.270 WSM issues

[pingpingping]

Help me figure out what's going on here...

I began reloading .270 WSM about a year and half ago. I started with 140 grain Sierra bullets loaded exactly to Sierra's book. I loaded up 20 or so and found that none would chamber, ie the bolt was very difficult to close. After some checking and research (including posting here), I concluded that the shoulder was not being "bumped back" enough. I sent the sizing die back to Lee who adjusted it to minimum headspace.

About a year later, as hunting season approached, I set out to reload some bullets with my newly adjusted die. After resizing some brass, I checked the empty cases in my rifle (Winchester 70, Super Shadow) and they chambered without problems. When I loaded up some Sierras the bolt again became difficult to close. I notice small marks on the bullets just above the case neck, apparently where they are engaging the rifling. I also tried some Nosler accubonds hoping a different ogive might fit my chamber better. I also tried adjusting the OAL to see if that would help. OAL did not seem to make a difference as far as ease of chambering. I had better results with the Noslers, only about half of the cartridges being difficult to chamber.

I took the half that chambered easily and shot some of them with fairly good results. However I noticed some of the bullets got set back completely through the case neck when being chambered. What is going on here?

 

[NCsmitty]

Are you having to seat the bullet so deep as to encroach into the ogive?

Are you able to manually push the bullet into the case by hand or against a bench.

If the bullet is not secure in the neck because the case neck is not tight enough on the bullet, you'll have to either get a new expander ball of the correct diameter, or stick your current expander into a drill and sand it down so the expander is .002 smaller than the bullet diameter.
Having a short action limits the COAL that you have to work with, and many SA cartridges suffer from powder space being lost because of deep seated bullets.

Your sizing issue is not uncommon, especially with WSM cases, as the brass is quite thick on them due to the high pressures that they generate.



NCsmitty

 

[243winxb]

Could the seating die be adjusted down to far? If running the round to deep into the crimper, this might bulge the neck or shoulder?

 

[pingpingping]

Hmmmm.....I was trying to avoid crimping at all. I was using the coal listed by sierra for a 140 gr bullet...in the neighborhood of 2.77" iirc, which I believe to be a hair long for my gun. But I now believe that two of the bullets I found set back through the neck did so from recoil, finding them in the magazine that way. One I know was pushed through the neck from chambering. Do magnum rounds need a crimp?

Or is this a possibility...
Is it possible that after Lee adjusted the die to minimum headspace that the shoulder could be bumped too far back, enabling the neck and bullet to protruded too far into the rifling? Just a guess here.

 

[pingpingping]

BTW...yep, just checked, I could push one in with moderately heavy force. Think I have multiple issues here.

 

[243winxb]

First the full length sizing die must size the neck area down enough so the expander can open it to the correct inside diameter. The expander should be .002" or more smaller than bullet diameter for correct neck tension on the bullet. Take measuremets with and without the expander after sizing. After the neck has been expanded, measure, seat bullet, has the neck diameter expanded by .002" or more? Lee Seating dies taper crimp then roll crimp. It might be possible that this die is post sizing the neck if adjusted down to far, or if it is out of spec. If your COL is to long, you will push the bullet deeper, but not make it loose from chambering the rounds. The full diameter of the bullet must stay in contact with the neck area, if seated or pushed to deep it may just fall into the case, unless stopped by the powder.

 

[pingpingping]

Thank you, 243win. Can you comment further on "post sizing," ie, what exactly is the die doing to the neck if this is happening? Could this make chambering a round difficult?

 

[243winxb]

You seem to have 2 problems???

Can you comment further on "post sizing," ie, what exactly is the die doing to the neck if this is happening?

1. Loose bullet- The seating die may size the neck down maybe .005" As the brass springs out, the bullet becomes loose.

Could this make chambering a round difficult?

2. Hard Chambering- If the crimper comes in contact with the case mouth too much, the neck or shoulder can get a bulge in it, keeping the round from chambering.Remember Lee seating dies taper first then roll crimp. Its possible to have a die out of specification.