bolt is tight when closing

[drdarrin@sbcglobal.net]

I you really want to figure out what's going on, try some of this.

http://en.wikipedia.org/wiki/Marking_blue

Coat the entire case, including the bullet, carefully chamber the round and look for where the blue is rubbed off.

If it was empty brass, I'd suggest just smoking the brass with a match or candle but since it's not, I'm sure you don't need that kind of excitement in your life.

[LynnJr]

If you have a dial caliper here is a quick way to check your brasses headspace.Electronic calipers run $10 at Harbor Freight.

Take a cartridge case and simply slide it over your current case so it bumps up against the shoulder.You can use a larger caliber or a piece of pistol brass.

If you look at the 2 pictures you will see a piece of 300 wsm slid over a piece of 6 Dasher brass.It has the shoulder bumped back 0.001

In your example you said the brass was tough on closing but you never mentioned how it extracted?

If it extracted smoothly without a click at the top of the bolt lift after being fired it is very likely the shoulder needs to be bumped back a small amount.

If you measure your rounds the longer ones will be the tight ones.

[khw9mm]

Sounds like it's an ammo issue. If you're serious about getting into precision bolt guns, I'd suggest you start reloading and properly sizing your brass.


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[CSACANNONEER]

next time I go. which may not be for some time I find out manufacturer. I would use my GMM I have but I feel its such a waste to use at a indoor 25yard range.

I'm betting that it is "new" because it was loaded in new brass instead of using used brass. But, I bet it was loaded by the same local 06FFL (ammunition manufacturer) who loads the "range reloads" and he didn't set his dies properly or have a QC dept to catch it.

[Simi-Surfer]

Sounds like the ammo.

[Scotty]

It could also be a high primer. I ran into that issue a while back. Had to cut the primer pockets deeper.

[jpx0123]

If you have a dial caliper here is a quick way to check your brasses headspace.Electronic calipers run $10 at Harbor Freight.

Take a cartridge case and simply slide it over your current case so it bumps up against the shoulder.You can use a larger caliber or a piece of pistol brass.

If you look at the 2 pictures you will see a piece of 300 wsm slid over a piece of 6 Dasher brass.It has the shoulder bumped back 0.001

In your example you said the brass was tough on closing but you never mentioned how it extracted?

If it extracted smoothly without a click at the top of the bolt lift after being fired it is very likely the shoulder needs to be bumped back a small amount.

If you measure your rounds the longer ones will be the tight ones.

extractions were fine. issue only when closing the bolt.

[thegiff]

Only other thing I can think of is the barrel might not be centered into the bolt, causing the extractor to hang up when trying to snap past the cartridge rim. I had a rifle with that problem, and found that a cartridge could be rotated such that it would feed easily when closing the bolt, and rotated some more and it would hang up when closing the bolt. I fixed it by grinding a little bit of clearance on the extractor hook.

[LynnJr]

extractions were fine. issue only when closing the bolt.

When your gun goes bang and the pressure builds to the 60,000 psi range your brass expands in any direction it can.

After the pressure is gone the brass relaxes or springs back towards its original state.

It doesn't spring back 100%.

If your brass extracts easily but chambers tightly 99 and 44/100 of the time it needs the shoulder bumped.

If it had been a mechanical issue the problem would not go away on extraction.

[jpx0123]

So the consensus so far is the ammo I have been using is the issue?

[killshot44]

That'd be a Yes.

[Pauliedad]

Goodmorning tag

[CK_32]

Ammo. I had this issue the first time I started reloading. My necks were not resized properly and I had the same issue you were describing. Snap caps are very undercut to fit into almost any action. Hold it next to a live your and you will see. More of the OAL of a 223 than a 308.

Try quality ammo and I'm sure it will resolve the issue. Range stuff is usually bottom if the barrel stuff by half azzed mfg's sold at normal quality MSRP. Avoid range ammo as much as possible. Only if desperate.


Also check your throat for any debris or fouling. I noticed when my throat was super dirty or had crud or on some of my guns like my cousins 91/30 that had some pitting/tooling it would be hard to seat and VERY hard to extract.

[jpx0123]

thanks to everyone. i'll try some better factory ammo. if the problem persists, I will be back.

[200Apples]

.
Here's my experience (which isn't much...)

Ruger M77 action, .308 chambering.

GGG (Lithuanina), other eastern-bloc stuff, American Eagle, Outback, Winchester, all load fine. Bolt closes as it "should". With Fiocchi, however, bolt closes with some effort and there's a crease left on the brass's datum line.

It's the ammo.

Go down and fetch ye moar.


:-)