Extraction problems of new unfired 6 PPC Lapua brass? Problem or not?

H

hardrockjr

New member
Just stumbled upon the situation described below while setting up bullet seating for a new rifle using new brass. Looking for shooters comments.

I have found that my rifles will not extract unfired 6 PPC Lapua 220 Russian cases after they have been chambered, but will extract cases after they have been fired. This happens (and was confirmed) on both my BAT and Marsh action rifles. I measured the bases of fired cases and they are about 0.002- 0.003" greater in diameter than unfired cases. Is this a normal situation? If not, what needs to be done to get the unfired cases to extract? Am thinking of a situation when fireforming and the round was chambered but had to be unchambered and extracted without firing. In that case, I would need to use a cleaning rod inserted into the muzzle end to push the round back into the action, but that seems a bit iffy, especially if force is needed to be applied to break the bullet free from the rifling.
 
Extraction of new 6 PPC brass

Lawrence W. said:
Why are you extracting unfired cases in the first place?
Click to expand...

Lawrence,

I chose a new Lapua case to go through the process of determining a new bullet seating depth for this new rifle. It is an iterative process of chambering and extracting a dummy cartridge and adjusting seating depth till I can get the bullet to just touch the lands of the rifling. That is when I discovered this situation. I was surprised to encounter this problem, and wonder if this is a normal thing. And yes, I can use fired cases instead but still raise the question on whether this situation is to be expected for new unfired brass cases.
 
I believe that your unfired cases are well short of fitting your chambers, and that when you close your bolts you are pushing the case to the front of the chamber, and not hooking their rims with your extractors. Once they are fire formed this is not a problem. Pull the bolts and put a case on the bolt face, hooked by the extractor, and move it fore and aft to see how much wiggle room you have between the front of the rim and the surface of the extractor that touches it when extracting a case. What you may find is that this clearance is pretty small. Question..why are you playing with seating depth on cases that have not been fired. I usually seat a little longer than jam, with at least .003 neck tension, so that cases are held against the bolt face before firing. I do not believe that this prevents the primer knocking them forward, but after they are chambered, as they go off, the extractor will act to limit their forward travel if the bullet does not. I ran into your exact situation with a case that had been sized for my rifle, when I tried it in my friend's three lug BAT. It would not extract. When I checked the extractor clearance on the rim, I found that there was almost none, and concluded that my case and the chamber that it was sized for, were just enough shorter so as not to allow the extractor to hook the case rim. There was not problem with cases that had been fired in his rifle. Also, I made a mental note to keep very close tabs on shoulder bump for that rifle, using a tight case for the dimension to bump back from.
 
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hardrockjr said:
Just stumbled upon the situation described below while setting up bullet seating for a new rifle using new brass. Looking for shooters comments.

I have found that my rifles will not extract unfired 6 PPC Lapua 220 Russian cases after they have been chambered, but will extract cases after they have been fired. This happens (and was confirmed) on both my BAT and Marsh action rifles. I measured the bases of fired cases and they are about 0.002- 0.003" greater in diameter than unfired cases. Is this a normal situation? If not, what needs to be done to get the unfired cases to extract? Am thinking of a situation when fireforming and the round was chambered but had to be unchambered and extracted without firing. In that case, I would need to use a cleaning rod inserted into the muzzle end to push the round back into the action, but that seems a bit iffy, especially if force is needed to be applied to break the bullet free from the rifling.
Click to expand...

Who chambered your rifles and how is your headspace set?
 
sounds like the chamber is to deep. I like for my 220 Russian cases to have a slight crush fit when preparing to blow them out. lee
 
hardrockjr said:
Lawrence,

I chose a new Lapua case to go through the process of determining a new bullet seating depth for this new rifle.
Click to expand...

Until the case is fire formed which involves blowing out the shoulder no useful information can be found doing what you are attempting to do.
 
Thanks to all.

Never thought about the new case being too short for the extractor to grab before firing. It makes sense. Anyway, I will keep the advice when fire forming cases.
 
And note that while the phrase is (quite correctly) "blowing out the shoulder" this does not mean that shoulders blow forward. If that chamber is slobbered in with excessive headspace then the cases will stretch at the rear to slowly and painfully fill the gap. Over time. And crookedywise to boot.

But they'll go boom when you pull the trigger

And come back out when you pull the bolt hannle

:)

al
 
One thing I am surprised

no one suggested was putting a false shoulder on your 220 Russian cases. I have to concur that you may have a too long chamber, but in reality it may only be .010-.015 too long. that would be enough to keep you from extracting the un fired case. Use a 25 caliber expansion iron after you expand to .243 and after you neck turn the brass. Then run it back thru your FL die with a .015 or .020 shim under the die. This should give the crush fit mentioned before, allow for good ignition, and allow you to fireform w/o worrying about seating depth. Seating depth is not an issue during fireform, or at least it should not be of concern, until the case is at least fitted to the chamber by firing it once. Just MHO.

David
 
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