Sizing BBTs

[EdinGa]

Should you? I don't need to for any of my rifles, but I'm of the opinion that they shouldn't be sized because of the design. Am I wrong? I think I've read that Bob doesn't recommend it, but I could be wrong about that too.

[rsterne]

Size 'em if you need to!.... They are designed so that the back of the nose is groove diameter, and the drive band 0.002" larger, because most chambers are about that much oversize.... However, not all barrels are the same, so if your chamber is long enough and they won't chamber properly, then sizing them until they do is perfectly acceptable.... I find maximum velocity at about 0.001" under groove diameter, but maximum accuracy may be there or up to 0.001" over groove, again it depends on your barrel.... If you do size them, I would do them nose first so that they guide themselves into the sizing bushing, not sure they would stay straight if you do them base first (but I have never tried it)....

Bob

[EdinGa]

Size 'em if you need to!.... They are designed so that the back of the nose is groove diameter, and the drive band 0.002" larger, because most chambers are about that much oversize.... However, not all barrels are the same, so if your chamber is long enough and they won't chamber properly, then sizing them until they do is perfectly acceptable.... I find maximum velocity at about 0.001" under groove diameter, but maximum accuracy may be there or up to 0.001" over groove, again it depends on your barrel.... If you do size them, I would do them nose first so that they guide themselves into the sizing bushing, not sure they would stay straight if you do them base first (but I have never tried it)....

Bob

Thanks! I've never sized any of mine. It's a little hard to chamber the rear driving band in one of my rifles but accuracy is fantastic so I leave them as cast. My Cayden chambers them like butter as cast. I don't want my chokes touching the mid body, so I figured if they were too hard to chamber sizing would eliminate the driving band and cause to much friction.

[Wayne52]

If I was going to size one it would be for a big bore and not the .22 or .25's.

[Back_Roads]

 Only issue I ran into when sizing a BBT was that to fit a Nova liberty I lost most of the band, along with velocity. That is and example of probably both barrel design, along with that particular molds final product.
  Another anomaly is my Hatsan Bull boss Barrel slugs outright at .257 , I have a BBT mold for that now also.
 

[Wayne52]

James I never did get BBT's to work in my liberty, I ended up using the NOE 218-25-RF sized down to .215 which works excellent in it, those Liberty's have a small bore for a 22 cal.

[Nvreloader]

And for those that don't know, NOE makes Nose sizing bushing also,
they are found in the bullet sizing area, in whatever caliber.
 https://noebulletmolds.com/site/product-category/bullet-casting-reloading/sizing-tools/bushings/22cal-bushings/
They work good.  HTH's,
Don

[rsterne]

The midbody is several thou smaller, eg. on a .257 it is only 0.248".... so even sizing a lot you should not get into it.... unless trying to use a .257 in a .25 cal of course....

Bob

[Wayne52]

The NOE 217-30-FN HP's are perfect in my Xisico Sentry in my signature, I wonder if those newer Xisico built JTS rifles will shoot them good because there's a possibility they're using the same rifling in those as they did in the Xisico Sentry's.   If they're still using the same rifling and bore I'll bet they'd shoot them really good.  My Airmax Dominator likes them a lot too.  My Prod and Disco both shoot them good too and chambering isn't a problem on any of the guns I've mentioned. 

[Spacebus]

For what it's worth they didn't shoot any differently sized or not with the 250-42-FN or 458-244-RG3 molds with my two gun sample group. However, the 42g BBTs don't shoot well out of my Eagle Claw, but the 244 shoot dead on accurate at 50 yards out of my .457 Challenger (both HP and FN).

[Wayne52]

Dj the accuracy of the NOE 458-244-FN out of my AEA HP Max really did surprise me in the accuracy department, I can easily pic off a squirrel when I'm out deer hunting with it.  I shot three squirrels with it during deer season, the last one was a red squirrel at about 70 yards.  It did make a mess out of the squirrel with a heart/lung shot but all 4 quarters and the back were still good, it was a lot of guts hanging out though.