Thread: Very hard extraction.

Good brass and modern rifles often don't respond to "conventional" over pressure signs. If you know the velocity, give me the barrel length, COL and fired case capacity in H2O and I'll run it in Quickload to see what it estimates the actual pressure you're running. As a for example if your powder lot is a bit faster than usual then you could be at over 70,000 psi based on the data you've given.

Originally Posted by Mauser308

The mark you are talking about is on the end of the case neck? Looks about 2-3mm in length?

Looks like a fairly major imprint where there shouldn't be any, to be fair as soon as the bolt handle mooves the case should be free and the rotation of the bolt should take the case with it. How many fired cases do you see with scraps and gouges in the case head from where the extractor has been pressed into the brass?

That scratch could be enough to prevent the case from rotating with the bolt head which could in turn give you massive extraction issues as the case just doesn't want to 'pop' free of the chamber walls. I suspect from my experience you are past primary extraction point without the case coming free from the point at where it's pinched...

The mark is on all 9 cases. I'll be taking the scope and bases off shortly ans the new rail has arrive so can get a better look at things.

There must be a reason ADI say 70 grains of 2217 is maximum load. What ever problem you have with extraction cant be helped by being at the pressure levels you are loading too. Drop your load back a few grains and see if there is any improvement. I would hope there is no stress fracture .

@Driverman the ADI manual is conservative. In the two 7mm rem mags i have had I ran 71.5-72gr 2217 with 162 amax seated to about 5 thou off lands. No pressure issues. It is a very common accurate load in nearly all 7mm mags.

Originally Posted by stug

@Driverman the ADI manual is conservative. In the two 7mm rem mags i have had I ran 71.5-72gr 2217 with 162 amax seated to about 5 thou off lands. No pressure issues. It is a very common accurate load in nearly all 7mm mags.

And mine too. And as has been previously stated it does this with factory loads as well.

Originally Posted by Mauser308

USB Camera...

I have one so may as well give it a go.

I had a Remington doing much the same.... The chamber wasn't straight with the bore.
I didn't, but heard of a guy putting the likes of a go gauge in the chamber and looking down the barrel to see this.

Had a look with the endoscope and, though the quality wasn't great, I could see a tag in the neck area that corresponds with the very light gark on the neck. I cannot feel it with a fingernail or pin. There is also one in the main body of the chamber.

Got a better video of primary extraction after removing the scope. Doing that anyway to put on a rail.

Originally Posted by Mauser308

Not a lot appearing to be out of place there. Clean the snot out of the chamber, then run a dowel with a patch on it around the neck and see if it catches the fibres. If it does likely you found the issue...

That is the plan when I can next walk.

Buy a Sako

Originally Posted by sako75

Buy a Sako

Or one of Toby's favourites, The Improved Sako, otherwise known as a Howa.

Nah, just a little teething problem to sort.