8mm floppy neck

[nekshot]

I am not really talented at working with old army barrels. I usually rebarrel, feeling more comfortable with factory specs. I dug out a vz24 and loaded some 323470 bullets and shot them for groub. everything was keyholing. I got a midsouth 8mm max and cast those. Wow,237 grains and these are huge and bad looking. Shot them and the keyholing stopped but I noticed the cartridge necks are very large. They measure 356 after ejected. I think specs are around .349 to .351. In my thinking this must be dealt with or I need a new barrel. If I don,t watch it I am needing about 3 new barrels for different actions. Any wisdom for a dummy?

[BABore]

Reform some 30'06 brass to 8mm. I just did some commercial Remington cases and it gained me 0.006" in diameter. Military 30'06 can even get you more. Don't be afraid of shooting a 0.327 or 0.328 boolit in your 0.323 groove bbl. It makes a nice sizing die.

[Bret4207]

Nekshot, I'm a little puzzled as to your concern. A large throat can be dealt with by judicious sizing of your brass. Is it brass life (split necks) you're concerned with?

[BABore]

Nekshot, I'm a little puzzled as to your concern. A large throat can be dealt with by judicious sizing of your brass. Is it brass life (split necks) you're concerned with?

Usually the accuracy problem with a generous chamber neck is the loss of boolit alignment when the case expands. You may have a boolit that is sized just over groove and is engraved when chambered, but the proper sizing only comes into play when the boolit is fully in the bore and the nose engraving only controls the front of the boolit. If the brass has to expand many thousanths to seal, then any control of the boolit's base is lost. Wack it hard with pressure and it can cant anywhich way allowing it to exit the crown unevenly.

To control the rear end, you have to eliminate that slop. Forget the groove diameter and first size to the diameter that will just slip fit into a fired case. This should be from a full powered round of new or once fired brass so normal springback is in play. The second test is will this size boolit fit the thoat and fill it well. Ideally, you want the boolit to slip fit into the fired case, fill the throat, and engrave the nose upon chambering. Get them all and it will shoot. Then there's the real world where chambers are too big and throats are long. Reformed cases will eat up some of that slop in the chamber neck because the brass is thicker as you get down farther into the 30'06 case's body. If the chamber's case neck is really huge, about the best you can do is find the thickest '06 Mil brass you can and reform it, then use the biggest boolit that the throat will handle. Beyond that and you have to play with powders and their ingition profiles to find the ONE that will get the boolit into the bbl gently.

[nekshot]

Bret, someday my kids are gonna get my junk. I have enough wildcat guns , I don't want another special treatment gun. 2 things bothered me. Will this large neck shorten brass life and do I need to open my seat die to match the neck diameter. The gun shot 13 grains reddot ok, but 28 gr 4895 did not seal and spit back. At first I thought this might be a good paper patch gun ( the bore slugs at 324) but I was not sure how to handle neck sizing the cartridge. It really is a nice gun not a beat up junker and I hate to take this barrel off. The bore cleaned up and has great rifling. The only problem to me is how to keep the reloading simple for the next generation.

[nekshot]

BaBore, I have been thinking about your advise, and I can see why military brass would help fill out the bore. Would a Lee collet die opened up be all I would need to load brass after fire forming?

[Rico1950]

nekshot,
With the Lee Collet die you will have to make a larger in diameter mandrel, a thousandth or two under your fired case dimension. Had a similar problem with my K98.
Shot great with the, please excuse, Nosler 180 BT and so so with cast. Bought the Karibiner mold way back and left @ .325" as cast diameter. As far as working the case necks too much, I called RCBS, turns out they will lap the neck area of their dies +.002" for $20.00. It worked for me!

[Bret4207]

If you over size the neck every reload then yes, it'll cause problems. Cracks and splits. Annealing the brass helps and so does partial neck sizing. It's also good to fireform the brass to fit that chamber.

I have a couple that have "big" necks and I honestly haven't had any real problems getting 10-15 reloads out of my brass.

[nekshot]

Ok, thanks fellas I feel more confident to enter into this big neck thing. I am going to look for some 06 military brass and if that still leaves a loose fit for the bullet I believe my options would be to paper patch or try bump the boolit up. I never bumped any but it does intrigue me.

[nekshot]

Success! I pried some 06 military brass from a local gun shop, and sized and cut to length and fire formed them. The cast bullet is almost snug. I just need to bump them a little for a perfect fit. Thanks everyone you helped me from rebarreling a nice gun.

[BABore]

While your at it, take advantage of the excessive chamber length in the neck area. Determine what the chamber length truely is and trim your brass 0.010 to 0.020 short of that. I found that I could chamber a case almost 0.045" longer than standard 8mm brass. It helps shorten up those long throats and gives you a longer case neck for boolit grip and alignment.

[nekshot]

Groan!!!! you would not believe how much neck I cut off getting these to proper length. (per reloading manual) The thought went through my mind this long length would be perfect for this long boolit. By the way, is it possible to buy military brass that is not corroded? I threw a couple of these away because they were too bad to use.

[BABore]

Groan!!!! you would not believe how much neck I cut off getting these to proper length. (per reloading manual) The thought went through my mind this long length would be perfect for this long boolit. By the way, is it possible to buy military brass that is not corroded? I threw a couple of these away because they were too bad to use.

Sure it is, just have to look around some.

An easy way to figure out max neck length is to trim a case to nominal. The cut off a ring from the end maybe 0.080 to 0.100 long using a Dremel. Retrim the shortened neck and deburr it. Deburr the ring as well. Seat a boolit into the case and slide the ring over the boolit nose, trimmed end up. Gently chamber the round and extract. The ring will have contacted the end of the chamber and been seated to the full length. Measure with calipers and then set yout trimmer to 0.010 or so under this amount. You have to pay a bit more attention to case growth as you have less margin for error now.

[nekshot]

Thanks BaBore, I can do that. I was kinda wondering how to do this with out a chamber cast. Will do this weekend and hopefully get some range results.

[Larry Gibson]

nekshot

Will this large neck shorten brass life and do I need to open my seat die to match the neck diameter. That is not that uncommon of a neck size in milsurp 8mms. Use a neck size die or an RCBS X-die for FL sizing for much greater case lie and no trimming. I use WW 8x57 cases and when one neck splits I anneal the case necks. I don't have to do it but every 8 - 10 firings or so, not much different than most other milsurp cases. Reformed cases from '06 are about the same as the necks do get worked quite a bit during firing and resizing.

The gun shot 13 grains reddot ok, but 28 gr 4895 did not seal and spit back. At first I thought this might be a good paper patch gun ( the bore slugs at 324) but I was not sure how to handle neck sizing the cartridge. I size all my 8mm cast bullets at .325 and they shoot very well in all 8mms I used (quite a few over the years). 323470 is a pretty light weight bullet for 28 gr of 4895 unless a 1/2 - 3/4 gr dacron filler is used. I suggest the filler, increase the cahrge (might try both as I use 30 gr H4895 with the dacron filler with that bullet) or switch to 2400, 4227, 4759 or 5744 powder. I also use Hornady GCs and my own (with .014 brass shim stock) and Javelina or one of Lars 50/50 alox type lubes. That Lovern style bullet is quite accurate in most every 8x57 I've used it in, no reason it shouldn't be in you rifle.

It really is a nice gun not a beat up junker and I hate to take this barrel off. The bore cleaned up and has great rifling. The only problem to me is how to keep the reloading simple for the next generation. Try the above suggestions for loads, you may be surprised at how well that rifle will shoot.

BaBore is spot on with how to make a max AOL case guage for your chamber.

Larry Gibson

[StarMetal]

nekshot

Will this large neck shorten brass life and do I need to open my seat die to match the neck diameter. That is not that uncommon of a neck size in milsurp 8mms. Use a neck size die or an RCBS X-die for FL sizing for much greater case lie and no trimming. I use WW 8x57 cases and when one neck splits I anneal the case necks. I don't have to do it but every 8 - 10 firings or so, not much different than most other milsurp cases. Reformed cases from '06 are about the same as the necks do get worked quite a bit during firing and resizing.

The gun shot 13 grains reddot ok, but 28 gr 4895 did not seal and spit back. At first I thought this might be a good paper patch gun ( the bore slugs at 324) but I was not sure how to handle neck sizing the cartridge. I size all my 8mm cast bullets at .325 and they shoot very well in all 8mms I used (quite a few over the years). 323470 is a pretty light weight bullet for 28 gr of 4895 unless a 1/2 - 3/4 gr dacron filler is used. I suggest the filler, increase the cahrge (might try both as I use 30 gr H4895 with the dacron filler with that bullet) or switch to 2400, 4227, 4759 or 5744 powder. I also use Hornady GCs and my own (with .014 brass shim stock) and Javelina or one of Lars 50/50 alox type lubes. That Lovern style bullet is quite accurate in most every 8x57 I've used it in, no reason it shouldn't be in you rifle.

It really is a nice gun not a beat up junker and I hate to take this barrel off. The bore cleaned up and has great rifling. The only problem to me is how to keep the reloading simple for the next generation. Try the above suggestions for loads, you may be surprised at how well that rifle will shoot.

BaBore is spot on with how to make a max AOL case guage for your chamber.

Larry Gibson

Apparently you haven't had any 8mm Mausers with groove diameters running .327 or larger. I can guarantee you that a sized .325 bullet won't should accurately in them. Now take my pristine unissued Yugo 48A with a dead on .323 groove, shoots my .325 bullets superbly, on that you are correct.

With that mention I have been successful getting softer undersized bullets to shoot decent by using Unique loads.

The Lee resizer dies, I think, very easy to lap out the neck portion of the sizer die. I had to do this with my 7.62x54R dies, but they are sold for a dual purpose with Lee, that is to load either .308 bullets or .310 ones.

Both BaBore and I have found out that our Lee 8mm dies don't require any sizing lube to size our fired brass. They are generous to say the least.

[nekshot]

Now I am starting to feel bad about all the barrels I pulled off these guns over the years simply because of my ignorance. Oh well I still have a bunch I can work with. When I saw this max 8 bullet from midsouth I was committed to getting some of these guns to shoot it. Thanks for all the enlightenment.

[Larry Gibson]

Starmetal

Well there you go; I should buy a lot more lottery tickets because I must be the luckiest guy in the world. All of my 6.5 Swede barrels run .266/.267and all of the 8x57 barrels I've run into over the years have run .323/.325. If you've the bad luck to find the larger ones then maybe you do need larger bullets. Nekshot says his barrel slugs at .324 so I guess he's lucky like me.

Larry Gibson

[StarMetal]

Starmetal

Well there you go; I should buy a lot more lottery tickets because I must be the luckiest guy in the world. All of my 6.5 Swede barrels run .266/.267and all of the 8x57 barrels I've run into over the years have run .323/.325. If you've the bad luck to find the larger ones then maybe you do need larger bullets. Nekshot says his barrel slugs at .324 so I guess he's lucky like me.

Larry Gibson

Ask BaBore what the barrel on his recent VZ24 measured at. Like I've said you haven't even touched the groove spectrum of 8mm's yet. Next you'll be telling me all the military 7x57's have grooves running .284-.285.

By the way my Swede runs .267, so what's your point?

Keep it off the pubic forum Larry and put it in pm's. Everyone knows we can't stand one another guts.

More of your Global Warming Bull pucky :takinWiz:

[Buckshot]

http://www.fototime.com/79DAE87BBF8BE29/standard.jpghttp://www.fototime.com/EB6FB73225EA2DD/standard.jpg

.............I have this really nice VZ24/47 ( I think the stock is Elm) and even without running a patched rod down the barrel I could tell it was going to have very strong rifling. When I got it home and cleaned it up it did in fact have a great barrel.

After getting it cleaned up I slugged the barrel with a .325" lube-sized slug. It went down thebarrel a bit too easily and upon inspection you could tell it hadn't bottomed in the grooves. I then took an unsized Lee C329-220-1R, smeared some lube on it and drove it down the barrel. The barrel was .314" x .327"! SHEESH!!! :-) I then took a Lee C338-205-1R, greased her up and drove it in a bit more after a few tries of attempting to chamber an empty case, to make sure I'd get a good throat picture.

I tapped it back out and it has a .329" throat, egads[smilie=w: I made myself a .327" push through die and use the Lee C329-220-1R slug. I lubesize it .329" then shoot it up through the .327" die and it shoots very well. The nose of the slug is a bit larger then ideal as the .314" land is common for 8mm's, but it works the best.

I have 3 Turkish Mausers in 8x57 (M38/46, M38, and M88/35) and all three are perfect at .314" x .324" with .326" throats and shoot a .325" sized cast boolit like a house afire.

................Buckshot

[StarMetal]

http://www.fototime.com/79DAE87BBF8BE29/standard.jpghttp://www.fototime.com/EB6FB73225EA2DD/standard.jpg

.............I have this really nice VZ24/47 ( I think the stock is Elm) and even without running a patched rod down the barrel I could tell it was going to have very strong rifling. When I got it home and cleaned it up it did in fact have a great barrel.

That's funny, I did the same thing with the Lee 329 bullet. I had some left over from when I sold my M95 Steyr.

After getting it cleaned up I slugged the barrel with a .325" lube-sized slug. It went down thebarrel a bit too easily and upon inspection you could tell it hadn't bottomed in the grooves. I then took an unsized Lee C329-220-1R, smeared some lube on it and drove it down the barrel. The barrel was .314" x .327"! SHEESH!!! :-) I then took a Lee C338-205-1R, greased her up and drove it in a bit more after a few tries of attempting to chamber an empty case, to make sure I'd get a good throat picture.

I tapped it back out and it has a .329" throat, egads[smilie=w: I made myself a .327" push through die and use the Lee C329-220-1R slug. I lubesize it .329" then shoot it up through the .327" die and it shoots very well. The nose of the slug is a bit larger then ideal as the .314" land is common for 8mm's, but it works the best.

I have 3 Turkish Mausers in 8x57 (M38/46, M38, and M88/35) and all three are perfect at .314" x .324" with .326" throats and shoot a .325" sized cast boolit like a house afire.

................Buckshot

Well a certain other member will tell you that you can't measure a barrel Rick or or say he's had millions of 8mm Mausers that never had that fat a groove. My recent Hungarian is dead on .327 but I've been able to get it to shoot with BaBores 8mm bullets.

Now my inissued Yugo is a different story with a perfect bore and the groove is .323 and shoots the Lee wonderfully.

[Larry Gibson]

I deleted my last message as starmetal just wants to argue once again. I'll bow out and not ruin another thread with him.

Nekshot

Buckshot has given good advice but I don't think you need to rebarrel or anything else if that is a 324 barrel. My advise still stands and suggest a different powder as recommnded. You should be able to seat the 323470 out so the GC is at the base of the neck. The throat will thus support most of the bullet during ignition and intitial accelleration. With 2400, 4227, 4759 or 5744 you should get very good accuracy in the 1650 - 1800 fps range. That's the last I will say here so if you want further information don't hesitate to PM me.

Larry Gibson

[StarMetal]

I deleted my last message as starmetal just wants to argue once again. I'll bow out and not ruin another thread with him.

Nekshot

Buckshot has given good advice but I don't think you need to rebarrel or anything else if that is a 324 barrel. My advise still stands and suggest a different powder as recommnded. You should be able to seat the 323470 out so the GC is at the base of the neck. The throat will thus support most of the bullet during ignition and intitial accelleration. With 2400, 4227, 4759 or 5744 you should get very good accuracy in the 1650 - 1800 fps range. That's the last I will say here so if you want further information don't hesitate to PM me.

Larry Gibson

No Larry, you'll bow out because you're wrong. There are indeed many 8mm Mausers out there with fatter grooves then what you mentioned. You'll not turn this around to make yourself look better.

Shall we take a poll of all the groove sizes on the board and see what we have among the members? [smilie=w:

[excess650]

My Turk is about .3255" on the groove as near as I can tell, and the leade seems to be about .3262" at the front. The necks on my fired RP cases are similar in size to the OP, but its what I would have expected from a "battle rifle". Over working the necks would be my only concern, but hasn't been a problem as of yet. Despite a less than shiny bore, it seems to shoot very well with some loads.

I've only been doing load testing at 50 yards, but shot a 3 shot group 1-1/2" @100 yards today just to check POI vs where I'm sighted at 50 yards. My eye sight isn't what it was 10 years ago, so I'm pretty pleased so far. I THINK that a bullet that engaged on the nose as well as at the leade would be better aligned, better supported, and more accurate. Unfortunately, the bullets that I've tried are all .314" or less on the nose, and the rifling seems to be worn larger than this. I'll have a better idea after I try the 8mm Maximum mould that I've just ordered.

BTW, the most consistent load that I've found has been 18gr AA 5744 F210 primers, RP cases. This was with my 225gr MM custom, but the Saeco 190gr and NOE 185gr both seemed to want shoot well with the same powder charge.

Does anybody have a 8x57mm pet load that they care to share?

[StarMetal]

My Turk is about .3255" on the groove as near as I can tell, and the leade seems to be about .3262" at the front. The necks on my fired RP cases are similar in size to the OP, but its what I would have expected from a "battle rifle". Over working the necks would be my only concern, but hasn't been a problem as of yet. Despite a less than shiny bore, it seems to shoot very well with some loads.

I've only been doing load testing at 50 yards, but shot a 3 shot group 1-1/2" @100 yards today just to check POI vs where I'm sighted at 50 yards. My eye sight isn't what it was 10 years ago, so I'm pretty pleased so far. I THINK that a bullet that engaged on the nose as well as at the leade would be better aligned, better supported, and more accurate. Unfortunately, the bullets that I've tried are all .314" or less on the nose, and the rifling seems to be worn larger than this. I'll have a better idea after I try the 8mm Maximum mould that I've just ordered.

BTW, the most consistent load that I've found has been 18gr AA 5744 F210 primers, RP cases. This was with my 225gr MM custom, but the Saeco 190gr and NOE 185gr both seemed to want shoot well with the same powder charge.

Does anybody have a 8x57mm pet load that they care to share?

I have a slightly elevated velocity load for that Lee 175 grains bullet that uses surplus 844 powder. When I get into my shop I'll look it up. It's the best that I've shot out of my Yugo Mauser so far.

Using BaBore's fat remake of that Lee I've shooting an inch at 75 yards with iron sights with the Hungarian Mauser I have and the load is 15.0 grains of Unique with a Dacron filler. I tried it both with and without the filler and the filler was much better in my example. The bullets were air cooled and left unsized at .327. My groove is .327 on the button with the Hungarian. The Unique more then likely bumped the bullet enough to get it to fully obturate. The Yugo groove was dead on at .323 and seems easier to get to shoot well.

Bruce took the original barrel off his VZ24 because the groove was so fat, but more importantly his neck was generous enough to let him use fatter bullets. He rebarreled with another Mauser barrel that has a tighter groove and he and I are basically using similar loads with similar results.

[excess650]

I've tried AA 5744 18gr up to 25gr, surplus 4895 from 35-38gr, and AA 4350 from 40-44gr. The best groups seem to be at the lower ends of those powder charges, but not the same kind of accuracy as the 18gr 5744. I have bedded barrel and action with a bit of pressure on the barrel....shortened barrel and stock, no handguard, etc. seemingly with no difference in accuracy compared to the ridiculous inlet that was there when I started. I may back off the 4895 down to 30gr and work up, and revisit AA 4350 in the 38-40gr range.

The AA 4350 loads are thumpers!

I found it interesting that 40gr AA 4350 shot roughly 1-1/2" at 50 yards, 41gr about 2", 42gr about 5", 43gr back to about 1-1/2" and 44gr barely stayed on 8-1/2" x 11"! Immediately after that load I tried the 18gr 5744 "yardstick", and it shot like it always does. I've shot about 100 rounds since it was cleaned, and the 'yardstick" still shoots consitently, but I'm looking for a bit more velocity if possible.

BTW, if you shoot a 7.5x55, try 22gr AA5744. My K31 loves it with the Saeco #315 and 200gr Lee.

[StarMetal]

I've tried AA 5744 18gr up to 25gr, surplus 4895 from 35-38gr, and AA 4350 from 40-44gr. The best groups seem to be at the lower ends of those powder charges, but not the same kind of accuracy as the 18gr 5744. I have bedded barrel and action with a bit of pressure on the barrel....shortened barrel and stock, no handguard, etc. seemingly with no difference in accuracy compared to the ridiculous inlet that was there when I started. I may back off the 4895 down to 30gr and work up, and revisit AA 4350 in the 38-40gr range.

The AA 4350 loads are thumpers!

I found it interesting that 40gr AA 4350 shot roughly 1-1/2" at 50 yards, 41gr about 2", 42gr about 5", 43gr back to about 1-1/2" and 44gr barely stayed on 8-1/2" x 11"! Immediately after that load I tried the 18gr 5744 "yardstick", and it shot like it always does. I've shot about 100 rounds since it was cleaned, and the 'yardstick" still shoots consitently, but I'm looking for a bit more velocity if possible.

BTW, if you shoot a 7.5x55, try 22gr AA5744. My K31 loves it with the Saeco #315 and 200gr Lee.


Okay my load that shoots very good in my Yugo 48A Mauser is 28 grains of surplus powder with the Lee 175 grain bullet, and with a Dacron filler.

[nekshot]

Success! I shot the fireform process and even using the military brass the gun shot in inches instead of feet and no keyholes. The bullets are loose in the cases and I need to mess around with what I can do to snug them up. Any one ever try aluminum foil? I am looking for the easiest way. How do you bump a boolit with out a lubersizer? I only use lee sizers.

[45 2.1]

How do you bump a boolit with out a lubersizer?

Options: Get a mold that casts larger, lap out your present mold to a larger size, Beagle your present mold to cast larger boolits, buy larger boolits or get Buckshot to make you a swage to increase your current boolits size. One of those will do what you want. Of course there are other options, but those usually lead people astray.

[nekshot]

Just finished reloading and shooting the reloads at 60 yards. 5 shots each round gave one and a half inch groubs. At 100 that should be with in 3 inches if we do our part. This sure beats the three feet I had originally. I am going to stop as my son is happy with it. Now I know why I never messed with these before. I don't have the patience for this complicated stuff. Thanks for all your help.