do we really need a chronograph to tune a barrel?

[RegionRat]

I had a barrel with a tuner on it. I could change the size of the groups with the slightest turn of the tuner ring. No way I would hang something on my barrel that can move around. I like to shoot groups at the distance I want to compete. I have shot great groups with bad ES and I have shot bad groups with good ES.

Would you say bullet stability is not related to ES and SD?

Yes

I have never seen an unstable bullet with a good ES/SD.
I have also seen stable bullets with a bad ES/SD.

Those are for two different sets of reasons.

One is the situation where a damaged or poor quality bullet is unstable and thus is due to external ballistics and variable drag induced by instability. Bullets that are not flying in a slipstream manner are the picture of dispersion.

The second situation is due to instability of combustion pressures and other potential barrel effects that directly result in poor ES/SD, yet with the bullet still flying in a stable manner.

So two different buckets, both giving bad ES/SD outcomes.

I also agree with Alex's old comments quoted above, but since there is no standard definition of good or bad for an ES/SD I will add my take... and that is, by definition if the group was good so were the velocity stats.

It could just be a matter of perspective, but being too picky about velocity stats is just as bad as ignoring really bad velocity stats.

Once you start discussing distances where the trajectory starts to inflect, the velocity stats have to be good enough to stay in the game or no amount of tuning or compensation will allow them to fly into the waterline. That is what I mean by good enough.

When some folks call those velocity stats bad but the group was good, then I would say those were not really bad velocity stats, they were good enough.

 

[MikeRu]

I would second the comment by Alex W. and say that the Magnetospeed attached to barrel could alter your group size. I would use it to find a velocity node and then typically tune within the node with the Magneto removed. FWIW I've seen it alter my group sizes, not just POI, in a direct test at short distance such as 200yds (no p values sorry).

Another big advantage is knowing your actual MV/SD when everything is tuned and working perfectly. Helpful for trouble shooting down the road, dialing up for distance, etc.

 

[drop_point]

Magnetospeed is great for one major reason: it works at the public gun range where lab radar does not.

 

[skeeljc]

Get a Labradar and never look back.

 

[JEFFPPC]

No, no, NO!

 

[JimSC]

I wonder how shooters managed before Labradar, oh yeah I remember. They let the target tell them how the load shot.

 

[skeeljc]

The Labradar is effortless to use. The data is valuable to let you become aware of changes (like velocity vs temperature, etc.). It is worth it just to let you know everything is going as planned. yes, the target tells the story.

I save the Labradar data from each day on my PC. The string matches each target. The target data is listed in my log book. I look at the data as I shoot and have gone back later to use it to figure out something.

 

[Ray123]

For 1 to 2 hundred yards ya don't need a chronograph with a high velocity round....as many times at the close ranges the fairly large S/D in velocity will be your most accurate load...just go with it. Unless your shooting subsonic, then it's like long range supersonic and fairly large variations will be a vertical spread on the target, which can be frustrating. I use a chronograph to check velocity, and S/D on most calibers I shoot cause I want to know, even if it's not necessary for that csliber and its implementation. MagnetoSpeed is usually a good chronograph but some don't like to attach it to the barrel...they have attachments for that. Tubb used to sell a fairly expensive one, but it might fit your needs, depending on your set up. It can be attached to a front rest, if your barrel is in the same place on each shot as it probably should be. But I just sent a new MS chrono back because the unit was electronically stuck in shot sensitivity mode...but the first unit has been great. Inferior products have been showing up it seems more often, even from manufacturers with a good reputation...the quality of the overseas electronic components may have degraded, or out of supply from normal quality vendors.

 

[JimSC]

Yes 10 feet ! 8 yards not sure there is one that would work .
Do you need one depending? Shooting Long Range
Yes

So prior to 2015, the year LR first went on sale, no one ever shot past 100 yards....good to know

 

[Dave M.]

Magnetospeed is great for one major reason: it works at the public gun range where lab radar does not.

Lab radar works perfect at the range. Use an external trigger or adjust the internal trigger sensors sensitivity and you won’t have any issues. Lab radar is the way to go if you ask me.

 

[JimSC]

Sorry not understanding your reply !
LR was Long Range Target shooting 1000 yard etc.
Depends Hunting only Could do fine with our one ?

do some research on the Wimbledon cup, pretty sure they did not have a LR in 1870. I do fine at LR and I only use a optical chrony or magneto speed to get muzzle velocity after I do my load development

 

[Ned Ludd]

OK...a 9 year old thread about whether a chronograph is necessary during load development gets resurrected...and people are still arguing about it. Aren't folks getting sufficient opportunities to debate the relative value of chronographs in load development and express their particular points of view when [new] threads come up on this topic just about every week? Do we really need to resurrect old threads to stimulate the discussion?

Here's the easy button:

Because you will get every possible answer imaginable on this topic, the relative value of a chronograph during load development is exactly what YOU think it is. No more, no less.

 

[M-61]

10 year old post.
Nice to see some members names I had forgotten over time.

 

[drop_point]

Lab radar works perfect at the range. Use an external trigger or adjust the internal trigger sensors sensitivity and you won’t have any issues. Lab radar is the way to go if you ask me.

None of the guys I know can get good readings at our range, but lanes are about 4 ft apart.