Rem 700 lock up questions

[Left_to_ Lobster]

A buddy has a factory Rem 700 in 7mm mag. He's had issues with the bolt locking up after about the 5th shot. He says it it only happens with factory loads with heavier grain rounds. He doesn't reload and he's not shooting one right after another. Rather using a spotting scope and checking his shots before shooting. Also he's had this issue with 5 different brands of ammo with the heavier grains. The bolt locks right up in the gun and it's very hard to unlock. Thoughts ?

 

[338 dude]

Sounds like overpressure in someway and fairly substantial overpressure I don't know about your cleaning regimen or if you have a borescope but my first guess would be check for a carbon ring since they are not hot reloads

 

[LaHunter]

What does the brass look like? Definitely sounds like over pressure. How many rounds through the rifle since the bore was thoroughly cleaned? I agree with Bill Cauley Jr above about the borescope and carbon ring. How is the bolt function with no round in the chamber? How long since the firing pin was removed and cleaned / lubed?

 

[25WSM]

Lots of things can cause this. Need pics of brass first. Body and primer area.
Shep

 

[Bob Wright]

Bought a used R700 that had a rust patina in the entire chamber. It caused sticky extraction. Look into the chamber with a bright light. If it's brown, lightly polish with a bore mop and bore polish. Otherwise, take it to a Smith, if you want another opinion. It might be a tight chambering that factory ammo does not like. Could be that nasty carbon ring if it's a used rifle with lack of maintenance.

 

[jdyoung]

A buddy has a factory Rem 700 in 7mm mag. He's had issues with the bolt locking up after about the 5th shot. He says it it only happens with factory loads with heavier grain rounds. He doesn't reload and he's not shooting one right after another. Rather using a spotting scope and checking his shots before shooting. Also he's had this issue with 5 different brands of ammo with the heavier grains. The bolt locks right up in the gun and it's very hard to unlock. Thoughts ?

My money is on the throat is loading up . Is he shooting regular (gilding metal) jacketed bullets and copper bullets without cleaning before switching from one to the other ?