7.62x40 Wilson Tactical Crimping

[Hawk]

Okay, I started this project a couple of years ago and got sidetracked.
I'm baaaaaack!
I have the Accurate mold 31-155W that Josh and Ian designed to fit this caliber. Thanks guys for the time and advice.
I'm powder coating this bullet and trying to use it to fire form brass. The lead is about a 12 Bhn. Casting the bullet, running it thru a .309 Lee push thru sizer after coating. Bullets are slightly out of round measuring .309 x .3095. I may have to get a .308 sizing die. I have about 500 of these. PC may not work on the final loading, but I'm trying to use what I have up.
I had a failure to feed stick in the chamber and had to tap it out from the muzzle.
I also have a Wilson chamber gauge, that I now use to check the loaded rounds.
The trouble I'm having is when loading, the neck on every 5th or 6th round is preventing the round from chambering.
The Hornady two die set that I bought from Wilson sizes the brass fine and all unloaded brass will chamber fine. The seating die does not taper crimp, but wants to roll crimp the brass. The neck at the mouth winds up being about .001" too large on the problem loaded rounds.
I don't have a ball caliper to check the neck thickness, but understand the design of the round allowed for the thicker neck brass due to forming the load from 223 or 5.56 brass. I'm using PPU brass.
I'm thinking that I need a taper crimp to smooth out the necks and let the round chamber, but this being a wildcat, not sure what taper crimp to buy.
Do any of you guys that shoot the 300BO taper crimp your rounds?
Trying to figure out if any .308 taper crimp will work or if, say a .308 Win. will be too deep to work with the 7.62.
Thoughts and advice will be greatly appreciated.

 

[popper]

Even though the 40WT is slightly longer than the BO, I suspect you are using the thick case PPU stuff. My Lee BO set doesn't crimp! It came with the Lee FCD that works fine but would be short for the WT. I use the RCBS hand neck turner for a wall thickness of 0.010", my cast are 0.3085. I mic all my rnds after loading to verify 0.330 max (AR15). The Wilson gauge doesn't check neck dia., at least the 4 that I have. I use it to set the die then it gathers dust. The difference between roll and taper is the angle of the crimp portion of the sizer. When I taper crimp pistol, I crimp just enough to get a shiny ring around the mouth. I crimp by feel, die hits mouth and then just a tad of pressure - no cam over. Are your cases all the same length? PC works fine for me - not sure why you are bothering with fire-forming brass for the WT. The 308W won't work. Actually I don't crimp rifle brass, just remove any bell at the mouth.
My guess, WT set doesn't crimp as jax bullets don't get expanded or flared much. Chamfering the mouth for a boat tail jax probably works fine. Maybe Lee can make you a special FCD? Insert is only 5 mm longer. Or an adapter 'ring' from a 308 case that fits between the shell holder and insert?
You using an M type expander? Pull some cast to make sure they are not sized down by the case - that alloy is pretty soft but the GC may help.

 

[quicksylver]

..maybe you should be looking for a Lee factory crimp die that would work or simply make sure your cases are trimmed and back off the seating die or seat and crimp in two separate stages

 

[Hawk]

Popper,
Correct, the Wilson does not check case neck thickness. I used it to make sure loaded rounds will chamber. Maybe I shouldn't be relying on this, I don't know.
All cases are trimmed to the same length with a Forster case trimmer. Case mouths are chamfered inside and out. The mouths are flared to prevent scraping off the PC coating.
I'm fire forming brass because there is a full grain of difference between fire formed brass and new formed brass as to max loads with any bullet. Once the brass is blown out, the accurate max loads are different. Anyway the bullets I am trying to use are not in fire formed cases.

QS, I want to seat and crimp in two steps, just trying to get a taper crimp die that I know will work with the longer than 300 BO brass.

 

[popper]

not check case neck thickness nor does it check loaded neck OD. That is why I mic mine, can't just poke it out in AR. Understand the fire forming and case vol. Then you need to neck size and probably turn (uniform) the neck too? You should be in the 2400 fps range, I get 2100 with a 145gr. PB (BO). Fastest I've tried, primer pockets go pretty quick after that, even with LC.
https://leeprecision.com/reloading-dies/rifle-dies/factory-crimp-die/
They list 40WT FCD as immediate overrun stock.

 

[Hawk]

Thanks, exactly what I was looking for.

 

[fiver]

I'd turn the necks.

for my 300's one don't care and one gets measured case necks.
when your dealing with that last .001...? [shrug]

 

[Hawk]

I've been loading cast in handguns for 35 years, but this case forming in rifles has me scratching my head.
Okay, I've got some additional info.
No pound cast and I won't be able to do it until after the holidays. Hoping the following info will be enough to help resolve the issues.

PPU .223 brass formed by cutting off the necks, forming in 7.62x40 sizing die and trimming to length:
0.300" inside neck dia.
0.013-0.014" neck thickness at the mouth.

LCOFB formed the same way:
0.306" inside neck dia.
0.010" neck thickness at the mouth

Fire formed brass:
0.333" outside neck dia. at the mouth (Don't really know if this indicates max chamber dia.)

Sierra 125gr. .308 bullets:
0.3078 - 0.3079" ( check 20 bullets to be sure) This surprised me that they are ALL UNDERSIZED.

Sizing 158 gr. cast bullets to 0.309"

Chamber drawing shows mouth dia. of the chamber at 0.334". I know this is not exactly what my neck chamber dia. is.

Seems obvious that the neck wall thickness of the PPU brass is the culprit.
What should the inside neck dia. be to have the correct tension on a cast bullet in a high velocity AR round? 0.002 or 0.003 under cast bullet dia.?
I need to turn the thick PPU brass necks so I wind up with the correct dia. for tension on the cast and J-word boolits, but don't want to over do it.

 

[fiver]

I'd say .334 is pretty close to reality.
so take that, subtract your .310 bullet diameter which leaves you 24 divide by 2 leaving you .0012
that's a zero tolerance case thickness.
you need at least .001 for release so .00115 is tight nuff for a bolt gun, a semi-auto would make me feel a little better at 11.
add .001 if your using a smaller 309 bullet etc.
yep you end up with cases different thicknesses for different bullets.

I wouldn't be too surprised about the bullet diameter, especially for a target type bullet.
they have a jacket and core thin enough to bump up and fill out the grooves when fired into the rifling.
kind of a weird thing about land displacement and bullets most people don't think about.

my 22 cal swage die makes a straight sided section of 223 with a small 224 'ring' at the base.
my 311 swage die is actually 310 for quite a ways with a short parallel 311 section on the bottom of the 170gr bullet, a 150 or smaller just comes out at 310.
my 308 die does the same thing, but with 150's and up, it just extends the 308 'ring'' further down the bullet for anything heavier, and anything 140 on down come out at 307.
I asked for them that way and had to wait and wait and wait for them all to get done like that.

they used to be called accuracy rings back in the old days, and you better have your neck anneal set properly or you end up with problems.

 

[Hawk]

Question:
I have two Forster case trimmers.
Would I be better off buying the exterior neck turning tool from Forster or a hand turning tool from them or RCBS, Sinclair or someone else?
Does anyone have any experience with these tools they would like to share?

 

[Hawk]

They are expensive for such a little gadget!

 

[fiver]

yes they are... LOL.
I gave away my RCBS tool some time back [well loaned it out and ain't seen it since] and ended up lucking into someone having a Lyman they let me have at a good price.
which thankfully I had a turner/lathe for, and more amazingly some spare cutters.

I would prefer a lathe type over a hand unit and would much prefer a powered unit I could control by hand over that.
your trying to make smooth consistent continuous cuts, it's pretty easy to screw that up and make 'threads' if you don't feed the cutter just right.
a little speed and a little lube seems to help.

 

[Hawk]

The Forster runs on their "Lathe type" setup, which seems to me might be a little easier to keep straight. The 7.62x40 seems to have a short neck compared to some of the other calibers, so the Foster might be a better tool for me.
Does turning the necks on other hunting type rounds (.270 Win.) really show much improvement in accuracy or is it really just for tight chamber bench competition guns?

 

[Ian]

Buy the Forster turning attachment if you already have the bench trimmer. It's good kit although fine adjustments are a bitch and the learning curve is rather steep at first. The thumb wheel controls feed rate precisely once you get your fingers programmed to operate it.

 

[waco]

https://www.opticsplanet.com/forster-outside-neck-turner-hand-held.html
I have this one. I like it, but it's a slow process.

 

[fiver]

the problem with the hunting rifles is we are usually looking for ways to fill all that extra space with brass or something.
'something' [chuckle] has included all kinds of tape, home plating processes, and brass rings and.. LOL
[I'm still pissin around with some cases like .0022 thick and thinking about another 308 rifle for the project, especially since I seen some Bergara rifles on sale for 699$ with another 10% off, I need another rifle like I need swamp water in the basement,, but damn]

anyhow:
the benefit to cutting necks is you end up with cases the same thickness all the way around which leads to better more consistent neck tension... if you need it,,,,,,,, .0005 variation in case thickness isn't even on my radar.
,002 is.

 

[Hawk]

Soooo, what I now have to decide is if I want to spend $100 plus dollars for a outside neck turner to save 500 pieces of PPU.223 brass when I have over 3,000 pieces if unused OFLCB? That's $20 per 100 or $0.20 each. Then I wind up with a tool that I probably will never use again.
I might be better off just spending the money buying another 1,000 pieces of 5.56 brass and making another batch of 7.62x40 from those.

 

[fiver]

or on buying another tool or two to measure other stuff.
in the long run your gonna end up with a bunch of reloading tools anyway, it's just a matter of how much your going to use them.

 

[popper]

RCBS is less$ than sinclair, I thought Hornady had a simple hand one but don't see it anymore. You do have to order the mandrel for caliber. I set mine by feeler gauge (mic thingy is worthless), lock it down hard. Got an oversized chuck on an speed controlled elec drill, put the case head in, press the hand tool mandrel into the mouth and uniform to 0.011' (BO) My cast are sized 3085 and I mic all the loads for 0.330 or less neck OD. Even factory BO brass is bad. I use 223 PPU, LC, FC, WW even have some Norma or something - needed uniforming. Maybe takes a minute per case but you only do it once. My mic'd fired brass mouth is 0.333.

 

[Hawk]

Okay, I bought the Forster outside neck turner for the bench trimmer.
Wasn't as expensive as I thought it would be. Now the wait begins for delivery.
I guess I need to buy a Tube Micrometer, also.