Rough chamber, high pressure, or headspace issue?

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longarm21

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I just tried out my brand new Remington 700 Long Range in 7mm Rem Mag, and after two shots, I started getting hard extractions - the bolt would lift fine, but it was the action of pulling the bolt to the rear that was very difficult. It took some serious strength to open the bolt after firing.

I was using Factory Remington Vital Shok with Barnes 140gr TSX in them. Now my reloading experience tells me this can be caused by pressure. The primers did show cratering and there was a small amount of stress on the casing just above the belt of the round.

Now with that said, after firing nearly a full box of 20 through the rifle, with several pull throughs throughout, There were some rounds that extracted without problem, but others that took me having to muscle them out of the chamber. What I did find notable is that replacing fired casings and trying to chamber them took more effort. The rifle however was chambering and extracting unfired cartridges perfectly.

A few observations after the range. The bolt face had a lot of brass shavings in it after going through a box. The chamber was very dirty with brass and carbon and who knows what else.

I came up with a few possibilities:
-high pressure loads - unlikely (since they are factory) but not impossible. I will try a different load and see if it continues.
-packing grease in the chamber causing high pressure? when I got home I gave the chamber a thorough cleaning and pulled a lot of gunk.
-rough chamber, bur in chamber requiring polishing
-headspace issue causing overpressure

Could use some advice here before I contact Remington on Monday. I really hope I don't have to ship it back to Remington to get it rechambered, or have the headspace adjusted as I have a hunting trip in August up in Northern BC.
 
ALL rifles will come with rust preventative in the bore... this must be removed. Every last bit. Otherwise, you can create all sorts of issues.

Assume you didn't clean your bore before shooting?

Just be careful that you didn't ring the barrel?

Hopefully, problems go away after proper cleaning.

Jerry
 
Gunk in chamber will cause pressure. If your worried about a rough chamber or a bur, just look at the fired brass. Your brass will make a mirror of your chamber, look for deep scratches or gouges in the brass. If nothing it might have just been the gunk in the chamber.
 
Ringing the barrel is caused by shooting a round with some form of obstruction in the barrel. The compression of air and gas overpressure bulge the barrel between the advancing bullet and the obstruction, resulting in a characteristic ring at the point of maximum pressure as you look down the barrel. This will generally result in having to replace the barrel.
 
really only guessing ,need good pics of the fired cases .Ones that were tight coming out and were not forced back into chamberto be able to see the case properly
 
Possible that your bolt handle was solder on in the wrong place. Camming notches are not contacting each other properly. OR there was crap in your chamber.
 
I examined the chamber with a light and it looks not bad. No visible burs, but the metal appears to be stained in two places - maybe oil from the factory? I will try to clean some more.
 
Does this barrel/receiver mating look off-centre to anyone else? I note the space between the barrel and the receiver on the left side of this picture. Could be just the angle it was taken.
 
So took it to the range today after a good cleaning and only one round was tight extracting out of ten. I think it's safe to say that it was probably the gunk in the chamber and the fact that these are a pretty hot factory load. Same load different lot number.
 
Just for $hits and giggles, next time your out shooting, watch the camming notches as you lift the bolt handle. Many Rem700 factory actions do not have enough contact to yank the shell clear enough.
 
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