How much is too much neck tension? Range update!

[MuthaFunk]

I've been neck sizing my 7.62X54r with a Lee Collet die set for 7.5x55 Swiss. It seems to work quite well but I'm using the .308 mandrill to size the necks and my bullets are .311. I've been getting some decent groups out of my hand loads but my Chrony says I still have an ES upwards of 75 fps per 10 rounds. I found I got slightly better numbers when I stopped using the Factory Crimp Die.

Is the added neck tension from using a .308 neck size and .311 bullets throwing off my accuracy?

 

[Gunneegoogoo]

Are you happy with your groups for your intended use?? If so, spend your thoughts on other things like buying a new rifle, or boobs.

If your goal is to be as insanely accurate as you can be, then start reading all the things I've been asking for the last 6 months, and open your wallet........and re-mortgage your house.

 

[MuthaFunk]

Lol! I've been keeping up on those threads. I guess I'm just trying to get my hand loading technique down better. I thought I should be able to get my ES #'s lower than the mid 70's.

I'm of the thought that even with the worlds greatest rifle, if my hand loads have an ES of 75 fps at the muzzle, I'm not going to get great groups.

 

[Gunneegoogoo]

Lol! I've been keeping up on those threads. I guess I'm just trying to get my hand loading technique down better. I thought I should be able to get my ES #'s lower than the mid 70's.

I'm of the thought that even with the worlds greatest rifle, if my hand loads have an ES of 75 fps at the muzzle, I'm not going to get great groups.

Left-Right will probably be just fine, but at longer ranges your vertical will likely be off. If 300yds is your max, fawgetaboutit. If you're gunning for 7,8,900 then fret.

I think I read that your crimping?? If your goal is precision, stop that now....... there is no such things as "too much" tension, its "what tension is right for you". If you're going to war, or shooting cape buffalo 50 yards away, crimp.

Low cost neck improvements are - clean brass (SS wet tumbler), neck brush-chamfer-deburr.....well, that's about it. After that you're annealing, turning......

 

[chrismc]

Yup, stop crimping, and i would suggest send a fired case into Lee and get them to make a proper die set for your cartridge - look on their website.
You may never see the accuracy you are seeking when you don't use the proper stuff for the caliber - too many variables like resizing, shoulder bump, neck tension, etc.

 

[bigedp51]

I've been neck sizing my 7.62X54r with a Lee Collet die set for 7.5x55 Swiss. It seems to work quite well but I'm using the .308 mandrill to size the necks and my bullets are .311. I've been getting some decent groups out of my hand loads but my Chrony says I still have an ES upwards of 75 fps per 10 rounds. I found I got slightly better numbers when I stopped using the Factory Crimp Die.

Is the added neck tension from using a .308 neck size and .311 bullets throwing off my accuracy?

You have .003 neck tension and this is what is recommended for a AR15 without crimping the bullet. Normally for a bolt action you want .001 to .002 neck tension. Now the bad news, as the case is repeatedly fired and resized the brass in the neck gets harder and springs back more. Meaning more neck tension and why reloaders anneal their case necks to make the necks softer.

I ordered a floating carbide expander for my .243 and it measures .2428 and wrote the company and they told me the expander was within limits. Meaning with new brass I would have .0002 neck tension. With a normal full length resizing die neck thickness also has a effect, meaning the thicker neck inside diameter is reduced more the a thinner neck and effects neck tension.

If you want to experiment order a larger mandrel and see if it makes a improvement in your group size. But military ammunition is crimped also so you are playing with a lot of variables. So in the end its uniformity and group size is all that matters. Plus you are shooting a old milsurp rifle with a pitted and frosted bore and not a benchrest rifle with a custom made barrel.

I'm not trying to be negative but a benchrest shooter has a tight neck chamber, neck turns his brass, uses a bushing die and anneals his cases for a constant neck tension. And we have dies and expanders that vary in size and cases with varying neck thickness and age and hardness. Meaning we deal with ball park standards and all you can do is experiment and see what works.

Now after you get you neck tension down to perfection your next question will be asking how far off the lands do you load your Mosin.

 

[PitBull1973]

On my LMT AR10 and M14 I do not crimp but all I use is LC brass. That being said I've purchased a national match die from Forster and had them hone the neck to .335 and my expander is .305. This setup gives me .003 tension. And yes I anneal my cases every reload. This is a way cheaper alternative then buying a bushing die from Redding

 

[Dogleg]

How much neck tension is too much? Put it this way; the method I use for necking up .300 RUM into .338 Edge is to charge new .300 RUM cases and then seat a .338 300 grain SMK or more recently the 300 grain Berger Elite hunter into the 30 cal neck. Run-out with the Bergers is seldom more than .003" and 1/2 MOA groups at 800 yards is more than a occasional occurance and ESs with these barbarian loads aren't any worse than with the ones put up in fired brass. That is to say, single digits. Long way to say excessive neck tension isn't your problem. The first thing for you to try is load hotter if you have some pressure room. Then different primer or different powder in no particular order.

 

[bigedp51]

Below is another example for loading a AR15 and not crimping jacketed bullets and getting less neck runout when seating. The more neck tension you have the more force required to seat the bullet and the greater chance of bullet alignment problems. (bullet runout) The Lyman type M die expander is used for more neck tension and the .226 "step" is used to start the bullet straighter in the case neck before hitting the increased .003 neck tension.

Below is from the Whidden custom die website. (and adds to the confusion and your knowledge about neck tension)
So if the bullet and case neck is smoking after seating the bullet you have too much neck tension.
http://www.whiddengunworks.com/product/expander-ball-kits-and-sets/


"The Whidden Gunworks Expander Balls typically allow the shooter the opportunity to adjust the neck tension from .001″ to .005″. The Expander Ball Kit comes with five Expander Balls. Each kit includes an Expander of the chosen caliber and decreases in size by .001″. Example: If an Expander Ball Kit for .243 caliber is ordered, the kit would include Expander Ball sizes .243, .242, .241, .240 and .239."

And also from the Whidden die website that sells standard full length and bushing full length resizing dies.

"The non-bushing sizer die typically yields more concentric ammo in our experience. It also fully sizes the case neck fully to the shoulder for smoother functioning. Neck tension can only be determined by changing expander balls with the non-bushing die."

 

[MuthaFunk]

Thanks for the suggestions fellas. I appreciate your time to reply! I am indeed doing the poor mans annealing with Templaque and a drill every 3 firings. As far a runout goes, I recognize I'm shooting a Mosin and don't expect the world from it. My particular Mosin has been modified into a fine range gun often shooting sub MOA groups. The bore is .311 perfectly shiney. For now I have my OAL set just off the lands and don't plan to play with that until I get more consistient load speeds.

I'm currently running Varget, 174 SMK's, and WLP's neck sized at .308 without crimp. I just picked up some H4895 to try as it seems that's another common powder for .308 and 7.62x54r loaders.

So if the neck tension isn't throwing my loads off. I know my scale is consistient as I've been cross verifing my weights with two other scales before charging. I guess I should be looking at getting some Federal Match primers next?

 

[burnaby]

My 308 Lee collet provides 1-2thous neck tension for my 308 bullets. Using simple addition a 311 bullet would have 4-5thous tension. That's a lot for precision. Recall YoDa said he saw a top shooter has so little tension that on extraction of loaded round the bullet can fall out if extracted too quicly.

I've been neck sizing my 7.62X54r with a Lee Collet die set for 7.5x55 Swiss. It seems to work quite well but I'm using the .308 mandrill to size the necks and my bullets are .311. I've been getting some decent groups out of my hand loads but my Chrony says I still have an ES upwards of 75 fps per 10 rounds. I found I got slightly better numbers when I stopped using the Factory Crimp Die.

Is the added neck tension from using a .308 neck size and .311 bullets throwing off my accuracy?

 

[burnaby]

On my 308 running Varget, Lee collet, Fed LR (not match), RCBS CM. SD/ES is min 4/12, max 5/14.

Thanks for the suggestions fellas. I appreciate your time to reply! I am indeed doing the poor mans annealing with Templaque and a drill every 3 firings. As far a runout goes, I recognize I'm shooting a Mosin and don't expect the world from it. My particular Mosin has been modified into a fine range gun often shooting sub MOA groups. The bore is .311 perfectly shiney. For now I have my OAL set just off the lands and don't plan to play with that until I get more consistient load speeds.

I'm currently running Varget, 174 SMK's, and WLP's neck sized at .308 without crimp. I just picked up some H4895 to try as it seems that's another common powder for .308 and 7.62x54r loaders.

So if the neck tension isn't throwing my loads off. I know my scale is consistient as I've been cross verifing my weights with two other scales before charging. I guess I should be looking at getting some Federal Match primers next?

 

[jethunter]

Varget will have to be run close to max to get consistent total powder burn in that cartridge. If your load is light then you may be getting larger ES due to inconsistent powder burn. What is your powder charge weight?

 

[MuthaFunk]

Varget will have to be run close to max to get consistent total powder burn in that cartridge. If your load is light then you may be getting larger ES due to inconsistent powder burn. What is your powder charge weight?

I ran some ladder tests and ended up at 44.3 gr which isn't exactly a full charge.

At this point I'm thinking my loads were so inconsistent that the ladder tests I did were bogus anyway. I think I'm going to get a proper RCBS neck sizing die with a .311 mandrill and rerun the tests to look for a new load.

 

[jethunter]

44.3 gr is quite light, maybe making 40,000 psi pressure or a bit less and could be contributing to your ES issue. Varget and most rifle powders don't burn 100% efficiently and consistently at those pressures. A heavier powder charge of Varget or even a slightly faster powder might help to shrink your ES.

 

[Gunneegoogoo]

Strong work on the tempilaq.

Stop crimping and see what happens.

I'd not fret about match vs LR primers, at least right now.

You could get a flash hole uniformer, might help.

Rather than experiment the RCBS die, why not just cut to the chase and get a bushing die??

 

[burnaby]

Bushing dies is a lesson in futility without neck turning. Great when you're trying to go from 1/2 to 1/4 or less MOA. Suspect OP's rifle is not in that range.

...
Rather than experiment the RCBS die, why not just cut to the chase and get a bushing die??

 

[Mystic Precision]

Thanks for the suggestions fellas. I appreciate your time to reply! I am indeed doing the poor mans annealing with Templaque and a drill every 3 firings. As far a runout goes, I recognize I'm shooting a Mosin and don't expect the world from it. My particular Mosin has been modified into a fine range gun often shooting sub MOA groups. The bore is .311 perfectly shiney. For now I have my OAL set just off the lands and don't plan to play with that until I get more consistient load speeds.

I'm currently running Varget, 174 SMK's, and WLP's neck sized at .308 without crimp. I just picked up some H4895 to try as it seems that's another common powder for .308 and 7.62x54r loaders.

So if the neck tension isn't throwing my loads off. I know my scale is consistient as I've been cross verifing my weights with two other scales before charging. I guess I should be looking at getting some Federal Match primers next?

You are shooting a Mosin Nagant rifle and you are getting sub MOA groups on occasion... You are DONE...

Enjoy the rifle, muck about if you want to experiment and learn but I do not expect you will see any more accuracy from this rifle regardless of how much more tweaking you do.

Just work towards consistency in the ammo. As long as a 5X5 rds average is stable, that's it.

Want more accuracy, get a rifle with a better barrel...

Jerry

 

[MuthaFunk]

You are shooting a Mosin Nagant rifle and you are getting sub MOA groups on occasion... You are DONE...

Enjoy the rifle, muck about if you want to experiment and learn but I do not expect you will see any more accuracy from this rifle regardless of how much more tweaking you do.

Just work towards consistency in the ammo. As long as a 5X5 rds average is stable, that's it.

Want more accuracy, get a rifle with a better barrel...

Jerry

I understand that the rifle is POS compared to the true target rifles available today. My groups aren't what I'm worried about fixing with this post. I'm trying to learn to be a better hand loader. If I had a nice Tikka T3 all tricked out for targets and feed it the ammo I'm making today, I don't think it would shoot any better than my Mosin. It seems like most reloaders can achieve ES and DS numbers far less than I. I'm obviously doing something wrong. As it is now, I've been able to shoot better groups with milsurp ammo with similar ES/SD #'s. I know from measuring the milsurp components the charges and bullets vary much more than the ammo I'm making myself. So what gives?

I'm trying to cut my teeth on reloading with this cheap rifle. Reloading is not a cheap hobby as I've come to find out. As far as I can tell, my Mosin should function as a simple ammo tester to blast rounds out of the muzzle to chrony. Am I wrong in this assessment?

If I've done my job in selecting match bullets, weighed them into groups, used verified equal charges of powder, and WLR primers, the only things left to screw up is the seating depth and neck tension. My seating depth seems to be quite consistent however I haven't got a comparator set yet to verify. My OAL is very close though.

I know I'm using .308 neck sizer and using .311 bullets so that's really the only thing I can think that's causing me problems... Other than perhaps my load being too light because my ladder tests and nodes were bung due to my neck tension issues.

 

[tjhaile]

I don't think you can get much more than about .003" neck tension with brass cases. Brass only has so much elasticity. Sizing the ID of the neck below that will only result in the bullet expanding the neck, such that if you were to pull the bullet after seating it, you will find that the neck ID is smaller than the bullet by that same .003".

Any rifle chambered for 7.62x54R is likely not accurate enough to notice any difference due to any difference in neck tension. The only real difference in this case is a little extra force to seat bullets. It may well be that the rifle and not the load is the biggest source of variation.