gunnutty

The rounds are both .30 caliber. The 7.62 X 54R holds a little more powder (maybe?) an the MN is built around this cartridge. With the 7.62, no action alteration would be required, and feeding is flawless. I think the idea advanced in another thread about chambering the 7.62 X 54R with a .308 barrel is a better idea. Better selection of bullets, and a new-condition modern bore. If you just had to have a different cartridge, I'd recommend the .303 British over the 30/40, just for better available components (brass). The two cases are nearly identical, with the 30/40 having a slightly longer neck. You might even be able to get a "pull" .311 barrel (Mauser or Enfield) on the cheap.

Rather than tearing apart the magazine box, I'd recommend having taper "blocks" (top to bottom and vise-versa) in the front and rear of the magazine. These wedge-shaped blocks would do the same thing that the Siamese magazine does. Those wedges should be easy to make from either aluminum or steel plate scraps. I'd do some geometry on the rear to ensure the angle is correct. The only kicker is that the overall internal magazine length will have to be very close to the overall length of the loaded cartridge. The blocks will ensure proper initial alignment, the close overall length will prevent the cartridges from shifting. I don't think that the issue is having a rim; it's having the SEMI-rim. If it were a full rim and provided the shooter loaded the cartridges right in the first place, the top cartridge would always stay ahead of the case below it. Instead, the Swift rim is shallow enough to allow the bottom case to slide forward of the top case, yet large enough to cause feeding problems when this occurs.

Never needed to block a magazine. If the cartridges are moving forward preventing reliable feeding, you probably need a block. You can play with a "junk" follower, shorten it, and TEMPORARILY, using adhesive, put an aluminum block in the magazine front. Or you can ride with the rifle muzzle-up. The feeding issues maybe aren't related to the cartridges moving forward. Dunno.... Perhaps a more experienced member has ideas.

The Swift has a rim... Are you loading each cartridge in front of the other when loading the magazine? If the cartridge on top has its rim behind the one below, if will probably push it forward. The swift is a "semi-rim", and this is supposed to alieviate the issue. If it isn't then a magazine block might be the way to go.

About the same as a .280 Rem. I'd go with the .280. It'll feed better.

A .17 Mach IV or .17/.357 would be neat. Or better yet, a .17 Ackley Hornet. Shooting phonograph needles can be such fun!

I think that the factory that made SB actions also made the military 93s/98s. If that's the case, I doubt that they would have converted to an investment process. They are probably straight millings.

MorganBoss: The M-N follower assembly is a marvel, isn't it? When running the heavier rounds through the magazine, I wonder if the follower springs are strong enough to lift the bullet end of the cartridge? I'd love to see some details photos of what you've done. My M-N is just sitting here, waiting for something to be done to it. I have an old American Rifleman article in which the author notched the receiver after the stripper clip guide and moved the bolt handle back accordingly. Much easier to manipulate, and expands the scope base opportunities. A rear base could potentially straddle the clip guide hump. I picked my M-44 up for a song at a show. It's a Polish model (so I was told) and in very nice condition. I'm very impressed with the metalwork and function. Much better looking than some of the WWII era Russian models I've seen.

The biggest problem with coverting to another cartridge is the magazine. The 7.62 X 54R is a short, fat, stubby thing. Actually, discounting the rim, I think it's a damn, fine cartridge. It performs almost as well as the '06 in terms of out-of-the-muzzle performance. The M-N magazine is made specifically for this cartridge. Anything with a longer body or larger diameter caliber just won't work as-is. I think an easy solution to getting a different cartridge to feed is the .405 Win. The rim and base diameters are VERY close. The .405 is around 0.100" longer, but that's close. I'd do the following: 1. saw the magazine immediately behind the integral magazine feed ramp. 2. mill or file the feed ramp 0.100 deeper, add the bevel incline back. 3. individually heat each side of the magazine shoulder stop red, then flatten between two steel plates, eliminating the shoulder. 4. weld the two magazine parts together again (eliminating the shoulder should lengthen the rear of the magaine enough so the two parts will meet or actually overlap a bit. 5. mill the underside of the reciever opening to match the taper of the .405 (plus the width of the magazine walls). 6. assemble the mess, check for feeding, and tweak as necessary. 7. open the magazine opening in the stock to accomidate the wider magazine. Half hour job, right? Heh. No, it'll take some work. I don't view this as that different than shortening a M1917 magazine box, straightening the bottom strap, and re-drilling the forward guard screw hole. Where there's a whip, there's a way. The .405 would be very fun in an M-N. It's probably the closest fit of any cartridge, other than a wildcat based on the 7.62X54R.

I have no issues with investment cast receivers. Sako and Ruger have certaily been pioneers in the casting field, and I'd feel safe behind any of their products. What does investment casting offer the consumer? At least some cost savings on the product. To the manufacturer? Reduced time needed to finish the product, and reduced expense in finishing machinery. The process involves using centrifugal force to move the molten metal into the mold; slag and lighter impurities "stay on top" so to speak and shouldn't enter the mold. Porosity or air entry is not an issue either. Every nook and cranny in the the mold is completely filled. The grain structure is VERY uniform and controlled. Parts need little, if any, final finishing. I think most of today's mass-produced bolt-action recievers with "flat" bottoms are probably investment castings. Round bottom recivers start as tubes. Winchester refers to their receivers as "precision forged". I suspect that that's another way of saying investment cast, or the action starts as a casting prior to forging.. The rear underside of the reciever on post-64 Mod 70s looks like a casting to me.

Why not reload the cartridge with a mild faster powder and lighter load? 4198 and RL7 and excellent powders to play with to eliminate the muzzle blast. You can handload to any 30-30 velocity you'd want.

MorganBoss: I'm intrigued by your M-N safety modification. Do you have some detail photos of it?

This is not Gibbs' data. It's Wolfe Publishing, I believe Roger Stowers. The book was printed in 1991, and he notes specifically about watching for pressure signs. These are listed as MAX. Also note the 26" barrel used in testing. I just put the data here as a reference. I'd say the pressures run in the "heavy" '06 range, or modern magnum cartidges. I look for the same pressure signs on a Gibbs as I would an '06 when handloading for a bolt actioned rifle. I can exceed factory velocities for an '06 virtually every time with handloads; I would definitely say I could do this 100% of the time with 8MM loads. I'm matching a specific load to my particular rifle, resized to my chamber and using components of my choosing. Velocity for a given caliber is pretty much a function of case volume. You can make the case short and fat, long and skinney, or put a belt or flange on the thing. The reality is that for a given barrel measured from the case mouth to the end of the barrel, for a given caliber and pressure, velocities should be identical. An improved 8MM-'06 should outperform an 8MM-'06 by approx. 75 to 100fps. I will of course use the dirty Economics phrase "All things being equal". Some barrels are "fast", allowing incredible velocities. Others drag, never meeting or exceeding anyone's expectations. I'd say the 8MM barrel used to gather the 8MM Gibbs data may have been fast. I know other Gibbs data from this book was on par with what I experienced.

I have the Ackley books but consider the loads listed as unsafe. There's another thread going about the .30 Gibbs. The book I have (modern) lists the 8MM Gibbs. It has a little bit more capacity that the AI. Max speeds for the 8MM Gibbs from a 26" barrel are: 150 gr 3346 170 gr 3202 200 gr 2913 220 gr 2797 back down a grain of powder, move to a 24" barrel, and you might lose 75 to 100fps. That's what I have.

I can honestly say I don't have any American Rifleman mags that old. Heh. "I knew Rocky Gibbs, and you're no Rocky Gibbs!" I have the entire book ("Gibbs Cartridges...") that I mentioned above. It's fairly modern (1991). I think it's out of print. I can post the data if anyone needs it I guess. I don't want to get into any copyright issues. Each chapter covers the history of a given cartridge, photos, data, and critique.

Actually, good point on the "C" ring. Now another question, as I have never seen this; if the '98 barrel seats on the "C" ring rather than on the barrel face, would it be permissible to have NO shoulder on the barrel?

If it's an original military barrel, you'll have to set the barrel back 0.150 inches plus to clean out the old chamber. I don't know that there's much of a shoulder to seat against the face of the receiver after that. There was a great discussion here a couple of weeks ago about all the work that it needed just to get the short magnums to eject from the Mauser. If you want to use the original barrel, I'd look at longer cases that will clean out the chamber without setting back the barrel: 8MM '06, 8X68, 8MM '06 AI, 8MM Gibbs. If it's a new modern barrel and you want 325 WSM, be prepared to do some work.

Wolfe publishing has (had?) a very good book about Rocky Gibbs and his cartridges called "Gibbs' Cartridges and Front Ignition Loading Technique". If you are interested in the Gibbs line, I highly recommend this excellent reference. I handload for the .30 Gibbs. Feeding? Fair with the first three or so in the mag, especially in the Mauser. The Mauser was made for cartridges with much more taper. It's nothing that I can't live with, but it an issue. It's what I consider a minor one though. I'm sure the mag and/or feedrails can be modified. What bullet weight are you looking at? I like the 180 gr for this cartridge, and the top three loads I have listed for the 180 gr bullet are (these are absolute MAXIMUM): IMR-4831 66 gr 3070 IMR-4350 64 gr 3054 H-4350 65 gr 3036 With a 180 grain Barnes X-Bullet (old style), 65 grains of IMR-4831, and a 24" barrel, I get 2950 fps. The test rifle had a 26" tube, so the velocity numbers are all in the ball park to my experience. To be honest, I stopped there. The rifle grouped well and I was getting the "advertised" velocity. Dies are a custom issue. Send a chamber cast or fired cases to RCBS or 4D (www.ch4d.com) for your chamber; talk to them and see what's best. You'll need to neck the case to .35 then back to .30 to move the shoulder forward so you can headspace correctly. If you don't have a .35 whelen or .338 win die, you'll need to get an expander. Fire-forming cases can be fun. I recommend Bullseye or W-231 topped-off with cornmeal or cream of wheat and a parrafin wax stopper at the casemouth. NO BULLETS, of course. Start at about 15 grains of W-231 and work up. Pour in the cornmeal till it's just to the top of the shoulder; push the bar of wax onto the case, forming a plug. Keep the cases upright on the way to the range. On windy days, you'll get a shower of cornmeal back in your face. I reommed Pachmayr Decellerator recoil pads for any rifle with recoil, and the one I have on my Gibbs does a splendid job. Am I happy? Yes. Would I do it again? Maybe. I like light carbines now, and a 6.5X57 with a 20" barrel would be just dandy... Any other questions? Don't blow yourself up! Approach all Maximum loads very carefully.

The .30 Gibbs is a .240 Gibbs necked up to .30 caliber. It's an '06 case with absolute minimal taper and a 35 degree shoulder moved forward, leaving the neck length about .250 inches. I am able to get a 180gr Barnes X-Bullet (old style) to 2950 fps out of a 24 inch barrel using IMR-4831. The rifle is capable of 3 rounds well under an inch (probably about 3/4 inch). I have the barreled action in a Ram-Line stock with a Deccelerator recoil pad. People bad-mouth the Ram-Line stocks, but it's probably the most "in-line" stock I could find. I think the polymer stock material also dampens recoil. I consider the recoil effect to be mild, even from a bench. All Gibbs cartidges are based-on the same case with only the neck diameter and neck/shoulder juction changing. The largest Rocky Gibbs created was the .338 Gibbs; the smallest was the .240. All are "true" wildcats in that a factory round should not be fired in a Gibbs chamber; they are not "improved" cartridges. This case would make an interesting .40. The shoulder/neck junction would be .455 inch diameter, located 2.145 inches from the cartridge base. The neck would be short (just under .300 inches) and would probably represent the maximum volume that one could achieve for this caliber from an '06 case.

Are there wildcats based-on the 240 Weatherby? The case has a .472 rim and a belt - no shoulder to sweat for headspace. It's about .450 just forward of the belt, so .45 caliber is probably out, but .400 would be a possibilty. That .400 Brown-Whelen sounds spiffy, but I wonder how it would feed. I have a .30 Gibbs on a Mauser and feeding is fair. I can put 3 in the mag without issues, but any more...

I've never tried, but I wonder if mounting it in a drill press would be "true" enough to be fairly accurate. I'd file it to overall length in a vise and chuck it in the press to put the round on it. Maybe it's a disaster waiting to happen...

It's a Berthier. The straight trigger and the V- spring between the trigger and magazine are dead giveaways. Maybe some epoxy filler for the pitting and a quick blast of Duracoat...

Yes, I had the serial number on top of the bolt handle. Davis' work removed all but the last two directly adjacent to the ball. I could probably dress them out with careful filing, but I'll keep them as-is. My bolt and receiver were matching numbers, and the last two fits well with the way many European miltary arms parts were marked. Kind of a "retro" feel. Heh... I don't think that there's a part on my Swede that doesn't have the last two numbers on it, wood and all. Maybe I could pass it off as "Swanish".