Bolt Won't Close on a Couple Factory Rounds - Same Box

[zog]

I have never encountered this - My bolt would not close on two of the rounds from a factory box. All other 18 rounds were fine.

Rifle is Sako 85 Finnlight

Ammo is Winchester Silvertip 300 WSM 150 gr.

I have shot nothing but this ammo, about 300 rounds in the last five years.

What can cause this?

 

[BuLLet]

Defective ammo, Dirty Chamber... Carbon Ring

Bullet seating even...

 

[FatBoy]

If you have other unfired rounds and an OAL gaugeI would check base to ogive and see if there is a difference. Then, I'd weigh the rounds and see if the ones that don't chamber are 20 or more grains heavier. Then check the base to datum line.

In lue of all that, color the whole damn thing in black sharpie and see where its dragging.

 

[zog]

So basically, the cartridge probably isn't seating far enough to allow the bolt to move forward enough so the lugs are hitting stops and not clearing into their recesses. The bolt closing isn't just really tight, it feels like it is hitting stops and can't move at all.

I'l try both of the above thanks.

 

[FatBoy]

Most likely the bullets are seating deep into the lands or you have a carbon ring and they are hitting that in the throat. You can usually see this with the naked eye as etching on the bullets around the ogive.

If you have a carbon ring this sometimes caused pressure too, usually some swiping on the case head.

 

[spife7980]

Color it with a sharpie. Itll show you were its contacting.

 

[EN2722]

As @spife7980 said, color the the entire projectile with a sharpie and then attempt to chamber the rounds. It'll show up. Another question, at what point when you are chambering do you start to feel the tension on the bolt handle? Is it in the beginning, middle, or end? I ask because I've had Hornady 243 ammo that did the same thing and after hours of checking everything I found out that the cases were outside of Sammi specs for case body and shoulders looked elongated.

 

[spife7980]

Not the tip of the projectile, that wont touch anything and just floats in space. Color the bullet away from the tip toward the bearing surface and just a smidge on the nose but also sharpie the case shoulders, neck and diameters because it can be more than just the bullet too.

 

[Snuby642]

L.E. Wilson Case Length Headspace Ga 8.6 Blackout

L.E. Wilson has been making precision reloading tools for over 80 years. The Case Length Headspace Gauge allows reloaders to measure case length from...

www.midwayusa.com

 

[spife7980]

^
Gross

 

[jay308]

I had a box of Winchester Super X in 300 WM that where crimped to hell and back. The crimp was way over done and prevented the neck of the brass from seating all the way in. About half of the box was this way.

 

[zog]

I just happen to have twin rifles so I was able to try the bad rounds in both. I made sure to clean both rifles well. Same exact bolt issue with those two rounds both rifles. I tried the other shells in the box and all worked perfectly in both rifles.


BEFORE Good round left, bad round right . . .

AFTER good round left, bad round right.

Looks like just what you all said - bullet is hitting lands and not allowing bolt to move forward enough to close. The COAL is identical, using digital calipers, so it's something other than seating depth. Maybe faulty bullet forging?. . .

I guess if it's only two rounds out of the 400 or so I have shot, it's not even a thing. I was just very surprised that they could be any different at all from a factory process. I just hope it doesn't happen when I least expect it.

 

[Snuby642]

Could be lightning or my eyesight but it looks like two different bullets to me.

Like the ogive is different?

 

[zog]

Could be lightning or my eyesight but it looks like two different bullets to me.

Like the ogive is different?

Here they are cleaned up. Same cratridges - Good one on the left, bad on the right, after cycling (or attempting to cycle) many times. The land-mark is actually more visible against the black now.

One other clue - no matter how I rotate the cartridge, the land-mark always is on that one side of the bullet -so I guess the cartridge must be off center somehow. I tried to close the bolt on the round repeatedly, rotating the round 90 degrees each time, and it only marks on that side of the bullet where you can see it in the photo.

I checked bullet diameter right at the top of the shell at .3075 for both with my digital calipers.

You are right - the bad bullet on the right looks different, slighty shorter or seated further. It's OAL is shorter by .02 but I assumed that is from the deformed tip from dropping it on concrete.

 

[Snuby642]

It was just a visual effect.

So the part about being dropped?
Before failure to chamber or after?

It does look crooked.
Maybe crooked from factory but dropped would be user error.

In that case next time drop them in mud or grass not concrete.

 

[zog]

So the part about being dropped?
Before failure to chamber or after?

In that case next time drop them in mud or grass not concrete.

Dropped them just now while I was testing them in my shop, so after chamber failure. They were having a problem new out of the box yesterday at the range. When I got home I measured identical OAL. Tip on the bad round got dented this morning and OAL is now shorter.

Good advice either way.

 

[Snuby642]

Sorry couldn't help it.

When I have ran into the lands, it's pretty much all the the way around, and eaven.

I think hitting on one side tells the story.
You could roll them on a flat surface for a quick look.

 

[Snuby642]

Bad handling at the factory or a goob at a store drops them.

Issues when chambering in a hurry.
Magazine issues.

Lots of things happened to my ammo.

I save all these things in a database.

When I shank a shot I go to my database and rotate out file problems to the guys looking.

A lot easier than making stuff up on the fly.

 

[NT1959]

I have never encountered this - My bolt would not close on two of the rounds from a factory box. All other 18 rounds were fine.

Rifle is Sako 85 Finnlight

Ammo is Winchester Silvertip 300 WSM 150 gr.

I have shot nothing but this ammo, about 300 rounds in the last five years.

What can cause this? I’m

I registered on snipershide just now so that I could respond to this topic... (long time listener, first time caller yadi yadi)

I hope it's ok to comment on an old thread.

Today, I was going through all of my old(er) inventory and thought I'd dig a little deeper into an issue I had with some cartridges in a box of Winchester Ballistic Silvertip 150 gr ammo for 300 WSM I'd marked "DO NOT USE! 4 cartridges will not chamber in either of my 300 WSM rifles"

I wondered if anybody else had the same experience as I had with this ammo. Google hit on this very SH thread.

I've put perhaps a half dozen boxes of this factory ammo thru my 2 300 WSM's (both stock, off-the-shelf rifles). I had attempted to reach out to Winchester Ammunition on 3 separate occasions over the years to see what their response would be about such failures with this ammo. Never heard back.

Anyway, today after I verified that the 4 cartridges wouldn't chamber in either of my 300 WSM rifles, that the bolt wouldn't close, I measured them with my Hornady headspace comparator using the E420 insert. WOW! The shoulders of these 4 cartridges measure between 3 and 6 thousandths bigger than what the rifles can take (based on fireformed case measurements); between 7 and 10 thousandths bigger than the good factory ammo cartridges. So, yes, they cannot be chambered, the shoulder is not setback far enough to fit the chamber's headspace.

I cannot remember if I was "in the field" (hunting) or at the range when I discovered these bad cartridges. Regardless, these incorrectly sized cases got past Winchester's QA and into my magazine. Not a happy thing.

I now (usually) reload for most of my hunting rifles.

My $.02

 

[Elite_KG]

I have has this issue with m-16 style extractors. The extractor is too thick at the end of the bolt nose. What happens is when the cartridge is held in the bolt face, the extractor outer face extends out past the OD or circumference of the bolt. The extractor protruding prevents or binds the bolt from rotating to the closed position. I just fixed one of these 2 weeks ago on a Defiance 300 Ultra-Mag.
Not saying this is your issue, but it could be. Look for rub marks on the extractor and gouge marks on the rim of the brass.