Tight case after firing

M

mikka

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Im at a loose end as how to solve this one. RPA quadlight action, feeding fine, after firing extraction is fine too but when you try to cycle the spent brass, unless it goes back in exactly as it came out it gets tight to cycle. It must be put back in exactly in the rotation it came out. Its not a chamber problem or a reamer problem Im sure. I had the barrel off a few times already, gave it a little more headspace and even a good polishing but the problem still remains. There is no concentricity problem either, tried any amount of different types of brass both new and used and still cant figure it out. Anyone here come across a similar one.
 
It sounds like your chamber is running out of square with the bolt face, either or both of them may be at fault.
 
Thats definitely what its looking like alright, Im certain its not the barrel work that I done. Im thinking it might just be the action itself thats running slightly off centre. Id be interested to know if theres anyone else thats come across this type of problem before.
 
Does the Quadlite have the mechanical ejector bar that works off the bolt stop? If so, check that it's freed up & you haven't got some crud stopping it from going right back.

I regularly dunk my Millennium bolts into solvent & swish them around to make sure that everything is OK.
 
Yes its got the mechanical ejector you mention but thats not the problem either. In hindsight I do notice more interference marking on one side of the bolt which may explain something.
 
Index a case that is fired so you know exactly how it sits in the barrel when it is fired.
Just a consideration but if you take the barrel off of the action and hold it in your hand and take a case in the other. If you still have a problem dropping the case into the chamber from this point it is the chambering job and would almost appear that it is crooked or bowed.
 
Vern said:
Index a case that is fired so you know exactly how it sits in the barrel when it is fired.
Just a consideration but if you take the barrel off of the action and hold it in your hand and take a case in the other. If you still have a problem dropping the case into the chamber from this point it is the chambering job and would almost appear that it is crooked or bowed.
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Ive done this and if put in at the correct rotation its fine but rotate it incorrectly and you see the problem. Its definitely something in the action.
 
Just an update on this one. After a lot of thought and careful consideration along with some very precise measuring I concluded that the bolt face was infact off centre considerably, it wasnt the bolt face but rather the conterbore into the bolt face which was greatly off centre. I dialed up the bolt and shaved around 2 thou from the side wall of the interference side and even at that I still didnt manage to make contact all around but at least its sorted. Not what you'd expect from a custom action although Id doubt it happens all that often. Thank God I worked it out in the end.
 
Mikka, how much clearance did your bolt face counterbore have on the cartridge head? When I bush the extractor groove in a Remington bolt face to install a sako style extractor, I make the bushing .010" over case head diameter. That seems to give plenty of clearance on the bolt face and helps it eject well.
 
Mike Bryant said:
Mikka, how much clearance did your bolt face counterbore have on the cartridge head? When I bush the extractor groove in a Remington bolt face to install a sako style extractor, I make the bushing .010" over case head diameter. That seems to give plenty of clearance on the bolt face and helps it eject well.
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Hi Mike, there was almost no clearance in the bolt face to start with which was very much part of the problem Id say. While this kind of clearance is fine in a bolt face on a custom action, it gives very little allowance for any imperfections that may be elsewhere in the assembly.

On another note Mike whats your take on the Sako extractor conversion. I read all sorts of mixed takes on them both good and bad.
 
Mikka, I see no problem with a sako style extractor as long as it's on a PPC sized case or larger diameter case head. The bolt counterbore also needs to be reduced from about .155" to .125" when doing a sako conversion and correspondingly on the barrel counterbore to fit. This allows more of the web of the case to be farther up into the chamber. The sako style conversion became popular on the old Sako .220 Russian brass as it allowed the balloon head of the case to be supported more fully by the chamber in effect pushing the case up into the chamber an additional .030". I won't install sako style extractors on .223 sized case heads. Just not enough brass thickness on those case heads to use a sako style extractor. If the primer blows, the extractor will probably leave the bolt as the case ruptures where the slot is cut for the extractor. I haven't seen a problem with larger diameter cases.
 
Thanks Mike, so basically what your saying is its OK on a ppc and .308 bolt but not on a .223 size bolt.
 
That's my opinion. The .223 sized cases are too prone to pressure spikes and overloads. What may be a safe load one day, may not be safe another.
 
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