Accuracy Versus Barrel Length/Weight (DPMS LR-308)
I felt it worth discussing since several people have asked the question of accuracy on the DPMS LR-308 rifles when comparing barrel weight (AP4, heavy, bull) and barrel length (16”, 18”, 24”). To clarify, we define accuracy as bullet grouping. For example, out of a 3 shot group at 100yd, if my shot placement has all three bullets under 1” center to center, this would be a sub-Minute of Angle (MOA) accuracy, which is very good. Additionally, at 200yd this would be all 3 shots under 2” and so on. We define drop compensation (holdover) as how many inches a bullet drops at a specified distance. For example if you sight your rifle in at 100yd, at 200yd you may need to place the cross hairs at 2” above the desired point of impact.
Most people feel they are giving up accuracy when selecting a shorter and/or lighter weight barrel. In general, ours and our clients’ experiences with these rifles, regardless of the barrel length or weight, will shoot sub-MOA. In my opinion, the accuracy of the bullet delivery is primarily compromised by the shooter, ammo, and fire control system (trigger), unless you just happen to get a lemon rifle which we haven’t heard of.
However, the question still remains do you sacrifice accuracy when going from a 24” bull down to a 16” AP4? The answer in my opinion is yes and no. Inherently a 12lb bench rifle with a bull barrel seems like it would be more accurate because of its weight, barrel diameter, length and you would be shooting off of a fixed rest. I personally find I am more accurate with this setup since the weight of the rifle is less affected by my movement and I’m shooting off of a rest. However if you put both guns side by side in the same setup (trigger, rest, distance, etc.) they will shoot relatively with the same grouping accuracy.
So the issue is what do you sacrifice or gain with barrel length and/or weight if they both have relatively the same accuracy. With a shorter barrel the bullet has less distance/time to build velocity, before the bullet exits the barrel and releases the gas pressure to atmosphere. With a longer barrel the bullet will have more time to effectively use the gas pressure to build more velocity before venting.
(The higher the velocity, the flatter shooting trajectory it will have, but not necessarily more accurate. Meaning that a 16” barrel sighted in at 100yd may drop 2” at 200yd where as a 24” may only drop 1”. This doesn’t mean the 24” is more accurate just flatter shooting for longer ranges and inherently will deliver more energy on target.)
So when choosing a rifle you must determine what type of shooting you want to do? If you are thinking brush gun for deer hunting and some field shooting that you will be carrying, the LR-308AP4, T, or L would be an excellent choice. (This doesn’t mean these guns will not perform out to 500yd.) The LR-308B would be a close second with an 18” bull barrel. If you’re thinking target/varmint then the LR-308, B, C would be good choices.
We generally recommend the LR rifles for the following conditions:
Deer or Bear Hunting, Tactical or 3 Gun Shooting: (DPMS LR-308AP4, T)
-Typical range 0 – 300yd.
-Free hand, minimum non-supported shooting.
-Brush, open field, collapsible stock easier for carrying & lighter weight, faster target acquisition & maneuverability, or when fleeing from a really angry bear.
-AP4 is optimal for suppressing an urban insurgency.
Deer Hunting or Mid range tactical/sniper or target shooting: (DPMS LR-308B, C or D9 Custom Rifle):
-Typical range: 0 – 500yd.
-Limited freehand, supported shooting platform.
-Light brush, open field, bench. With a collapsible adds to more maneuverability in brush and general carrying. Recommend a bipod (but adds front end weight when freehand shooting.)
-LR-308B or D9 Custom is a good bridge between tactical and bench shooting. This is an excellent choice for suppressing urban, rural or any other type of insurgency.
Bench Shooting: (DPMS LR-308 24”)
-Typical range: 200 – 800yd.
-Completely supported shooting platform.
-Open range.
-Excellent for not letting the insurgents get close.
Hopefully the provides you with additional information to make the best choice possible for your shooting needs when choosing a DPMS LR or D9 Custom LR firearm. Please contact us and we would be glad to provide you with a long range AR platform rifle. (If we don’t have it, we probably have it on order, or will build to your needs.)