[Muleskinner]

A friend with a chronograph was at the range today.  I chronoed my 348 load using 64.5 gr. of R19.
Here are the results.

Highest Velocity = 2270
Lowest Velocity = 2260
Max spread = 10 fps
Standard Dev = 5 fps
Mean Velocity = 2265

Given, I have a carbine, not a rifle.  And, I am still 1/2 grain under the "max" of 65 grains.  But this still makes the 2506 fps reported in Handloader kinda far fetched in my rifle.  I was hopin' to break 2450, loping off 50 fps for the short barrel.  As it turned out, I think I may get over 2300 by crankin' it to 65 grains, but that's still 150 fps slower than I had hoped.  Didn't check other loads, cause I was so enamoured with this load's 1-1/4" groups.  Might just have to buy a chronograph.  Or, on second thought, maybe ignorance is bliss.  Imagine the problems I might encounter with my other pet loads for my other rifles.  So much for believing published velocity data.

 

[J.D.]

Heh, heh, heh, welcome to the real world of handloads and velocities.

I don' tknow where the people who publish reloading data get their information, but in my experience, nearly all published velocities are exaggerated.  

Manufacturers hype? Publishers attempting to improve advertisers relations?
Who knows, but I now suspect ALL published velocities.

Maybe I should trade my chrono for something that offers less frustration and more enjoyment.
J.D.

 

[Muleskinner]

Been handloadin' for 20 some years, never used a chrono.  Always got a good accurate load an' used the loading data velocities to figure what mine were doin'.  A friend with the same rifle and a chronoed WW760 load told me to chrono his load from my rifle.  If the velocity is poor there too, then its a slow barrel.  If I match his velocities (2440), then the published R19 data is bogus.

 

[IDShooter]

Muleskinner,
    Since getting a chronograph a few years back I've found that virtually every powder manufacturer's data produces slower velocities than those listed. I also generally get slower velocities than those shown in my old Hornady manual, but the difference is not so extreme. The only manual I currently have that gives velocities pretty close to what I actually get is the Speer manual.
      As for magazine article data, a lot of it seems to be in the same category as powder company data, but it varies a lot from writer to writer and article to article.
      Take it all with a grain of salt.
      The good news is the trajectory tables are usually wrong too, and critters die just as dead no matter what the numbers are (whithin reason) so you have to just get out there and shoot. That's the fun part anyway!!          IDShooter

 

[J.D.]

I am one of those who recently bought a chronongraph, after reloading for 30 years without one, and with the results I have seen are disappointing.

I think I was better off without the chonograph. I seem to have lost some the enjoyment of shooting, since I became aware of the technical side of reloading.

More Shooting, less  chronographing= more enjoyment for me.
Still enjoy shooting that '71 though, regardless of velocity.
J.D.

 

[Sky C.]

Mine is a Browning 71 with 24" bbl...  Geez these 71's are nice!!!

Have started on a mission to develop an accurate CB load using a 235gr. wide meplat GC design with hopes of getting into the 2250fps - 2300fps range for hunting deer/elk.  Have hit the velocity numbers without leading but also without sufficient accuracy so far.  Have gotten good accuracy with velocity in the 1750fps to 1800fps range so I know the rifle's capable.

Have any of you found a good load combination to suggest that you could share to assist in my quest?

Thanks in advance-

Sky C.
Longmont, CO

 

[Bill Lester]

Muleskinner,

May I ask what kind of chronograph you used? A common problem with the older Chronys was that if the ends weren't fully spread you could get erroneous data. I believe the current models have fixed this problem.

One thing to keep in mind is that the powder manufacturers generally use test barrels with SAAMI minimum dimensions. In most instances they will bump velocities beyond what we see with production sporting arms and their looser tolerances.
Often the test barrels are of longer than what we'd consider normal. That helps create velocities higher than we'll see in "the real world" as well.

I've had a chronograph for many years. Sometimes I'm disappointed in the loads I've tried but at least it's the truth. In my opinion use of a chronograph is also the best way to warn you of excessive pressures . They're well worth the cost and effort.