30 Gibbs Reamer

[jkpq45]

If I had a 30 Gibbs reamer available, would anyone want me to cut a chamber or three for them?

[quickdtoo]

4D and Elk Ridge both have the reamer for rent.

Tim

[jkpq45]

I've got my eye on one of my very own, from a reputable source.  Just curious if anyone wants to take the Gibbs plunge with me.

[quickdtoo]

The 30 Gibbs has been discussed a few times, Mac was gonna have one done, but never did. In a 26" barrel it has some promise, but not so much in a 22", that means a stub or rebore for a Handi,  Ammoguide agrees.

Tim

[mauser98us]

I personally don't think the Gibbs is a good fit for the handi. It either requires Rocky's hydraulic forming tool,which is slow and messy,or a good bolt action with a relatively short throat so you can jam the bullet into the leade and properly fireform without thinning the web area. Also misfires are a problem if one fireforms with cream of wheat or someother fire forming agent. That being said,if you have a bunch of properly fireformed cases that just need sizing, I say go for it. Just my experience with Gibbs stuff.Great if you want something really different.

[jkpq45]

The cartridge is meant to headspace on the shoulder; is there any downside to annealing, expanding, then resizing to bump a new shoulder onto the case?


I guess with the filler method you run the risk of not having perfect shoulders after the fireforming method.  I guess I could load a wheelweight 150 grain gascheck boolit ahead of an appropriate charge of pistol powder (the book says 6-7.0 gn Clays, if I recall) for a good fireforming load.  That would allow me to scoot the boolit out into the leade as well as bump the shoulder as I discussed earlier.

[quickdtoo]

Seems to me a better way would be to neck 280 brass up to 35 cal then form a false shoulder to headspace on in the FL Gibbs die, been there done it with other chamberings, it's more positiive than seating the bullet long into the lands. 

Tim

[jkpq45]

Hi Quick,


Thanks for your experienced advice.  Is there any reason .280 Rem brass would be preferable to virgin .30-06?  Is there any trimming/reaming required in either case?


Thanks!
jkpq45

[mauser98us]

Makes a better false shoulder,which is the other method that quick mentioned that I forgot about in  my previous post.

[jkpq45]

Well, the reamer is on the way, at a good price.  I'm taking the plunge and will post results according to the chronograph Santa brought me.

[jkpq45]

Turned a 30-06 Rem700 barrel down to fit into a 12ga handi barrel on an SB-2 frame, leaving the profile of a 3" 12 ga shell on the chamber end, then cut the chamber with the 30 Gibbs reamer.

Chamber's rough (a couple places where a chip obviously got stuck between the flute and the chamber wall) will do better next time I use the reamer.

Loaded up 22 pieces of brass with LPP, Hodgdon Clays, Paper Towel, Corn grits, compacted with 3/8" stationary drill bit, then topped with wood glue.

Let dry overnight, then made lots of popcorn-smelling smoke with little poofs of paper towel in the pasture....

Nicely formed brass.  I didn't cut the chamber as deep as the drawing above suggests; other sites/diagrams suggest a case length in the ~2.464" range.

Now, for those 147gn FMJBT j-words I got from Top Brass at the last show for... what was it?  $0.12-$0.15 apiece, as I recall.

Here's hoping I can hit 2950-3000 FPS....  Candidates for powder include Alliant 4000-MR and Rel-17.