Chronograph suggestions

[TC338]

I have a RCBS chrono but I don't think that it's very accurate. I'm very careful with my loading and it's telling me I have almost a 100 fps spread for 5 rounds out of a 308 running Varget. Anybody have any experience with the RCBS chrono? Better chrono that won't break the bank?

 

[Barrelnut]

ProChrono for a good traditional optical chronograph. Not too expensive.
MagnetoSpeed otherwise if you don't mind having something on the end of the barrel.

 

[SidecarFlip]

BN.... My issue with the magnetospeed is, it changes barrel harmonics and far as a 100 FPS spread on 5 shots...

I shoot 10 and average them.

Lots of factors cause variance in FPS readings, from neck tension to propellant variation to even how fouled a barrel is....

Always better to pop 10 and average the readings.

\besides, it massages your shoulder......

 

[TC338]

ProChrono for a good traditional optical chronograph. Not too expensive.
MagnetoSpeed otherwise if you don't mind having something on the end of the barrel.

How does the magnetospeed do with muzzle brakes? Mine circles the entire barrel so some of the gasses will be directed straight down toward the chrono.

 

[Barrelnut]

How does the magnetospeed do with muzzle brakes? Mine circles the entire barrel so some of the gasses will be directed straight down toward the chrono.

Not a problem. I have a 300 RUM with the same type break you use. Never had an issue. The sensors don't reside in the first 6" or the arm. That first 6" is made to take the muzzle blast.

On heavy rifles with varmint barrels and such, it doesn't seem to affect POI. It does affect it a little with lighter sporter barrels though. Doesn't seem to affect groups or load workup. Just that the POI will have to be adjusted after taking the arm off.

Flip is right -- just make sure the 100 FPS wasn't a fluke caused by one/two low/high velocity shots.

 

[SidecarFlip]

Personally, I've found (doing Berger load workups) for my 300 WM and my 308's that one, barrel condition has an impact on velocity, two, neck tension and neck cleanness impacts velocity and three powder load as well. I load carefully using an Omega automated trickler and beam scale but I can get variations so I always use an average of 10.

IMO strictly, all chrono's are about the same, it boils down to convenience and personal preference.

Having said that, I did shoot one of the uprights on my Chrony once....ooops.

I have to remember to dial the scope all the way down to increase the FOV so I can see the legs..... oh well. a length of TIG aluminum filler rod replaced the injured leg.

I must say that wet tumbling cases certainly goes a long way toward having clean necks....