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Concentricity Issue?

BrowningBanger

Active Member
Joined
Jul 27, 2013
Messages
25
Location
Ellensburg, WA
So after loading up my first batch of ammo for my new 6.5-284, I ran into an immediate problem. The round was getting "pinched" into the chamber, and loading was impossible for the load that was supposed to be .010 of the lands. So I thought, hey, I might have had a bad measurement on the COAL, so I moved onto the next depth at .040. this one loaded fine, and shot alright until I went to feed one from the mag, in which case the bullet got stuck in the chamber. Upon removal there was only one side of the bullet with any wear on the surface, and it looked like it was just sheared off. Is this a concentricity issue or something worse? I am going to have a bad time getting things figured out if I cannot address this issue right away.
 
I suspect more than one problem here. I doubt it is concentricity. Some pictures would help. I am having a hard time understanding "and it looked like it was just sheared off"

Jeff
 
Sorry to play 20 questions....

How are you measuring distance to the lands?

What made you extract the unfired round?

If you single feed a round of the same OAL (NOT from the magazine) do you get the same result?
 
Sorry to play 20 questions....

How are you measuring distance to the lands?

What made you extract the unfired round?

If you single feed a round of the same OAL (NOT from the magazine) do you get the same result?

20 Q is fine.

Distance to lands was done using the Frankfurt arsenal COAL gauge.

The fact that my bolt would not close all the way without major pressure in which I was not comfortable doing made me extract the round.

If I feed the round as a single, It would only do it on some of the rounds, even those that were supposed to be .100 off of the lands
 
20 Q is fine.

Distance to lands was done using the Frankfurt arsenal COAL gauge.

The fact that my bolt would not close all the way without major pressure in which I was not comfortable doing made me extract the round.

If I feed the round as a single, It would only do it on some of the rounds, even those that were supposed to be .100 off of the lands

Wow. Something is screwed up - that diagnosis is free :rolleyes:

More 20Q!

On the single fed rounds that exhibit this issue, are they still only marked up on one side of the bullet? At 100 thou off, do you see/not see the issue 50/50, less, more?

From your first post I am assuming this is a brand new rifle? Is it a custom or factory? Can you index a case to see if the bullet wear always occurs on the same part of the throat (i.e. Always at 3:00)?

New brass? If previously fired, how was it prepped?

Multiple types of bullets tried with same issue, or just one type and lot?

I agree with Broz that it is unlikely concentricity - I am just trying to figure out what to ask to narrow down the potential issues.
 
The weird part was that it happened about 1/2 the time. enough to where I was checking to see if each round would actually feed into the chamber without forcing it. I fired 37 rounds of factory 120 grain NBT's through the gun as to break it in, and there was no faults or abnormal pressures during loading/unloading from the mag or singles. This makes me think that maybe the chamber doesn't like the VLD style bullets? or were they seated so wrong that they were coming in at a stupid angle? I was shocked to see this happening, and it made me upset. I would like to be able to load up these bullets without relying on factory ammo. (obviously). and to make this known, I am not a beginner in reloading, but the first time for this rifle. I will try to see if the wear is happening on the same side every time, or if it is cause by a weird entry into the chamber. Please keep the ideas coming, Im sure one of them will be right. BTW, the rifle is a factory Savage 11/111 LRH. It shot .5 MOA with Factory Nosler NBT's in the 120 grain variety.
 
Please excuse my ignorance, does this rifle have a plunger type ejector?
If so, when a bullet is seated so that it is very close to the lands, and the cases are unfired or FL sized, the cartridge can be pushed to the opposite side of the plunger and the end result is contact on one side with the rifling, although it may look like a crooked chamber or throat it most likely isn't in the presence of a plunger type ejector. If the rifle doesn't have a plunger ejector, then I would have a chamber cast made to assess what the cause is.
Do your fired cases show any signs of chips or the like in the chamber?
Is it possible that a partial ring of bullet jacket material is stuck in the throat and forcing the cartridges to one side?
Have you cleaned the rifle since finding this problem?

Hope this helps you out.

Cheers.
gun)
 
You said you didn't have an issue with the break in. Was that with virgin brass? But have issues with the once fired brass? Do you have a concentricity gauge? I would be checking fired but unsized brass and sized once fired brass first. Then I would be checking runout of the bullet.

If you can get to a borescope inspect the throat to see if it was cut properly. Since I have acquired my borescope I have discovered some rifles with crooked throats. I could see that the lands are longer on one side and shorter on the opposite side of chamber.

Is this a custom rifle? Was the action trued? There is a possibility that the bolt face is not 90 degrees to the chamber centerline. I encountered this once with a custom rifle. It shot virgin brass perfectly but once fired brass shot horribly. Once the bolt face was squared properly and headspace readjusted it shot fine.

This is going to require some effort on your part to solve the issue. When you do please be sure to post your findings here.
 
Can you compare the factory ammo to what you are reloading? I found that I was not pushing back the shoulder on some 300 WM ammo, which caused the bolt to close hard. Once I compared the factory to what I was doing, the shoulder needed to be .015" - .010" shorter. Try to eliminate one thing at a time. When I get frustrated with a project, some times I can not see the trees because on the forest. I will leave the project for a day then try to look at it from a different direction.
 
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