Gunsmithing Benefits of tight neck chambers?

[want2Baccurate]

Would anyone be willing to provide an article or explanation about tight neck chambers? Are they most useful for all barrel lengths or just shorter ones? I have been reading a little about them on a bench rest website, but finding information is difficult(keeps wanting to reference neck turning of brass).

A benefit of a tight neck chamber is increased velocity, correct? The reason I ask is because I have the option to purchase a tight chamber neck barrel and was wondering what the differences/ benefits are.

Any help/ links for information are appreciated.

 

[former naval person]

Re: Benefits of tight neck chambers?

Depends upon what use you plan for the barrel/rifle. You'll probably have to turn necks on all your ammunition, and will not be able to use factory ammo...match or otherwise. For a Tactical/field rifle, it is probably impractical. For a dedicated bench gun that you don't mind doing the extra ammo prep, it might help. For a person with OCD it is usually necessary. JMHO

 

[want2Baccurate]

Re: Benefits of tight neck chambers?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">Depends upon what use you plan for the barrel/rifle. You'll probably have to turn necks on all your ammunition, and will not be able to use factory ammo...match or otherwise. For a Tactical/field rifle, it is probably impractical. For a dedicated bench gun that you don't mind doing the extra ammo prep, it might help. For a person with OCD it is usually necessary. JMHO </div></div>

I handload so factory ammunition is not a major concern of mine anymore. (although it is nice to have a backup)
This rifle will probably see more shots from the bench than anything. Since I have access to longer ranges in CO, I would like to make as much use of them as possible, so I was wondering if tight neck chambers assist in shooting long range.

Edit: long range to me meaning 500+yds.

 

[eddieharren]

Re: Benefits of tight neck chambers?

Tightneck chambers have no bearing on velocity. Tightneck chambers enable the shooter to make the necks absolutely concentric. (No thick or thin spots in neck walls) Absolutely a must in BR but a PITA for hunting. One good thing about turning necks is, you only have to do it once.

 

[flounderv2]

Re: Benefits of tight neck chambers?

FYI. some calibers do not seem to like tight neck chambers. There was a writeup about the .284 on accurateshooter a while back and that a tight neck .284 had a tendency to not be as accurate.

 

[want2Baccurate]

Re: Benefits of tight neck chambers?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: flounderv2</div><div class="ubbcode-body">FYI. some calibers do not seem to like tight neck chambers. There was a writeup about the .284 on accurateshooter a while back and that a tight neck .284 had a tendency to not be as accurate. </div></div>

This will be for a .30-06 Springfield. Have you heard any reports about accuracy with this cartridge?

 

[eddieharren]

Re: Benefits of tight neck chambers?

If you plan on trying to get the best accuracy possible from your 06, consider having it chambered with a tightneck reamer. The 06 once ruled across the course and highpower matches. It is over 100 years old and still a fine, accurate cartridge.

 

[GreatGonzo]

Re: Benefits of tight neck chambers?

I may be wrong, but I think the main reason/benefit of a tight necked chamber is brass life.

When you get new brass, you turn it all to the same thickness, then when you shoot through your tight necked chamber, it only grows a little bit. That way, you only have to size it down a little bit to reload. This prolongs brass life by working the brass minimally. There may be a small gain in accuracy, but it likely won't be seen unless you are shooting from a bench with some really good bench equipment.

Typically, the cartridges that you see tight neck chambers for are bench rest cartridges, ie: 6 ppc, 6 br, 6x47, 6.5x284, etc.

You do what you want, but chambering a 30-06 with a tight neck is begging for trouble imo. Too much factory ammo around of varying neck thicknesses. I would engrave a HUGE WARNING on the barrel that said NEVER use factory ammo. You can control what you do with the rifle, but what if you suddenly weren't around anymore...

 

[lightman]

Re: Benefits of tight neck chambers?

There are a few benefits to tight neck chambers.You can turn them to give you the fit that you want.Turning necks lets you make more concentric necks.Turning necks lets you get the most good from bushing dies.It also lets you make a tight fir for your chamber.For long range benchrest,its probably worth while.For hunting or tactical use it is probably better forgotten.My br rifle is tight neck,and so are a couple of my varmint rifles.The br rifle is worth the work,the varmint rifles are a pita,although very accurate.
As far as neck turning,I use a hand held tool(Sinclair)and turn the case with a cordless screwdriver.It takes a few seconds,and once is good for the life of the case.
To answer your questions,barrel length has nothing to do with neck turning or tight neck chambers and will have very little if any affect on velocity. Hope this helps, Pete

 

[want2Baccurate]

Re: Benefits of tight neck chambers?

Sounds like I would be better off not wasting the time/money/energy on a tight chamber until I really get into accurate shooting such as benchrest.

If you guys wouldn't mind, could you also tell me about tight bore diameters and how they would affect shooting? I have seen tight bores mentioned before, but haven't looked into them much. I'm off to google right now to see what I can find, but I figure some of you will know as well.

Edit: After looking around for a bit, reading some old threads on here I've come to 2 conclusions. Tight bores were designed to address smaller bullets made in different countries, and as such shouldn't be necessary for consistent diameter match bullets like we have today. The other think I learned is that tight bores are used more by those who have shorter barrels in order to compensate for the velocity loss.
My barrel is 28" so I doubt this will be a concern.
Does anyone have data on the use of tight bores with new match bullets (in the 180+ gr.) and long barrels?

 

[Keith Johns]

Re: Benefits of tight neck chambers?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: want2Baccurate</div><div class="ubbcode-body">Sounds like I would be better off not wasting the time/money/energy on a tight chamber until I really get into accurate shooting such as benchrest.
</div></div>

Thats how I feel about it and a lot of other BR reloading practices. I like loading simple. If Black Hills ammo will shoot half MOA in these rifles, my simple-jack reloads will too.




On the tight-bore question.... I dont know much but I did build a 308 Palma with a Krieger tight bore.
It was harder to clean. Accuracy was the same as the .300/.308 bores. Velocity might have been higher but if so, not much.

I didn't feel it was helping in any way, but someone on here will be able to tell you a lot more.

 

[Country]

Re: Benefits of tight neck chambers?

On the qusetion of a tight neck chamber it al depends on how tight is tight? You could have a tight neck reamer that cuts the chamber that still allows factory cartridges to chamber but only lets the neck expand a small amount . Then you could have a chamber cut to so tight that you have to neck turn to get any case in. The subject is complicated and wide ranging .
However the basic answer is that if the neck clearance is reduced and the case neck turned to a more concentric form this helps to reduce neck tension variations and that helps bullet seating accuracy , less runout and that all helps the bullet to enter the bore in a more concentric manner and that reduces in bore yaw.
This all helps better accuracy potential .
Is it really a good idea on a hunting rifle ? well not really because if the chamber neck is too tight feeding froma magazine may become difficult in some actions and the chance ofa jam up if any small piece of crap gets into the chamber neck even one single granual of unburnt powder can jam a tight neck case.
Very experienced shooters can run a tight neck chamber hunting rifle but I would suggest with respect that you are not experienced enough yet to take full advantage while avoiding the pitfalls.
There is a reloading method that I have devised many years ago that gives you some of the advantages to tight neck chambers while only having a standard factory chamber . It revolves around partial neck sizing and using body dies in place of Full length sizing dies. You can also neck turn if you want and not loose any accuracy from increased neck to wall clearance.
On the question of tight bores , it is generally accepted that .001 or .002 undersize bore can sometimes result in better accuracy but it all depends on projectile diameter , jacket thickness and bullet construction. If the bore is too tight and the bullet swages down too much the jacket can spring back after the bullet exits and a loose core can result. With most target bullets being made on thin jackets for concentricity reasons I don't believe in tight bores , well tighter than the bullet shank . If my bullet is .308 all over then I want my barrel to be .308 groove diameter because when the powder pressure hits the bullet up the bore the bullet is going to be obturated into the groove diameter anyway so you don't want it going bigger or being swaged down too much . However some bullets are not perfectly the right size and slightly undersize is common especiall in the shank area even if the base pressure ring is the correct diameter.
So you could have a bullet with a .307 shank and a .308 base. This is where a .307 barrel could help.

 

[Greg Langelius *]

Re: Benefits of tight neck chambers?

I honestly don't know what transpires within the bore during firing.

I would conjecture that bullet obturation would be more positive, and this could lead to greater pressures, velocities, and copper fouling. But this all purely a matter of my own personal conjecture.

I personally don't use anything but SAAMI chambers. I would hate for someone else to put an incompatible factory cartridge into one of my barrels and have a mishap. I mean, I'm not gonna live for ever and I like my descendants.

Greg

 

[former naval person]

Re: Benefits of tight neck chambers?

And...by the way, you'll have to have the barrel fitted to your action anyway...if the barrel is a high quality piece, and the price is right...just have the gunsmith open the neck to SAAMI standards. Problem solved. JMHO

 

[sobrbiker883]

Re: Benefits of tight neck chambers?

Not good for beginners.

Shoot your '06 until you can shoot as good as it will or the barrel's shot, whichever comes first. By then you will have a better idea of what you really need/want than you ever will have by surfing.

 

[want2Baccurate]

Re: Benefits of tight neck chambers?

Thank you all very much for your information and viewpoints. I was finding much the same information last night about tight necks and chambers. I think what I will plan to do is buy a barrel with a standard bore and a minimum SAAMI spec chamber. After that I think I will shoot the crap out of it, and then look to rebarrel it in something fancy. From what I have been reading, '06 barrels can go quite a long time with modest reloads, and still last a long time even with hot ones.

 

[hntbambi]

Re: Benefits of tight neck chambers?

I shoot a tight neck for my 22PPC and 6PPC switch barrel 40x. It is great for loading at the range. I neck turn to .0085" wall thickness on Lapua brass and I don't have to resize for quite a while, when the base needs reduced slightly. I shoot, punch out the primer, reprime, charge, seat bullet and shoot again. It is stupid accurate and very fun on varmints.

Will it help on your gun or a different cartridge? I don't know.

 

[Mike Casselton]

Re: Benefits of tight neck chambers?

<span style="font-style: italic"><span style="font-weight: bold"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: want2Baccurate</div><div class="ubbcode-body">Thank you all very much for your information and viewpoints. I was finding much the same information last night about tight necks and chambers. I think what I will plan to do is buy a barrel with a standard bore and a minimum SAAMI spec chamber. After that I think I will shoot the crap out of it, and then look to rebarrel it in something fancy. From what I have been reading, '06 barrels can go quite a long time with modest reloads, and still last a long time even with hot ones. </div></div></span></span>

You are correct here. Don't try to reengineer what has been working for thousands of other people. If anything new comes along that makes huge gains in accuracy and velocity, you'll read about it.

If you want to learn more about the loading techniques for Benchrest and Hi-power shooting, get the benchrest shooting primer and Glen Zediker's book on handloading for competition. If that isn't enough to convince you, then two more books come to mind. Tony Boyer's book on Benchrest shooting and Mike Ratigan's book.

Start simple and learn to shoot with basic handloading. From there, you can experiment with all the other playthings that cost huge sums of money. Money that could go into more primers, powder and bullets...