Concentricity .. how important?
- Thread starter BigSwede
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rockwind
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hi, i have type s match 2 die sets for 3 different calibers (basically a micrometer seater and a full length neck bushing resizer) my gap 4s 6.5 saum, 6.5 crredmoor, and 308. i've tried all sorts of tricks, read redding's tech tips that they suggest,,, redding basically says don't expect anything under .003 runout and then they say concentricity doesn't really matter, and their final trump card is blaming the brass. but who knows, maybe they are right, i am new to this. but i can't help thinking it is something i am doing or not doing. i tried the floating shell holder, i tried the o-ring, i tried the bushing numbers up, numbers down, locked down, not locked down, squaring up the shell holder and die with a piece of flat steel, what else,,,,i forget.
I personally think its hard to beat a Forster FL die with neck honed to proper diameter. Its cost effective and produces very straight ammunition when combined with their BR seater. I shot a 1.65" and 2.25" group back to back at 852 yards with this combo last weekend with my Beanland 6.5x47.
rockwind
Well-Known Member
hey,, yep, forgot, i did that with my 308, ordered the collet die. it did help! but i gave up on my old 308 after that. the gun i mostly shoot is my gap 4s 6.5 saum and lee doesn't make a collet die for that,,,, i have to send them some fired cases and they can make one but it takes a while,,, probably be better off ordering a custom die somewhere since it takes a while. but still,,,, the **** redding dies for my 6.5 saum were 250 bucks! it's pretty **** irratating to just throw that away
bigedp51
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A standard full length die with the expander removed will make the case as concentric as it ever will be. And this is where the Forster full length die shines. The Forster die with its high mounted floating expander can not pull the case necks off center. The neck of the die holds and centers the case neck as the expander enters the case neck.
A neck sizing die does not support the case body and shoulder and can create more neck runout than a standard full length die.
And with a bushing die the bushing can move from side to side and even tilt. And if you reduce the neck diameter .004 or more this can induce neck runout. This is why at the Redding website they tell you to reduce the neck diameter in two steps if reducing the neck .004 or more. And bushing dies work best with custom tight neck chambers with neck turned brass. The expander with Redding bushing dies is to be used if you do not turn your case necks. And and Redding recommends the neck should be sized .002 smaller than expander diameter to make the inside of the necks uniform.
And again, at the Whidden custom die website they tell you they get the most concentric cases with non-bushing full length dies. And they do not make neck sizing dies and this should tell you something.
If you do not have a Forster die you can remove the expander and use a expander die to expand the necks and reduce neck runout.
Below I installed a modified Forster expander and spindle assembly on my Redding full length .243 die to reduce neck runout. The spindle had to be shortened and a rubber o-ring is installed under the expanders lock nut.
I also installed the Forster expander assemblies on all my older RCBS dies to reduce neck runout. The RCBS expander on the left is raised as high as it will go and are not high enough to perform like the Forster expander.
A neck sizing die does not support the case body and shoulder and can create more neck runout than a standard full length die.
And with a bushing die the bushing can move from side to side and even tilt. And if you reduce the neck diameter .004 or more this can induce neck runout. This is why at the Redding website they tell you to reduce the neck diameter in two steps if reducing the neck .004 or more. And bushing dies work best with custom tight neck chambers with neck turned brass. The expander with Redding bushing dies is to be used if you do not turn your case necks. And and Redding recommends the neck should be sized .002 smaller than expander diameter to make the inside of the necks uniform.
And again, at the Whidden custom die website they tell you they get the most concentric cases with non-bushing full length dies. And they do not make neck sizing dies and this should tell you something.
If you do not have a Forster die you can remove the expander and use a expander die to expand the necks and reduce neck runout.
Below I installed a modified Forster expander and spindle assembly on my Redding full length .243 die to reduce neck runout. The spindle had to be shortened and a rubber o-ring is installed under the expanders lock nut.
I also installed the Forster expander assemblies on all my older RCBS dies to reduce neck runout. The RCBS expander on the left is raised as high as it will go and are not high enough to perform like the Forster expander.
Another thing that might help with the expander ball on Redding dies is to not screw the expander down tight on the spindle and do not screw the spindle down tight on the lock nut. This will allow them to free float some. Seems to help me some on my Redding bushing dies.
rockwind
Well-Known Member
gotta say,, tried it, done it. couldn't say for sure it helped me,,,,
i had been getting used to the not so great run out numbers as i was reloading, but there was one time, i was reloading some x2 fired hornady 6.5 saum and i don't know how i did it, but the runout was great,, like .002 or less and i thought i had figured out the secret formula but what was sad was i had resized about 78 pieces with the best rkunout i had ever got and when i go to put primers in them, 40 had blown pockets. i was so sad, leaving me with less than half of what i . and i can't recreate what ever i did with the dies to give me those good run out results. weird
i think i might try the expander mandrell as a second second step again and see if that helps.
Rich Coyle
Well-Known Member
I'm afraid I will sound like a lying internet idiot, but here goes. After I discovered Forester will hone dies to my desired diameter I ordered a full length sizer for the .270 Win and 6.5 CM. I get .000" run out coming out of the die. Seating bullets normally causes run out, though.
rockwind
Well-Known Member
what do they run, dollarwise? i keep thinking about doing that
bigedp51
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I know you are not lying I get the same results as long as the necks are uniform.
Are you using the Forster or Redding benchrest seating dies?
These two seating dies can even slightly correct neck runout.
Click on the link below for the entire article, you must have Adobe Reader.
Reloading: Seating Die Runout
Seating Die Induced Runout - A Comparison by Germán A. Salazar
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=0ahUKEwjsyonB-OLRAhXHOSYKHZSSCcoQFggaMAA&url=https://reloading.cc/forum/attachment.php?attachmentid=8532&d=1425564920&usg=AFQjCNEWbAvlft5hI_jioGKFvXlZelLjzw&bvm=bv.145063293,d.eWE&cad=rja
#1 - Redding Competition Seating Die (sliding sleeve type, threaded die) The Redding, which I expected to finish high, did what I thought couldn't be done - it produced rounds with an average runout that was less than the average case neck runout of the brass used. In none of the ten rounds loaded did the Redding increase the runout; it either held exactly the same or it decreased. The Redding, with an Average Runout Change of -0.0003" is the winner. The negative sign, of course, indicates a reduction in runout. However, it's important to note that we're using a mathematical calculation that gives a result that is smaller than the precision with which we can measure runout, so take the numbers as what they are - smaller than we can reliably guarantee and more of a ranking indicator than an exact measure of probable runout results. This applies to all the dies.
#2 - Wilson (chamber type, for arbor press) I expected the Wilson to come out on top, given it's long-standing reputation as the best seating die and its near universal use in Benchrest shooting. It didn't quite work out that way, but the Wilson was very good, with only three rounds increasing runout and an equal number decreasing, the remainder were zero-change. Wilson Average Runout Change: +0.00015".
#3 - RCBS Standard Die (standard threaded die) I expected the RCBS to be dead last, maybe by a big margin; was I ever wrong! I was really surprised, quite pleasantly, by the RCBS die's performance. Three runout increases, an equal number of decreases and four zero-change made for a very creditable score. RCBS Average Runout Change: +0.00025".
#4 - Vickerman and Hornady (tie) (both partial sliding sleeve, neck only, threaded dies) These dies share a lot in common, being of universal use for a given caliber, in this case, .30 caliber. You can seat bullets in anything from a .300 Savage to a .300 Winchester Magnum with these dies as they just capture the neck of the case in order
to align it with the bullet. However, as your Economics professor taught you, there is no free lunch. That universality of application reduces precision, though certainly not to a level that would render them useless. With more increases in runout than decreases, the Hornady lost ground. The Vickerman had a lot of zero-change rounds, but increased 0.002" on a couple and that really hurt it's average performance. So, the Hornady and Vickerman with an Average Runout Change of +0.0006", bring up the rear - very much to my surprise. These are very useful dies, however and let's keep some perspective, with an ARC of about half a thousandth, I wouldn't be concerned about using them for Highpower match loading.
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Rich Coyle
Well-Known Member
bigedp51,
I'm one of the sharper posters here. I don't know what seaters I have. They don't have names on them. They usually mess up the .000" by a few thou. Very annoying. I drilled a hole in a bar of aluminum so I can slide it over the neck and bend them back to .000". The bar is relief bored so the bullet does not contact the bar; just the neck does.
I'm one of the sharper posters here. I don't know what seaters I have. They don't have names on them. They usually mess up the .000" by a few thou. Very annoying. I drilled a hole in a bar of aluminum so I can slide it over the neck and bend them back to .000". The bar is relief bored so the bullet does not contact the bar; just the neck does.
Rich Coyle
Well-Known Member
I think I paid about $50. But it could have been $60. To me that was one of the best loading buys I made.
DartonJager
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How many here have heard of this method that I've read from a few sources
First de-prime brass using a Lee universal de-priming die
Then remove FL sizing expander ball and resize case
Lastly size case mouth only with a Lee collet die
Going to try this but I don't own a run out gauge so I will test by rolling each round on a dead flat piece of machined stainless and a piece of marble tile
Will reload 10 rounds using my Forester FL BR die & BR seating die then use the above method to reload 10 more using my Redding FL sizing die with expander ball removed then Lee Collet die , check all by rolling then shooting
Will do this for my 300wsm
First de-prime brass using a Lee universal de-priming die
Then remove FL sizing expander ball and resize case
Lastly size case mouth only with a Lee collet die
Going to try this but I don't own a run out gauge so I will test by rolling each round on a dead flat piece of machined stainless and a piece of marble tile
Will reload 10 rounds using my Forester FL BR die & BR seating die then use the above method to reload 10 more using my Redding FL sizing die with expander ball removed then Lee Collet die , check all by rolling then shooting
Will do this for my 300wsm
