This great little o/u combo needs a bit more oopmh to be red deer legal in my neck of the woods. I need something like a 180 grainer at 2300 fps at combo gun-friendly pressures. Would it be much hassle to rechamber to a necked up 30 caliber wildcat on the 7x57R? Would the .520 rim of the 7x57R be a problem with this type of extractor, or could I go all the way to the .540 rim of the 30-40 Krag? Anything to shed light on this would be greatly appreciated!

73s, LA1TOA Inge

What is it chambered in now?

I presume you're working with an M24 currently chambered for the 30/30 and want something without a significant increase in head thrust out of respect for the tip up action. My first thought was about the same as yours - 30/40 Improved. but depending on what sort of cases are available in your neighborhood how about the 307 Winchester or 30/444 (aka 309 JDJ)? Instead of the 7x57R I wonder if using the larger 7x65R or 9.3x74R cases as the starting point for your wildcat would give you more flexibility?

I have not even bought the gun yet, as I would like to have my options figured out first. I have been thinking about an exposed hammer combination gun for some time, for a lot of reasons. They are not the most common of guns, however, even if there are lots of hammerless combos.

You are indeed right about my respect for the action's limitations. Most cases available in the US are also possible to obtain here in the Old World, even if this was a lot easier before your government became so scared of us. The 307 Winchester gives a bit too little powder space. I have a 356 M94, so I am quite familiar with the case. The 309 JDJ is interesting, but needs a bit of case work. The Russian is a more obvious choice to me.

The question is, however, how feasible such a conversion would be? Which cartridge is a question one might leave for a nice winterstorm contemplation in front of the fireplace. But it does need a functional extractor. Any input is greatly appreciated.

I think Hornady may have provided you a solution with a factory round they named the 308 Marlin Express.

http://www.chuckhawks.com/308_marlin_first_look.htm

Looks interesting, but I am still concerned about chamber pressures and action thrust. Since I am more then somewhat biased towards handloads I am also concerned about the long term availability of factory cases. I was thinking more in the line of plenty of powder space, it is not going to be a bench rest gun anyway. The chambering issue aside, how complicated is the rechambering operation of such a combination gun, wand how complicated is the fitting of the extractor, when I start with a 30-30?

Ok, I'm going to have to give some educated guesses here. To get an absolutely correct answer, you'll have to ask someone who calls thmeself an expert, which I am not.

The brass availability is a non-issue, a red herring. Stocking up is easier than dealing with a wildcat. 7x57R brass is not so readily available either. And the dies for your dreamed up wildcat will cost a bunch.

The Marlin 308 compared with the 30-30, rechambering etc. Probably a little more chamber pressure with the 308 M, but not enough to matter. Probably less action thrust in the 308 M - because it has less taper, and sharper shoulder.

I think that if you can't rechamber the 30-30 to the 308 Marlin - then forget it. It's that simple, because I think this 308 Marlin is your path to most likely succeed.

If you are really determined to do this, and want very high likelyhood of success, and since you don't seem to mind a wildcat - go the simple route and rechamber to 30-30 improved. That way you dont have to mess with the extractor, and you get a little more performance.

KB

I just realized that you are writing from Europe somewhere.

I'm wondering why you are thinking of messing around with a combo gun in 30-30 when you have the great Euro guns already chambered in 7x57R, 7x65R, 8x57R, 9.3x64R, etc.?

I always though that the 7.62x53R Finnish/Lapua round would be great in a combo rifle/shotgun. I don't think rechambering per your original question is an option for that cartridge because of pressure, extractor etc. I have one for the single shot Encore, and like it so far.

KB

KB; I appreciate your input. Europe, yes, Norway, to be specific. There are indeed great combination guns here. They are mostly hammerless, however, and I would like a hammer gun because I want to be able to carry with the hammer down. This is impossible with most European hammerless guns.

The 7,62 Russian may have a too large rim for the extractor, but the pressure is not a problem since I only shoot handloads. How much larger a rim do you think the M24 extractor could handle with a bit of tinkering?

IF

quote:

Originally posted by rp15oryx:
KB; I appreciate your input. Europe, yes, Norway, to be specific.

The 7,62 Russian may have a too large rim for the extractor, but the pressure is not a problem since I only shoot handloads. How much larger a rim do you think the M24 extractor could handle with a bit of tinkering?

Regarding the M24 extractor, I wouldn't dare to make a guess about it relating to adapting for the 7.62 Russian. I don't know.

However, I can make an educated guess that it could be adapted to the 308 Marlin, but that is a guess that I'm far more comfortable with.

Incidentlly, although you could get your magic 2300 fps using the 30-40 Craig cartridge, I would avoid even thinking about it. I just don't like the 30-40, and it's clearly obsolete, and best left dead.

I suspect you can easily obtain 2300 fps with 180 gr bullets with the 308 Marlin, maybe more and still within the pressure limits of the action.

KB

Thanks a lot, KB, I'll discuss the Marlin round with my gunsmith then. Btw, The 180 at 2300 fps is no magic number, but a legal requirement for big game in my country. Again, thank you for your input.

IF

Man, I've told you, the .30 Blaser!

Why not the .307 Win? You already have the .356 M94, so you have brass you can form from, using .308 dies and 30-30 shellholder. A 30-30 rim, no extractor work, and increasing body dia from .421 to .471. I imagine you could get a little more from the new 308 Marlin (depending on pressures), but you have the parent brass already. AI that, and get a little more capacity too.