Trying to reload some once fired S&B brass for my savage 110 fcp... I cannot get the to chamber... any advice? I have some unfired Lapua brand brass... loaded it, shot fine. The S&B was fired out of an armalite...

I dont know if I even can with my die set... its the RCBS competition set, with the neck sizer that takes a bushing

set it up to bump headspace. they slide riht in the chamber, but will not go into battery

If your only neck sizing once fired brass shot out of another rifle, the other rifles chamber dimensions are different than yours. You might try to bump the shoulder further back, but I believe you may have to full length size the brass, fire it, then you can neck size after that since it will be formed to your chamber dimensions.

This is all the info we have, so the only things I can say for certain is the RCBS Gold Medal Match die set I googled comes with a full length sizing die that uses a neck bushing . . . and you should certainly know what your dies can do.

Beyond that, there are 4 possibile causes for your problem that quickly come to mind:

1) Neck too long to fit chamber of your gun. In most cases,  you can eliminate this cause with a simple measurement of COL.

2) Neck too fat to fit in chamber. Can happen if fired from a different gun. But if you did resize it and have the correct neck bushing size, this shouldn't happen. Measuring an unfired Lapua case, a new unused Lapua case, and an S&B case that doesn't fit should quickly tell you whether this is possibly the problem. Unlikely.

3) Shoulder not bumped back far enough. Case shoulder hits the chamber's shoulder wall but there's too much case behind it to allow the bolt to close. Using a fired S&B case (fired from a different chamber) and a fired Lapua case (your chamber), measure the BTOs. If the S&B is noticeably longer, this is likely the problem, or at least one of them.

4) Some section of the case body is too fat for your chamber. Comparing measurements of fired S&B and Lapua cases at multiple points along the body should give you an idea where the problem is. Since you actually did FL size the S&B case (**assuming I found the correct RCBS die set), the issue - if one exists - would likely be near the bottom of the case. This problem could be coupled with #3 above. It could be your sizing die just wasn't screwed down far enough. Rarely, it could be a bad die.

** If you have only a neck sizing die, you need to FL size using the body die which does come in the RCBS 3-die Competition set.

I have the same rifle. Read allot of posts on this rifle and all said same thing. Shoot only Lapua brass in a Lapua magnum rifle. Like others have said, full length resize should correct your issues.

You may need to invest in a body die from Redding to bump the shoulder and size the body.  Then use your GM series neck die to size the brass.
You will need different bushings for each brand of brass.
You will need to work up different loads for each brand of brass.

best to stick with one brand of brass to make die adjustments easier for you