Fitting feed/nib into section

[CVR]

I'm having a lot of trouble getting a Moore 94A nib and feed into the section. It turns out that the read end of the section is about 0.25mm narrower than the front end. I've never seen a section like this one, but it must not be terribly unusual.

 

The feed's OD is right around 5.55mm, and moves easily into the front part of the section, which has the same ID. It then hits the flange between the front and rear parts of the section, and won't go in any farther.

 

Obviously, lubrication isn't going to help. I've tried heating the section a little, and the feed may have gone in a bit deeper.

 

Should I just heat the BHR section more and force in the feed and nib? What temperature is safe? The rear part of the section will need to expand/yield 0.25mm, which seems like a fair bit. Perhaps even more, if the nib needs to go in, as well.

 

I remember having trouble getting the feed out when I started work on the pen because of the tight fit.