Magnetospeed tightens groups ???

[CTK]

I went to the range today to try Varget in my x47L. This is a lightweight hunting rifle with a 23" 2b contour barrel. Varget and the 130VLD grouped okay. 37.5gr averaged about .4". I was working up to 37.5 and shot one of 4 shots with Magnetospeed attached. I fired all Magnetospeed shots at a single, separate target. 4 shots of different charge weights went 2" low and .75" left of predominant POI of loads shot without Magnetospeed. The 4 shots with the Magnetospeed grouped into .18". 4 shots are too many to be a lucky group. What the heck? Example of what a barrel tuner can do on a lightweight barrel?

 

[Ned Ludd]

Absolutely. With a different rifle and/or load, it can just as easily do the exact opposite and open your groups up significantly. I love the ease of use and reliability of my MagnetoSpeed, but I don't have it attached to the rifle when shooting groups that I need to interpret reliably for load development.

 

[CTK]

If I am working up in charge weight, I load 4 and shoot one at a different target with the Magnetospeed. That is how I got this mysterious group. I may hunt with a Magnetospeed attached this year

 

[Capt. Oblivious]

As gstaylorg said it goes the other way as well. First 5 shots at the top was with the Magneto attached and the 7 shots below that was without the magneto

 

[fredo]

I've been wringing out a new 8 lb. 6.5 SAUM with my V3 strapped on the #3 contour 22" barrel.
While testing for pressure & velocity potential, accuracy has been wonderful!

Now that I have my baseline data ironed out, I can shoot without the V3 and tweak load/node as needed...

Have done this for the last few rifles during load development, and have not yet experienced where accuracy degraded from removing the V3. Potential for POI shift, YES! But just haven't seen a good shootin' load go to crap without the V3 strapped on?

YMMV...

 

[Laurie]

Absolutely. With a different rifle and/or load, it can just as easily do the exact opposite and open your groups up significantly. I love the ease of use and reliability of my MagnetoSpeed, but I don't have it attached to the rifle when shooting groups that I need to interpret reliably for load development.

+ 1 on this. My findings and methods exactly. I usually load initial test batches as 2, + 1, 3 + 1, 4 + 1 etc, the +1s shot first with the bayo' fitted as a pressure / rough MV indicator before taking the bayo' off to shoot groups (assuming that the singles didn't throw up any over-pressure rounds).

I use a single aiming mark for the chrono rounds and sometimes a 1.5gn or 2gn charge variation range will produce a huge (usually vertical) spread, other times up to 10 shots with different charges shoot into a surprisingly respectable group. Infuriatingly, groups with the bayo' on are sometimes much better than those without!

It's certainly made me think hard about the value of a barrel tuner. My next 223 long-range rifle chambered for 90s rebarrel will have incorporate one.

 

[JEFFPPC]

This is the reason all my competition rifles have tuners. I use Bob Greens.

 

[Ned Ludd]

+ 1 on this. My findings and methods exactly. I usually load initial test batches as 2, + 1, 3 + 1, 4 + 1 etc, the +1s shot first with the bayo' fitted as a pressure / rough MV indicator before taking the bayo' off to shoot groups (assuming that the singles didn't throw up any over-pressure rounds).

I use a single aiming mark for the chrono rounds and sometimes a 1.5gn or 2gn charge variation range will produce a huge (usually vertical) spread, other times up to 10 shots with different charges shoot into a surprisingly respectable group. Infuriatingly, groups with the bayo' on are sometimes much better than those without!

It's certainly made me think hard about the value of a barrel tuner. My next 223 long-range rifle chambered for 90s rebarrel will have incorporate one.

I like your thinking. I have a second .223 build for the 90s currently underway that should be almost complete. In it, I have tried to apply everything I have learned so far from the first one. The new one will have one of Erik Cortina's tuners installed. Observing the effect of the MagnetoSpeed was part of the motivation for going that route for me as well.

 

[dcali]

Entirely possible for a weight to make it shoot better. Also possible it makes it shoots worse. But 4 shots is not only not "way too many" to be a coincidence, but it's "far too few" to make any judgements.

 

[CTK]

Entirely possible for a weight to make it shoot better. Also possible it makes it shoots worse. But 4 shots is not only not "way too many" to be a coincidence, but it's "far too few" to make any judgements.

I am not suggesting that I discovered anything earth shattering. Probably could never duplicate the result. All I know is that 4 shots of different charge weight landed in a slightly ragged hole when shot with a Magnetospeed attached. They were even fired at different times with the Magnetospeed being reattached. 4 shots into one hole, with a 2" poi shift is a heck of a lot more likely to be a result than a coincidence.

 

[Medic505]

I use tuners from Bryant Custom. Mike builds one I can't tear up and it works. I was working on loads in a new barrel with a new tuner a couple years ago, twisting the tuner, making things worse, probably even said a bad word or two so I figured I'd chrono my load to at least make the trip to the range worthwhile. Strapped on the magneto and shot a small one hole group. I spun the tuner out about half an inch and things started coming together. I've been sold on tuners ever since.

 

[Ned Ludd]

Entirely possible for a weight to make it shoot better. Also possible it makes it shoots worse. But 4 shots is not only not "way too many" to be a coincidence, but it's "far too few" to make any judgements.

Agreed in the OPs one example. However, I have shot literally hundreds of groups with the MagnetoSpeed first attached (for MVs), and then removed (for group spreads), both with the exact same load, on the same trip to the range. I can assure you the observation that the MagnetoSpeed can both enlarge some groups and shrink other groups (like a barrel tuner would be expected to do) is real. Unfortunately, I have yet to come up with any pattern based on the load/caliber that would allow me to predict what the effect will be in advance (larger/smaller). My guess is that that would probably be the same as trying to optimally set a barrel tuner in advance with no prior knowledge of the settings. So the best I have come up with is that it does happen, therefore I shoot the groups for dispersion/precision separately from MV determination.

 

[dcali]

I have a theory (untested) that the varying reports on magnetospeed impacts on precision/POI may have something to do with how tightly they are attached to the barrel. It's conceivable that a softer attachment might not impact things as much.

 

[mysticplayer]

Shooting buddy had a cranky barrel that just didn't want to play nice. Put on his magnetospeed to see if velocity variations was the problem... barrel shot like a lazer.

This barrel now wears an equal weight "blob" and shoots amazingly well.

Why? Don't know, don't care. We now test with and without to see if a weight can help. Some barrels just prefer a weight on the nose.

Jerry

 

[Ned Ludd]

I have a theory (untested) that the varying reports on magnetospeed impacts on precision/POI may have something to do with how tightly they are attached to the barrel. It's conceivable that a softer attachment might not impact things as much.

I believe you're right. How tightly the strap is locked down, as well as where the unit is placed likely change how it affects groups. I try to put it in about the same place every time, ~1/2" from the end, but I just eyeball it, so it's probably not in exactly the same spot every time. Moving the weight in/out is how a tuner works, so I'd assume the same holds true for the MagnetoSpeed.

 

[CTK]

I did not want to say this because thought everyone would call BS on me but.... My 280ai also shot pretty darn well with the Magnetospeed attached. The Poi shifted to a similar spot as my x47L. This was also with different loads. Perhaps a weight on the end of Sporter barrels can have a positive impact in some instances. These are full custom hunting rifles done by Borden and Beanland. They can shoot pretty well on their own. I am not drawing conclusions, just asking questions about an unexpected result. One of those "blobs" might be fun to try.

 

[mysticplayer]

Some wheel weights and 2 hose clamps... now you can test and see for yourself.

Easy.... and fun. Just snug enough so the weights do not move.

Jerry

 

[Fulvio]

I went to the range today to try Varget in my x47L. This is a lightweight hunting rifle with a 23" 2b contour barrel. Varget and the 130VLD grouped okay. 37.5gr averaged about .4". I was working up to 37.5 and shot one of 4 shots with Magnetospeed attached. I fired all Magnetospeed shots at a single, separate target. 4 shots of different charge weights went 2" low and .75" left of predominant POI of loads shot without Magnetospeed. The 4 shots with the Magnetospeed grouped into .18". 4 shots are too many to be a lucky group. What the heck? Example of what a barrel tuner can do on a lightweight barrel?

The MagnetoSpeed attached to the barrel acts as a passive tuner. By putting more weight at the muzzle the harmonics change. In my case, using 32" heavy barrels in 300 WSM, 7 SAUM, and 284, I had every time the same result: the group was higher and tighter. Based on that experience, I am now using a tuner on all my barrels.

 

[Laurie]

The change in the POI with the bayo' fitted may be partly down to barrel harmonics, but more to deflecting the muzzle blast slightly which in turn changes the bullet's angle of departure. Most people mount the bayo' as per a service rifle bayonet, ie at 6 o'clock, so it deflects some gasses upwards and the POI rises.

The device works at any position on the barrel, so you can see this effect by mounting it elsewhere. Not that it's unduly important .... as long as people remember that getting a zero with the bayo' fitted will induce an error.

Group size and pattern is a different matter entirely.

 

[CTK]

What about those cheap Limbsaver rubber tuners. Worth trying with low expectations?