Home Forums Reloading Big Game Rifles Win 70 300WSM chambering problem..

Hey guys,

I have a M70 Win Featherweight 300WSM that I'm having a problem with. I haven't shot it much, and when I did it was with new Win 180gr power points. As I remember, it shot the new stuff pretty well. So, the other day I decided to neck size some of the once fired cases. I made 3 rounds with 3 different loads for a total of 9 rounds. When I went to shoot them, 5 of the 9 would not chamber! So, I full sized the cases that didn't chamber (to the point of camming over) and they still wouldn't chamber! I did find that sometimes one would chamber if I changed its rotational position. I also found that some of the once fired new ammo cases would not chamber, and I have never had that happen in a case fired in the same gun (I understand that repeated neck sizing sometimes requires a body die)..so I started to take some measurements. New ammo had neck runout of .002-.003 and had a base dia. at the web of .550..very consistant...Fired cases of the new ammo and the neck sized cases had virtually zero neck runout, and the bases measured at the web had .003 runout and the bases measured .553-.556 So we have zero neck runout with .003 base runout and a max expansion of .006 on the web. Is this an excentric chamber or within "normal" specs?..or is there a problem with the FL sizing die (too big), and not sizing enough? I think I have a big excentric chamber..Well, it's 2:15 a.m. out here in the East and I'm going to bed! Can I have all the answers when I wake up?

Thanks guys,

art

Sounds like you're a victim of the infamous Winchester "out-of-round" WSM chamber. Here's the best description that I've found of it so far:

Interesting defect on WSM

BTW, what's the serial number range of your Featherweight (please feel free to 'X' out the last two or three digits)?

Thumper: Welcome to the world of the WSM and the M70.I had the same condition you did in more than one(2,3,4?)M70 rifles chambered for the WSM.Here are my solutions:

1)Sell it.
2)Rebarrel it by someone who knows what they are doing and get a properly cut chamber.
3)Buy a Kimber (I never had the problem with a Kimber,)and hope it shoots.
4)If #1-3 are not viable options, sell it!!!!!!And buy a 300 Win Mag.

Never assume anything.
First thing I would do is take a candle and "Smoke" a couple of the offending rounds that won't chamber. Then attempt to chamber those rounds to see exactly where you're making the contact that won't allow you to fully chamber those cases.
Then go from there.

Bob and the others hit it. I quit the WSM.

Thanks guys for all the input..I read the thread (Interesting defect on WSM) that Gasman posted and that seems to be the problem to me. I feel good that my suspicions appear to be correct...and I feel bad that I now have the problem to deal with!!..I knew I could depend on "the fire" to smoke out the Boogyman living in my 300WSM chamber!

Thanks again.....art

It's not the WSM cartridge fault.
It's the guy cutting the chamber.

I'm putting together my 3rd 300 WSM and have sold off all my
belted.

I did sell my M70 Featherweight 300 WSM though. It was crap
and a case in bad QC.

Hopefully the new model 70's will be better. With FN at the helm
they should be.

I believe Bill Leepers excellent post on out of round WSM chambers in M70's mentions that the threads are not continuous in the M70 and when the barrel is made very tight to the action the chamber goes out of round.

I have such a M70 in 7mm WSM with a chamber thats .0019" out of round. Thats substantial however the FL die makes them able to chamber. Because the rifle is so accurate I have kept it.

here's a couple problems with WSM's -
The chamber has to be spot on - To get the performance the pressures are high, couple that with tough cases and you have a high degree of possible issues. These show up at the reloading bench. BTDT. Shoulders move forward on sizing as the case gets squeezed in. I"ll bet that's happening here.
You sometimes have to REALLY cam over to get the shoulder back.

Personally I can't see what they do over the older chamberings. I won't get excited over 3/4" of action length and the 3 oz it saves, especially when it's smack dab in the middle of the rifle and effects balance so little.

My .02

Dave

I highly respect your viewpoint and experience Dave and take it for
good intel.

I just have not had any problems with either the two WSM's I have now.

Your post does make me aware though that the guy that's cutting the
Chamber on this new Rock barrel had better know what he's doing.

I had Clay Spencer cut the chamber on my 7wsm a first class smith!

Bob - No problem. Do you shoot factory or handloads? Neck size?

Dave

He has a great reputation, just wish he was located on the left coast.

It's nice to just walk a rifle in,I always end up having to ship!

Dave,

Never shot a factory round out of any of them.

And neck size.

SU: +2.As usual right on.... It is not the cartridge; it's the factory QC. I mentioned the Kimber because the chambers seem to have been more finely cut, and the Kimbers I messed with never exhibited the same problem.

I tried everything..could not make them work.

Bob,

When I worked for Kimber out of Clackamas,OR we received several, in return, SS fluted barrels in 22 LR. The barrels were supposed to have a "Match Grade Chamber". These were actual Wilson barrels that we chambered.

To make a long story short. I went out to
Colton, OR where they chambered the barrels to do "a what the heck is going on" inspection.

I found a, and I'm not kidding here, (Steve Timm could probably confirm)
drunk illegal nodding off while he chambered "our" 22 LR barrels! The guy could barley stand up.

Hundreds of these barrels were sold.

I had the same problem with a Winchester M-70 Laminate in 300WSM. the fix was after sending it back twice for the factory to take care of was to send it to Hill Country Rifles and they put a proper Krieger barrel on it so chambered and no more problems. Crooked chamber from what Hill Country said. Its not a bad rifle now. I should shoot an elk with it.

SU: When they got to NY,who'd they replace that guy with.....? If he's still with them, maybe that explains why some Kimbers don't shoot

I'm glad he didn't work on my new 257 Roberts!

Oh I think they've cleaned up..for the most part.

But I sometimes wonder.

Cheap labor is cheap.