Several months ago, I bought a LMT MRP 5.56mm rifle during a Black Friday sale. I'm a bit of an accuracy enthusiast with AR rifles, but I also like a practical weight carbine suitable for general use.
Over the past several months, I purchased 4 different barrels for this rifle, I figured I would share my results as it might be helpful to others. I spent considerable time with each barrel over the months, each one has at least 200 rounds downrange. Today's results were fairly representative of my more extensive testing with each barrel.
Today, I fired two 5 round groups at 100 yards with each barrel, except the Bartlein barrel as this is the primary barrel I use and it has already proven to be extremely accurate. I only fired one group with the Bartlein barrel to re-zero the scope as it was getting dark. I was going to use a 32x nightforce scope for this test, but I was pressed for time, so I used the vortex 1-10 razor that lives on this rifle. All shots felt pretty good, I don't think there was much in the way of shooter error. Ideally I would have used 10 round groups, but again I was pressed for time.
All groups were fired using handloads consisting of 73 grain Berger bullets and IMR 8208. This particular load shoots as well as anything I've tried in every AR I own.
First up, the factory LMT 16 Chrome lined Barrel. This produced groups measuring 1.53 and 1.72, velocity was 2,573 with an extreme spread of 50 and SD of 15.9
Next up was the most disappointing to me, this is an $800 Factory LMT 5r cut rifled 16" barrel. I spent considerable time with this Barrel when I bought it, it is frustrating because it wants to shoot better, but it almost always throws a shot in every group.
Next up are two barrels that I had D Wilson convert, I'm very pleased with both of them. The first is a Daniel Defense 14.5 heavy SOCOM profile carbine length CHF Chrome lined barrel. This thing consistently hovers at or just under 1 MOA. Ejection is at 3 o'clock, it's gassed really well for a fighting carbine. Groups were .837" and .973" ( ignore the upper right target, I shot this unsupported as I was just getting on paper)
Lastly, I re-zeroed the Bartlein barrel that I primarily run, probably pushing 1,000 rounds through this Barrel at this point. It consistently puts five rounds between .3" and .75", with numerous 10 round groups that have been in the .6's. The first cold/very clean barrel shot went slightly high, the next 4 went into .347", group size was .744" . It's worth noting that the Bartlein barrel was much faster than the 16" LMT factory barrels, 2,680 FPS, vs. an average of 2,580 FPS for the two 16" factory LMT barrels that I shot today.
All groups were shot with a Vortex 1-10 razor, not the best optic for shooting groups, but it's very practical and it works great for the type of shooting I do. Here are some additional photos showing the barrels, rifle, stuff like that
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