Brass neck thickness variation, does it show up on target?

[Bronsin]

BTW: I use 3-in-1 oil as a lube. This made a big difference by keeping heat down. Heat is the enemy while turning necks.

PopCharlie

I use Tap Magic Aluminum

 

[dcali]

This might be an unpopular opinion, but for F Class, you'll never see the difference. You can make a good rifle shoot in the 2s in ideal conditions with unturned brass and factory bullets, and that is good enough to win any match. I stopped when I realized I was getting beaten by guys who Don't turn and haven't looked back. My rifle shoots just as well as it did when I turned.

I think we tend to do a lot of stuff because we can, we know it won't hurt, and it's easier to just do it than test it. And once you start doing something, there's a psychological resistance to stopping. Theses days, I try to shave off every possible second I spend at the loading bench. Not turning really helps with that, and like I said, it hasn't hurt my F class guns at all.

Leave the neck turning for benchrest when you're trying to cut another 20 thous off your group size, or when you need to in order to make your cases. If you don't have either of those problems, it's wasted time and money.

 

[RedfootRanch]

BTW: I use 3-in-1 oil as a lube. This made a big difference by keeping heat down. Heat is the enemy while turning necks.

PopCharlie

I have found @group therapy 's Hobo Oil be the best lube I have found for turning necks.

 

[Mark611]

Just a question bulletmaker, how do you size your cases?

 

[dcali]

Just a question bulletmaker, how do you size your cases?

If you mean me, I use an off the shelf Redding bushing die for my TR rifles.

 

[TA17rem]

Little heat from neck turning dont hurt the necks it actually improves them. Ever heard of annealing? The necks get a hell of a lot hotter from annealing than from turning necks.
Sizing necks I use to just use neck bushing die but now use it in conjunction with full size die and just bump the shoulder/body so cases after few firings go easy into chamber.

 

[gunsandgunsmithing]

Little heat from neck turning dont hurt the necks it actually improves them. Ever heard of annealing? The necks get a hell of a lot hotter from annealing than from turning necks.
Sizing necks I use to just use neck bushing die but now use it in conjunction with full size die and just bump the shoulder/body so cases after few firings go easy into chamber.

No...when the mandrel gets hot, it expands. When the cutter body gets hot, it also expands but at a different rate due to different mass and since most are made of aluminum, it also expands at a different rate than the mandrel. Annealing doesn't even happen at all until it gets way, way hotter than you should ever get from friction on a neck turning mandrel. There's tons of threads on here that get into annealing in detail here if ya wanna do a search and some research on the subject. You're on a good site with a lot of knowledgeable people/posters. Stick around. It's a great site.

 

[gunsandgunsmithing]

you turning necks with power tools???

Yes and no. I also do them on a lathe, fwiw. Again, there are threads on here and a search function. Welcome aboard! There are people here of all skill and experience levels. All are welcome.

 

[TA17rem]

Yes I understand and I also turn my own necks and make many wildcat cartridges as well. I'm not new to any of this. I use hand neck turning tool, there isn't enough heat to do anything. I also anneal my necks.

 

[bks22345]

This might be an unpopular opinion, but for F Class, you'll never see the difference. You can make a good rifle shoot in the 2s in ideal conditions with unturned brass and factory bullets, and that is good enough to win any match. I stopped when I realized I was getting beaten by guys who Don't turn and haven't looked back. My rifle shoots just as well as it did when I turned.

I disagree. I think it all depends on your components and what you have to work with.

I shoot F class and I am NOT very good at it, but I’m always trying to figure out why. I am always chasing vertical at 1000 yards so I sat down one day with a box of spent brass. I always load a round, shoot, and put it back in the empty hole so I can look at my chrono results and know the velocity of each piece of brass. My chrono said I had an ES of high 40s. No bueno. I started checking the neck thickness in 4 quadrants of each brass. Those that were faster were thicker and consistent (say .016). Those in the middle were thinner and varied considerable. The slowest were thinner and a little more consistent (say .0152-.0154). I had about 400 pieces of Lapua 284 that I received with a 2nd hand gun and have no idea whether these were from different lots or not. My numbers may be a little off but I walked away with the idea that big variations in neck can make a considerable difference in ES. I started skim turning them to get them all consistent, and was able to get my SDs to high single digits with ES’s in the 20s. I still cannot shoot but my ballistics are getting better.

NOTE: All of these SD/ES numbers were over match strings of 22-30 shots.

 

[Doom]

I disagree. I think it all depends on your components and what you have to work with.

I shoot F class and I am NOT very good at it, but I’m always trying to figure out why. I am always chasing vertical at 1000 yards so I sat down one day with a box of spent brass. I always load a round, shoot, and put it back in the empty hole so I can look at my chrono results and know the velocity of each piece of brass. My chrono said I had an ES of high 40s. No bueno. I started checking the neck thickness in 4 quadrants of each brass. Those that were faster were thicker and consistent (say .016). Those in the middle were thinner and varied considerable. The slowest were thinner and a little more consistent (say .0152-.0154). I had about 400 pieces of Lapua 284 that I received with a 2nd hand gun and have no idea whether these were from different lots or not. My numbers may be a little off but I walked away with the idea that big variations in neck can make a considerable difference in ES. I started skim turning them to get them all consistent, and was able to get my SDs to high single digits with ES’s in the 20s. I still cannot shoot but my ballistics are getting better.

NOTE: All of these SD/ES numbers were over match strings of 22-30 shots.

I would say your conclusion is pretty spot on. Trying to perform actual tests on this subject is extremely difficult especially when you try to tie it to on-target performance. There are just too many variables at play to do an accurate test. Your ES/SD conclusion based on your data is interesting, but here again it applies to your specific cases and rifle chamber. Does it carry over to someone else's situation? Maybe, or maybe not. Was it the result of neck tension or misalignment with the bore? I give!