Bolt hard to close

[HuntTN]

I recently purchased a weatherby vanguard 300 win mag and finally got it out to shoot. I had a half a box of 180gr federal trophy copper bullets laying around and figured that would get my scope dialed in. I shot 5 rounds and had it shooting where I wanted it. I let the barrel cool and was going to shoot the last 5 to see how it shot. When I loaded the next round I noticed the bolt didn’t want to close so I took the round out and looked it over and everything looked good so I grabbed a different round and same thing. 4 of the last 5 rounds had the same problem. The bolt would close but had to use pretty hard force to lock it down. That ended the shooting. Got home and measured the good vs the bad round every way I could think to measure and couldn’t find a difference between the two knocked the bullet out of a bad one and tried to just load the case and still same problem. Painted it with a sharpie and no marks or problems with the case. I can’t figure the differences between the two. Ran some reloads I had made up with no problem as well as some other factory loads. What do I need to check or what Else could cause this problem? Thanks.

 

[Mag_7s]

If I'm reading this correctly, it sounds like you were using factory ammo, which should be well in specs. Maybe there was a piece of debris in the chamber/shoulder area. Have you tried to clean the chamber using a mop and then test another round?

 

[Macintosh]

Ditto the above--does 300win mag headspace off the belt? If so that's where it would be causing the hangup. Is it possible a tiny piece of brass shaved off from feed ramp or extractor got lodged into the chamber-rim where the belt seats? I'd give that a very good cleaning and try again. seems odd that diff shells from the same box of ammo do and dont have the issue--if you have any of the first shots that you could rechamber, do they now hang up, or are they still chambering normally? That might confirm if the issue is with the brass or with the chamber--if the brass that chambered normally earlier is now chambering hard, that means it's the gun.

 

[Wapiti1]

Clean the chamber, paying attention to any brass shavings where the belt sits in the chamber. I would suspect a sharp edge at the breech may be shaving brass and it is building up in the belt recess of the chamber. To fix this, you need to polish the edge with abrasive cloth on a carriage bolt head. Pretty simple to do, and you use 320 or 400 grit paper.

I would also remove the ejector and make sure the spring, hole, and ejector are clean. A sticky ejector can do what you are describing, but typically will put a noticeable mark on the case head. Do the same with the extractor.

If niether is the problem, then I would throw away the brass that doesn't load easily and keep on shooting. It could just be a min spec chamber.

Jeremy

 

[HuntTN]

Ditto the above--does 300win mag headspace off the belt? If so that's where it would be causing the hangup. Is it possible a tiny piece of brass shaved off from feed ramp or extractor got lodged into the chamber-rim where the belt seats? I'd give that a very good cleaning and try again. seems odd that diff shells from the same box of ammo do and dont have the issue--if you have any of the first shots that you could rechamber, do they now hang up, or are they still chambering normally? That might confirm if the issue is with the brass or with the chamber--if the brass that chambered normally earlier is now chambering hard, that means it's the gun.

The spent brass chambers normal. Have check all brass with a precision mic and nothing seems off there. I’ll give it a good cleaning this evening. Seems like if something was in the chamber they would all be hard to close but all other factory ammo I’ve tried loads fine.

 

[Macintosh]

Not sure I understand you, are you saying that the empty brass from the first 5 rounds that chambered normally STILL chambers normally, and that the other brass still chambers hard? Or does ALL the brass now chamber hard?

 

[HuntTN]

Not sure I understand you, are you saying that the empty brass from the first 5 rounds that chambered normally STILL chambers normally, and that the other brass all chambers hard? Or does ALL the brass now chamber hard?

All brass that chambered normal still chamber fine. Didn’t shoot any ammo that didn’t chamber normal but did knock a bullet out of one and it’s still hard to close without bullet.

 

[Mag_7s]

HuntTN, this is a pretty tough one, especially since it is factory ammo. Sounds like you have looked into about everything that could be causing a stiff bolt close. The only other thing I can think of is maybe there is a bad batch of brass, and a few slipped past the QC. I think I would just do a deep clean of the chamber, boltface and lug recess. Discard the remaining rounds and try new ammo. If the problem still persists, take to a smith.

 

[Wrench]

Typically the only thing that will give the result you have is well out of dimension ammo and foreign objects in the space occupied by the brass.....and in rare cases carbon rings.

I'd measure the case length on the fired and hard to chamber brass....and pay close attention to the shoulder. Sometimes if the crimp operation is too aggressive it will swell the case at the shoulder. The swell will be very difficult to spot, but a straight edge against the body will show it if examined closely.

Brass shaving on the bolt face and debris under the bolt lugs are other hiding spots for losing headspace.