I'm thinking on buying a 44 cal. mold with the gas check and using it to load with #2 alloy for mag rifle and then using the same bullet (with out the gas check ) in a 44 special load. Would there be a problem ?
Subject comes up once in a while, and I've read many responses. From what I gather there are those that says yes, you can shoot gas-check bullets w/o gas checks with no noticeable difference. And those that say no, you may get leading (from step base bullet not sealing bore) and they won't be accurate. I've only tried it once with Special level loads in Magnum brass; not any appreciable difference as far as I could tell, but they were light loads in my 7 1/2" Ruger...
By keeping your loads below about 1100 FPS you shouldn't have a problem without GC. Have shot 7.62x39 at 1500 fps without GC and din't notice much leading. The lead I have is from an indoor range not knowing how hard it really is. Shot plenty of it out of a G-17 and G-36 with no leading at all.
Something most shooters and casters neglect is the lubricant. I spent a LOT of time working on a cast bullet load for my Sharps and could not get above a certain point (about 1,200 fps) and a certain level of accuracy (kind of poor) until I started making my own lube. Once I did the load fell right into place. The bullet size and lube are more critical than the use of a gas check and I've run BIG bullets up around 1,500 fps (500 gr.) with NO leading and good accuracy. These are plain base bullets sized correctly for the barrel using heat treated ww material.
Gas checks serve several purposes,the main on is to protect the bullets base when both high velocity and pressure are present in a given load. You can have one or the other and not have leading issues but at some point when both high pressure and high velocity are both present even with a hard alloy leading is going to become and issues without a gas check or paper patched bullet.
Gas checks also help seal the bore and to protect the bullets base from velocity/rifling induced defects that high pressures gases will take advantage of. Gas checks also allow you to shoot a much softer alloy at higher velocity and pressure than the alloy could normally withstand such as you would cast for HP or FN cast hunting bullets.
Gas checks also provide and advantage when shooting cast lead bullets in Marlin Micro-Groove bores. The gas check provide a little extra grip for the cast bullet so it doesn't skid on the shallow lands and grooves.
I shoot lots of gas check type bullets with the gas check left off in my 30-30 plinker loads which are around 12 BHN and cast from Wheel weights. I also shoot 38 Special HP's I cast myself from 50/50 alloy with the gas check left off. Bullet fit is key gas check or not.
The problems have been:
finding gas checks
Finding gas checks that don't cost as much pre check as the bullet
I never needed a gas check except for small caliber high-velocity rifle loads.
In you case, you will probably need them for the rifle.
The bullets shoot fine without the gas check (they are just heel-based bullets like so many were before 1910 or so) and won't lead if the are large enough and soft enough.
I find that Lee Liquid Alox is all I need for mine, but I sold by gas-check mold about 20 years ago. The Liquid Alox is a "miracle worker" for eliminating leading and a little is all you need (if your bullets are brown/amber, you used WAY too much). It is very tenacious and seems to really seal the bore even with slightly undersized bullets. I have taken bullets that lead, tumbled them in LLA, and gotten zero leading afterwards.
Lead is such a different world than jacketed.