Velocity Questions with 460 S&W XVR

[memtb]

What should I expect as reasonable velocities using 400 grain cast in 8 3/8” 460 XVR? Cor-Bon advertises 1525 fps with 395’s. I’m getting a little over 1400 🤬 with my 400’s, with very difficult case extraction! I used a wooden dowel to drive the cases out, as to not risk damage to the firearm.

So far the powders that I’ve tried are AA1680 and WW296. I didn’t want to try LilGun because of lots of bad press!

I do not have access to another chronograph to verify velocities, but this one appears to be very close with other firearms......so, I’m thinking this is a representative velocity.

Soooooo, what should I expect for velocities? I would be OK with a solid 1400 with good extraction. I’m not opposed to some resistance to case extraction.....but, this is a bit much! 🤬

Thanks for any and all comments.....even the less than agreeable ones! 😁 memtb

[DougGuy]

You haven't given members much to go on without posting the loads you are using.

[Gunslinger1911]

A quick thought, if you are getting sticky cases with a "reasonable" load, look at how much bullet is in the case.
I had this issue with my 500; load developed with same weight bullet, but shorter shank (less case capacity = higher pressure with same weight).
Your load data ?

[memtb]

Thanks guys. Hornady brass, WW LRM primers, 400 grain cast (Accurate Mold) sized to 0.452”, OAL 2.240”. AA 38.0 grains = 1304 average, terrible accuracy, some extraction resistance WW296 31.0 grains = 1457, with very difficult extraction

Gunslinger1911, I considered the seating depth as a possible issue. If I measured correctly, I could not lengthen the OAL to the next groove without extended beyond end of cylinder. Perhaps, I should seat a bullet for OAL, and prove rather than measure the clearance! I may have mis-measured! �� memtb

[Stephen Cohen]

My brother has that exact gun and runs my cast 320gr at high 1;900s with outstanding accuracy and no signs of high pressure, I believe he uses 38gr H4227. Hope that helps Regards Stephen.

[Gunslinger1911]

memtb, 460 max load with 296 shows 34g at coal at 2.185 with a 400g cast GC.

If coal is maxed out, could your chambers be rough ? Even a Smith, been known to happen.

Worst case, buy (heaven forbid !) a box of high performance ammo and see if it sticks.

I feel your pain sir ! The 500 was really yankin my chain till I figured it out (well, actually John Ross figured it out)

[shooting on a shoestring]

Check the taper of your chambers. They should have a thousandths or two taper, smallest near the front by the throats and larger at the rear. This lets the fired cases extract easily.

I’ve had a couple or revolvers with hard extraction that either were straight cut without taper or had reverse taper that caused really hard extraction. A finishing reamer remedied all just fine.

Also pay attention to the finish of the chambers. Now days you can’t assume chambers are properly tapered and finished. I’ve had 1 revolver that had hard extraction just bc of the poorly polished surface inside the chambers. Fixed by a light honing. Made a big difference for me.

[memtb]

Thanks guys, I need all of the adult supervision that I can get.

The chambers appear to be nicely polished.....but, me looking at chambers is “like a hog look’n at a wrist watch, it just don’t mean much”!

Chamber taper: not certain if I can get addressed locally......and is several pay grades above my capabilities!

With powder supplies as they are I may be stuck with only these two for a while!

Keep the ideas and suggestions coming....I’ll start pull’n them out of the hat until something works! memtb

[500aquasteve]

273704

I guess you might be able to check the ends of each chamber


Are the stickers randomly choosing a chamber, or is it the same ones?

[memtb]

Steve, really not certain if one was considerably worse than the others. When I had extreme difficulty with typical extraction.....I was angered enough, that I didn’t pay close attention when driving out with a dowel! I must learn to be more observant! Thanks! memtb