When the Guide Guns were first introduced, they all had factory porting. later only 444 and 450 Marlin chambered guns had porting!
I was visiting a gun store (an every day routine) when GG first were release. 2 men each bought one in 45-70. The next day there were 2 used GG's for sale used, one unfired the other fired twice! Several months later I bought a used GG, and the counter guys gave me a partial box of Factory ammo (the only factory 45-70 I ever shot!), it was the box the two friends shot from. 300 grain soft point Winchester. I loaded 4 rounds and slow fired them all! What a mild round! I have fired 336 and 1894 Marlins in 44 mag that kicked worse!!! All I can assume is the "Two Friends" didn't know how to hold a Center fire rifle!
My standard load for the Guide Gun is 400 grain RN hard cast with gas check over a heavy load of IMR 3031 at 2100 fps (from a 26" 1886) and is about 3900 ft lbs of ME. The Winchester factory ammo is about 2350 foot pounds.
In a test to see how well the gun performs as a back up dangerous game rifle, I set a 6" bullseye target at 50 yards. The object is to keep all 5 shots in 6" but fire as fast as possible. I fired all five rounds in about 1.75 seconds, but my group was 1.5"!
Ivan
