BC gap and velocity loss??

[toad67]

Went out and shot 3 cylinders of varying charges of TITEGROUP with the same bullets and primers as before. Velocity was within about 50fps of what I'd hoped for, as well as smaller ES's, average of 50. Weird thing is the N320 was more accurate, maybe just me today though.

 

[DWalt]

There is a good article in one of the Speer loading manuals about that phenomena. I will summarize: Every revolver is a law unto itself. And don't believe MVs published by anyone.

 

[toad67]

There is a good article in one of the Speer loading manuals about that phenomena. I will summarize: Every revolver is a law unto itself. And don't believe MVs published by anyone.

It's a lesson that I learned with this one. Now I'm scratching my head as to whether I want to try some more N320, even with its velocity fluctuations just because it seemed to be more accurate. Or maybe try some different bullets, powder....hmmm, the fun of hand loading.

 

[Mike-AK]

Velocity difference is often very small according to the data, but I will say that my 686 with a .008" gap has a lot more cylinder gap blast than my tighter revolvers. It shoots just fine, but I wouldn't want to hold my finger next to the front of the cylinder, though.

 

[Ivan the Butcher]

This may sound silly, but do you ever cross-check/calibrate your RCBS against any other scale?

I have a digital scale, an auto Hornady L-n-L & an old Ohaus 1010 and I occasionally do a comparison (even using the LEE dippers as well) just to insure I'm really dealing with accurate weights.

Not all the time, but just occasionally for my peace of mind.

Cheers!

They sell "Check Weights". Mine are from the early 80's and from Lyman. I have 2 digital and 3 beam Scales (the Dillon is worthless!) but the other 4 are all within the same 1/10th grain. All from the factory and never changed. I see scales now in the 1/100th & one in 1/1000th grain. For what we do 1/10th is plenty accurate.

Ivan