How much is too much when it comes to neck clearance?

[Ccrider]

I think .004 is perfect .005 will work over five is too much

Interesting. I was wondering whether .004 may be too much. I have been testing some Dasher brass at .011 in a .269 chamber. My loaded rounds have been .265. I have not seen any problems. They do require the use of a smaller neck bushing.

 

[338 dude]

Interesting. I was wondering whether .004 may be too much. I have been testing some Dasher brass at .011 in a .269 chamber. My loaded rounds have been .265. I have not seen any problems. They do require the use of a smaller neck bushing.

The thing that I find strange even with.004 Clearance my bullets will not drop into a fired case I anneal after every firing but I guess there was still a quite a bit of spring back

 

[338 dude]

Also as mentioned earlier I based my statement on my rifles and sooting on the neck and shoulders sealing off combustion

 

[Ccrider]

The thing that I find strange even with.004 Clearance my bullets will not drop into a fired case I anneal after every firing but I guess there was still a quite a bit of spring back

Mine will not drop in, but they will slide in without much force.

 

[Eric Leonard]

i have .272 neck BRA chamber ,loaded rounds with unturned brass and 80 gr flat base bullet is .2691 ,,I just turned 50 cases so its .267 loaded round and gonna see if they shoot any different,,

 

[Longtrain]

I run a Lapua Blue Box no-turn neck on my Dasher @.2704, loaded rounds are between .268 and .2685, so between .0019 and.0024 total clearance. Works, no issues.

 

[Doug Beach]

I’ve shot tens of thousands of rounds through .308’s with .008” total clearance. 100% of my discarded brass has been to thinning forward of the web. I have never had a cracked neck.
When the firing pin hits the primer, the case will be pushed as far forward as possible. This will cause the shoulder angle to center the front end of the cartridge in the chamber. The only way this wouldn’t happen, is possibly with jammed bullets, or an interference fit between case neck and chamber. My ¢.02, worth every penny.

 

[MagnumManiac]

Lets say i have a case that when i skim turn and uniform the necks they measure .271 over a loaded round (after being sized with a .269 or .268 bushing)- is a .275nk too much having .002 per side? Ive shot this exact combo in this neck or a .278nk thousands of times with no issue just seeking others opinions.

.004” is perfect.
This is exactly what I aim for when ordering my reamers.
I have run tight clearance...not worth the headache TBH.
As you are aware, factory barrel clearance often runs .006-.008”. Which is ample, to say the least.

Cheers.

 

[jackieschmidt]

For short range Benchrest, I use around .0025 overall neck clearance in all of my chambers.
I turned some necks to have .004 a couple of years ago, I convinced myself the Rifle did not perform as well. So I stick with what has worked for years.
A bullet will slip easily into a fired case.
probably what is more important than the actual clearance is to have all of the necks the same so to insure the same seating pressure.

 

[RegionRat]

On my 30 cal hunting rig necks, I don't turn brass and have been happy with the 0.340 necks.

0.3085" + (2 x 0.013") = 0.3345 compared to 0.340 means 0.0055 to 0.0045 loose depending on the brass batch.

Any tighter and dirt and weather can remind you of why mil specs were done the way they were. You could go looser, but I don't think it adds anything to the party.

 

[Cmrem700]

Another issue that is related is that when necks have to be sized down a lot, bushing dies with floating bushings may not do their best work, as far as concentriciy goes. One way to get around this is to use a one piece die that has the desired neck ID. In my experience, this approach produces the best possible concentricity, better than a FL bushing die. Of course the matter of whether these differences in concentriciy show up on targets is another subject for discussion.

Great thread! Question, when using a bushing full length die how much can you size the neck down with a bushing before concentricity is compromised?

 

[Uncle Ed]

This is a very old thread and the proper neck clearance was covered some time ago by Saddam Hussein's cat.

 

[Bc'z]

This is a very old thread and the proper neck clearance was covered some time ago by Saddam Hussein's cat.

I'll add if you got someone in a sleeper hold and thier still moving....
You have to much neck clearance!
Happy new year!!

 

[75vmax]

243. 14 twist I run a .268
243. 12 twist I run a .270
243. 8 twist I run a .272
My head spaces are .002 differences on all 3 rifles. I dont resize my brass just knock primer out and goto the next rifle. All shoot great. After the 3rd firing I throw away brass and start over.

 

[Intheshop]

From the cast bullet side of things;

Where it's a good idea to experiment with different diameter bullets,which changes clearance. With a medium jam,and everything else held dang close to the same..... I've seen blowback that I assume is antimony? at certain clearances,and not at others. It shows as these tiny spheres(buggers) that are distributed very equally around the neck and back on some of the shoulder. These are relatively high pressure loadings,not really "reduced". Think starting JB,book loads with a medium jam.... the pressure is "up there".

The point I'm trying to make is that different clearances effect this distribution. Not,what the makeup of what's being deposited. It just "shows up" with cast. I've got some rigs that shoot so well that I put up with it. Others,where the clearance can be changed to clean that bit of it up,without it changing group size. These are bughole rigs BTW.... so when one goes from < 1/2" @100 to one inch plus with a neck clearance change,it gets noticed. I also have cast rigs that show more "normal" blowback patterns where it's just powder fouling on the case. Read with interest in Boyer's book on the patterns and have used that as a metric. Not that it works that way on every rig.

Beats the snot out of me for "why". The antimony buggers wipe right off. Just always found it interesting that the neck clearance played a roll in it. I don't really have a set number for clearance.... it falls into place as a natural course when setting up the bullet for that particular chamber. Using the target as the qualifier. But generally it ends up around .003 or 4 total.

 

[Spike A]

I always find neck turning threads interesting.. as its one of the "techniques" of reloading i have not dabbled in and set here for hours at times pondering if i should..... at the end of most threads i always feel as if posted threads seam to be 50% each way... so I always end up figuring that I Have had good results to which I am happy with the way I am currently doing things so why add another step that I could potentially cause an error and make another mistake factor.... But WHO knows.... Maybe ill gain that .05" of a group... OR make it that much worse

 

[PopCharlie]

I'm having a 6br built by Jeff Walker. It will have a .266 neck. I plan to shoot loaded ammo at .263. If my math is right (?) This will give me .0015 on each side. I'm thinking this will be good. But, my wife says, whenever I think, it's always my first mistake. What do you guys think?

 

[338 dude]

I'm having a 6br built by Jeff Walker. It will have a .266 neck. I plan to shoot loaded ammo at .263. If my math is right (?) This will give me .0015 on each side. I'm thinking this will be good. But, my wife says, whenever I think, it's always my first mistake. What do you guys think?

In my OPINION that is a minimum clearance but should work just fine

 

[Kracken McGraw]

243. 14 twist I run a .268
243. 12 twist I run a .270
243. 8 twist I run a .272
My head spaces are .002 differences on all 3 rifles. I dont resize my brass just knock primer out and goto the next rifle. All shoot great. After the 3rd firing I throw away brass and start over.

Humor, I like it!

 

[Bc'z]

I'm having a 6br built by Jeff Walker. It will have a .266 neck. I plan to shoot loaded ammo at .263. If my math is right (?) This will give me .0015 on each side. I'm thinking this will be good. But, my wife says, whenever I think, it's always my first mistake. What do you guys think?

I think we're married to the same woman, if not they gotta be sisters!
Your brass will let you know if it's enough clearance.
I had a clearance issue in my 06' with lapua brass. Chamber neck .340, loaded round was .337.
Now I could've bought different brass to solve the problem, thought about it a lil bit.
I thought it a better idea to buy a used 21st Century lathe, and new cutter head....
I found out I should listen to our wives, it would've saved me $200.