neck tension issue?
neck tension issue?
Another question for someone more knowledgeable than I....I've got a couple of loads with 39 blitzkings one with 10x and one with H4895 that are pretty decent. I have shot some .5inch 5-shot groups at 100 yrds. I am neck sizing with Lee Collet die and I can tell when seating bullets that some go in harder than others. Using Hornady Brass. I have shot a few groups also where I will stack 3-4 shots real nicely then have one an inch right and a touch high. If two do that they are stacked just as nicely as the main group. They are not noticeable flinch shots. Does this sound like a text book neck tension issue? I have shot groups where all five stack nicely, i would say its just me, but its a reoccurring issue where 1 or 2 out of 5 are off the group, mostly right in that same spot. Thanks in advance. I'm about ready to just go buy a redding competition die set as i am getting frustrated with the lee seater too. that and maybe some norma brass.
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Jim White
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Re: neck tension issue?
Ok...I'll give it a go, hopefully I won't overlook something but if I do I'm sure someone would chime in and help out. However, accuracy is a personal thing. For some it's driving nails and for others, its 1 MOA or less...and there is plenty of space in between.
1. It you want the upmost accurate ammunition then first off, you need to evaluate your brass quality, for it is the foundation of the ammunition. Brass prep is a must and as a minimum; this includes sorting cases by weight, uniform the primer pocket, deburr the primer flash hole, measure the neck thickness, chamfer the case mouth both inside and outside and trim if [and neck turn] as necessary. When all of this is done you'll have confidence that the brass is all consistent as it can be and the good news you only have to do it once.
2. Neck Tension; As mentioned you need to measure your case necks. If they're out of whack you'll need to turn them to the degree that they're within .0003 of each other and this effort should require of just knocking off the high points/sides. You shouldn't have to turn the whole case neck for 360-deg from the neck/shoulder junction to the case tip to accomplish this. With neck thickness uniformity, neck tension will vary and it does effect accuracy to some degree or the other. Be mindful though of the initial neck thickness because you don't want the necks to thin and you don't want to much neck spring back or you'll be splitting necks unless you anneal.
When seating bullets you want .002 to .003 of neck tension for a bolt gun. For a gas gun I'd use more but what ever number you come up with it has to be consistent.
3. Run out or wobbly ammunition. Bullet run out issues definitely has an adverse effect on accuracy. It can be caused by many things but ideally you want .003 or less however anything above .006 really needs to be scrutinized. As mentioned, many things can cause excessive run out but it usually comes down to reloading technique and/or reloading equipment. Ununiformed necks certainly doesn't help the bullet run out situation and besides its easy to check.
4. Pick good quality reloading equipment. As far as Lee dies, some love em' others don't, I don't have any experience with them either way. When you size/resize a case, whether it is full length or neck only, use the expander ball and plenty of lube. The expander ball will help alleviate some of the neck uniformity issues. The lube will help alleviate some of the bullet run out issues. Regarding brand of dies, predominantly, I use Redding followed by RCBS. I do have a set of Forester/Bonanza 308 dies and they have served me well. For plinking pistol dies I have some Hornady and Lyman in addition to RCBS but for the accuracy work, it primarily Redding for rifles and RCBS for pistols.
5. When actually load testing, make sure your position and all is solid. I find that scope shooting tends to lead one to sloppiness in position set up and all as compared to an iron-sights shooter. Still need that NPA and all.
When you shoot a group and you have a flier, set that case aside and mark it. Check out the measurements and if good try it again and if it repeats something is amiss with that case.
6. Many of the things described herein can be alleviated with good quality brass from the get-go. Regarding Hornady brass, I have to add that with the exception of their Creedmoor brass, the rest of it is subpar. If you can procure some Norma, Lapua, RWS or Nosler brass it saves an enormous amount of prep time. It has to be checked but you'll find very few are set aside.
This was basically a brief summary but I just got back from Atlanta today so its been a long day.
HTH,
1. It you want the upmost accurate ammunition then first off, you need to evaluate your brass quality, for it is the foundation of the ammunition. Brass prep is a must and as a minimum; this includes sorting cases by weight, uniform the primer pocket, deburr the primer flash hole, measure the neck thickness, chamfer the case mouth both inside and outside and trim if [and neck turn] as necessary. When all of this is done you'll have confidence that the brass is all consistent as it can be and the good news you only have to do it once.
2. Neck Tension; As mentioned you need to measure your case necks. If they're out of whack you'll need to turn them to the degree that they're within .0003 of each other and this effort should require of just knocking off the high points/sides. You shouldn't have to turn the whole case neck for 360-deg from the neck/shoulder junction to the case tip to accomplish this. With neck thickness uniformity, neck tension will vary and it does effect accuracy to some degree or the other. Be mindful though of the initial neck thickness because you don't want the necks to thin and you don't want to much neck spring back or you'll be splitting necks unless you anneal.
When seating bullets you want .002 to .003 of neck tension for a bolt gun. For a gas gun I'd use more but what ever number you come up with it has to be consistent.
3. Run out or wobbly ammunition. Bullet run out issues definitely has an adverse effect on accuracy. It can be caused by many things but ideally you want .003 or less however anything above .006 really needs to be scrutinized. As mentioned, many things can cause excessive run out but it usually comes down to reloading technique and/or reloading equipment. Ununiformed necks certainly doesn't help the bullet run out situation and besides its easy to check.
4. Pick good quality reloading equipment. As far as Lee dies, some love em' others don't, I don't have any experience with them either way. When you size/resize a case, whether it is full length or neck only, use the expander ball and plenty of lube. The expander ball will help alleviate some of the neck uniformity issues. The lube will help alleviate some of the bullet run out issues. Regarding brand of dies, predominantly, I use Redding followed by RCBS. I do have a set of Forester/Bonanza 308 dies and they have served me well. For plinking pistol dies I have some Hornady and Lyman in addition to RCBS but for the accuracy work, it primarily Redding for rifles and RCBS for pistols.
5. When actually load testing, make sure your position and all is solid. I find that scope shooting tends to lead one to sloppiness in position set up and all as compared to an iron-sights shooter. Still need that NPA and all.
When you shoot a group and you have a flier, set that case aside and mark it. Check out the measurements and if good try it again and if it repeats something is amiss with that case.
6. Many of the things described herein can be alleviated with good quality brass from the get-go. Regarding Hornady brass, I have to add that with the exception of their Creedmoor brass, the rest of it is subpar. If you can procure some Norma, Lapua, RWS or Nosler brass it saves an enormous amount of prep time. It has to be checked but you'll find very few are set aside.
This was basically a brief summary but I just got back from Atlanta today so its been a long day.
HTH,
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dsandfort
- Junior Member
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- Joined: Thu Aug 09, 2012 12:19 pm
- .204 Ruger Guns: Savage 12 BTCSS
Re: neck tension issue?
Nice Jim.
One quick check you might want to do is measure neck diameter of loaded ammunition. That will give you an indication of neck thickness variations.
One quick check you might want to do is measure neck diameter of loaded ammunition. That will give you an indication of neck thickness variations.
Re: neck tension issue?
Thank you for this info...I will check some of this stuff out. I am not looking to shoot 1-hole groups at 100, I mean I would love to be able to do it, but I am happy with my .5 inch groups(probably as good as my ability is anyhow), I just hate the fliers here and there when I am pretty sure it's not me flinching on them. I have a Forster F/L die I am going to run some through that and shoot some groups and see if I have the same issue of fliers here and there. I'm not shooting competition or anything, this is just a plinking gun to fiddle with the buddies on Sunday afternoons. We do shoot quite a bit at smallish 3-4" targets at 300plus, so I do need at least some accuracy.