Hook - that information says nothing about the round being 'over pressure', only too long for some cylinders - which is whatcha get with long heavy slugs Ammo makers cannot go over SAAMI pressure limits on these cartridges witihout identifying them - even ammo marked +P+ has to be within the same SAAMI pressure limits as other cartridges within that caliber pressure range - they may be at the top of the pressure range for that cartridge but they are within pressure limits.
Two cartridges that, I believe, come in the same case size are the 45 Colt and the 454 (yes, maybe???) - anyhow, you can fire the lesser powered cartridge through a revolver chambered for the higher pressured cartridge but not the reverse and to avoid interchanging the cartridges, they call one the 45 Colt and the other the (what??) 454?
Now, the following is a diatribe on the Buffalo Bore statement and an attempt to add some clarification and trips over into rifles but in pistol calibers. I don't know which genius at Buffalo Bore wrote that add but he should read from Marshall Stanton at Beartooth Bullets regarding the slow 1:38 twist in Marlin rifles (whether 44 magnum or 444 Marlin calibers), the micro groove barrel and heavy cast bullets before making a blanket statement like that and although this is a Handgun site, the following applies......
One other thing Marlin rifle shooters must contend with is Marlin's tendency to 'over bore' rifling in magnum pistol calibers - revolvers in these calibers are just fine but it seems that in a couple of calibers, 41 and 44 magnums, the bore on the Marlin rifles must be slugged to find the true bore diameter and then the reloader must find slugs that fit. The bore on the 41 Magnum Marlin rifle may run as high as .412 or even .413 and although it will shoot jacketed slugs with some degree of accuracy, cast slugs have to be sized to properly fit the bore. As well, as 44 magnum Marlin rifle may have a bore that runs to the .431 - .432 diameter and while jacketed slugs may grab enough of the rifling to stabalize, .429-.430 cast slugs (without a gas check) may just sort of skid down the barrel and never stabalize.
Here's an example: I have 3 444 marlin caliber rifles - all 3 are Winchester Big Bores. One wears a custom barrel that favors a .432 diameter slug and prefers the 330-350 weight slugs from Beartooth; one other wears a straight 20" Marlin 12 groove 1:38 twist barrel that loves the Beartooth 330 gn gas check and the last one wears a 18" 1:12 twist barrel that also loves the heavier 335 gn slugs. I have some 405 gn gas check I haven't tried out yet but I'm getting there. The point here is that Buffo Bore is wrong about Marlin rifles and their barrel twist rates and if you want good information you should go to either Veral Smith's website or to the Beartooth Bullets website and find out what extensive testing of heavy for the bore slugs and the Marlin Microgroove barrel hass done for those 43 bore calibers (44 magnum and 444 Marlin).
As for the pressure designations - I will repeat: If they are marked 44 Magnum, whether just 'Magnum', '+P', or '+P+', they are still 44 Magnum slugs and must remain within established SAAMI pressure limits in order to be safe. Those pressure limits apply to all revolvers or pistols chambered for that caliber, period. The only caveat the ammoo makers should provide regards overall cartridge length and whether these rounds will fit in the chambers of all handguns or rifles chambered in that caliber. This is what Buffalo Bore has done, nothing else (except make a bit of an incorrect statement about Marlin rifling).
Oh yeah, one more thing - if you have one of those rifles (Marlin) and want to shoot heavy cast slugs with incredible accuracy, get on down to Veral Smith's website or go to Beartooth Bullets website and get both the information on bore lapping and the materials (kit) to do it. It will make you happy. JMTCW. Mikey.
