I'm in the process of putting together the specs and components list for a custom build, I'd like to have completed this year. This rifle will be used for mostly hunting deer at ranges out to 1,000 yards. Going into this project I've got a couple of requirements. 1) 300 Norma Mag; from everything I've read this cartridge has a lot of knock down power. 2) Suppressor; protecting my hearing is very important and I understand that even a couple of shots taken every year, while hunting, can be very harmful. 3) Lightweight; I hunt on foot, so having the absolute lightest rifle possible is a requirement.
As I've thought through this build, I've relied heavily on the experience and viewpoints, found on forums, internet searches and the guys at my local gun shop. I imagine there will be some questions regarding some of the decisions for this build. So, I'll address those questions first, before asking my question in regard to barrel length.
1) Why 300 NM; I want a cartridge that I can be 100% confident will drop animals in their tracks.
2) Why Suppressed; Protect my hearing. Also, lots of people are getting them and I want to be included.
3) Why Lightweight; I generally hike 10-15 miles a day while hunting. As they say ounces=pounds=pain.
Now on to my question. I understand that 300 NM's typically have 26-28" barrels. But, by the time I add a 7" suppressor, I'd be up to a barrel length of 33-35". Which is too long considering how much time I spend hiking in brush. I'm leaning towards cutting the barrel down to 16". Giving me an overall length of 23" with the suppressor attached. Recognizing that the 10-12" of barrel loss will result in a decrease of ~350 fps, according to a guy on Snipershide. I am expecting the 300 NM velocity, shooting 225 ELDM, to be ~2775 fps. By comparison that's approximately the same velocity of the 300 NM's smaller .30 cal brother, a .30-06 shooting 178 ELDM, in a 24" barrel. I understand that we're not comparing equal bullet weights. The sacrifice in velocity is worth it to me. Mostly because I'll be shooting a suppressed magnum. Which honestly, just sounds Bad A$$.
Also, I know this gun will have a lot of recoil. Recognizing the importance of getting a really good zero, I plan on using a Lead Sled, while sighting in my rifle. This will remove all of the variables of me as the shooter and get the scope really dialed in. My experience as a hunter is that I am a much better shot on game than at targets. Looking back at my track record while hunting, I think it's safe to say that I'm a "quarter MOA shooter all day.....if I do my part"
Finally, if you have any recommendations for which scope to use, I'd really appreciate it. My preference would be for something in the 25-35x magnification range. I subscribe to the idea of aim small...miss small. Considering the distances, I could find myself shooting, I'd like to be able to really zoom in and shoot at a tuft of hair on the vitals. As opposed to a deer that just looks like a silhouette in my scope. I haven't started looking at scopes yet. But, am inclined to consider something from Vortex. Based on what I've heard about their incredible warranty program.
So, back to the question being asked here in this post. Do you think I should go with a 16" barrel length. Or, should I accept the increased barrel weight and length, by stepping up to an 18" barrel?