Bolt Extraction Sticky

[338winmag]

A friend has a custom 300 WM that has been used for a couple of seasons and has at least 300 reload rounds down the barrel. The exact same reload formula has been used since its first outing.

For some reason, extraction (dummy rounds, brand new brass, 3x used brass, different bullets, prep rounds) all seem to have a sticky extraction (this is before shooting and after shooting with live rounds). The chamber, bolt and barrel are super clean.

If he places the brass into the press and does a once over, it appears to correct the issue. The big concern is this has never done this before. Would a Go gauge give a clue if there is an issue?

Thanks
3382inmag

 

[Oldtrader3]

Sounds like maybe the chamber is slightly oval and when he resizes the case, it is small enough to chamber?

 

[Kodiak]

If he places the brass into the press and does a once over, it appears to correct the issue.


3382inmag

What "once over?"
Is this with a loaded round? Into a resizing die?

Are the cases over-length, need trimming? Are the cases within spec. dimensions, neck thickness, etc.?

Hummmm, a strange one.

 

[Guest]

I can't imagine the chamber has "shrunk" over time. Any lengthening would certainly not provide this sort of resultant problem. I think a go-gauge is a waste of time and effort and won't tell you anything useful. It could easily be an oval chamber, as Charlie mentioned, but that seems odd to only now be manifesting itself as an issue, if he's had 300rds down the barrel with no trouble. Also, the problem disappearing when cases are resized leads me to believe it's one of a few issues.

It could be a dirty expander ball pulling the shoulder forward on sizing. That would create a long case shoulder and trouble chambering and extracting. Is there resistance when closing the bolt?

It could be an issue in the neck area of the chamber. I'd be curious to see if the neck area of the chamber has a buildup of either carbon or some brass flow, and has become shorter. I've seen a ring of brass deposited at the end of the neck in a chamber more than once, especially in high-pressure magnums. I believe it's brass flow from the case, via vaporization (for lack of a more technical term) at the time of combustion. It could cause brass to wedge in place and stick. It should, by that same mechanism, cause some pressure issues and velocity spikes, so if he's not chronographing his loads, it might help to understand what's happening.

It could be an issue with the brass needing to be annealed, but that doesn't explain why it happens with new brass.

Beyond that, it could still be a dirty chamber. I'd be curious as to how the chamber's been cleaned and with what. It's possible there's some residue in there that is causing the chamber to be a little "grippy" to the brass.

 

[300WSM]

338,

First and foremost this has nothing to do with the chamber. Especially since you say this worked good then now with the same load not working so well.

I have witnessed this...I have experienced this myself...I would be willing to bet dollar bills that you have an EXTRACTOR issue.

Trust me when I tell you an extractor that has become ill will give the operator fits loading and unloading the rifle. Sometimes it is only one of them, just loading the round, sometimes it is both loading and unloading.

If the load hasn't changed and assuming every round he has used in this rifle was within pressure specs, look at the extractor.

I echo again, don't chase your tail on this one by looking into a chamber that won't up and change with normal use....look at the extractor.

May I ask what rifle is this?

 

[BeeTee]

I saw the same thing with my 7RM. In my situation, case length grew just enough to cause more difficult bolt closing on a resized case or loaded round. It took 3-4 loadings to get to that point.

When you identify a case(s) that chambers harder than normal, mark it (or them). During the next full-length resizing session, put a 1/4 turn more on the FL die, size the case, then try it in the rifle. Ideally, you want the bolt to "just" close easily. I needed to adjust the die for a firm bump of the shell holder and die at the top of the stroke. That's where I'll keep it from this point on. BT

 

[338winmag]

Thanks everyone.
He is brnging the rifle over tomorrow afternoon and we are going to look at all things mentioned here.

This is a 100 % custom built rifle. Not sure all the parts.

thanks again
338winmag

 

[JD338]

I would tend to agree that the issue is with the FL resizing die not full resizing the case and/or the expander ball.
Let us know what you find out.

JD338

 

[SJB358]

Steve are you measuring them using the Headspace gauge dial? Seems odd they close tight if there bumped enough to chamber like BT mentioned or the neck is engaging the front of the chamber due to case stretching.

 

[300WSM]

Thanks everyone.
He is brnging the rifle over tomorrow afternoon and we are going to look at all things mentioned here.

This is a 100 % custom built rifle. Not sure all the parts.

thanks again
338winmag

Here is a couple more things to look for and will help eliminate some ideas...

#1 are there any nicks on the case head after putting them in the chamber. ? This is one way that points straight to extractor problems. If the case has a little bur or nick on the case head stop right there. You need to address the extractor.

#2 Are these cases used in the same rifle? If so that eliminates the re-sizing problem. If they are used in different rifles then that very well could be a problem...the reloader could possibly not be turning the die set a legit 1/4 turn after it bottoms out on the shell holder.

Good luck

 

[FOTIS]

Have a gunsmith check the chamber.

 

[338winmag]

Sorry for the late post reply.
He is an excellent reloader, but even so we reviewed everything. Inspected cases, measurements and practices. Look at the extracter, chamber, and then looked at one last thing.

The rifle's bolt's alan bolt tensioner. Guess what? It was loose. Barely loose but .... that was the issue. Everything is back to norm. A few small twists of an alan wrench and it is chambering and extracting as it should.

Thanks all
Steve

 

[300WSM]

Sorry for the late post reply.
He is an excellent reloader, but even so we reviewed everything. Inspected cases, measurements and practices. Look at the extracter, chamber, and then looked at one last thing.

The rifle's bolt's alan bolt tensioner. Guess what? It was loose. Barely loose but .... that was the issue. Everything is back to norm. A few small twists of an alan wrench and it is chambering and extracting as it should.

Thanks all
Steve

338, that is good to hear. Now if you guys can figure out a way to get those shelves stocked at the gun stores then you guys deserve a medal. Not until then. :lol: :lol: :lol: :lol: