Brass much thicker right by neck?
- Thread starter The Oregonian
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Have you tried bumping your shoulder back while sizing. I was having similar problem until I bumped the shoulder .002. I would also get a new bushing
To clean you chamber of carbon plug the muzzle with a couple of patches stand it on that end and fill the barrel with your favorite carbon solvent and let it soak for awhile . drain it out and use a chamber brush to clean the chamber follow up with a chamber bore mop . Lee precision makes a simple case trimmer that is caliber specific simple to use not expensive and will give good results . what does your brass look like before it is cleaned are the necks heavily carbonized ?
The Oregonian
Well-Known Member
Yes, I bump the shoulder...I think/hope it is the case mouth peening.
The Oregonian
Well-Known Member
It was off by a couple of thou during that video but I rezeroed just after. I do deburr case necks and chamfer.
greenejc
Well-Known Member
Try trimming and reaming the brass after three shots. It may be flowing forward into the neck and being stopped by the chamber. This would result in thickening the neck at the mouth like you describe. Trimming it back and reaming the inside slightly should stop the problem. I don't use Nosler brass, so I've had almost no experience with their brass. I know I haven't had your problem with any of the brands I do use, though. I haven't noticed a neck thickness problem in my Remington 300 winmag brass even after 6 or 7 uses. I do have to trim at around the 5th or 6th reload, though. I just started using Sig brass in the .300s because I couldn't find Remington brass at Cabela's or Sportsman's Warehouse. I don't know if it will do what your Nosler brass is doing.
greenejc
Well-Known Member
This probably isn't free bore that's doing the neck thickening at the mouth. Peening when polishing could do it, but having the case at maximum length would also do it. When a case is fired, pressure causes the brass to flow forward toward the bore. In effect the case stretches toward the mouth. A chamber is reamed so that the case neck fits inside a slightly wider area than the bullet, and there's a ledge where the case neck is supposed to end. On the .28 nosler, according to the Lyman 50th reloading manual, the width of the neck is 0.32 in. The bore is 0.284. Maximum case length is 2.590. If the case has stretched by the third firing to that length, it is butting up to the end of the chamber and the brass can't flow forward, so it thickens at the neck. If it has stretched, trimming it back to trim length and beveling the mouth slightly should take care of it.
greenejc
Well-Known Member
No, free bore is the area between the end of the chamber and the point where the bullet engages the rifling. It can be long or short depending on the barrel manufacturer. A longer free bore lets bullets be seated out farther in the casing without effecting pressures. A shorter free bore lets lighter or shorter bullets be seated nearer to the rifling in the barrel. The chamber of a 30-06 for example has a final diameter the size of the neck of the cartridge or slightly larger, at 0.3397 to maybe 0.3399. The Free bore is reamed to 0.308-0.3085 and varies in length. But it always is made to allow the cartridge to chamber with the bullet short of the rifling. If you reload, you don't want to seat bullets so far forward that they can contact the rifling, either. It will cause excessive pressure with what should be safe loads. For instance, Barnes recommends a seating depth which puts their X bullets about 0.050 away from the lands. A tight free bore is used in a match grade barrel to help allign the centerline of the bullet with the centerline of the bore. Commercial barrels are made with a little leeway for reliable function/feeding/extraction. If you are reloading, make sure you measure your free bore and seat the bullet a couple of hundreths away from the lands at least. It won't really effect your rifle's practical accuracy, and it will keep you from locking up an action due to an overpressure spike. The brass thickening at the neck is a case length problem, I think. Hope that answers your question.
greenejc
Well-Known Member
I use regular dies (RCBS and Lee) and commercial chambers. I trim to length and bevel the mouth of the case. I'm not going for 0.2 inch groups from my rifles. I'm perfectly satisfied with a 1 inch or less group from the commercial barrels I use. If the brass is thick at the neck mouth the trimming takes care of it. I generally just go by feel when seating the bullet into the case neck. For conformity and even tension, in my 30-06 ammo and my 300 winmag ammo, I use a Lee factory crimp and crimp the bullet in. If the cases have been trimmed, this gives a uniform tension to the neck and increased accuracy. Maybe from 1.0 in. at 100 yards down to 0.75 inches. And yes, it works on bullets without a cannalure. For my 25-06 and my varmint weight .308, I just seat the bullet for concentricity. Neither of these rifles seem to be sensitive to case neck tension, and both regularly shoot 0.5 inches at 100 yards, and around 3 1/2 to 4 inches at 600 yards. The Ruger 25-06 is a little better at 600, and is easily minute of prarie dog at 500 yards. My brass for this rifle is generally mixed brands and a lot of it is 270 Win. necked down and trimmed to length. Eventually (maybe this year) I'll put a Shepherd 6 to 18 Dual Reticle Scope on this rifle and be able to get precise hits to its potential. Then I might select brass for accuracy, but right now, 250 to 350yards off a camp chair and sticks is a lot of fun. The P-dogs explode nicely, too.
greenejc
Well-Known Member
Another thing to remember is that different bullets even by the same manufacturer have different ogives. I use Speer HotCor and Sierra Gameking bullets extensively, along with the Sierra 180 grain ProHunter. The ogives on the sierra bullets are slightly different, and the Hotcor is also different. One of my seating dies are set to seat the bullet with the sharpest curve about 0.04 from the lands. This keeps any of the rounds from being jammed into the lands on chambering. I have a second 30-06 seating die that is set up especially for the 180 and 200 grain Gameking projectiles which seats them a little farther out. They're about 0.02 from the lands and grooves in my Ruger, and a little farther from the -03A3's lands. This allows for closer to maximum charges with these bullets while keeping pressures down and a shorter jump to the rifling for slightly greater accuracy. But I don't use that die much, as the other die produces more than adequate accuracy for most of my needs.
vancewalker007
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I found a trim to length for the 28 stated to be 2.57. You stated earlier you were at 2.575-2.58. I would pull the bullets on some of the cases that will not chamber then trim them to 2.57 and try a few with just a bullet. Note, you may need to touch it again with your sizer to sweeten up the neck. Also, you never mentioned if you were bumping the shoulder at all. Not bumping the should on a FL die can cause some weird effects on chambering. You only need you die set to bump it .001- .002. More than .0025 can cause excessive working of the web area of you case.
On the bushing you are using you may want to try a .316 then the .314. It will minimize over working the necks. On my 7 LRM I use a .315 then a .313. I only use the expander on the .315. I am using thinner brass than you have so I have to go down to .313. I've found over the years that not using the expander on the final bushing step seems to give me more consistent tension.
On the bushing you are using you may want to try a .316 then the .314. It will minimize over working the necks. On my 7 LRM I use a .315 then a .313. I only use the expander on the .315. I am using thinner brass than you have so I have to go down to .313. I've found over the years that not using the expander on the final bushing step seems to give me more consistent tension.
