Extraction problems

Hi guys I have been using a 7mm Mag for long range gong shots for the last year. Not using a super hot load Federal brass weight sorted 73gr 2225 under a Sierra 168 match doing about 2960fps with good accuracy hitting gongs out to 1600m. I have put about 700 rounds through it with no issues. During the last couple of shoots I have had about 30% of the brass with difficult extraction. The bolt is not stiff to lift but cannot draw the case out of the action. A sharp tap on the bolt handle with the ammo box or similar breaks it loose. The primers do not look overly flat and no other signs of over pressure. All case lengths checked no difference between the problem and no problem cases. At no time are the rounds chambered with any moisture on them as I know this can cause difficult extraction

During the last shoot in Culverden I segregated the cases that had the problem. On measuring them in front of the belt, problem cases .513 no problem cases.512 after sizing problem cases .512 no problem cases .511. So the die is not bringing all the cases back to the same size.

Before sizing if you re chamber a problem case it will chamber with non stiff bolt close but again will catch in the chamber again. If sized it will extract no problem.

As an aside I looked at the chamber and barrel with a mates bore scope to gauge throat erosion after 700 rounds to find no sign at all, I am using the David Tubb Boron Nitride bullet coating system. The one thing I did notice was the chamber how do I put this was not super smooth in that it looks like it needs a good polish and the brass always looks the same with very fine radial rings around them. I have tried to photograph but no easy.

My own thoughts are possible hotter batch of powder causing a lift is pressure. I need to rechrony loads to see if things have changed

Any semi sensible suggestions would be appreciated.

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Attachment 74323

How many reloads have you done? Might just be time to bin.

Have you been doing some annealing? Looks like the shoulder may have been annealed and softened?

@stug some brass has probably done 10-15 reloads ( No loose primer pockets yet) how would this be an issue? All brass is weight sorted so some has been reloaded a lot some only one or two times as it might have just been purchased.
@Echo yes my brass is annealed every reload with an AMP machine could you please explain what your point is thanks

10-15 reloads is pretty good. The base of the case will be work hardened, hence why it is not staying at .511 You can/use to be able to buy a collet type die that would resize the case just in front of the belt properly. Might be hard to get know, they weren't that popular/common when they came out.

Here is the website for the collet die Innovative Technologies - Reloading Equipment

@stug thanks never heard of them before. my wife is in the USA I will see if she can bring one home.

If its been fired 10-15 times its toast, tight primer pockets or not, bin it, its not worth the hassle, its done its work, needs retiring & owes you nothing.

Some brass will last longer than others.

Some cartridges will only last 5-10, some like the 6 PPC with tight chamber to die tolerances will do 40 plus easily, ie usually out last a barrel.

thats an awsome run out of your brass. retirement for sure. Time for some Norma

@stug thanks for the info on the collet die. I contacted Larry he was very helpful and sent one of to my wife's hotel pronto. Yes it works as well as the guff says. All problem brass has had the treatment and is now back to factory spec. You can even run loaded ammo through it with no problem. The top of the die acts as a go/ no go gauge. If it drops down to make contact with the belt no bother running it through the die. It is a very clever solution to the problem

Attachment 75212
Loaded round about to be sized
Attachment 75213
Top of die acts as a go/no go gauge note this case needs to be run through the die
Attachment 75214
Collet on loaded round
Attachment 75215
Die and collet

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I hope the next thread is not about head separation

That is pretty impressive life for a 300 wm. My first loading with the 300 was with hornady brass and only lasted 4 reloads and the it cracked where your sizing mark is. Interestingly the hornady brass sized to the same point on your federal. The same Forster FL die sizes my Norma brass right to the belt.

Cowboy it will look like the die is sizing up to the belt however due to the spring back in the brass over time your die will not be able to size it back enough.

Unlike non-belted cases, the belt prevents conventional full length dies from traveling far enough down the case. This limits the amount of resizing, and brass is plowed rearward. The brass builds up just above the belt at each reloading, and cases expand. Neck sizing dies don't bump the shoulder back or resize the tapered case wall. The best solution is to full length resize accurately, and use this collet die to reduce case width.

While you are having no problem go with it. That was me for 10 yrs then with the new barrel and tighter chamber all of a sudden closing the bolt became stiff.

Innovative Technologies - Reloading Equipment

Dermastor I shoot 7 mag also and 10-15 reloads is quiet a good run for that brass
Now most metals including some ferrous ones have spring in them once that is gone from constant expansion and contraction
ie Resizing when they expand they will not bounce back a little '' its only thousandths of an inch'' keeping it tight in the chamber
This may not be your problem but it can happen then if you don't trim cases properly or too long they can hammer forward into the lands
when fired jamming the brass tightly in the chamber ''can and does happen'' then comes the AR 2225 I found that in my rifle it was too slow
tending to have higher pressures and that mixed with old brass long brass could form a similar problem that you have
If you have been shooting and had no problems until now the I doubt whether your chamber is rough or dirty enough to jam cases once fired
If your bullets are hard to push into the chamber when loading then it could be bulging of the base of the brass as somebody has already said
and the bush will fix that
The last thing is are you sure it is the case sticking and not your bolt hooking somewhere
Mate be very careful with slow burning powders such as AR 2225 in 7mag as secondary explosions can occur and raise pressure to dangerous levels
Most people I know use AR 2213sc up to 150gr projectiles an AR 2217 up to 180gr
I'm not saying it can't be done with AR 2225 but I would be very careful
cheers