Odd groove in one shot 270 brass

[tikka270win]

I just put some one shot brass from my tikka t3 270 win. through my tumbler and found that about one out of every five has a weird groove all the way around about.02 from the top of the neck. What could cause this? And is it a cause for concern? Im not sure if maybe it has something to do with the chamber, but shouldnt it happen to all brass if that is the case? And i am getting little dents on the shoulders on quite a few of them

 

[Kevin Thomas]

Tikka,

The indentations on the shoulders sound like your run-of-the-mill lube dents. This is caused by an excess of lube during the sizing process. Being non-compressable, that lube will "go" somewhere when it gets trapped between die body and case, and the only way it can go is to push the brass in a bit. This leaves the dents you've described. Use a bit less lube, and keep the shoulders mostly free of the stuff, and this problem will disappear in short order. In the meantime, the brass should be fine.

Not quite sure about the "groove" you're describing. Be possible to post a pic of these? Could be a number of things, but would like to see them before hazarding a guess.

 

[tikka270win]

I was using the hornady one shot spray when i sized those, since i have switched to the imperial wax though. And i will post pics as soon as i get a chance.

 

[tikka270win]

Well the pics arent very good because the camera wouldn't focuse that close to really see the groove, but you can see by the black on the neck where that groove is, not all of them are black in the groove. And one of them did end up losing a chunk on the tip.

 

[Kevin Thomas]

Tikka,

would I be correct in assuming that you got this brass as once-fired factory ammo? If so, I'd say the "ring" is merely the remanant of what was the original factory crimp. At least, that's what it looks like in teh top picture here. Don't worry about it, and it shouldn't affect anything as far as reloading goes. Depending on the length, you may find you remove it by trimming after a firing or two. As for any that actually loose a piece of the neck, that brass is already too hard, and the case is probably not worth messing with. Annealing may help, but once they have a divot out of them, why worry about it. Brass is cheap compared to what else we're investing here.

 

[tikka270win]

Tikka,

would I be correct in assuming that you got this brass as once-fired factory ammo? If so, I'd say the "ring" is merely the remanant of what was the original factory crimp. At least, that's what it looks like in teh top picture here. Don't worry about it, and it shouldn't affect anything as far as reloading goes. Depending on the length, you may find you remove it by trimming after a firing or two. As for any that actually loose a piece of the neck, that brass is already too hard, and the case is probably not worth messing with. Annealing may help, but once they have a divot out of them, why worry about it. Brass is cheap compared to what else we're investing here.

Well the groove appeared on both remington brass which was factory ammo, but also appeared on Winchester brass which i bought as virgin brass, and i dont crimp. Thanks for all your help, I'll just give the brass a couple firings like you said and see if the grooves stop. The gun is a pretty much brand new Tikka, so I should have nothing to worry about there.

 

[Kevin Thomas]

Okay, if it has appeared in the factory ammo, I think that was probably the cause. If it appeared in the component brass, is there a chance you're crimping it when loading? Most standard seating dies incorporate a crimp feature. Most of us simply bypass this (it's not needed in about 99% of reloading) by adjusting the die upwards to where it seats without the crimp engaging the case mouth. If you weren't aware of this, you could have very easily been crimping without even knowing you were doing so. Either way, if you adujst the die up to where it's not crimping (refer to the dies instructions on how to back them off to avoid this) and just size normally, I'm guessing this will disappear after another firing or two.

 

[johnnyk]

Looks like it needs de-burring to me. JohnnyK.

 

[backwoods83]

Put a mic or caliper on the neck of a fired unsized case, looks kinda like the chamber has a little bit of a loose neck and is not sealing as fast as it should, were they sooted up on the necks before you cleaned them?

 

[tikka270win]

Put a mic or caliper on the neck of a fired unsized case, looks kinda like the chamber has a little bit of a loose neck and is not sealing as fast as it should, were they sooted up on the necks before you cleaned them?

Yes they were sooted on the necks before i cleaned them. How can i check for a loose neck?

 

[backwoods83]

Use a micrometer or caliper and measure a case that has been fired and not resized, the hornady brass in a good chamber should measure .309-.310" and about .306" after sizing. Sometimes to tame of a load can do the same thing, what's your load data?

 

[tikka270win]

Use a micrometer or caliper and measure a case that has been fired and not resized, the hornady brass in a good chamber should measure .309-.310" and about .306" after sizing. Sometimes to tame of a load can do the same thing, what's your load data?

Now that i think back i was working up a load with this brass for 110 gr. vmax. So maybe it was the loads with less powder that sooted the necks? The best load i had was 47 grains varget with the 110 gr. vmax, although i never did get the vmaxes to shoot every well. OAL length of this load was 3.265 (to tip of bullet).

 

[backwoods83]

A stout charge of H4350 would have been a better choice, keep the varget for a 308 or 223.

 

[tikka270win]

A stout charge of H4350 would have been a better choice, keep the varget for a 308 or 223.

I agree 100% now, but i had about half a pound left over from my 22-250 and thought varget might work with the lighter bullet. From now on im either going to use RL 17 or H4350. I just bought a box of 130 grain nosler ballistic tips and plan to use RL 17.