I have a relatively new Browning X-Bolt in 300 WSM, Stainless Stalker.
A lovely rifle (not pretty) that shoot 180gr bullets very well.
I loaded cartridges this time last year (winter in SA) and shot successfully.
In November, I traditionally cull our kudu cows as it is the best time to do so. While out in the field I was alarmed to note that two-thirds of my cartridges could not be chambered.
I put them in a box and labelled it "Do not fit."
This week, winter again, I tested them out of curiosity and all chambered!
I would not think that the heat of November (90F) would make such a big difference.
Any other explanation other than the heat of the cases caused expansion? The chamber itself affected?
Must I adjust my resizing?
Any comments are appreciated.

I've never had this occur, nor heard of it occurring, and it intrigues me. I wonder if this phenomena is unique to WSM cartridges ( I don't shoot any ) ? My best guess is that maybe the cause of non chambering is heat related brass expansion since the rounds chambered in cool conditions but did not in hotter temps. In November was your ammo in hot containers in a hot place of your vehicle interior from which you promptly loaded your rifle ?
If that makes sense you might have to bump brass shoulders back a fraction more to ensure chamber clearance in warm temps and maybe place ammo inside a chilly bin in the vehicle ?
As I say only my best guess but hope it helps.
Cheers.

Yes, they were a little warm, but nothing out of the ordinary, I would have said. Just very disconcerting trying to load a cartridge and it does not work, and neither does any other one in the magazine!

Definitely not heat related. You can't expand a brass case that much that a bolt action won't cam it into place.
Maybe dirt in the chamber? Or a stray powder grain?
Or, worse case, they are banana shaped due to a crooked chamber. IE, the base is not perpendicular with the case. Just a very remote possibility. They fit one way, but not another, with respect to how they are oriented in the chamber. Check that.

Years ago I was testing hear effect on my hunting ammo.

Walking in 115 degree heat my cartridges become almost too hot to touch!

In the middle of the summer, I left a few loaded rounds in the sun here in Dubai.

About 2 in the afternoon I took them and fired them.

No effect on velocity at all.

Just the normal variation.

375/404 with Barnes X 300 grain bullets loaded with H4350.

There has to be a "and thats the rest of the story"
voodoo, black magic, comes to mind! but Im sure a witch doctor lives near you?? Just a little humor to make for a better day..

quote:

Karoo
posted 08 June 2022 23:11
Yes, they were a little warm, but nothing out of the ordinary, I would have said. Just very disconcerting trying to load a cartridge and it does not work, and neither does any other one in the magazine!

OK, so probably not heat related.
Can you describe "non chambering" in more detail ? How far into the chamber would rounds go before they would go no further ? How difficult were rounds to extract again or did you have to push them back from the muzzle ? Any marks on the brass indicating some foreign matter within the chamber ? Anything else you can add...??

OK, I don't know if this will help but---
I recently bought a Ruger American Predator. Some of the rounds would not chamber. I thought WTF!
After playing around a little I found the extractor (one that snaps over the rim) was tight and sticking which would not let it snap over the rim. Working the extractor helped as well as not babying the bolt while chambering worked.

Just something to look for!

P.S. I have no idea what the Browning extractor is like.

Hip

Did you check the trim length before you loaded them?

I'm not familiar with that rifle either.
but I do know you have to fully full length re-size the 270 version every single time you load the case.

anyway I'd suspect the extractor also.
especially if they went almost in but didn't, and then later did.

A few months ago I purchased a Browning X-Bolt stainless stalker in 7mmWSM. It came with 80 odd rounds of factory ammo and about 100 empty cases, some of which the previous owner had resized and primed, others were just once fired and not deprimed or resized. The owner said he had never got around to reloading for the WSM. He was assistant manager of a hunting and fishing shop so got plenty of factory ammo.

With the rifle came dies, new can of powder and primers.

I set up the FL die in my press and as the once fired cases chambered nicely in the X-Bolt I backed off the die just to neck size the cases. This did not work as the partially sized cases would then not chamber, just couldn't cam the bolt closed at all.

I wound the FL die down until I got cam over on my press an then the resized cases chambered as easily as the factory ammo does. Never come across this phenomenon before in loading for many other different cartridges.

In line with Lamar's comment about the 270WSM cases needing to be fully full length resized to rechamber after every firing, I think it must be something specific to the WSM case or maybe the X-Bolt rifle/chamber. I haven't reloaded any ammo for the WSM yet and our climate here is temperate so we don't get excessively hot weather but maybe I should try heating a resized case to be sure it still chambers smoothly as it does now under moderate temperatures.

Thanks for the response.
The cartridges would not allow the bolt to come near to closing, as I remember.
Possibly dirt in there, but I would be surprised.
I did FL resize but shall check my settings again.
I'll also check the trim length as suggested, though these are either once-fired or twice-fired cases.

The cartridges would not allow the bolt to come near to closing, as I remember.

Does this mean you couldn't push the bolt forward enough to enable turning the bolt handle down ? Or pushing the bolt fully forward could you only partly turn the handle down before the the bolt would turn no further ? Was the extractor actually engaging the extractor groove on the case ?

The info above from Lamar and Eagle makes it seem to me there is some particular sizing procedure required with WSM brass to ensure proper chambering.

It is common for rifles to not accept neck sized or partially sized cartridges. In fact, partially sizing brass in a FL die makes the situation worse because doing that pushes the shoulder Forward without going into the die far enough to push it back where it belongs.
That is why neck sizing in a FL die usually does not work. I know you know that.
Also, it is not unheard of for a rifle chamber, dies, and brass, to be entirely incompatible with one another; and given the tolerances between rifle makers, die makers, and ammo makers, it is amazing anything works as well as it does.
Check your sizing protocol.
However, this is not a don't fit/then fit scenario. That is from a crooked chamber or crooked cartridges. Cartridges only fit one orientation. It has happened.

dpcd is correct. A full-length sizing die reduces the case diameter, and the brass has to go somewhere. The only place it can go is forward. When the case shoulder reaches the shoulder in the die, it is pushed back where it should be. If you back the die out, the case does not have the shoulder pushed back to the proper length and results in a case that is too long at the shoulder. If you want to neck size only, the best way is to buy a separate neck sizing die. They are not expensive. I have neck sizing dies for cartridges I load fairly often. Usually for neck sizing new brass, I only need a little graphite in the neck. No lube is necessary on the body, speeding up the process. Bob Hagel explains this situation in more detail in his book "Game Loads and Practical Ballistics for the American Hunter".

Never had temperature make any difference on it but check that the primers are not proud. Could be that they were right there and a hot action would not let it close.

I would think that the camming of the action would be enough to seat the primers at least or near flush.

Hip

Definitely not the primers; any bolt action will easily cam a primer in place, hot or cold.

Not true on the bolt camming. Second fired Norma brass in 7 Mag. Primer would not seat flush with a single stage press! Took some work with a primer pocket tool to seat them flush. Had the same thing happen with Norma 300 Win Mag brass , maybe third fire. Now I just check the all!

If they wouldn't seat in a press you have more problems than not fitting in the chamber. Which, in the OP's situation, they ultimately, did.