I just got in a 1903 Springfield sporter for rebarreling. It was a Donaldson Wasp and someone decided they'd rather have a .219 Zipper. Well, the Zipper is a longer case, but it doesn't clean up a Wasp chamber! But, the breech looks like a Remington 700 with an extractor cut. I thought a 1903 was a cone breech? I'll confess that I've never rebarreled a 1903 before but I've done many pre 64 Winchesters. Are they the same design? Is the cone the same angle?

Yes, originally they were the same-design cone breech and so was the 1917 Enfield/Rem 30. However when rebarreling, it's easy to change to a square breech as was used on the P14 Enfield in 303. The square breech is necessary to maintain headspacing on the case rim rather than the shoulder.

Actually IMO the square breech is not only a LOT easier for the smith to do, it's also a lot safer for the shooter under case failure conditions.
Regards, Joe

I won't disagree with the safety factor J.D.! I've see two instances where someone "missed" the dimension on a cone breech and the shooter would blow a case occasionally and couldn't understand what was going on. I'll just put the new barrel back on with the breech designed like the old one. Should be fine. Thanks!

Actually though J.D. I remember doing a pre 64 by boring a flat face into the breech the same diameter as the bolt face +.010 and coning back from the outside of that. That design would work fine with the rimmed case, but I think I'll stick with the Rem. 700 design.
Blair

"The square breech is necessary to maintain headspacing on the case rim rather than the shoulder."

I have done a number of the model 70's with the coned breech for the magnums. Where does a square breech make it "necessary"?

Because the belt dimension is ~0.200" instead of only ~0.060"-0.070" like the rim.
Regards, Joe

My friend has a model 54 Winchester in 30 WCF (30-30 Win) and I swear I remember that having a coned breech. The 22 Hornet is rimmed and I know it has a coned breech on M54 and M70's.

So it can't be strictly a headspace issue for that flat breech on the Springfield???

Go back and look again, I've never looked but IMO you'll find enough differences to be readily apparent. The usual cone breech angle and bolt head dimensions are such that there is no support for the front of the case rim since the bolt head comes forward far enough to enclose most of it, leaving not enough room for the slanted breech face to contact the rim. You'll need a little right-angle jog or ledge in the cone, to allow for firm case rim support.

That's why the P14 is made with a flat breech, the Brits have always been more practical with their bolt rifles than we have and so they weren't married to the cone breech concept. When we adopted the P14 and called it the M1917 the US Ordnance Dept immediately changed to the cone breech, IMO strictly because it was their own invention for the 1903 and the 'not invented here' mindset was/is endemic in their group.

Anyway, take another look and take some measurements, I believe you'll find that some changes are necessary in order to safely headspace on the rim.

If I'm wrong, then folks like P.O. Ackley and Harvey Donaldson and Jim Howe were also wrong 'cause that's the way they did it too.
Regards, Joe

Another modification not to be overlooked when doing a rimmed cartridge conversion is the nose of the bolt has to be shortened so that the depth of the bolt face matches the thickness of the cartridge rim. Then of course the extractor has to be cut and rewelded or a new piece welded on the front to handle the new rim. More involved than it seems at first.

quote:

Originally posted by J.D.Steele:
Because the belt dimension is ~0.200" instead of only ~0.060"-0.070" like the rim.
Regards, Joe

The belt dimension is .220". I still don't understand what the hell you are stating here. Am I missing something here? Are we talking rimmed VS belted? I thought the original query was with the diff between coned or flat breech and you bring up headspace being an issue. Please clarify.

Jim

I recently chambered a Mauser 98-type action in .30-30 and didn't make any such modifications to the bolt. I put a raised ring around the chamber mouth to headspace the cartridge on, holding the cartrdige out far enough for the extractor to hold the rim.

Going into the project my customer told me he didn't care if it feeded--he shoots from a bench and loads one at time--but surprisingly the rifle actually feeds pretty well.

Jim,
The rifle described is chambered for a rimmed cartridge (219 Zipper). If the rim is to contact the barrel breech, the cone, if closely fitted, is unworkable in conjunction with the rimmed case. There needs to be a flat surface for the rim to seat against.
It is possible to modify the nose of the bolt so that it more resembles a mauser then fit the barrel with a counterbore and extractor cut. This may be what was done on the rifle in question. Regards, Bill

Okay. I will concede; I didn't realize he was referring to the rimmed case, I took it to mean he was referring to a magnum belt. My Bad.

Jim

quote:

Originally posted by Toomany Tools:
I recently chambered a Mauser 98-type action in .30-30 and didn't make any such modifications to the bolt. I put a raised ring around the chamber mouth to headspace the cartridge on, holding the cartrdige out far enough for the extractor to hold the rim.

This is known as safety breeching in some circles; IIRC the 1924 FN/Yugo Mausers are done this way. The little horn-like protrusions on the left face of the Mauser 98 bolt head are cut back to the same dimension as the rest of the head and an extractor clearance cut is made in the right wall of the barrel's little protruding ring. My first encounter with this breeching system was a Donaldson Wasp 98 Mauser back in the late '60s, it's not hard to do.

Sorry I did such a poor job of explaining the coned-vs-flat requirements, guess I can't really communicate unless I can wave my hands or draw pictures.(G)
Regards, Joe

Looks like I might need to get a photo of what has been done to this breech and maybe that will help some. I'll do that next week but I might need some assistance posting.
Blair

[IMG:left] [/IMG]

[IMG:left] [/IMG]

[IMG:left] [/IMG]


The reason for rebarrelling in the first place. The case on the left hasn't been fireformed yet. The one on the right has been fireformed in the 219 Zipper/Donaldson Wasp chamber

Rick Jamison has actually patented that shoulder profile. If you see men in dark sunglasses parked in a white van near your house............

I finally caught up with my friend with the Model 54 Win in 30 WCF (30-30). The breech end of the barrel is flat with an extractor cut. It is not recessed like the Springfield barrel shank pictured in this thread.

I always thought that the coned breech was to
insure feeding under bad conditions.
Good luck!

I finished the barrel with a coned breech. I'll show a photo of the finished barrel when it gets back from bluing. It still has a flat section for the case head to sit on so it should work fine.

[IMG:left] [/IMG]

Well, it took longer to get the barrel blued from someone in the next town than it did from John Farner all the way across the country. Anyway, what I tried to do was leave a flat .010 larger than the diameter of the bolt and tapered back from that. I think I used a 100 degree included angle. Maybe the Zipper will feed fine and maybe it won't. I hope the customer remembers how to stack the cartridges in the magazine! Think it was a waste of time or do ya'll think it may feed a bit better than a square breech?

Nice work! Good engineering job on that too!

An old gunsmith told me there was no reason to use a cone breech on a springfield for rimless cartridges. He used a regular flat Mauser style breech. Will that work, or are modifications needed?

quote:

Originally posted by lee440:
An old gunsmith told me there was no reason to use a cone breech on a springfield for rimless cartridges. He used a regular flat Mauser style breech. Will that work, or are modifications needed?

The barrel that came out was a flat faced breech. But the Springfield has always had a great reputation for smooth feeding and I think that was due in large part to the cone breech. I'm not the expert here, that's why I started this thread....seeking knowledge.

Winchester 54 30-30 factory barrel.

Bruce