What neck tension works best for you in 6.5x47mm Lapua?

[kevinbritvec]

I have a Forster 6.5x47mm sizing die and intend to have the neck honed because it constricts the neck too much. I'm thinking .004" under my loaded round's neck measurement. I figure that would get me .003" neck tension with spring back if I don't use an expander ball and very little effort to withdraw the expander ball if I do use it.

For those of you using bushing dies, what size have you settled on?

 

[lbran]

for benchrest shooting, use 1 to 2 thousandths under loaded round, for hunting use 2 to 3 thousandths under loaded round, just my 2 cents! happy shooting!!!!!

 

[Drop Port]

What ever it likes, try it first if it gets worse after honing you know what to do.

 

[alphapygmy]

My loaded brass measures .2910 so I had a Forster die honed to .2875. Like the OP i figured around .001 springback to get .0025" tension. Bullets seat very consistently, it shoots very well, and all the sized brass comes out with less than .0005" runout everytime. Before when I tried bushing dies I could never get consistent brass runout no matter what I tried, some .0003" some up to .006". Between the cost of the bushing die and some bushings it's the same price to buy several Forsters and have the necks honed.

 

[savagedasher]

I have my dies honed to the neck size of the gun chamber - 0.002 I use that die for bumping the shoulder . Then I use a bushing die for bullet interference . Normally I can just neck size ever two reloadings . This give me a option of doing partial neck sizeing also.
Larry

 

[savagedasher]

I have my dies honed to the neck size of the gun chamber - 0.002 I use that die for bumping the shoulder . Then I use a bushing die for bullet interference . Normally I can just neck size ever two reloadings . This give me a option of doing partial neck sizeing also.
Larry

 

[500Stroker]

Get yourself a custom full length bushing sizing die that is cut off the dimensions of your fire formed brass. When you order the die get some bushings if different sizes to play with. You can slightly alter your neck tension by just using different neck brushes and brushing techniques. Drop me a PM if you need more help.

 

[M14AMU]

 

[kevinbritvec]

Get yourself a custom full length bushing sizing die that is cut off the dimensions of your fire formed brass. When you order the die get some bushings if different sizes to play with. You can slightly alter your neck tension by just using different neck brushes and brushing techniques. Drop me a PM if you need more help.

I really am not a fan of bushing dies, I prefer full length dies with proper neck dimensions. Obviously I'm willing to pay for the die to be honed by Forster, I'm just looking for suggestion based on other peoples results.

 

[kevinbritvec]

My loaded brass measures .2910 so I had a Forster die honed to .2875. Like the OP i figured around .001 springback to get .0025" tension. Bullets seat very consistently, it shoots very well, and all the sized brass comes out with less than .0005" runout everytime. Before when I tried bushing dies I could never get consistent brass runout no matter what I tried, some .0003" some up to .006". Between the cost of the bushing die and some bushings it's the same price to buy several Forsters and have the necks honed.

Thanks. It looks like .0035" smaller than measured neck diameter worked for you.

 

[alphapygmy]

Thanks. It looks like .0035" smaller than measured neck diameter worked for you.

I also have a .2865 and the jury is still out on results. It's shoots virtually the same as the .2875. I was even thinking of trying a .2885 just to see what happens. It's very consistently under .5 MOA with ES around 10-12 and SD around 3-4. I think the trigger nut is the biggest factor now.

 

[500Stroker]

I really am not a fan of bushing dies, I prefer full length dies with proper neck dimensions. Obviously I'm willing to pay for the die to be honed by Forster, I'm just looking for suggestion based on other peoples results.

I have had very favorable "results" using custom FL bushing dies. I have won several matches, shot perfect points targets and one perfect points match and have had sub one inch groups, all at 600 yards IBS and Club matches.
Having different bushings to select from also allows you to adjust for different bullet lots and many other conditions that can gain you an edge.
Good Luck

 

[skiutah02]

To be fair, I have not shot this barrel at a match yet (I compete in FTR and "dabble" in Open), but this was testing from a 47L I will shoot next time I dabble. Loaded round is 0.2885 and I'll use 0.0005 neck tension. The bottom line from the target is that is seems to make little difference on the target (for this barrel anyway) which, in my experience, is the exception. The two high shots are from a rest screw up on the first two shots. Some things of note. 1. Shot at 600 yds 2. Sticker is 2in for reference 3. I'm not great at shooting from a rest. 4. red is 288 bushing, blue is 287 bushing, green in 286 bushing and measured diameter of neck after bushing sizing is very close to those values.

 

[kevinbritvec]

I have and use Sinclair's expander dies. The reasons I want to modify the die is to reduce the overworking of the brass and the overworking of my arm. For anyone considering the purchase of Sinclair's expender mandrels, pay the extra money for the carbide version, they're worth it.

 

[CTK]

I started out with a .289 bushing. Just ordered a .288. Carbide Redding's are sold out everywhere and had to get steel. 289 is approx .001 under loaded. It holds the bullets firmly. Have read that I need more tension for hunting. Once again, 289 seems real snug. Will I see any accuracy or poi changes by changing bushing size?

 

[Joe R]

I know that everyone likes to control neck tension with bushings but to me that doesn't seem like a very good way. From my way of thinking bushings transfer any variance in neck thickness to the inside of the neck where they have a direct impact on neck tension. That is not a good thing, because no matter how careful you are turning necks there will be variances, and those variances will impact neck tension.

I believe that the outside of the neck has minimal importance. The only importance it has is how thick the necks are because that has an influence on spring back. IMO the part of the neck everyone should be focusing on is the inside of the neck, or more appropriately inside diameter. The inside diameter is what influences neck tension, if one can transfer neck wall variances to the outside of the case it is that much better.

So the question is how do we control neck tension from the inside of the neck? What if instead of honing die necks (an irreversible and often problematic process because dies are hardened) we were to use a mandrel to expand the necks to provide the desired neck tension? What would a mandrel do?

Well, ... a mandrel would control the inside diameter of a case neck much more precisely than any bushing ever can. It could also transfer neck thickness variances to the outside of the neck where it doesn't interfere with neck tension and bullet release. That's good isn't it?

Sorry, gotta go the wife wants to watch a movie now. Let me know if you're interested in learning more, otherwise this is it.

Kindest regards,

Joe

 

[Martin52]

.....

Well, ... a mandrel would control the inside diameter of a case neck much more precisely than any bushing ever can. It could also transfer neck thickness variances to the outside of the neck where it doesn't interfere with neck tension and bullet release. That's good isn't it?

Joe

I just picked up on this when thinking about John Whidden's product, expander ball kits. By selecting a bushing so the fired case neck is reduced minimally, then selecting an expander ball that ever so slightly expands the neck to the required dimension, the result should be improved consistency in the internal diameter with minimal working of the brass. I turn my case necks but am rethinking the expander ball might not be a bad thing. I have used a K&M mandrel but found the lack of case body support created run out of 4 to 5 'thou.

 

[M14AMU]

On my .308 Winchester brass I neck turn the wall thickness to .012" and THEN I run it up into a Sinclair mandrel that is .3075" diameter! Using an arbor press....I seat by feel and even though I don't have a pressure guage hooked up....I'll guarantee it's mighty consistent on seating! When I DON'T USE THE MANDREL....or turn the necks the variance in seating pressure is very obvious! Needless to say I'm not of the school of thinking that neck turned brass is only for tight necked chambers.

 

[dkhunt14]

I just picked up on this when thinking about John Whidden's product, expander ball kits. By selecting a bushing so the fired case neck is reduced minimally, then selecting an expander ball that ever so slightly expands the neck to the required dimension, the result should be improved consistency in the internal diameter with minimal working of the brass. I turn my case necks but am rethinking the expander ball might not be a bad thing. I have used a K&M mandrel but found the lack of case body support created run out of 4 to 5 'thou.

I have found that the mandrel verses expander ball causes less runout. It also gives even neck tension. It needs lube to keep from causing runout. I anneal and use graphite and the mandrel goes in like soft butter. Matt

 

[mikecr]

K&M is too large. Use Sinclair/PMA