Magnetospeed v3 and Berger VLD 168

[Unofficial Gun Addict (UGA)]

Hello,

I've been attempting to work up some loads for a couple of .30 cal rifles using Berger VLD 168gr bullets. I've never before encountered as much consternation attempting to get consistent groups out of a bullet before. It seems like I'm getting close but when I test out to 200 yards, I get about 1/3 fliers, even though the other 2/3 s are great.

I'm not 100% sure, but I think I may have isolated the issue this morning when I was out at the range. I've recently switched over to the magnetospeed v3 from a more traditional chronograph. I've been using it exclusively to work up the current batch of loads I'm pursuing. Today... Same deal. 4 shots good, 2 shots fliers. So, I decided to take the magnetospeed off.... Result, no fliers. I was down to my last 6 bullets, so further testing is needed, but it's the first time I've eliminated any kind of fliers from these VLDs. Working the lands... And powder charges has made no difference.

Groups look like this with magnetospeed attached:
Cal. / powder charge. / dist off lands / 4 shot grp / 2 flyers distance from center of 4

1. 308 / 42.2. / .080 / 1.25" @ 200 / 2.99" @ 200
2. 308 / 42.4 / .080 / 1.28" @ 200 / 2.66" @ 200
3. 308 / 42.6 / .080 / .95" @ 200 / 2.18" @ 200
4. 308 / 42.8 / .080 / .75" @ 200 / 2.77" @ 200
5. 308 / 42.8 / .040 / 1.30" @ 200 / 3.18" @ 200

Group looked like this after taking the magnetospeed off:

1. 308 / 42.8 / .040 / 1.65" @ 200 (6 shots) / no flyers

Now I realize that one group of 6 shots doesn't make a huge sample from which to draw any realistic conclusions, but I think it is definitely worth pursuing as it may be coincidence, or it may not. I intend to load some rounds based off of #3 and #4 above, shoot them without the magnetospeed attached and will post the results.

 

[MudRunner2005]

Anything that touches your barrel, throwing off the natural path of harmonics, will cause you to throw shots. That's why I develop my loads first, THEN I use my MSv2 to get an average velocity out of 10 shots.

 

[Mikecr]

Now you need to start all over again with nothing touching your barrel..

 

[steeltraps]

I have said this before, size of barrel matter with Magnetospeed. With a #9 krieger I get 1 moa rise in groups, but with my cylinder bore 284 I get no POI shift at all. I think the ONLY true way to know for sure is to put it on YOUR rifle and see.

 

[Unofficial Gun Addict (UGA)]

Well, from everything I've read before purchasing the magnetospeed, a shift in point of impact was to be expected, however, the feedback from users suggested that no change in group-size was observed. I'm heading back out to the range here in about half an hour and I'll test a couple of loads listed above (#3 & #4) to see if there's any appreciable difference with respect to flyers. I'm not necessarily concerned with group-size, just to see whether I get flyers or not. Will post my findings.

James

 

[Unofficial Gun Addict (UGA)]

Wow.... What a difference. I guess all the hype about the magnetospeed not changing one's group size doesn't apply to my configuration (tikka t3 tactical heavy barrel). Not having it on made a huge difference. I think I got a single flyer out of 12 rounds without the magnetospeed on, versus the 4 I consistently got out of 12 rounds with it on. On top of that, the single flyer I got was only 1.44" from center of the group.


Here's the after: (no magneto)
308 / 42.8 / .080 / .60" @ 200 (5 shots) / 1.44" @ 200 (1 shot)
308 / 43.0 / .080 / 1.74" @ 200 (6 shots) no flyers

The 42.8 gr load would actually equate to 5 rounds into .30" at 100 yards, with a single bullet .72" from it's center. I'm going to be using this for hunting, so I can live with that. Not sure I would have found a suitable load with the magnetospeed attached. I'll be loading up some verification rounds, but feel pretty confident that this will hold.

I actually think the single flyer I got could have been my fault, as it was the last shot out of that 6 shot group... And I was feeling pretty excited about what I was seeing downrange. I might have rushed that last one.

If you are using the magnetospeed and having difficulties with flyers... Take it off and give that a shot.

 

[Unofficial Gun Addict (UGA)]