Reloading 300 WSM

[JAYgs8163]

I have 200 rounds of 300 saum that have been trying to sell. Ranges from 155 to 180 grain.

Go start a thread in the classifieds and post photos and provide payment options.

 

[skookum]

Hello All,
I am loading for a Tikka T3 chambered in 300 WSM. I am using AGD brass and I have bumped the brass 5 thousandths using a sinclair 35 degree bump gauge insert. This will be the 3rd or 4th firing on this brass. The issue that I'm running into is difficulty closing the bolt. I suspect the base of the brass is not being sized enough. Has anyone else run into this when loading for their 300 WSM rifles. Any input or help would be appreciated. Thanks.

Are you having difficulty with a fully loaded round or are you trying a newly sized case?

 

[EE_Reloader]

Alright so I have sized 5 cases, 5 thousands and have taken length measurements. The Berger manual calls for 2.090" as trim length. They measure
2.0905"
2.0840"
2.0945"
2.0935"
2.0925"
So I am long and need to trim, however the case that measures 2.0840" still shows stiff resistance when trying to chamber the case. I will probably look at getting a body die first.

 

[gareyg]

FYI, long ago I actually had a similar bolt-close problem with my .300 WSM. I eventually found that I was simply not fully completing the bottom of the sizing stroke on my press (Thick .300 WSM brass takes a little more leverage at the very end than other cases I reload). oops!! When I ensured a full complete stroke my problem was resolved. Just something to check. Milling a few thou off the base of the die would probably have worked similarly.

ETA I always trim and chamfer. Always.

 

[EE_Reloader]

To answer a few more questions, the rifle is factory, I am using a Redding Type S die, the brass is not new and I am sizing on a Zero press.

 

[zeeman]

I shoot a lot of 300 WSM and have the same problem. Also with case separation at the head. Found out it was too much full length resizing and also I ended up bumping the shoulder back a bit. Solve the problem. Would also check on overall length of brass.

 

[FEENIX]

Alright so I have sized 5 cases, 5 thousands and have taken length measurements. The Berger manual calls for 2.090" as trim length. They measure
2.0905"
2.0840"
2.0945"
2.0935"
2.0925"
So I am long and need to trim, however the case that measures 2.0840" still shows stiff resistance when trying to chamber the case. I will probably look at getting a body die first.

Measure your base-to-shoulder junction, the 1.802" dimension.

 

[JASmith]

Try coating your resized case with a dark Marksalot (or Prussian Blue) and try chambering.

The resulting shiny spots shild help determine where the interference is.

It may not explicitly capture interference at the start if the throat, but if nothing else is shiny, then it is time to whip out the calipers and compare with unfired but sized brass.

If the case is indeed stretching, watch for incipient separation at the base. Pulling a separated case out if the chamber can be A PITA.

 

[Rotten]

I had a similar problem with 270 wsm. What I found was that the wsm cases would spring back the shoulder if I didn't anneal the brass. Some would spring back .005 and some wouldn't. Even bottoming out sizing for on shell holder wouldn't push the shoulder back far enough until I started to anneal them.

 

[EE_Reloader]

Measure your base-to-shoulder junction, the 1.802" dimension.
View attachment 598509

So the cases are definitely not 1.802", closer to 1.810".

 

[EE_Reloader]

I had a similar problem with 270 wsm. What I found was that the wsm cases would spring back the shoulder if I didn't anneal the brass. Some would spring back .005 and some wouldn't. Even bottoming out sizing for on shell holder wouldn't push the shoulder back far enough until I started to anneal them.

I'm gonna try annealing them and see what kind of results I get.

 

[Rotten]

I'm gonna try annealing them and see what kind of results I get.

I would purchase a case length gage so you know what your setting is for head space when you size the brass. Hope you find the problem.

 

[FEENIX]

So the cases are definitely not 1.802", closer to 1.810".

That could be your issue. Good luck!

 

[LoneTraveler]

If you are having problems with the bolt closing on loaded rounds. Check your seating die, If the seating die has a crimping ring. Make sure the seating die is adjusted so the case mouth is not hitting the crimping ring in the die.
If the case mouth is hitting the crimping ring, As the press breaks over, No place for neck to go, The pressure will shove the shoulder into the body of the case. Enlarging the case body diameter where the shoulder taper meets the case body. Just . Just a few thousands swell at body shoulder diameter can be a problem when it comes to bolt closing.

Have ran into this problem a few times with friends setting seating die to far in press. First loading with new dies.