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Bolt tough/sticking

I'm fairly new to the 6br, and have questions. I'll start with the rifle, the one I have started life as an XR 100 the rem. chamber was redone, the bolt was redone and a sako extractor added. It has a Maclennan barrell that's 30" with a 1-8" tw. Its cut so that I don't have to turn brass,.268" I think).
After breaking it in with the Diamond line ammo I've been loading as per suggested and tried 31gr. of varget behind a 107gr SMK. They shoot well but I find that the bolt more often than not is tough to lift to eject the spent ones. The bullets are loaded far enough out to just touch the lands so that closing the bolt you "just" start to feel pressure closing the bolt.
I backed the load off to 30 gr.of Varget and although they still shoot dynamite I still get a bolt that's tough to lift.
I've tried seating the bullets a few thou deeper too.
The brass is not showing any obvious signs of pressure/stress and i'm looking for suggestions.

I'm reading of people loading in excess of 31 gr. of varget and doing ok

I'm reading of people loading 20 thou short of the lands and people loading into the lands and doing ok

I was wondering if maybe the shoulder of the cartridge is causing the troubles ?

Would love some ideas, and as i'm fairly new to the extreme end of precision loading, please use small words, laff.

M.
 
Try taking a fired case that was hard to extract and smoke it via a candle flame and re-chamber it. It should show you any place it is touching. .272" is no-turn, .268 is a turned neck. That does your fired case measure in the neck, should be whatever your neck is less 1/2 thou for spring back, i.e., a .272 nk would create a fired case of about .2715"
 
My mistake, reading too many numbers on things around here.
Loaded cartridge measures .270" and a fired one measures .272"

M.
 
Will a fired case allow a bullet to drop back into the neck with no resistance ??
If it won't, it needs to be turned down, and that will show pressure if not corrected.
A lot of rifles will not take 30 grains of Varget safely ..........
 
Preacher said:
Will a fired case allow a bullet to drop back into the neck with no resistance ??
If it won't, it needs to be turned down, and that will show pressure if not corrected.
A lot of rifles will not take 30 grains of Varget safely ..........

I have a number of minimum and no-turn chambers, and NONE of them will allow a bullet to drop into a fired case, and ALL of them are perfectly safe,and accurate).

A bullet not dropping into a fired case is NOT a valid test of anything.

If a case neck has 2 thou spring back, and you say it has to clear a bullet in a fired case, then that means you are saying that the neck must be 5+ thousandths LARGER than loaded neck diameter...

... that eliminates all "no-turn" chambers, and takes you right back to factory chamber necks - that's a real bummer!!!

:, :, :,

.
 
Sounds like you might be a tad high on the load. Max for the 6br with 107 gr smk is 29.4 of varget, according to the 6mm br web site. Hot weather will cause your load to be a tad hotter also. I've used 30 of varget & just begin to feel a little stiffness in bolt. Mine is also a .272 no turn neck. It seems to shoot best at both 2.350 -.025 off lands, & 2.380 +.005 into lands. I stay between 29 & 29.4 gr. It shoots .2 to .3 at 100. I have seen where others have reached higher velocity but I don't like living on the edge. The 6br is a fine caliber just the way it is; at,29gr).
My 2-sense, Greg
 
Tried 30 gr. Varget on Sunday at 300, it shot fantastic, I'm not saying it doesn't shoot, but it still gets tough to lift the bolt sometimes. BR web page says 30 is classic accuracy.
quote
Classic accuracy load for the 107 SMKs. Works well in many guns. You can hot it up, but start at 30.0. Try Wolf,Russian) primers too.

I've had people suggest the 31gr. i've read about people being over 33. I don't need the hottest load in the world or need to be the fastest load, I just want something that shoots and doesn't harm the rifle.
Could the shoulders of the cartridge be too high?
would this cause sticking?

M.
 
Oh, and I just tried putting a new bullet in a fired case, it went but it took a firm push to do it. It would have been tougher if it wasn't a boat tail.

M.
 
Icepick, yes they did say that, starting at 30 & hotting it up, but where I was referring to, was in the load data guide on the same site. Must have been two different references. What concerns me is the pressure.
Maybe someone can answer this: I've heard that you get an increase in pressure if you seat your bullet deep in neck. Then I heard that you increase pressure by seating bullet jammed into lands. Is there a difference either way? It just seems like early pressure vs late pressure. Does anyone have an answer???
 
gambleone said:
Maybe someone can answer this: I've heard that you get an increase in pressure if you seat your bullet deep in neck. Then I heard that you increase pressure by seating bullet jammed into lands. Is there a difference either way? It just seems like early pressure vs late pressure. Does anyone have an answer???

When starting with a new rifle, I make the first batch of loads in steps, and with one row of five jumping and the next row, jamming.

It has been my experence that there is either no noticeable difference, or at times, .3 gr of difference between the point where pressure shows... that is to say, if the 35.0 gr jam load shows pressure, the 35.3 gr would show the same signs.

But I have had more rifles not show any difference at all - both rows show pressure at the same time.


.
 
Cases not showing ANY SIGNS of pressure problems.
I think i'm gonna have to get creative with my resizing.
I susect shoulder problems.

M.
 
If it was me, I'de back down on the powder charge and start over.
We shoot "80" grain Bergers with 30.0 to 30.5 grains of Varget.
Any more really starts showing pressure signs.,stiff bolt or won't open) And real hard on brass! ;)
 
I spoke with the guy that made the Barrell for me, we,re getting together next week to research this, he think's its proably a die set up thing.
M.
 

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