Forster Outside Neck Turning Accesory Help

[DIM]

Hey guys, simple question how to measure outside neck diameter, do I measure diameter of the neck after I neck size it or after I seat the bullet in, someone told me I have to measure neck after firing, I’m looking to do some neck turning and I got SAAMI standards not sure how those measurements were taken. It looks like they talking about neck sizing then expanded, getting confused with expansion part.
I would appreciate any help
Thanks

 

[something vague]

I'm confused about the question.

If I understand what you're asking, the expansion they're refering to is probably the expansion of the ball in the F/L resizing die. So this measurement would be after F/L sizing. Again, this may not be what you're asking though.

 

[DIM]

In the manual it came with it stated: "Case to be neck turned must have neck resized and expanded first... OK I neck sized so now I have to expand it??? I only neck size previously fired brass, which is expanded after firing, but when I neck size it constricts brass for proper bullet seating, I just don't get the part about expanding brass for neck turning.

 

[USSR]

You need an expanding mandrel, which sizes the inside diameter of your neck so that it fits properly on the mandrel of your neck turning tool.

Don

 

[DIM]

You need an expanding mandrel, which sizes the inside diameter of your neck so that it fits properly on the mandrel of your neck turning tool.

Don

I was at my local store asking for expander and I was told no such thing exist, but I know sinclair makes great tool for it, but my neck turner is by forster, by the way Don are you from north or south region of the finger lakes?

 

[Ol` Joe]

The Forster tool is designed with the pilot sized to fit a case neck that has been expanded with a Forster expander ball. Use a Forster sizing die and the proper pilot. Don`t forget to lube the case outh and cutter to help keep a clean cut.

Neck turning IMO isn`t a good idea on cases meant for a commercial chamber. The normal SAAMI chambers of fatory rifles are a little sloppy to start with and turning just adds to the poor fit. The only time one needs to turn is with a custom chamber with a tight neck such as in a benchrest rifle. Turning in them is designed to fit the neck to the chamber in addition to evening up the neck wall. I know some brass is uneven in thichness and turning helps improve runout in them. I doubt the improvment in runout helps accuracy though when the brass is no longer supported properly in the now oversized chamber neck..JMO

 

[DIM]

I doubt that my chamber is SAAMI since fired brass is measured 0.004" ,more then max allowed by SAAMI which gives 0.012" - 0.010" neck clearance I'm only trying to even the walls because sometimes I get fliers and I thought it could be neck thickness of the brass I'm using.
I did shaved some brass to even it to 0.012” neck clearance it seemed to stop those fliers but my groups open up from 0.25” to 0.6” – 0.8” and this is not what I expected from neck turning, I just tossed all turned brass to the dumpster…

 

[Walkalong]

Doubtful IMHO. Look elsewhere.

 

[woods]

Best to buy good brass to begin with. If the brass has too much of a variance in neck thickness, outside neck turning will not do that much to correct the problem anyway, the neck will still be off center from the case center


You will do more good by sorting your brass by neck thickness variation than outside neck turning. If you had a tight neck then turning will do a lot of good but if you have more than .002" or .003" variance then turning benefits will be marginal at best.

 

[USSR]

I was at my local store asking for expander and I was told no such thing exist, but I know sinclair makes great tool for it, but my neck turner is by forster, by the way Don are you from north or south region of the finger lakes?

Not familiar with the Forster tool (I use Sinclair's), but I don't like the idea of neckturning without prepping the neck by using an expander mandrel. I'm at the south end of Seneca Lake near Watkins Glen.

Don

 

[Walkalong]

The Forster does use the trimming mandrels for its turner. The many neck turners on the market designed to use matching neck sizing mandrels do a much better job.

Sinclair - good stuff

K&M - What I have. Works great.

to name a couple.

 

[ranger335v]

Neck turning can help reduce the LARGER thickness variations and that can't hurt accuracy. It's generally conceeded that shaving more than about 60-070% of the circumference is counter productive or the already poor neck to chamber fit only gets worse.

Any such shaving does move the neck that much away from the chamber center line BUT firing and resizing it once or twice corrects that pretty well.

Precise turning requres a very snug but not hard fit to the mandrel. Expander balls do vary a tad, all things do, and brass springback varies too so you may or may not have to use a special expander to get a proper neck fit for turning. Few reloading retailers carry dedicated expander mandrals, you will have to go to specialty mail order sources such as Sinclair International for that.

I doubt that a truly precise fit for a truely precise cut just to clean necks up for factory chambers is needed, or even very helpful. If you can get the degee of circumference cut you seek it will help a little and that's all you gonna get anyway.

 

[USSR]

Neck turning can help reduce the LARGER thickness variations and that can't hurt accuracy. It's generally conceeded that shaving more than about 60-070% of the circumference is counter productive or the already poor neck to chamber fit only gets worse.

Since I don't have anything chambered with a tight neck, that's how I do it. The brass is Lake City M72 Match, and even with this being done, it still won't shoot as well as my Lapua brass.

Don

 

[243winxb]

Outside Neck Turning With Forster or Lyman Tools

First you FLRS your brass in a STANDARD die with the expander installed. Then you place the brass in the turner. Take a light cut that removes brass 100% around the neck, all the way to the shoulder. All done , simple. If your chamber is large, and the bushing die has to size brass down more then .010" to hold the bullet, you should not outside neck turn. A FLRS bushing die will improve accuracy in a factory chamber with or without neck turning. Instruction for the Forster unit. http://www.forsterproducts.com/client_images/catalog19938/pages/files/Outside_Neck_Turning_Accessory_OT1010-002.pdf If you have a tight neck rifle, then you need to measure the neck of a bullet seated and turned dummy round to get the correct diameter. Or buy a tool to measure neck wall thickness. You will need 2 die sets, standard & bushing. But can work with just standard dies. You must only size about 1/2 of the neck with the bushing to get the best accuracy.

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[DIM]

Thank you all for replying, now I start to think that I took wrong step when I decide to neck turn my brass, it looks like my chamber is a bit loose when I measure fired brass and compare to the ones with bullet seated it has 0.010” – 0.012” variation. I think idea which Woods posted is more suitable for my situation, I would have to batch sort my brass not just by weight but by neck thickness as well. I just thought it could be avoided by outside neck trimming… Does anybody thinks that the brass I neck turned deserves a second chance, since its fire-formed if I play with seating depth it can still be of use?

 

[DIM]

Not familiar with the Forster tool (I use Sinclair's), but I don't like the idea of neckturning without prepping the neck by using an expander mandrel. I'm at the south end of Seneca Lake near Watkins Glen.

Don

Too late I already use Forster original case trimmer and I got the neck turning attachment for it, which comes with neck turning pilot and this
http://www.midwayusa.com/viewProduct/?productnumber=154104

Watkins Glen, nice place, I was going to get Harman pellet stove from Montour Falls, so how’s SGS have you shop at this place, or you go to Mikes?

 

[USSR]

Watkins Glen, nice place, I was going to get Harman pellet stove from Montour Falls, so how’s SGS have you shop at this place, or you go to Mikes?

Haven't been to SGS yet. I go to Mike's because I work in Elmira and it's on the way home.

Don

 

[something vague]

I would still play around a bit with your neck turned brass and see how it shoots in your factory chamber. It's not going to hurt anything except for maybe some accuracy. It will at least teach you something in the process, especially if you are to compare it to some of the same brand of brass that is prepped the exact same way minus the neck turning. To a point, we learn more from doing things wrong than we do from always doing things the right way.

You must only size about 1/2 of the neck with the bushing to get the best accuracy.

I don't know that I neccessarily agree with this proccess. I've tried sizing all sorts of different amounts of my neck and always come back to sizing the whole neck producing the best accuracy. But this is out of factory chambers but one being an extremely tight factory chamber. But to each his own. Saying that you must do this to get the best accuracy is going a little too far IMO.

 

[woods]

I use a Lee Collet Neck Sizer for prepping the necks prior to outside neck turning and it is a snug fit. Unlike most, I am turning for tight chambers and turn all the way and a little into the shoulder to help prevent do-nuts



I turn for .003" neck clearance in the chamber and then use the Forster reamers, which are .003" larger than diameter, after once firing. After firing the .003" outside clearance translates into .003" inside neck clearance and the reamer will be a tight fit




I set the outside blade to just lightly clean up the outside. That way the brass is trapped between the inside reamer and the outside cutter and will take the thickness down .0005" or so




but it will be very very consistant.

 

[DIM]

I have Lee Collet neck seizer set, but I been using RSBC neck seizer, not sure what’s the advantage of the LEE over RSBC. RSBC is not collet, but when I use LEE I see the lines left by the collet on the neck... here what the groups looked like before neck turning

now they more like 0.6" - 0.8"

 

[DIM]

Haven't been to SGS yet. I go to Mike's because I work in Elmira and it's on the way home.

Don

No never made it to SGS, they got interesting website, usually I go to Mikes, but when he’s out I go to the local stores in the valley, NY State tax is not the best one, I was told there is a shop not far from Kennedy’s in East Smithfield PA.