad]

except for hunting rifles, I either remove the ejector or cut the spring shorter.

 

[Willie]

This will be a primarily hunting rifle for a son. That's why I don't want to remove ejector. Trimming the spring seems to be best solution.

I am going to load 10 more rounds, checking concentricity at every step and shoot 5 without ejector and 5 with, prior to trimming the spring.

 

[DCRYDER]

I would also think this is happening during extraction. Round should be fully in chamber before ejector puts pressure on it. The body of the case (especially body/shoulder junction) should prevent side pressure on the neck or bullet. When pulling the bolt back the bullet of the loaded round smacks the side of the chamber after the shoulder leaves the chamber.

 

[Willie]

I would also think this is happening during extraction. Round should be fully in chamber before ejector puts pressure on it. The body of the case (especially body/shoulder junction) should prevent side pressure on the neck or bullet. When pulling the bolt back the bullet of the loaded round smacks the side of the chamber after the shoulder leaves the chamber.

 

[Willie]

You would think so, cause that's usually the case. I hold the round as I extract it, so it's not slapping anywhere. I'm gonna be out of town for several days. Maybe my mind will clear and I'll tackle it again. I do appreciate all the ideas. Thanks guys.

 

[Willie]

UPDATE
I found the culprit, by accident. I drove the ejector retainer pin out to shorten the spring. The ejector and spring were stuck and would not come out. After 30 minutes of compressing and releasing the ejector, it finally moved out enough to get a good grip. Ejector was fine, spring not so good.

I held the bolt up to light and could see a blockage in the retainer pin hole. I took a punch and tapped the blockage, back and forth from both sides. Out pops a roughly 3/8" vee shaped part of what appeared to be a smaller diameter roll pin. No idea how that got in there. I had depressed ejector many times and it had never binded up, but on recoil, it must have at times.

Anyway, I am no longer getting any additional runout or scuffs on the bullets upon chambering. Pretty freaking crazy. Its like the guy who puts a marble in the door of a car at the factory. Can't believe none of you told me to check for that. LOL