18" or 20" barrel for .308?

[1911-A1]

I'm looking at a. 308 precision bolt gun build, and I would like to see how much capability I lose going from 20" to 18". I'd like to keep it short, but not if it hurts its ability to perform well at long ranges. The idea is to put a can on it and possibly a folding stock for transportation.

[orkan]

Been there done that.


Basically, compute for 15-25fps per inch of barrel loss. Yet some barrels shoot fast, others slow.

Expect 2500-2575fps from an 18"
Expect 2525-2600fps from a 20"

This, given a stout load of varget and a 175SMK.

[Abraxas]

Been there done that.


Basically, compute for 15-25fps per inch of barrel loss. Yet some barrels shoot fast, others slow.

Expect 2500-2575fps from an 18"
Expect 2525-2600fps from a 20"

This, given a stout load of varget and a 175SMK.

Does the Hornsbys improve your grouping?

[orkan]

Doesn't seem to. Causes the safety nazi's to lose their ****n minds however.

[jpipes]

You'll likely lose approximately 10fps per inch removed, but you'll only know for sure when you test it. A good barrel, with a good chamber, coupled with good handloads and good bullets and I bet you won't have any problems to 1k. For reference, my 20" Brux sends sierra 2156 palma bullets at 2890 via 8208 xbr. Im at 2650 with 175 smk's and Varget. Both are using Winchester brass.

[rundm]

I am guessing that the 2800+ speed is with the 155 gr palma bullets? I am able to get there with my 20 in AI with the 155gr lapua but the accuracy is not the same as with the 168's or 175 sierras. Does the xbr powder meter well? I havn't tried anything except for varget.

[jpipes]

Yes sir, this are the 155 bullets with a "palma" designation. Higher BC than the original 155 smk. I love them, and found them to shoot slightly better than 155 Scenars in my rifle.

XBR meters very well, and has shown to be very temperature stable in my testing. I use two chargemesters to dispense powder, so I can't speak to how it meters out of a standard powder measure. It's more ball like, so it should be fine. In my opinion, it's THE powder for heavy bullets in .223 and 155 class bullets in .308. I've been extremely pleased with it.

[1911-A1]

Is there any difference in accuracy between the two lengths?

[Iraqgunz]

Barrel length does not = accuracy. There are many past threads that covert this topic.

Is there any difference in accuracy between the two lengths?

[Pappabear]

I'm looking at a. 308 precision bolt gun build, and I would like to see how much capability I lose going from 20" to 18". I'd like to keep it short, but not if it hurts its ability to perform well at long ranges. The idea is to put a can on it and possibly a folding stock for transportation.

As you have been told, your not going to lose much, but I wouldn't spend money to cut 2 inches off a 20 inch barrel. Just my thoughts. If your buying a custom, thats another story.