Neck Tension & New Cases

Full Curl

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I got a new rem 700 in 270wsm. Floated and bedded the barrel in a new HS stock. Been working on load dev for the last month and not really getting to where I want it. I bought 300 pieces of new win brass. Ran them all through an expander ball to evenly open the mouths and then trimmed them all for consistency. When I seat bullets some go in nice and smooth while others have noticeably more resistance leading me to believe that I have a wide range of neck tensions with loaded cases. I'm just working with the new brass now so have no experience resizing these cases and using them for a second firing. I'm not sorting cases or bullets but should be able to get more accuracy than I am currently. I found a few loads that will get me to 1"MOA at 100yds or maybe just under. I seem to be vertically stringing more than horizontally so I was wondering if neck tension could be a factor? I usually use Norma or Lapua cases in all my other sticks and have not noticed this before. Should I see more consistent neck tension when loading these Win cases for the second firing? I don't neck turn and don't plan on getting into that. Just wondering if Win cases might be a little lesser quality and be causing some of the accuracy issues I'm finding. My goal would be .75" MOA which I think is definitely attainable with this rifle. Interestingly enough, some of my best groups have come from Nosler Custom Grade factory ammo. Wish I knew or could get my hands on whatever powder they charge those with to give it a try. I'm loading the same bullets in my hand loads… 140gr Accubonds. Any insight would be appreciated. Thank you.
 
l don't even bother with load development with new brass. case volume will change. first firing velocity will be low because some of the energy is lost in frieforming the case and neck tension will change as the carbon builds up in the neck. i would only work with about 50 cases at.a.time
 
While learning the "hard way" i agree with what rcoody says. Going forward, use brass you've already fired in the rifle for load development.
 
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You need to anneal Win brass after first fire to even up the neck tension then sort it all by measuring the neck thickness in a few spots with a ball mic and sort out the extremes then it's OK, any more I just buy the Norma and for go all the mess with the poor quality of the Win.
 
Yes neck tension could be your problem. I would weight sort brass and use a bushing die when you load next time.

As stated above you can get changes from new brass. I personally have never experienced big changes from new brass to fire formed other than when they need to be annealed
 
New win brass just plain sucks. If you spend a crap load of time weighing and measuring neck thickness (which I've heard varies up to .005") Along with all the normal case prep, you might keep half... Maybe.
 
I don't foresee your neck tension variables changing much if you have a variety of neck wall thicknesses. An easier way than using a ball mic to get a clue on how much the thicknesses vary is to measure the OD of loaded rounds and compare.

If the necks vary as much as .005" as one poster suggested I think you should turn the neck walls to match the thinnest ones. I sure wouldn't use a bushing die with variable neck wall thicknesses unless the necks were passed over the sizer ball AFTER being reduced slightly by the bushing.

Or if you don't want to skim turn the necks then segregate by thickness.
 
I don't foresee your neck tension variables changing much if you have a variety of neck wall thicknesses. An easier way than using a ball mic to get a clue on how much the thicknesses vary is to measure the OD of loaded rounds and compare.

If the necks vary as much as .005" as one poster suggested I think you should turn the neck walls to match the thinnest ones. I sure wouldn't use a bushing die with variable neck wall thicknesses unless the necks were passed over the sizer ball AFTER being reduced slightly by the bushing.

Or if you don't want to skim turn the necks then segregate by thickness.

when I had my WSM reamer built I had them do it with a .315 neck just so I could use the win brass and tru up the necks, I just prepped up 100 cases of win brass and surprisingly I didnt have to chuck to many , they all cleaned up at .0135 for the most part they were all .016 to .0135 a few were .0165 to .013 but yes there were none that were even :( but with a lil time in brass that rifle shoots sub .250 with win brass , but it is the only brass available for me ("available" if you could call it that lol )
 
Thanks for all the replies. Maybe I have been spoiled with my Norma and Lapua brass in my other rigs because I never ran into issues like this. I don't have a ball mic to measure neck thickness and don't really want to get into neck turning. Starting to think that I should have just paid the cash and gone with the Norma cases from the start. I'll measure some loaded round necks and see what variation I get. I never really saw much of a difference in new to once fired cases in my 7mm rem mag or my 300wm, but those were both with Norma cases. Thanks for the replies, gives me some things to think about and consider. I do have some once fired Nosler brass... is that any better than the Win? Thanks.
 
Thanks for all the replies. Maybe I have been spoiled with my Norma and Lapua brass in my other rigs because I never ran into issues like this. I don't have a ball mic to measure neck thickness and don't really want to get into neck turning. Starting to think that I should have just paid the cash and gone with the Norma cases from the start. I'll measure some loaded round necks and see what variation I get. I never really saw much of a difference in new to once fired cases in my 7mm rem mag or my 300wm, but those were both with Norma cases. Thanks for the replies, gives me some things to think about and consider. I do have some once fired Nosler brass... is that any better than the Win? Thanks.

As long as the nosler brass is all from the same lot it should be pretty consistent. People are getting huge weight differences from lot to lot with nosler brass. Other than that I don't know too much about it.
 
Anybody recommend any case prep for new Norma brass or is it good to load right out of the bag for load development?
 
Got to the point where I had it with the Win brass. 3 firings from some cases and primer pockets were getting too dam loose. I bit the bullet and ordered some Norma. Probably should have done this from day one. Hoping the Norma is close to what I've found with the Nosler cases.
 
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