Now you guys got me curious ... Is there an online program , ect where I can get a close est . of the velocity I can expect from a 16" barrel 458 Lott ,,, 416 Rem , or Ruger , or 500 AccRel ... ??????????????????????????? Thanks .

Quickload. I have access to someone elses copy but my MAC isn't compatible. I think a few here have it.

Gumboot

I run the Quickload program on what you request and with a "known" load from a couple of different rifles I have in 458 Lott. Quickload tends to "Over Estimate Velocity" depending on cartridge by anywhere from 100 fps to 200 fps. With this particular known load with a 500 gr Swift A Frame Quickload over estimates by 100 fps both in a 22 inch rifle and a 24 inch rifle.

This known load does 2262 fps in a 24 inch barrel and 2172 fps in the same tube at 22 inches. 90 fps less or 45 fps per inch of barrel. If that trend continues at 16 inches it would be doing 1902 fps. Quickload says 2110 fps is what it would do in a 16 inch barrel--minus the over estimate of 100 puts it at 2010 fps. I think it would be more like the 1900 fps or so in a 16 inch barrel and that is what it looks like with other loads too. The ticket would be drop bullet weight to 400 grs and velocity would be back up again.

Dropping to a 416 Remington looks like around 50 fps per inch. This correlates with some rifles I have that I chopped from 24 inches to 22 inches. So you would have a 400 at close to 2000 fps or so. I think that muzzle blast would be rather interesting on both those cartridges at 16 inches!

Quickload is a wonderful and extensive program that I have used for development of all my cartridges. One has to realize that it can give you some great starting points, and I have found that pressures are very close, but velocity estimates is almost always a little high in all cases. That has been my experiences with it.

Michael

..... Thanks ; . there is a reason for all this ???? I about broke the front sight off my 375 the other day because of the 20 " barrel . .. I have noticed with my wife's 308 Compact , that the barrel doesn,t get banged on stuff very much .....
.
. Tho 20 " is miles better than 24" .. . A 416 Taylor I had built with an 18" barrel was sure handy to have around .... Tho it weighed a ton .., Well 8.5 lbs ......It still got ok velocity ......

One thing you have to expect is a crazy increase in muzzle blast.

John

..I,ve been doing pretty noisey things all my life .I have pretty seasoned ears .
.
. 80 grains or less of rifle powder isn,t that bad .... I have gotten so I put plugs in real quick sometimes before the shootin starts tho ...... It is more the inconvience of not being able to hear very good for a couple days than the damage I,m doing .......... I also use a pair of peltor electronic muffs also now ..

I've noticed that with over 350 grain bullets in handguns, I can get pretty much the same velocity from a 4" barrel, vs. a 7" barrel or larger.
The heavier bullet stays in place long enough to build pressure to the same velocity, and, only a 2" really has a noticeable drop in velocity.

I'm wondering if this occurs with some of the big bores, and, if so, where does it start? 510 Wells?
.600OK?