The gunsmith (Hamilton Bowen of Bowen Classic Arms)who is converting my Ruger M-77 RSM to 404 Jeffery just sent me a note stating a problem he has run into. He said that several of the RWS 404 Rimless Nitro Express rounds that I sent him to test the rifle with, misfired. He said the problem, he thinks, lies in the fact that these rounds were trimmed excessively short, creating a headspace problem.

In fact, he is corrct about the factory loads being short. I have a bunch of hand loads ready to go with the cases trimmed to 2.865. This is the published minimum length for 404 Jeffery brass. The RWS factory loads, however, are trimmed to a case length of 2.835. That's .030 of an inch shorter than the published minimum.

Hamilton says he headspaced the rifle .009 short on purpose to try to negate some of the problem. He says I should have no problem with handloads if I use current data. Is this correct? Are there old specs for the 404 case?

I guess the only way to find out the answer is to wait until the gun arrives and shoot a bunch of hand loads to see what happens.

It is not the case length for headspacing, but the case shoulder.

There can be a good variation among 404 Jeff brass shoulder & headspace length, partly due to manufacturing tolerances and partly due to the long slight tapered shoulder.

I chamber a 404 Jeff by using a go gauge, and brass from different manufacturers, selecting the worst case brass and cutting the chamber accordingly. I want the chamber to be short enough for good ignition with short headspace cases, but long enough to chamber a long headspace case without excessive bolt handle force. Its a compromise and takes care and proper test firing to sort things out.

Also need to check the firing pin protusion out of the bolt face. Specs are 0.055" to 0.065". I go with 0.065" on a DGR that has to digest any and all makes of ammo.

I also make up a case length gauge out of a piece of cut off barrel. I chamber it like the barrel chamber, so that the loaded cartridge fits in with the base of the case flush with the end. This lets one check the case length, if the bullet is seated out too long and hits the rifling, and for bulged cases or one with a ding in the crimp, preventing it from chambering.

Every once in a while, you do find an advantage to having a belted case!

John is right that it is the base-to-shoulder dimension on which the cartridge headspaces, not the case mouth. If I recall correctly, the .404 Jeff has a bullet diameter of .425. I would suggest running a .458 expander into your cases, then sizing the necks back down to bullet diameter but stop at the point that the case will just enter the chamber with a slight resistance. This will provide you with perfect headspacing and sure-fire ignition.

Hamilton says if I fire-form my brass, I won't have a problem. Trouble is, on a Dangerous Game rifle you want full-length resized brass for smooth feeding. I guess I'll have to find out if the sizing on my dies matches up with the chamber, allowing reliable ignition.

john Ricks is correct it's not your case length thats the problem, it's the shoulder location.You need to first fireform your cases. I use a few grains of Bullseye to do this. Just plop some in a case hold the gun upright and fire away. Next size your cases in a FL sizer, but don't move the shoulder back. Size just to the base of the neck, no further. Your misfires will disappear, and your DGR will be totally reliable.
I'd also check your firing pin protrusion just to be on the safe side.-Rob

For gahunter et al, .404, Hoo Boy! I really like that ctg., but not the headspace problems since ammo and cases became available again. The pre-
WW II DWM and Kynoch ( Ely, ICI) ctgs were within the published Brit. Rules of proof and CIP tolerances. This was .006 to .010 less than Max ctg. Headspace. When RWS made the short run using equipment wished on them from DWM to satisfy needs of the various African game depts having orphan 404s for game control they held to within a span of from .002 (-) to .012 (-) Later when RWS made a serious production mostly to satisfy the needs of wilcat builders these tolerances got a bit looser ( for empties) The ammo crept up to an occasional .015 (-). But. The neck anneal proceeded half way back the case body. Inconsistently. The last run of RWS which appeared after the so called Argentine made case Misadventure sadly had from .008 (-) to .022 (-) case headspace. Can't say about any ammo made same time because I had no certain way to identify when or what lot in terms of time of mfg. Oh, there's worse! There is ammo out there, even down to the old familiar yellow and red box of 10. U.K. made,too,! It reads .404, but doesn't say Jeffery. It looks close to the untrained eye, but not to the Micrometer. Then it starts to resemble in body another famous Brit. similar caliber, but with the long slow almost no shoulder of the Jeffery. It has reasonably consistent headspace tolerances - for this day and age- about .010 spread from longest to shortest headspace. 'Course in a ctg. headspace gage these run from .032 (-) to .043 (-) On a fire pin protrusion of .067, my normal, This means that by the time the fire pin has completed driving the ctg. .043 deep into chamber to shoulder contact there will be .024 left of forward pin movement to ignite the primer......unless the shoulder is annealed so much that the pin actually re headspaces the brass case even shorter.
gahunter. Do, PLEASE (!) have your smith make a Wilson style ctg. case headspace gage based on the chamber he made for you. John Ricks method same as I used, old piece of big barrel. Next take some fired cases that will still go into chamber. Use a spare primer punch from another die to drive out spent primer, insert new primer and fire it. Back to the gage. What you discover will give you an awakening you arent apt to get any other way. Safely,too. It is even more revolting when you do this with brand new unfired cases. You can shorten case headspace as much as .045 with 3 primers. And when you go to the dark continent with the outfit, take along the ctg. headspace gage. Also include a sight align collimator and spuds for the calibers you ( and or other members of your party are using)
Do I still think highly of the .404? Absolutely! I just wish there was better fodder for it. Have even been tempted to file the bases down on the Ultra mag cases for about a half inch of body, size them ,maybe polish a dab, form them as you would 404s Change the extractor to accomodate the looser fit between it and the rim surround of bolt head. I guess you'd have to overstamp the base .404 to satisfy foreign customs and put the ctgs in unmarked plastic boxes to take along, but that might solve it. On the enfield there is a much easier method which can also be applied to Mauser, but can't answer for the Ruger. This was intended for other .404 wannabees, too. Gee, Maybe whoever is making the .450 G&A also has cases available long enough and stiffer in shoulder.

Mr. Burgess, welcome to this forum. Your reputation has preceeded you.