View Full Version : 40xb

03-23-2010, 02:17 PM
Need info on replacing a bolt in a Rem 40XB. 22 LR
Have a DCM 40XB RF without a bolt assembly,, found a used 40X bolt assembly but
It will not close
It is not lack of head space because with the bolt disassembled and using
the bolt body only,, it will not turn down into lock position
the bolt handle contacts the receiver before the locking logs can rotate into lockup cuts of the receiver
Any Ideas
I have installed at least 40 barrels on 52's and Anschutz 54 and a few 700 Rem. Center fire but don't know about this problem


03-23-2010, 03:51 PM
Contact Gene Davis. He knows 40x's inside out and he is not far from you.
The last email I have for him is

Just curious - what year is your 40X? or Serial # on the Barrel?

03-23-2010, 04:17 PM
Serial # 13xxx

Slick Willy
03-23-2010, 05:29 PM
XB`s are 700 actions this one is a722 standard , the curved bolt handle on a Xb won`t work in standard stock without some wood modification for the bolt handle.If the bolt has a checkered bolt knob it is for a XB

03-23-2010, 06:00 PM

Fitting a barrel is fitting to the bolt and is a totally different affair than fitting a bolt in the "middle" between an existing receiver and barrel.

I believe it is lack of headspace. Bolt nose sections were made in different lengths to fit the barrel/receiver combination, yours is too long. Either try different bolts, or nose section, or chuck up the bolt lug section and remove very little from the back of the lugs, maybe less than .005 at a time.

Very low serial for an XB.


03-23-2010, 08:00 PM
Maybe you did not read the problem
When the bolt body only is installed it will not turn to lock up
At this point it has nothing to do with the head space between the barrel and bolt nose section

03-23-2010, 08:13 PM
reposition the handle

Kent Owens
03-23-2010, 09:03 PM
homermoore is right. Reposition the bolt handle by removing it and silver soldering it back on, or you may get lucky enough that you can remove some metal from the front of the handle and get it to work. I did just that on one of 'em a couple of years ago.
40X bolt handles have a very loose tolerance on where the bolt handle is positioned. Initially they fit the rifle they were made to fit, some would work in other actions and some would not.

03-23-2010, 09:53 PM
i heard a rumor on the rimfirecentral.com forums that this company is producing replacement 40x rimfire bolts, if that is what you are interested in. i think they have a good reputation. i don't own one myself. thought this might help out.

03-24-2010, 07:16 AM
This is an intriging question, i have played around with numerous 40X's, both versions 700 and 722. I have never had a bolt that won't close in a receiver, factory or Kiff bolts. The straight handle and curved handle are interchanable except for wood. i did have one that the bolt would not close, lockup, all the way, but it was due to the barrel setback. I hope the OP comes up with the answer, and let's us know. Thanks, Douglas

Kent Owens
03-24-2010, 09:36 PM
I've worked on quite a few of 'em too and I had to remove metal from the front of two Kiff bolt handles to get 'em to work. Dave realized this and he told folks the bolts would require some fitting.

03-25-2010, 07:25 AM
Homermoore and a few ,others had the right answer
reposition the bolt handle

I did not reposition the handle, but surface ground the front side of the bolt handle to
allow the bolt to rotate.
grinding and reassemble the headspace space checked .043
Thanks everone for the help