What is the standard rifling depth for big game calibers? Specifically .35?

.oo4"

Meaning 0.004" per side, or 0.350"/0.358".
Regards, Joe

Duh! Thanks Joe & Butch

And that .004" would be for modern, American-made, barrels.

Metric barrels are slightly fifferent, as are many older American barrels.

Some, particularly in the early U.S. barrels and many British barrels, had tapered groove depths. That is, they were tighter at the muzzle end than at the chamber end ...sometimes by as much as a couple of thousandths. (Or, even more, in some older BP barrels.)

Reason I'm asking is I have a gun on 3 day inspection, it was a 30-06 rebored to .35 Whelen and they are telling me when they rebored it that the grooves are .005.

Does that mean the bore is actually .348?


thanks,

Rob

Have somebody check it with a pin gage if you are worried about it.The bore is easy to check and the groove size much more time consuming. Probably pushing a lead slug through it and measuring it would be easiest.
Butch

Cerrosafe cast of the rifling at the muzzle, or expand a lead slug into it. Driving WILL work if done properly but expanding between 2 close-fitting rods is a little better IMO. Driving against a rod is almost as good as expanding between 2 rods, but I've found that simply driving a slug into the bore can sometimes result in a canted or un-filled-out slug that will always measure smaller than the true dimension.

BTW don't be too concerned if the dimensions are a thou or 2 off, as long as the bore isn't reverse-tapered at the muzzle. Many original 8mm bbls actually measure 0.325"-0.328" in their grooves, especially the 1908 8x56 M-S and the 1888 Commission rifles. I possess one Krieger 7mm bbl that was ordered intentionally with a 0.285" groove size.
Regards, Joe

I would just call the guy who re-bored it and ask. There is a fellow up in Oregon that does a lot of these '06 to Whelen conversions and advertises 0.005 depth. I think they do this because the Whelens get fed Cast bullets quite a bit and the deeper groove promotes that venture it is said. The below is from their website: 35 cal. ( .359" groove diameter)
http://bellmtcs.com

There you go, Mike Bellems rebore guy is Jesse Ocumpaugh and he did this gun. I emailed and was told that the grooves were .005. After JD's post it didn't make sense to me that the numbers don't jive.

Kellum does a lot of TC Encore work and that's probably where the cast bullets come in.

Jesse Ocumpaugh's website shows that his .35 caliber rebores have a .349 Bore-.359 groove, so there's the .005 depth of rifling.

Is the over bore size (+.001 over .358) a concern with regular clad bullets?



thanks,

Rob

the .001" MIGHT be a concern if you planned to shoot thousands of rounds through it. There is some small possibility of gas leakage around the bullet and maybe some increased gas cutting of the bore by the gases as they speed up in passing the bullet.

But, in fact, for hunting rifles I wouldn't be the least concerned. I have used .223" diameter bullets for many years in some of my hot-loaded .220 Swifts with .224" bores. So far that does not seem to have resulted in any undue wear, and I have shot thousands upon thousands of such rounds in them in aggregate.

If you read Ken Waters' Pet Loads on the 358 Win, he writes of a 358 Mannlicher Schoenauer with .366 (9.3) bore & that rifle shot well even with 0.008" over spec!

The old 6.5X54 Mannlicher Schoenauers (both of mine) have 0.269" grooves rather than the nominal 0.264" (0.005" over spec) and they perform fine. I get 2" to 3" groups with open sights at 100 meters.

You are sure to get good performance in the 35 Whelan as long as the job is done properly.

I wish I could get that reboring service here in New Zealand - my old 30'06 Sako barrel is a prime candidate for a 9.3X62 chambering.