neck reaming

[jrayborn]

I am preparing to form some 7.62x25 brass from .223 brass and may need to ream the necks. I have never done any neck reaming so I'm not sure what the best way to go about this is. Does anyone have any insights on what tools to look for if I find I need them?

Thanks.

[ourflat]

Is this build for a 300 BO? If so, just do a search in the forum or go to the military rifle section and you will find a bunch of info to reform/size and case trimming!

Frank

[spfd1903]

I bought a .311 inside neck reamer from Forster that fits in their hand cranked lathe. I purchased 500 pieces of 7.62 x 25 brass from Starline last Fall, so the .311 reamer is needed to allow larger cast boolits to fit in the mouth. For re-working the .223 brass, the location of the new Tok brass case mouth is in the thicker part of the .223 brass, resulting in an i.d. less than .308 . I believe Forster makes a .309 reamer, if you don't want .311.

[scb]

I've tried reamers that go in a case trimmer both forester and RCBS. I wasn't satisfied with that method. The only method that I tried that works the way I think it should is to bite the bullet and buy the neck reaming die and reamer. I just recently got one from C/H and it's every bit as good as an RCBS and a good bit less expensive. Just my $.02 Oh and FWIW the neck reamers in the old Lee Target loaders worked well too.

[Bullshop]

In necking up in caliber outside neck turning works good if the necks are too thick. In necking down in caliber sometimes inside neck reaming is required. The reason is that in necking down in caliber often produces a " doughnut" or ring of metal that is higher/thicker than the rest of the neck. The doughnut will be located at the neck shoulder juncture at the base of the neck. This doughnut is easily detected by slipping a bullet into a fired case neck. The only way to remove it is to inside neck ream.
If I am understanding correctly you are necking up so if the resulting necks are too thick after sizing outside neck turning will correct the problem.
Necking up seldom requires any neck turning because by going up in caliber you are thinning the neck. If however you are shortening cases past the original neck they may be too thick and need turning.

[jrayborn]

I think I am necking down. The .223 brass gets reduced in size at the 1" length and reduced in diameter substantially to hold the 30 cal 7.62x25 Tokerev bullet. I am pretty sure I need to ream, I can feel the "donut" Bullshop, as when I final trim the brass the Hornady pilot gets tighter the last .030-.040 in. So I was looking for advice on a reaming setup. I have a drillpress...

Anyway I am off to the C H website to take a peek.

Thank you to everyone!

[Bullshop]

My inside neck reaming arrangement has been in use for quite some years now. I use the Forster trimmer assembly for both inside neck reaming and outside neck turning with the proper tools installed for each operation. I bought these tools shortly after I realized that a greater degree of accuracy was possible than what a factory stock Win 94 in 30/30 shooting factory ammo was capable of.
Still learning!

[GRUMPA]

All I use to neck ream is something that looks like a drill press. I get all my reamers from places like MSC supply and they come in so many sizes it isn't funny. I'll never use a bench reamer because with the volume I do it's pointless and slow. I made some of these (7.62x25) cases just recently, fond out the diameter of his boolits needed to be .310 and I just reamed accordingly.

[9.3X62AL]

Specific to the 7.62 x 25 and my ChiCom Tokarev pistol--throat and grooves run .3105", but the tight neck won't chamber a cartridge holding a .311" bullet. Neck reaming did the trick, reducing neck thickness sufficiently to allow safe chambering of a cartridge with proper-sized bullet in place. The .308" Forster neck reamer mounted in the Forster case trimmer does a fine job of this chore. This applied to my home-formed cases derived from W-W 9mm Win Mag brass.

[MBTcustom]

Neck turning creates uniform neck thickness and concentricity. This is because it is piloting off the inside of the neck and cutting the outside to suit. I personally think that neck turning is the more important function because it will create a concentric neck that releases consistently.
However, your boolit might be rolling over speed bumps on the inside of the case, so a light cleanup with a reamer will make it all better.
My thought is that the inner neck condition is not nearly as important because when it's "go baby go" time, the neck releases from around the boolit (yeah it depends on your cartridge) and the boolit is being effected very little by the inside of the neck. Basically, I'm saying that the most effect the inside of the neck can have is at the time the boolit is being seated (which is not to be discounted).
My philosophy as she stands now, is that if a boolit can be seated cleanly in the neck, and pulling it shows no damage, then neck reaming is unnecessary so I do not do it. Just go ahead and use that donut as a nice park bench for your boolit to rest it's buns on. LOL!

[country gent]

I perfer outside turning over neck reaming also for rifle rounds, but it depends on what Im trying to accomplish. On one round I do both when I form the cases. ( since I made the original 500 I havent needed anymore). I neck ream in a die that supports the case and reamer in the same plane on centers. This is for several reasons. 1) a reamer tends to follow the existing hole and dosnt true the neck thickness or concentricity. By supporting the case and reamer you get more accurate results. 2) thin necks will expand around reamer if not supported. As cutting presssures increase a taper can be formed. 3) by hand unsupported you mau not geta straight neck to the case. If there is enough thickness to do it I neck ream .003-.005 small cleaning up the inside of the neck giving the smoother polished reamed finish. I then neck turn to size to obtain loaded round dia wanted or needed. This is done on a piloted turning tool. Neck turning the outside will normally get me .0004-.0005 wall thickness runout. Reaming lighlty first then turning gets me around .0000-.0002 runout in thickness.
Useing a reaming die accomplishes alot of good things. It makes holding cases easier as the die takes care of it. The neck cant expand around the reamer. the reamer is supported in the dies bushing so it dosnt float and cuts straighter and truer. Hand reamers are available from tool supply shops in .001 increments. Remeber when reaming to allow for beck clearence when a bullet is seated. and to allow for the press need to hold the bullet.Neck wall thickness X 2 and bullet dia gives a accurate idea of finished Loaded round dia

[fouronesix]

For me, the only reason I ream is to remove the donut. Otherwise, correctly done outside turning is the best way to establish a certain neck wall thickness or to thin, overly thick neck walls.

[ohland]

Otherwise, correctly done outside turning is the best way to establish a certain neck wall thickness or to thin, overly thick neck walls.

I _assume_ one turns the outside AFTER the case is necksized, that is the case goes back down over the expander plug.

[9.3X62AL]

I _assume_ one turns the outside AFTER the case is necksized, that is the case goes back down over the expander plug.

Generally not, sir. The reaming/turning "rationale" is often to remove metal from the case neck/mouth the thickness of which restricts free bullet release. Forster's instructions specify with their case trimmer-mounted reamers to ream fired/unsized case mouths in their nominal-caliber reamers, the assumption being that fired brass has been expanded fully in the given firearm's chamber and any brass cut by the reamer's assumed "release diameter predication" (usually .002" over bullet diameter) does indeed need removal.

This is not NECESSARILY the way to ALWAYS proceed, though. Citing the example of the reformed 7.62 x 25 cases I made from 9mm Win Mag brass c. 1989, there was a fair amount of metal to displace from those necks. I sized the cases, AND removed the expander assembly prior to running the cases over the reamer. This gave me a bit of "cheat" on the reaming operation, and I netted about .002" more metal removal by so doing. I should emphasize here that I was addressing a unique chamber dimension issue in a ChiCom Tokarev Type 54 pistol (undersized necks). I suspect that such an issue is common to these pistols, though--bullets pulled from Chinese ball ammo show a .307" diameter, but the barrel has .311" grooves and almost .312" throat. .312" boolits run very well to 1300+ FPS (Lyman #313249), 92/6/2 alloy and beeswax/Alox lube. Lee 100 grain RN shoots even better at roughly 1100-1200 FPS......6.8 grains of AA-7 with the Lees, 7.5 grains with the 85 grainers.

[Cowboy_Dan]

It is my understanding that to form 7.62x25 from .223 you need to remove brass from the entire length of the new case. Otherwise, the capacity will be significantly lower and preasure will spike.

I haven't done this myself yet, but I have looked into it in case my Yugo m57 needs me to. I've told my brother to save all of his split necks from his AR just in case. Now I just need some dies to reload the brass I have.

[WRideout]

It is my understanding that to form 7.62x25 from .223 you need to remove brass from the entire length of the new case. Otherwise, the capacity will be significantly lower and preasure will spike.

I haven't done this myself yet, but I have looked into it in case my Yugo m57 needs me to. I've told my brother to save all of his split necks from his AR just in case. Now I just need some dies to reload the brass I have.

I make 7.62x25 from range pickup .223 cases, and the only thing I have noticed is a different point of impact from ones fired in a commercial Tok case. I'm using 6.0 gr of Unique, and the Lee 100 gr RN boolit, and don't have any pressure signs with either.

Wayne

[9.3X62AL]

I went a different route for brass in the 7.62 x 25 initially, opting to reform 9mm Win Mag instead of 223 brass. Since that time, out of curiosity I have reformed 50 223 cases to run in the 7.62 x 25, and they do decent work. Radially, the 223 case is only .006" smaller than is the 7.62 x 25, and the case expands upon the first firing in generally "equal" fashion. These 223-based cases weigh about 4 grains more than Starline commercial cases, so I reduced powder charges about 10% and get good performance.

[flashhole]

This link may help answer some questions. I reform 223 to 221 Fireball. Different cartridge for sure but the steps and the tools may be very similar to what you need to do. I use the K&M reamer/turner.


http://shootersforum.com/showthread.htm?t=54312&highlight=flashhole

[M-Tecs]

Link isn't working for me

[flashhole]

I pasted it in again. It worked for me. Any luck now?

[M-Tecs]

Works now. Thanks

[firefly1957]

I also turn 223/5.56 cases into .221 fireball i have found i get great accuracy this way.
I remove the decapping assembly from my die lube the cases and run them in if i do not remove the decapping assembly i loose cases to the neck expander.
Then i rough trim them and put them back in the die using a reamer in a drill to ream the necks the cases are then final trimmed and annealed and ready to load when i reinstall the neck expander depriming assembly. Last batch i used a drill instead of reamer inside looks good but i have not loaded any yet.