Can we use the magneto speed in load development?
- Thread starter ericbc7
- Start date
http://forum.accurateshooter.com/index.php?topic=3864782.0 Regards JCS
michaelnel
Old and In The Way
sbhooper said:
That's exactly what I do. I am not going to shoot in competition with the chrono on there, I don't think it should be on there while I am developing loads.
Eric, I work up my loads without the Magneto Speed. Once I get my accuracy load, I attach the Magneto Speed and log all the pertinant information, ie: Avg. Velocity, Es & Sd., Temp, humidity etc. The beauty of the chrono is quickly determining what's happening when groups stop shooting to par. They help you see velocity changes when temperatures change (especially if using a temp, sensitive powder). As well as what happens when other changes are made, ie: seating depth adjustments, charge weight changes etc. Also very important when changing powder lots. I have not noticed any changes in accuracy with or without the Magneto speed attached, perhaps I'm just lucky however I do notice a very slight shift in impact point which is probably more noticible with the thinner barrels. I personally feel they are invaluable to keeping a rifle in tune.
I spoke with the manufacturer about this. Some people notice POI shift some don't and it doesn't sound like its predictable based on barrel characteristics. W/ the device on, my rounds are typically 1" high. I reason that if a MS can move the group then it can affect group size so I don't do load dev. with the Magnetospeed attached. I find a charge weight that I like and chrono it after. It's the only down side that I see to the MS.
I did a comparison with my 6mmBR/30" barrel with and without my MagnetoSpeed installed. I tested at 600 yds with calm to light right to left crosswinds and some very light mirage. Overall the conditions were pretty good. I measured the target/group on my computer using the On Target Precision Calculator Target 2.1 Program. The first 4 shot group without the MagnetoSpeed measured 1.346" wide x .540" tall and the second 4 shot group with the MagnetoSpeed installed measured 1.390" wide by .506" tall. The group with the MagnetoSpeed installed was 4.281" down and 1.291" left center to center from the group without the MagnetSpeed installed. When I shot the second group the right to left wind was just beginning to increase but just slightly. I made no sighting corrections when I shot these groups. To me the group size in this test with and without the MagnetoSpeed seemed consistent. I normally load test without the MagnetoSpeed installed and when I find a good load I slip the MagnetoSpeed on for the velocity checks. The group to group displacement does seem to vary according to caliber and loads and of course the distance you are shooting. Again this test was done at 600 yds. I have posted these results before when this issue has come up.
michaelnel said:
I second this approach. I have shot a load development with and without the Magnetospeed on the same day just to see what it would do. It definitely effects POI, but it also effected group size in my testing.
Now I develop a load and then shoot rounds over the Magnetospeed to check velocity, SD, and ES.
I like to use the Magnetek chrono a lot like a ladder test during load development. I check Speed, ES and group size in rough measurements that way all at the same time and use a lot less ammo. When I find the ball park, then I do final group testing without it on the barrel. I would think that every gun would be different, but on my rifles F-Class rifles I have seen little if any group variation with or without it. I Group test at 200 to keep wind effect small, while still allowing enough distance to actually see group size changes easily.
skiutah02
Silver $$ Contributor
I echo what most others have observed. I've used the MS to do load development for 4-5 rifles and 8-9 barrels. In general, but not always, my groupings are not affected with the MS on the barrel (> 50% no grouping change), but POI is nearly always affected (only 1 of the barrels gave same POI with/without MS). On some barrels it moves up (most common) but it also can move down (less common). Unfortunately the first barrel I tried the MS did not affect POI or groups, but I learned (the hard way) that this was the exception (for me). So IMHO the MS effects are barrel specific.
As a consequence, I have now changed my routine during load development. I usually start with a few shots (2-3 each) over a wide range of powder loads to check velocity, very basic ES and pressure signs when trying new powder/rifle/barrel/etc just to get an idea of things. May use these to zero scope or break in barrel. Of late, I have just shot into the ground. I feel comfortable doing this as feel experienced enough with my calibers to use this to more quickly home in on a potential load and gauge safety. Then shoot powder charges wo MS for groups/elevation with rough idea if vel is going to suitable/usable (see Cortina method or OCW). Then as my powder charge window is getting refined, will shoot a set (5-6) for ES and for groups with and without MS to see if any effect. All the above is at 100yds. Then further powder refinements at 300, then 600 (potentially). Then seating depth tests (no MS here). Once feel comfortable with a charge/seating depth, will investigate ES/SD. In any case, if accurate to 600 but unacceptable ES, will potentially shoot at matches at 600 with this load, but will continue the quest for a 1000 yd load.
Still learning, so take this with a grain of salt.
Drew
As a consequence, I have now changed my routine during load development. I usually start with a few shots (2-3 each) over a wide range of powder loads to check velocity, very basic ES and pressure signs when trying new powder/rifle/barrel/etc just to get an idea of things. May use these to zero scope or break in barrel. Of late, I have just shot into the ground. I feel comfortable doing this as feel experienced enough with my calibers to use this to more quickly home in on a potential load and gauge safety. Then shoot powder charges wo MS for groups/elevation with rough idea if vel is going to suitable/usable (see Cortina method or OCW). Then as my powder charge window is getting refined, will shoot a set (5-6) for ES and for groups with and without MS to see if any effect. All the above is at 100yds. Then further powder refinements at 300, then 600 (potentially). Then seating depth tests (no MS here). Once feel comfortable with a charge/seating depth, will investigate ES/SD. In any case, if accurate to 600 but unacceptable ES, will potentially shoot at matches at 600 with this load, but will continue the quest for a 1000 yd load.
Still learning, so take this with a grain of salt.
Drew
The magneto has pros and cons with respect to load development. I use it in the initial load development where I am firing a series of increasing charges to gain an understanding of FPS and max charge. This is a very simple and quick process with the magneto.
Once I have the powder range figured out that I expect to work in I take off the magneto and run through the usual fine tuning of charges and seating depth. I can't think of any argument against putting mass on the end of a barrel and it not affecting harmonics so I don't go there. Each to their own as to what they see but I believe the argument of mass on the end of a barrel affects harmonics and therefore tune is sound so I haven't explored it.
Then I stop at the range and take my 100 yard finalised load to a club day. At the club day I run one relay without the chrony and another relay with the chrony - this gives me an understanding of vertical with no chrony, the second gives me numbers under match conditions. I can rinse and repeat this on as many club days as I want. The advantage is I get to work on wind and positional technique while gathering data and analysing my load. So far I have used this out to 900 yards. Last weekend I shot it at 800 yards with the magneto on and still came away with a 50% x count.
My ideal is to do the fine tuning of powder and seating depth with a chrony on but setting up a decent chrony on a busy range is too much.
Once I have the powder range figured out that I expect to work in I take off the magneto and run through the usual fine tuning of charges and seating depth. I can't think of any argument against putting mass on the end of a barrel and it not affecting harmonics so I don't go there. Each to their own as to what they see but I believe the argument of mass on the end of a barrel affects harmonics and therefore tune is sound so I haven't explored it.
Then I stop at the range and take my 100 yard finalised load to a club day. At the club day I run one relay without the chrony and another relay with the chrony - this gives me an understanding of vertical with no chrony, the second gives me numbers under match conditions. I can rinse and repeat this on as many club days as I want. The advantage is I get to work on wind and positional technique while gathering data and analysing my load. So far I have used this out to 900 yards. Last weekend I shot it at 800 yards with the magneto on and still came away with a 50% x count.
My ideal is to do the fine tuning of powder and seating depth with a chrony on but setting up a decent chrony on a busy range is too much.
mikegaiz said:Why would you buy something to help you test loads that affects the accuracy of what you are testing, when you have options that give you test results and do not interfere with accuracy? Am I missing something?
Pros and cons (for me). If you don't utilise it during the portion of precision development there is no impact. Typically the sample sizes are very small at this stage and have to be shot under either match conditions or simulated match condition to verify.
My input is based on F-class requirements - I can see long range BR being different again.
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