Do all Contenders have oversise bores?

[blaser.306]

I have a 30 Herrett super 14" that I have been getting mediocre to good(ish) accuracy from. I have tried several different moulds Noe 165 gr (rd) copy, Noe 312266 152 gr fp and a few others as well. All of these have been sized .310" and gas checked , After receiving a "care package" from a member down south that contained some of Rotometals chamber casting metal I may now know the reason! This barrell has a .314" throat .310" groove and .303" bore!!! I just for fun tried to load a dummy round with a 316299 sized to .314" seated to just behind the top edge of the front driving band , And much to my suprise it actualy chambered with no resistance at all just a little bit of freebore!!! I am considering getting one of NOE's 314 155 gr fn and shooting it as cast full diameter what are your thoughts about the sise difference from throat to bore. I do not fear that it is excesive and obviously will start load development over again in the spring . Just looking for thoughts and opinions. I also have a 375 win super 14" that slugs out @ .379" , So much for a standardised bore diameter!

[nhrifle]

You may want to give T/C a call. That might be the spec they use, maybe from the same standpoint that Ruger was overboring their Mini14 -- handloaders were apparently blowing up their guns with overpressure ammo so they opened up the bore a bit to relieve pressure. If that is not what they intended the barrel to spec at, maybe they will fix it for you.

[blaser.306]

You may want to give T/C a call. That might be the spec they use, maybe from the same standpoint that Ruger was overboring their Mini14 -- handloaders were apparently blowing up their guns with overpressure ammo so they opened up the bore a bit to relieve pressure. If that is not what they intended the barrel to spec at, maybe they will fix it for you.

I may try and call TC , I am more interested in making this bbl work! The last time I had contacted TC/ S&W they all but hung up when they realised I was from out of the US and They could not make a sale to me so had no interest in holding a conversation as to what I needed.

[Fishman]

My 10" 30 Herrett is .308x.300 as it should be.

[357maximum]

I beleieve you can make that work well you just need to treat it for what it is. I have several TC barrels and their quality control is/was somewhat "loose" so you never know exactly what you have til you measure it. All of them have been shooters once the size needed and load workup were done properly though.

[crappie-hunter]

This is most likely what is causing you grief with your herett.

http://www.bellmtcs.com/store/index.php?cid=120

[wallenba]

Like Fishman, my original 14'' 30 Herret also is .308 x .300, and accuracy is good. My 18'' MGM barrel is also spec, and shoots much tighter groups. Sorry yours is off. Sometimes it happens. I have several 'off' guns.

[blaser.306]

Thanks for the replies, Like I had said i just want to make this one work! With the bore groove diameter it would amke a great donor BBL to be rechambered to 303 british! However it is a 30 Herrett and that is what it will stay. I spent 2 1/2 hours and 4 separate phone calls to T/C this morning! The first resulted in immediately being disconnected, The second I was transfered to a "tech" and wound up right back at customer service on hold for 40 minutes the third and fourth were completely pointless. So it would appear that I make it work or put it on a shelf! I love a chalenge anyway.

[leadman]

I have had chambers that were not what they should be but all the barrels were in spec.

[uscra112]

You may want to give T/C a call. That might be the spec they use, maybe from the same standpoint that Ruger was overboring their Mini14 -- handloaders were apparently blowing up their guns with overpressure ammo so they opened up the bore a bit to relieve pressure. If that is not what they intended the barrel to spec at, maybe they will fix it for you.

ASAIK Ruger just changed the chambering of the Mini-14 to 5.56x45 from the tighter .223 Remington. The bore and groove remained the same. People were shooting milsurp ammo in the early ones and making trouble for themselves.

I've also got a factory .30 Herrett barrel, and it slugs a pretty normal .3005" x .3085".

[uscra112]

This is most likely what is causing you grief with your herett.

http://www.bellmtcs.com/store/index.php?cid=120

Bellm is talking there about the .357 Max. a cartridge that was originally designed for revolvers. The SAAMI chamber is a revolver chamber, and totally unsuited to rifles. Not only is there no seat, just a forcing cone, but the SAAMI pilot diameter is just .346", which is way smaller than .35 caliber bores, so it was/is easy to get the chamber off-center. (Which they often did!) Found this out when I had Dave Manson making a .357 Max reamer for me. There's nothing I've ever read that indicates that the Herretts (any of them) had THAT problem. But the fact that T/C was using a pistol reamer in a rifle barrel tells me that the manufacturing management up there must have been a teeny bit haphazard, so I can easily believe that a .303 blank got used to make a .30 Herrett barrel!

[nhrifle]

Ok, that makes a little more sense to me than just blaming reloaders. There have been years worth of warnings about firing 5.56 in a .223 chamber, especially in warmer weather. Never have seen that proven to me and not sure I would want to be near the shooter when proof is obtained! A friend lost his prized match AR due to either a case head separation or OOB discharge and he still has a flinch from time to time. I still get a little teary when I think about that.

[NVScouter]

My 357Herrett has a .357 bore I need to remember while loading. The 357H is notorious for not shooting light boolitz well but mine loves 110-125g and I think its due to the tight bore. I shot some as cast 190s over my starting g load for 180s and had immediate pressure signs. .360 as cast glad I didn't start them at my hunting load.

[brotherdarrell]

I have a 7tcu that slugs out @ .284"/.279". It is an 8 groove from the late 80's that is chambered crooked. Needless to say most bore riders are not an option in this barrel but my Lee soupcan does ok out to 100 yds.

brotherdarrell