Need help with an interesting problem

[amlevin]

I have a newly built .223 and have a "sometimes" problem

The cases are all Lapua Match that have had the necks "skim cut" just to even them out (now ~.0005" total variance in neck wall thickness.

Neck sized after fire forming. OD is .248" with seated bullet and .2535" fired.


While shooting these cartridges, one or two in a batch will stick on extraction. The case(s) from subsequent shots extract with no sticking whatever. Each case that sticks has no pressure signs and the groups are nice and tight, unlike what may occur if the sticking case had a pressure spike.

Chamber is kept clean and the extracted cases that had stuck aren't exceptional.

Any Ideas? Why would one or two cases stick like this yet the majority just extract like normal? Oh yes, all are trimmed to the same length.

 

[22BRGUY]

Any possibility of a small piece of brass or dirt holding up the extractor itself?

 

[jonbearman]

How does the bolt feel when closing as in resistance?

 

[357Mag]

Amlevin -

Howdy !

Have you FL sized all the cases ? Or, are you NS + shoulder bumping ?

Have you checked any/all cases for consistency of base diam, shoulder diam ?

Just wondering....


With regards,
357Mag

 

[jlow]

Agree with the above poster as to the question on FL sizing. It could well be that some of your brass was fired with a hot load and it expanded your case/case head enough to cause a problem aggravated with yet another hot load. Have you put any of those hard extractors in a case gauge or just pop them in the chamber to see if they slide in easily? Another method would be to check your prep but unfired brass in case gauge/chamber for the same problem.

 

[BCoates]

I have a Rem 700 and a Savage that don't extract every case depending on how the cartride is fed. On the Rem 700 I think the extractor is not slipping into the groove. On the Savage, I think the extractor is not gripping the case properly. In either case it is not a load or case problem. It just depends on how the cartridges are loaded.

 

[dkhunt14]

How are the cases sticking? Are they hard from start of bolt lift or sticky at top? Or do they just slide out hard when you slide the bolt open? Matt

 

[GrocMax]

If not a case of sticking anywhere, and if this is a Savage use a larger detent ball under the extractor claw, the factory detent ball is small, it wiggles around a bit, occasionally you'll get cases that the rim diameter is on the small side, and its wiggled out, and the extractor doesn't grab enough rim for primary extraction to occur. The larger ball forces the extractor over the rim always. I'm trying to remember the diameters but got BF.

Factory is I think 1/8"-.125", large ball is 9/64-.140"

 

[chkunz]

Are you shooting near max or over max loads?

 

[Scott Harris]

I've seen your problem when the F/L sizing die does not size the base of the case adequately. In my case it happens when I use my 223 "match" chamber reamer and the shooter is using a factory die. Unfortunately, the "match" reamer seems to use a really tight base dimension and some standard dies do not size enough for this chamber spec. Live and learn, I will order only SAAMI-spec chamber reamers from now on. You can address this problem with a small-base die or custom sizing die.....or try different factory dies in an attempt to find one that sizes the base adequately

 

[Tozguy]

When that exact problem happened to me, a Redding body die (pn 75111) was the solution.
I only used it on the tight cases because there were only 1 or two of them per batch. Case length was not changed by the body die so resizing must be minimal.

 

[amlevin]

How are the cases sticking? Are they hard from start of bolt lift or sticky at top? Or do they just slide out hard when you slide the bolt open? Matt

Bolt lift is perfectly normal but when I try to extract the case it "pulls back". I have to slap the bolt knob from front to back to get the case to extract.

Loads are well under max.

Checked a bunch of cases yesterday with a case gauge and found that the base of the cartridge didn't want to enter the gauge easily. Ran them through a Redding Body die and it improved.

Will be taking the rifle to the 'smith soon as I have a nagging suspicion I need the bolt re-timed. Could be an accumulation of issues, case bases expanded and not fully resized and not enough "cam" when the bolt is opened.