Can I Do This At Home?

[Longcruise]

An alternate title would be "Should I Do This At Home"?

The question is, can i rent a chamber reamer and do a re-chamber on my own?  I don't have a lathe or any of that sort of thing.  Would have to be done with hand power.

Is this doable?  Am wanting to rechamber from 308 to 7.5X55.

[gunnut69]

This rechamber would be a problem.  The clymer charts indicate a smaller pilot diameter for the 7.5  This would allow wobble and create a bad chamber.  Also rfeloading for the slightly different bore would be problematic at best..  Why would you contemplate such an alteration?

[Longcruise]

This particular alteration would be for the purpose of eliminating the freebore in the .308 (NEF Handi Rifle).  The 7.5 because it is inherently accurate and I'm all set up to reload for it.  I can have it done by the local gunsmithing school but am looking at about $175 which is cost prohibitieve for an NEF gun, relatively speaking.  If it can be done by myself, it would be more cost effective.

You are surley correct about the pilot, since the bore of the Swiss K31 is .307 although it shoots .308 bullets very nicely.

Could a different pilot be used with the 7.5 reamer?

And of course, can I do it at home? :-)

[John Traveler]

Yes, you can get a chamber reamer with replaceable bore pilot bushings to fit that .307 bore.  European .308 Winchester/7.62 NATO rifle bores are about 0.001" tighter than US standard .300 bores.

However, the 7.5 Swiss may not use a .300" bore, which presents another problem:  if the bore size is not a +/- standard size, you would have to have a custom bushing ground.  Expensive.  Plus, the 7.5 Swiss may not be readily available as a rental reamer.

As for doing it at home, unless the .308 Win and 7.5 Swiss chambers are really dimensionally close (and they probably aren't), you can't do acceptable rechambering without a lathe.  A drill press or hand-held drill will not work.  The final hand-reaming of a chamber is strictly for removing the final few thousandths of an inch for perfect headpace adjustment.

HTH
John

[John Traveler]

I forgot to mention that $175 charge for a rechamber job seems sorta high.  

On reflection, that probably includes the cost of a custom ground pilot on an uncommon reamer.  You are paying for the reamer.

[Longcruise]

Thanks guys.  All indications point to dropping the project!

They would have to rent the reamer at the School and a new ejector would have to be installed.

The whole thing seems more and more impractical.

Thanks again.

[naedlaen]

Longcruise,

If the Freebore really, really, really bothers you-

as a poor man's wildcat, check into running the standard 308 reamer in to the depth that provides the throat that you want.  Then use 30-06 brass and the 308 dies.  Or 7x57 brass if the chamber is short enough to allow.  In fact, you could maybe deepen the chamber to the point of the shoulder neck at the same location as the 30-06 AI (Ackley Improved) to use factory ammo to fireform.  The only kink in this is resizing the web near the case head.  That might require some thought (444 marlin die?)  or pitch the brass when need to resize the web.

30-06 AI is also an option with the ackley dies.

Somebody with real gunsmithing expertise jump on this if it is really, really silly.

Just ideas that anyone considering should view with extreme care and should research to the nTH degree.

Neal

[gunnut69]

Actually naedlaen the conversion to 1 30-06 AI may be the most cost effective.  $175 is a bit high for a rechamber, IMHO..  Of course this is assuming the barrel is sufficiently meaty to handle the longer case and not create thins spots at the case body/shoulder junction area.  The NEF's are usually OK in this reguard.  I don't know about the 'floating' wildcat though.  The difference in length between the 30-06 and the 308 is about 10mm.  Hardly enough to force us to go to the extra trouble.

[Longcruise]

The 30/06 AI might be just the solution.  I need to shop around on the rechamber cost.  I got the 175 figure from the colorado school of trades in Lakewood.  That was for the Swiss though and they did not have there own reamer.  It's probable that they do have the AI though.  In the past they have been very reasonable in cost so I assumed that 175 was about as good as it gets.