Thanks - the bullet diameter is .500 and I don't know the twist rate - and I haven't slugged the bore yet.
NECG (?) I think makes peep sights that clamp onto weaver-type bases... I did think of that, but there's not room to put it on with the scope -but I could certainly site the rifle in with it on and then just keep it in the kit that goes with the rifle...
Grizz, I just did a quick search over on the Marlin Owner's board and found this information:
Twist rates of Handi Rifles:
.17 HMR 1 in 9"
.22 LR 1 in 16"
.22 WMRF 1 in 16"
.204 Ruger 1 in 12"
.22 Hornet 1 n 12"
.223 1 in 12", late models are a mix of 1:9"/1:12", 2007 Marlin produced barrels are 1:9"
.22-250 1 in 14"
.25/06 1 in 10"
.243 1 in 10"
.270 1 in 10"
.280 1 in 10"
.308 1 in 10"
.357 Mag 1 in 18¾"
.357 Maxi 1 in 18¾"
.35 Whelen 1 in 16"
7mm-08 1 in 10"
7.62x39 1 in 9¾"
7x57 1 in 10"
7x64 1 in 10"
7mm Rem Mag 1:9.5"
.30/30 1 in 10"
.30/06 1 in 10"
.300 Win Mag 1:10"
.38/55 1 in 18"
.44 Mag 1 in 38"
.444 Marlin 1 in 38" (original)
.444 Marlin 1:20" (2007 models)
.45/70 1 in 20"
.450 Marlin 1 in 20"
.45 Colt Carbine 1:16"
.45 Colt/410 1 in 16"
.500 S&W 1 in 18¾"
20 ga. 1 in 28"
12 ga. 1 in 35"
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So the 500 S&W is 1 in 18 & 3/4" which is probably the same as the S&W revolvers? Regardless, should be able to stabalize the heavies just fine. I've not read or seen any reference to problems with the 700 grain bullets at 1300 fps (revolver speed). I probably won't be finding out - I think a 700 grain pill at 1500 fps from this rifle would be a bit much...
![Shocked :shock:](./images/smilies/icon_eek.gif)