Bolt will not close on some Factory Ammo????

[CjC73]

So I picked up a rifle pretty cheap and previous owner was upfront about this issue. Said some factory rounds would not let the bolt close. But shot fine when bolt did close. I ran the factory ammo he sent thru the rifle (not firing them). Some chambered fine, a lot chambered with more force than normal and one or two wouldn't allow me to close it at all. I took one round that chambered easily and the one that wouldn't and did some quick measurements and didn't notice anything that stood out. I tried the round that didn't chamber in another rifle, chambered fine. I have some more factory ammo to try and also want to resize some brass to see if it will chamber.

Any suggestions on what could be the issue? Bad chamber reaming (this is a factory rifle)? Bolt lugs?

 

[Willie]

Might be very short freebore. Use a magnifier to check for lands imprint on bullet ogive. Then cover entire round with a Sharpie, chamber round and examine cases for where it's marking.

 

[jepp2]

did some quick measurements and didn't notice anything that stood out

Can you share what you measured?

 

[CjC73]

outside neck diameter.
length to ogive
diameter in a couple places of the case
tried to get length from where the shoulder starts to base of case.

 

[Texas10]

I suspect that measuring the base to shoulder datum would reveal what's causing the issue you are having. Easy to fix if it's a Savage barrel or a Remington with a barrel nut.

What is the make and model?

You can buy or rent a go gage in the proper caliber & chambering and if the bolt will not close on the go gage, it was set up with a short chamber.

 

[Uthink Uknow]

OAL of case, perhaps.
You may be running the case into the end of the leade. If this is the case, you may be crimping the neck into the bullet and that is a no-no.
It just sounds like a short chambering job. It doesn’t take much in difference of lengths to throw the whole job off.

 

[CjC73]

it's a Winchester M70. Factory, no mods to it.

the ammo in question is factory ammo. not reloads. I want to size some brass and try, hope to try that tonight.

 

[Milo 2.0]

I would check to see if it the bullet hanging things up, you can do that by marking the bullet or pulling a couple and just try the brass alone.
Try firing a couple cases that feed, then compare to cases with pulled bullets.
I had the same type issue, Tikka T3 and Nosler factory ammo, stumped me. It was not the bullet, and bolt closed on a GO gauge. And not every case, just random ones. I borescoped the chamber neck area, did not see squat, finally got mad enough and just rammed a few home and fired them. The problem, whatever it was solved itself, whatever it was was miniscule in nature.
Of coarse that did not stop a WTF email to the ammo mfg, which I was able to back out of somewhat gracefully, lol

 

[CjC73]

finally got mad enough and just rammed a few home and fired them.

so you just forced the bolt closed and fired?

I have some empty brass I'll try tonight... some 1x fired and some new Hornady brass.

 

[Milo 2.0]

Actually, now I remember, the first fired pc of brass had a dent on the shoulder, none after, it was just a spec of something in the chamber, came out first rd fired.

 

[Milo 2.0]

so you just forced the bolt closed and fired?

I have some empty brass I'll try tonight... some 1x fired and some new Hornady brass.

In a way yes, once I rammed it in, bolt closed easy. I had run a GO gauge and had taken many readings, did not make sense.

 

[CjC73]

ok, so things to try tonight
- measure brass OAL
- try more factory ammo thru it
- get the round that didn't chamber and force it closed
- try new and 1x fired empty brass
- try to resize some brass and chamber

 

[jepp2]

Said some factory rounds would not let the bolt close. But shot fine when bolt did close. I ran the factory ammo he sent thru the rifle (not firing them). Some chambered fine, a lot chambered with more force than normal and one or two wouldn't allow me to close it at all.

So you have fired cases, loaded and unfired that the bolt would close on, bolt would close hard, and the bolt wouldn't close on. And you have taken measurements on all 4 groups of these for:
-outside neck diameter.
-length to ogive
-diameter in a couple places of the case
-tried to get length from where the shoulder starts to base of case

And you noticed no differences? How are you going to know what to size the fired brass to, if you can't determine what is causing the bolt not to close?

 

[CjC73]

I have loaded factory ammo. 1x fired brass I bought on a forum. And new Hornady brass. No fired brass from this rifle yet.

First is to determine why it won't close on all rounds. If I resize a new case and it chambers fine, then I'll just pull bullets and resize everything.

And Im taking it to a Smith tomorrow so he can look at it. If anything. I'll send it back to the factory

 

[MislMan]

Used rifle... carbon ring maybe?

 

[CjC73]

Used... Slightly. Previous owner said only a few rounds.

 

[mike06]

Two friends of mine one with a Tika 270 win the other with a Rem 700 270 win Both using Hornady ammo bolt was very hard to close. I measured the headspace with a RCBS case mic. Their rounds showed a +.003 on my gauge. I then bumped the shoulder with a Redding body die to zero on the case mic gauge problem solved.

 

[Texas10]

If you don't already have this, be sure to get it or something like it ASAP. Without it you can't set up your sizing dies properly, nor diagnose your chambering issue.https://www.amazon.com/dp/B000PD5VN8/?tag=accuratescom-20

Also spend $25 or $30 and get one of these so you're not working blind.https://www.amazon.com/Best-Sellers...zgbs/industrial/401578011&tag=accuratescom-20

Try to find one with a 2 cm focal length. Someone on this site was selling or knew a source for a close focus camera. You'll need it to verify your cleaning methods are working, diagnosing barrel issues, etc. Very handy to have.

Good luck, I hope the issues turns out to be minor and easily fixed.

 

[carlsbad]

Most likely cause is that the chamber is a few thousandths too shallow. A go gauge will not close in it. .

 

[Clancy]

Are you feeding these rounds from the magazine? Just a thought, but it could be that the claw extractor just isn’t wanting to slide over the case head on some rounds, which could be fixed easily.