Use of .308 cartridge.

[lemmy 0]

Hi all,

I know this has been covered somewhat, but I couldn't locate it by using the search. I wanted to get some information on using .308. Main thing would be a barrel for .308, I'm sure I could come up with a Garand barrel to convert. Is there a better option? Does anyone produce new barrels for the Johnson?

Next would be the magazine. I would assume a spacer is necessary. I first thought at the rear of the mag, but that would interfere with loading? Then I thought at the front with a slight ramp, or is that even necessary?

Would anything else need to be changed?

So, instead of re-inventing the wheel (and coming out with a square one) I thought I'd ask.

Thanks

[ryche_me 0]

Lemmy:  I kicked this idea around using 8mm and a DROR barrel some years ago. I figured that i could make a spacer for the front of the mag with a low feed ramp on it.

The idea never got off the ground  (yet!)   but i don't see why you can't do this with the correct cartridge load and a chamber spacer from 30.06 to .308.  We used to do it on    Garrands  all the time when .308 was cheaper.

The head is the same size so there would be no bolt face, extractor issue.  so it looks as if a spacer with a helping feed ramp might work.

Anybody else with some ideas on this???

Ryche

[lemmy 0]

Hi Ryche,

The chamber insert seems like a good idea to test the magazine and feeding mods. At least if it doesn't work I didn't waste money on a barrel.

Thanks

[Brian Alpert 0]

I have a 308 JSAR bbl.....actually an original bbl which was set back and rechambered to 308.  As I recall....and it's been several years....it shot OK.  I don't recall any feed problems but I carefully loaded the magazine so that the cartridge bases sat on the rear of the magazine

[Joseph Scott 0]

The use of the inserts to convert to .308 was considered unsafe years ago as they would come out and the next round has excess head space and would rupture.  The original specification was for those to be "locked in" by use of a high pressure round made by White Labratories. Even this procedure was not considered successful.   To set back a .30-06 barrel for .308 requires the rear collar to be moved forward two complete turns (1/16" x2= .125) so that the sight and lug comes out on top again.  Then the center collar must be moved forward the same amount.  This keeps the proper spacing of chamber in relation to the bolt face.  Then the chamber can be reamed for .308 which is 1/10" shorter than .06.  Even when surplus 7.62 ammo was available and cheap, the ammo savings did not justify the cost.  If someone does it, mark the barrel .308/7.62 out where it can be seen to prevent future dangers in years to come.