120 lapua scenar-L with xbr 8208

[joedirt199]

So got to test some of the 120 gr hpbt Lapua Scenar-L bullets I got from grafs. Started with 27 grs of XBR 8280 and produced a wonderful .33 moa. Hornady brass loaded 2.27 oal, which I may shorten this as it looked like I may be hitting the rifling a smidge since there were small lines around the bullet after unchambering them even though my overall length tests showed I had plenty of room.

27.0 grs XBR avg velocity from a 20" BHW barrel 2442 fps, standard deviation 16, moa .33"

27.5 grs XBR avg 2483 fps, sd 12, moa 1.01"

28.0 grs XBR avg 2538 fps, sd 19, moa .89"

Got to shoot the Alexander Arms upper build kit with the 16" extreme lightweight barrel and it was a little inconsistent. Function was fine and looks to have a nice tight chamber since the expended shells are right at the size of my sized BHW brass. Guess it needs more rounds down the barrel as I only put 24 rounds through it. That or I need to play with the specs on those rounds.

[1911man]

Got some nice groups and some pretty good SDs there. The velocity on that 28.0 grain load is nice.

[bj139]

Nice groups. Are the best groups often 5 to 10% below maximum load?

[joedirt199]

There is usually a couple accuracy nodes, one lower velocity and one higher velocity. I made a jig for my magnetospeed so that it would not have to be directly mounted to the barrel and mess up the groups. Worked pretty good. Was mounted to the free float rail and extended out to the end of the barrel with some aluminum L shaped material.

The tiny group had me worried as that was where I started and only saw one hole for 3 shots. Thought something was wrong. Will have to load some more to test repeatability

[1911man]

There is usually a couple accuracy nodes, one lower velocity and one higher velocity. I made a jig for my magnetospeed so that it would not have to be directly mounted to the barrel and mess up the groups. Worked pretty good. Was mounted to the free float rail and extended out to the end of the barrel with some aluminum L shaped material.

The tiny group had me worried as that was where I started and only saw one hole for 3 shots. Thought something was wrong. Will have to load some more to test repeatability

Do you mind sharing a picture of your set up for the magnetospeed? I have been thinking of coming up with something similar.

[joedirt199]

Trying to upload some pics but says I am at my limit even though I have down sized them to meet the forum limit.

[joedirt199]

https://forum.snipershide.com/forum/sniper%C2%92s-hide%C2%AE-armory-supply/s4-sniper%C2%92s-hide%C2%AE-equipment/6571516-magnetospeed-adapter/page2#post6613149

Here is a thread from snipershide where I heard about modding the magnetospeed. Mine is under Mattc51 near the end.

[1911man]

Thanks.

[Sticks]

I picked up a 13 slot rail for the bottom of mine and just used the last slot. Using the pistol/picitiny rail adapter that they sell for it.

Worked great the first couple of times, but now is giving me sensor reading errors. Samson Evo., which is a big ass tube. The bore height is a little over double the magnetospeed height bar.

[joedirt199]

Looks like the sensor is pretty close to the end of the barrel which can cause interferenece. May need a longer rail piece to push the magnetospeed further out.