I have been casting bullets for my 470 nitro for low velocity practice rounds. I am using the RCBS 500gr FN mould. These bullets have four grooves, and a shoulder. When I seat the bullets, I use the last lube groove to as a cannelure for crimping, rather than the shoulder. I did this rather arbitrarily, as it gives me about the same overall cartridge length as my jacketed hunting rounds.
The question is:
Since the instructions for the sizing/lube press tell me to not "lubricate the cannelure" I have only been lubing the first three grooves. My loads are only about 1200 fps. Is this a potential problem?

I've been using Carnauba Red lube in 435 grain 4 groove and 500 gr 4 grove bullets for the .470 NE ... AT velocities up to 2200 fps. Three grooves of lube worked fine.

Thanks, Mike. I used these last year, but as I was sizing a batch today an element of doubt crept in.

for 1200 fps one lube groove should be plenty.
you might have too much lube there and are affecting your accuracy potential.

While my low velocities help reassure me that I have enough lube, I must admit I don't understand how having too many grooves lubed would degrade accuracy. Could you explain, please? None of the instructions or manuals I've read mention this, but that doesn't mean it's not real. One kind of assumes that the right number of grooves to lube would be all of them!

Mostly I use these to practice at 25 yard targets, offhand, so "minute of elephant" is adequate, but I also cast lead bullets for practice in my scoped 416 Rigby, and accuracy has been so far disappointing. These are loaded to about 2000 fps, using gas checks. I'd like to get them to shoot better than they do.

This saves a ton of money for anything like high volume practice shooting. With the cost of jacketed big bore bullets so high, I figured I paid for all the equipment after casting just a few hundred bullets. Besides, it's fun.

MARTY
for your 416 there may be several factors effecting your accuracey which you need to eliminate such as
is you bore smooth, have you pushed a bore slug through your barrel to get a feel if its rough
how do your cast bullets fit the throat of your rifle
does the base of your proj protrude below the case neck
you may want to try a slower powder

Cast bullet accuracy can be quite good in the .416 calibers. Here is a group shot with a 400 gr cast GC bullet w 35.0 gr AA5744 fired from a .376/.416 Steyr Improved (AKA .416 Aagaard). Rifle is a commercial FN Mauser action with a Douglas barrel on a synthetic stock.

Velocity is abt 2000 fps ... group shot at 100 yards.



(the smaller holes in the target are a five shot group with a 6.8 SPC ... 110 gr Sierra Prohunter projectiles, 30 gr H322, WSR primers on SSA brass. The flier was called.)