Help Gunsmiths

[ras308]

I acquired a savage 24F some time ago from my uncle, the bullets tumble even at 25 yards.  I have loaded 40 to 75 grn. (just to exaggerate for showing other gunsmiths), they all tumble.  I took it to a local gunsmith and had it recrowned, same thing.  He did not have the equipment needed to air gauge the barrel, etc., but said the bore looks very clean, no pitting.  I watched him push tight patches through the barrel and he could not tell any difference, as far as loose spots.  I know the patch procedure is not an exact science, but that's the best he had.  I plan on having the barrel gauged, but wanted some suggestions.  Thanks.

ps.  My Dad's rifle shoots great with all the same loads???

[gunnut69]

I suspect bore damage.  Using a strong light applied from the side look closely at the terminus of the rifling, that is the last inch or less.  Be sure to look completely around the circumference of the bore.  Check for damage in the last inch or so..  By the way, what caliber rifle does your 24 have?

[Iowegan]

The reason bullets tumble is almost always because they aren't spinning fast enough (or crown problems). That means the velocity is too low or the bullet diameter is too small for the bore diameter. I would say either you are using the wrong ammo or the bore is shot out.

I had a customer bring in a fairly new 308 rifle. He was sighting it in for deer season when all of a sudden his groups spread and bullets keyholled with a new box of ammo. Seems he mistakenly bought 7mm-08 ammo.

[gunnut69]

I have also seen rifles with muzzel end damage to the rifling(cleaning rod wear and factory deffect) that tumbled bullets.  The reason was the extremely uneven release of the high pressure gas behind the bullet.  Check that muzzel, the 222 is a mild mannered round and usually guite accurate.  Slug the bore if you're worried about diameter problems.  I'm betting on crown/bore damage at the business end..