doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com mystery caliber 9.3x??

I cant for the life of me figure out if this stalking rifle is 9.3x72r or if its a variant of that cartridge. I read a good number of threads on the 9.3x72r changes but the case dimensions dont seem to have changed enough to prevent older guns from chambering modern 9.3x72r ammunition

proof mark


wax cast and case



*this is a factory new case, not loaded ammunition or fired brass
*I know the caliper says .320, I re-measured it in a more stable position. The measurement came to be .312. This obviously doesnt include rim thickness


Slugged the bore with a .40cal soft lead musket ball. Groove is .365-.366"

Looks like i need to cerosafe it. I'd really like to use this rifle for opening day. Has anyone had success ordering 9.3x72r reamers?

Is the brass sized? How does the throat of the case measure compared to the specs on a 9.3x72R chamber? You can coat the case with a sharpie to see if it is binding towards the mouth of the case or the base. Could it be chambered for a 57 mm case? The .360 2&1/4" or the European equivalent? I sold a British rifle chambered for the 2&7/16" round, I bet the continental guns had odd ball lengths too.

https://www.armedconflicts.com/topic/view/116611#

no pun intended but i believe thats the case and you are right on the money

How about a 9.3x82R? If so, it wouldn't hurt hurt to shoot 9.3x72R in it - sort of like shooting a 22 short in a long rifle chamber. Whoops, I see now that the chamber may be shorter or slightly tighter but what I don't see is where the rifling begins. Using Cerrosafe instead of wax would give a much better idea of the chamber, especially if it was blocked long enough to include a bit of the rifling. The key is the length at which the rifling starts.

Sounds about right, I think the 57R case is the most common after the 72R and 74R variants. You should be able to trim 72R brass to 57mm and fire form. I'm not to familiar with the ballistic on the European variant but from the proof marks I believe it calls for a 283 grain bullet at about 1650 fps. Very similar to the .360 2&1/4" NE.

I'm leaning that way. I still have a lot to learn about reloading though. I'm unsure if i'd be too much pressure/bolt thrust if i reamed it to 72r


SKB, after googling your suggestion i found:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=405731&page=1


I'm going to cerosafe the chamber. I believe you are right on the money

journeymen,
The 118.35 mark on your rifle is the bore (not groove or bullet) diameter, expressed in gauge measurement. In my experience, this most often found on rifles with .358-.359" groove diameter. Also it is found on several different old 9.3 nominal cartridges and often the 9x58R S&S. This mark was used before 1912 and at this time there were different case forms. In terms of the number of rifles made, yours is likely chambered for one of the 9.3x72R cartridges. For this reason, I recommend you make or have made a Cerrosafe chamber cast. The wax chamber cast will show general case form, but not precise measurements. At the time this rifle was made, there were "D"(Deutsche), "E"(English), 360, and "N"(Normalizert or standardized). Based on the above photos, I think you may have the "D" form 9.3x72R. The case that would not fully enter the chamber is likely the "N" form case, since it is the one that is generally available now. The "N" form was intended as a compromise to allow one cartridge to be used in the other three rifles by a minor rechambering. Many rifles were so altered without the requirement to have them reproofed because the "N" form ammunition was loaded to the appropriate pressure for all and a bullet that is safe in various diameter barrels. If you run an "N" reamer into a "D" form chamber, you remove only a minimum amount of chips. If you have a "D" form chamber and don't want to rechamber it, if you dieform a "N" case and fireform it in your rifle, you can then load it using the common "N" dies (The chamber wall will prevent such expansion that the case won't chamber). You can physically size a loaded "N" cartridge in a 38-55 die so it will chamber, but you would need a file/trim die, or the type sizing die that holds the decaping rod in a separate threaded bushing, so that removing it will allow the bullet to pass through the die. If you do that, you will have to decide on your own to do it as I am not advising you to do it. Also, due to the 9.3 case being a few thousandths larger than 38-55, you can't, nor do you need to size it all the way to the rim. I hope this helps. It could still be one of the other cartridges.
MIKE

Good info, my mistake in thinking that was the bullet weight in grams.

Strange co-incidence though, 118.35 grams is 283.18 grains.

Thanks for setting me straight Mike.

The factory load for the 9.3x72R used a bullet around 200 grains, the 9.3x57R around 170 to 200 grains (Accurate molds has several in this area), Some folks have luck using the standard Lyman 366408 at 250 grains.

SKB,
A bullet that heavy would be OK for more modern 9.3s (9.3X57{M88}/62/64/74, etc.) but the standard bullet for the 9.3x72R N is the 193 grain Express type bullet. Formally other bullets were used such as 185 or 200 grain in jacketed bullets or in black powder rifles 250/260/280 grain lead (note, 9.3 jacketed bullets are too hard for 9.3x72R).

HalfaDouble,
The Lyman 366408 was one of the most common cast bullets for 9.3x72R and it served many people, especially those with black powder rifles. Many with nitro proofed rifles for lighter bullets were disappointed with this bullet's accuracy. This problem was often addressed by facing off the mold until it drops about 200 grain bullets. My favorite is the 208 grain H&G 512c, but this is no longer available. The rifles with .358-.359" barrels can use the 185-200 grain 35 Remington bullets or any of the various jacketed or lead pistol bullets. For slightly larger than .358 barrels, there was an old Lyman mold for 38 bullets thar dropped from the mold as 173 grain SWC .362" and would be useable in a great many rifles.

Mike

Mike,

Thats my next question, bullet type, I assume "soft lead" bullets are more appropriate? Would "hardcast" be too hard to work with the rifling

Yes, Mike, I had my 366408 shortened back in the late 60s or early 70s. Turned out about 185 grains. Used it in several 9.3x72R drillings and a beautiful Sempert and Krieghoff kipplauf and even a 9.3x82R bolt and a 360 2 1/4 Purdey double. Unfortunately, all gone now. I still have a good supply of 200 grain Norma and 193 grain RWS jacketed for the 9.3x72R. I have never tried them in my 9.3x57 Mauser or my 9.3x74R although I did try some 250 grain 366408 bullets I had cast in the pre shortened mould in the 9.3x74R with good results. My current small 9.3s are 9.3x57R (360) Husqvarnas, a combo and a 33 single. For these I had two moulds made up by Tom at Accurate, the 170 and 200 I mentioned previously. The Huskies have a very slow twist. The 9.3x57R (360) rounds are loaded in my old 9.3x72R RCBS dies. Of course they seldom if ever need a full length resize but I only size down to just above the web anyway. I use 9.3x72R brass by Norma and DWM to make the 9.3x57R (360). My standard cast bullet alloy for 1200 -1500 fps is 1 to 20 but I might go to 1 to 16 in rifles where I might be seeing 1600-1700 fps. Commercial bullets that claim hard probably use antimony to get there and oddly that might give problems with leading in some rifles. The only bullets I cast hard are some linotype ones for the 22 Hornet which I may not have needed to but I was given the linotype and that was the only use I could think of for it. No lead will be too hard for your barrel but it may not give the best results. The factory jacketed bullets for the 9.3x72R were soft metal, copper or gilding metal, to be kind on the older barrels.

journeymen,
I use wheel weights and drop them in water from the mold. This makes a hard bullet and I try to size my bullets .002" over groove diameter, but I'm not overly strict about that. I use a .364" bullet in a 9.3x72R with .358" grooves. These came from a joint casting session with a friend, using my mold and his lead. They are not my usual WW and we sized the whole pile to .364" because his groove diameter was .362". I intended to resize my half to .360" but I tried some and they shot great without leading the barrel, so I didn't resize them. Note Halfadouble's advice above, you may want to go by his rather than my experience.

HalfaDouble
I will comment on your post tomorrow, my wife is calling me to supper.
Mike

HalfaDouble.
When dealing with old metric ammo it is always welcome to read of other people's experiences, thanks for yours. I had actually been looking for a decent 9.3x57R an found a BF advertised as such. When it arrived however the rifle barrel was 12.17x44R. I could have returned it but decided to play with it instead. I made cases from 8x50R Lebel and used .509" 50 cal. bullets with 5744. When other chances came up, I was a day late and they were sold before I saw them. I think your 33 was one of them, I was especially sorry to have missed it. I am hesitant to drastically shorten 9.3x72 R cases when I can use something else. I use original length (2.125-.130") 38-55 cases even though they are up to 1/8" short. When I make 6.5x58R S&S cases from them they stretch enough to be more like 1/16" short. I am making 8.25x57R/360 Hagen brass now from them for a new project. I just seat the bullets "out" to the normal oal. The only complications are usually the requirement to alter the rims and may need to size the necks in another operation to be able to hold the bullets. I brought back from Germany a supply of RWS 9.3x72R cases and bullets and stumbled into an opportunity to add to the bullet supply with a quantity of S&B 193gr .366" bullets whereas the RWS were .364". Both of these bullets can be used in rifles with groove diameter all the way down to .352". For the more powerful 9.3s I use bullets from a supply of old Speer 250 gr. and both RWS and Norma 286gr. The 250 gr Speer stabilize in the 9.3X72R S&S which wouldn't work with bullets as long as the 258 gr. H Mantel or 293gr TUG. The S&S is an entirely different cartridge than the 9.3x72R N (.473" vs .427" base dia.).
Mike.

I have some cerosafe on order. I was able to scope the bore and the chamber seems a little rough, bore looks superb luckily

I too think this is your chambering. I have chased down several of these in the last couple of months. You can look up some of my posts in the German section above for detailed discussions. A couple of general comments.

- The 9.3/57R - .360 is 15 mm longer than the 9.3x72. This is much longer than accounte for by the 15mm.
- Many of the break action stalking rifles are found in this caliber.
- There are at least three distinct versions of the 9.3x72R, even without drifting off into the Sauer and 82mm versions. It is not uncommon at all to have a chambe that won't seat a modern 9.3x72R Norma case. I bought one drilling on a GB auction. The austion house said that they presumed it was a 9.3x57R since the 9.3 x 72R ammo lacked 1/4" chambering (very similar to yours). I contacted them and asked them to use a new unfired case or a resized clean case. THey did and the 9.3x72 fit perfectly. The old guns are very sensitive to oversized or dirty cases, even to a small degree.
- I bought another drilling, marked exactly like a 9.3x72, but the ammo wouldn't fit, not even empty cases. I neck sized the cases in a 35 Whelen die, and they fit. A lead slug of the bore showed it to be a true .357 barrel.

As a general rule, in an older gun, my first guess would be that it is a tight chamber in the longer version, or it is not actually a .366 bullet. For years, all the ammo loaded used a reduced diameter bullet with a short driving band. These are not readily available any more and you really need to use bullets of the proper diameter, with the neck sized to the proper size.

If it is a stalking rifle, my first guess would be that it is a 57mm case.

Keep in mind too that just because it is modern ammo, it isn't necessarily exact. I recently bought a high grade O/U combo gun with an 8x57R rifle chamber. It was made in Berlin in 1938. New factory 8x57R ammo wouldn't chamber. I tried new 7x57R. Same story. A barrel slug showed a .323 groove diameter. I found that old German military 8x57 form the WW II era went right in (but of course didn't extract). My guess was correct that the old ammo had the correct .469 base diameter. All the new ammo (S&B) was made to the "30-06 standard" of .473. This was true even though it was European ammo. The rifle was made to such close tolerances that it wouldn't chamber the world's # 1 standard case head. To solve it for the future, I took a 308 reamer and just barely relieved the breech end of the chamber to a proper size, and used a small fine stone in a Dremel to relieve the hardened extractor the same few thousanths. It is undetectable except under a magnifier and you can make ammo from any appropriate donor case.

AGS The 8x57 and 7x57 were not made on the same head size cases, nor were the rimmed versions. The 8x57/I/IS/IR/and IRS were made on the M88 case head diameter of .468", whereas the 7x57/ R were made on the M93 case head diameter of .473"(The 30-06 is said to have been copied from the 7x57). It is possible that S&B made those 8x57R cases with the same draw dies as the 7x57R (M93). Modern manufactures often make ammo with case heads different diameter than original design. My brother had a 6.5x55 caliber rifle and was handloading with modern American cases (with correct headstamp), with .468" head diameter. Actual measurement of 30-06 and other 06 size cases often show head diameter of .468". This is all OK as long as they use the smaller size but can cause confusion if they use a larger size. We often talk about "tight chambers", and they do happen, but the problem can also be the ammunition rather than the chamber.
Mike

Journeymen, how is the Cerrosafe cast coming?

You are correct and the point I was making was that some of the 8x57 R is made with the .473 head. I checked some S&B 7x57R and it is .473, so again it wouldn't work to fireform. THis was a case where precision caused a problem. A little slop would have come in handy.

AGS,
Yes, sometimes a little slop does come in handy. I was fortunate enough a couple times to buy once fired cases from a firearm manufacturer and had way more 7x57R cases than 8x57R cases and made up some 8x57R cases using the 7mm ones. They were close enough that "polishing" rather than "turning" the head diameter (after sizing as much as possible) allowed their use. A lathe, where I worked made things easier, without access to a lathe, a drill press would also work. BTW, this exercise is what taught me the difference between the cases.
Mike

we have lift off.

Ordered a 4d reamer and re-cut the chamber, you guys were right it was a slight diameter/taper difference. Cut and checked the chamber with two live cartridges. Cut, extract, clean, drop round in... I didnt have to go full depth with the reamer. I stopped with 1/8" or so of the rim cutting portion behind the barrel face. I did it by hand and held the barrel in a bench vise

I definately recommend you to use a lot of cutting fluid and clear chip every 2 full rotations. Test fired two shots, measured the brass, no deformation, bulges ect. They measure very close to new brass. However it does seem the gun is off face as the primers definately show signs of flow. I'll post pics of those later

journeymen,
I apologize for not making it clear that I have a reamer for the "N" version of 9.3x72R. It threw me off when you said you had ordered Cerrosafe. Since you live within driving range, I could have saved you time and the cost of a reamer.
Mike

Der Ami, no harm no foul. I was worried that i'd screw something up and liquify the solder holding on the barrel lug.

This is what the primers looked like. I talked with our gunsmith at work and he said it might be the jacketed bullets causing a higher pressure, given it was proofed for black powder.



The gun is also off face. It will readily close on a .003" shim. I assume ideal is .001" to .0005"?

journeymen,
The 193gr normal bullet for the 9.3x72R doesn't raise the pressure significantly because it was especially made for use in older rifles (basically has a thin jacket that is undersized except for a short "driving band"). This bullet is not common in the US and there is no way to know what bullet the rifle was fired with, in the past. Bullets intended for the more powerful 9.3s(such as 9.3x62 or 74R) could very well raise the pressure. I believe current ammo is loaded to about 18,000 C.U.P., older ammo may have been loaded to 12,000 but I don't know for sure. I do have a couple boxes of ammo marked " Schwach Ladung"(weak load). I don't know the pressure nor velocity (too rare to shoot over the chronograph), but it does have the jacketed bullet. You can have a lot of fun shooting it with cast bullets from Lyman mold #355408(origional or shortened to about 200 gr) or 358315(200gr) or 358318(250gr) or RCBS 200-35(200 gr) which ever stabilizes in your rifle at appropriate velocity for a black powder proofed rifle. The single locking lug underlever rifles such as this one were not intended for high pressures.
Mike

I'm out of my depth on this one. I know the lockup is out. I dont know what surfaces i should add material to or if thats the correct course of action to bring it back to face. The small red circle is around what i think is a clearance cut on the barrel lug

journeymen,
I don't think the "problem" is as devastating as you seem to think it is. I would be hesitant to do any welding to "correct" it. If it were mine and I was concerned about it, I would concentrate on the wear of the hinge "pin" and/or the underlever "pin". You could check to see if this would help matters by making up simple straight pins a couple "thousandths" larger, before making up new screws and or reaming the holes "round". You should be able to use it the rest of your life with 12,000 psi loads normally and 18,000 psi loads only for hunting.
Mike

Journeyman;

See PM I just sent you.

Regards;
Stephen Howell

Journeymen, what does the breech face look like? Hard to tell from the pics but looks more like just a corroded surface abound the firing pin hole that lets the primer center enter the "potholes" and then get smoothed off when the action is opened. If so, no biggie.

Another thing, what is the rim thickness on those S&Bs?