quote:

Originally posted by RIP:
That does suggest that the bore diameter of the rifling is about .0001" smaller than the diameter of the supposedly non-bearing nose portion,
or something equally inconsequential.
Cosmetic marking.
I could measure groove diameter from a lead slug of the barrel myself, but measuring the bore diameter requires more than my calipers.
Does the barrel maker specify it to be CIP spec?
And what do Todd's calipers say about the diameter of the nose and the driving bands.
The unmarked shank ahead of the base band is just the design of the bullet.
Tight bore or cosmetically oversize nose of bullet?

The crumbled nose and gash in the side of the one solid: Looks like one of Doc M's concrete block T-rex tests.
So accept that as exceptionally tough elephant anatomy encountered, or question it as metallurgical defect that can happen randomly?
Just sayin' ...

RIP:

Stupid question. Wouldn't the markings on the nose of the bullet indicate that the bullet is being pushed into the rifling when Todd closes his double and wouldn't that result in higher pressures? I had the same trouble with the BBW#13,s in my little 9,3X74 Chapuis so I switched over to the North Fork solids. Nor did I have any trouble with the Barnes flat nose solids in my .470.

The CEB #13s nose projections were designed to be small enough to clear the tightest bores originally. However they were not designed to have a lot of slop either. Maybe the barrel makers can't convert metric to standard or just don't care about bore diameter. I'd measure the bores in your gun if you are having problems and call Cutting Edge if the bullets are too big.

Sam

Dave,

I remember that discussion very well. Tested them in my 9.3 when you brought it up. It didn't cause an issue in my 9.3 or my Merkel 500NE at the time.

I didn't notice any issue closing the 577 either but your post lead me to check it just now. I took the rifle apart so that the ejectors are down flat, placed the round in the chambers and NO, there is no issue. The rounds sit flat on the rims so I don't think the bullets are in contact with the lands at that point.

I just measured the 577NE bullets. Forward of the driving bands .573"; on the driving bands .585", between the 3rd and 4th bands .568". So RIP is correct in that they are designed a bit larger in diameter forward of the bands. It just so happens that in my rifle, there is the slightest contact made with the lands forward of the bands. Doesn't seem to be an issue however.

Todd and Dave,
The CIP specs for these old Nitro Express cartridges often leave me

Consider those for the 577 N.E. 3":

Bullet diameter maximum: 14.83mm = 0.5838582" = 0.584", not .585"

Barrel minimums:
bore/land diameter minimum: 14.55mm = 0.5728" = 0.573" not .577"
groove diameter minimum: 14.85mm = 0.5819" = 0.582" not .585"
Twist = 762.00mm = 1:30"





So there is some room in the leade-only throat for the bullets to chamber, as Todd seems to indicate,
and they might do so with no marking of the bore-riding bullet nose until they begin moving into the leade after ignition.
Actual chamber is hopefully larger than these minimums, in the leade area.

I wonder what barrel maker made the barrels for the VC .577 NE?
Any of the specs I see are .585" for grooves (Pac-Nor),
which is consistent with a CIP minimum of .582",
and very good considering .584" CIP bullet maximum.
I don't have any barrel maker specs for bore diameter, but it is generally assumed to be .577" for the common barrel,
also consistent with a CIP minimum of .573".

Todd's barrel must be very close to .573" bore/land diameter if it is marking the .573"-diameter bore-riding nose so superficially.
If the barrel was a .585"/.577" groove/bore as I thought was common, it would not mark the nose like that.
Just a nicely tight barrel from VC.
Maybe Todd can recover a bullet from each barrel and see if both barrels do that.
Any differences must be on the order of .0001" to .0003" by SWAG.

Some great info there RIP. I'll try to recover a couple of bullets from both barrels and we can take a look. Might not get to it right away as the Whitetail season is in full swing right now and for some reason, the other hunters frown on shooting at the ranch's range during the season. Might sneak in a few shots one day soon however!!

Todd,
I understand the problem with range shooting during deer season.
It is because of the yayhoos hunting deer around the range.
You might be the one getting shot if you go to the range.
I got by with doing it with special permission and the keys to the range, between noon and 1 pm and making it quick,
deer hunters go to lunch too, and I did not get shot.

I did find that Lothar Walther .577 NE and .585 Nyati barrels have .573" bore/land and .582" groove diameters,
8 grooves, and 1:20" twist.
From LW web site:

http://www.lothar-walther.com/377.php

Hey Rip,

Yep, damned "yayhoos" hunting during hunting season. Go figure!! BTW, this here yayhoo saw the largest Whitetail deer he has seen in 43 years of antler addiction on Sunday of this past week. Went thru the gate, closed it, got into my truck, put it in gear, looked up to see this old boy standing in the road 40 yards ahead trying to figure out WTF I was doing! Put the binos on him and checked him out real good. I'm thinking maybe 180" or so which isn't bad at all for a free range deer in North Central Texas! Got the rifle, loaded it, and then tried to figure out how to get out and away from the truck without spooking him. I wasn't going to shoot this great beast from the truck. Nope! No Way! What would have been the point as that ain't huntn, ya know. Decided to let him pass until next time. But I do know he exists now and I've seen him on at least one of his travel routes. If I don't learn his patterns this year, maybe I'll figure him out next year. Then hanging him on the wall will mean something!!

Sorry the the off topic rant but I got a little "Buck Fever" there for a moment. Yep, I'm with you. A quick trip to the range during the middle of the day, probably the middle of the week as well, and I'll try to get some additional bullets.

RIP, I'm not as involved with wildcatting and such as you are but I have a question about your numbers. In the posts above, you mentioned that the max diameter for the 577 is actually .584" not .585". Also, .583 bore/land as a minimum. The .583" min. is probably no issue, but do you think Dan at CEB should make adjustments to the 577 bullets since I measured .585" across the bands, this being .001" larger than the maximum you uncovered?

Todd,

Allow me to rant a bit off topic too!
This morning I was driving along the Western Kentucky Parkway doing about 70-75 mph at 6:11 AM CST when a monster buck trotted across the 4-lane.
His rump cleared the pavement about 50 feet before I got to him, no time to stop.
Close call!
I swear he was pushing 180 inches too, with a lot of palmation and spread and points.
Darned Dangerous Whitetails!!!
Last year a stupid young one froze in the headlights and I was able to brake under control in a 55 mph zone at 4 AM and rolled into him, just tipping him over with my bumper.
He got up off the pavement and ran off!!!
I have totaled two cars and killed two deer, one every 22 years, since 1981.
I am due to kill the third by automobile in 2025,
if my luck holds up.

Back to topic:

You should measure that solid that was not damaged much.
On the bands you have slugged the barrel to show the groove diameter.
Should be just like slugging with a lead slug.
If the fired bullet is less than .585" then your groove diameter is smaller than the .585" diameter of the unfired bullet driving bands.

Heck, measure the marked nose and see if you can tell if it is less than .573" on the nose markings.

If you have an even number of grooves in the barrel, you will be able to get the slugged diameter of the grooves from the fired brass bullet that is not deformed except for the rifling marks.

I suspect you have a minimum spec barrel.
It might be .573" bore and .582" groove.

The old CIP specs must be for the old cup-and-core softs and jacketed solids.
With solid brass bullets, I would want them to be no greater than groove diameter on the driving bands.
That would be whatever your rifle barrels slug, measured from the fired brass solids,
or a lead slug driven down the barrel with a wooden dowel, or mild steel rod, of appropriate size, whatever it takes.

Maybe ask for a .5720"-.5725", or .5720" +.0005"/-0.0000" nose diameter to be a bore rider nose.

So, homework when you can get to it.
One CEB solid from each barrel, fired into 5-gallon Homer buckets of water (sealed lids)lined up end to end in a train on the ground or on a long table/platform, see how many it takes to stop the solids.
I will guess 7 buckets in a row.
Or just shoot into a swimming pool at the deep end.
Then measure the fired bullets.
Or just slug the barrels with lead slug for groove diameter.
We know your bore diameter is very close to .573".

It only takes 3 Homer buckets of water to catch most softs from a rifle.
Will take more for a solid.
How many for a CEB .577 NE solid would be interesting to know.

RIP,

As always, good info Sir!!

The fired bullets, both the "pristine" solid and the Non-Con. Across the bands is now .581" from the unfired .585"! The nose on the "pristine" is still .573". This is of course from the right barrel. I'll need to get to the homework assignment to confirm the left barrel as well. Interesting stuff!!

Shoot left barrel into swimming pool and you are done.



So the bands were sheared/smeared in the grooves between the rifling marks of the lands,
decreased from .585" to .581",
and the nose is still .573" and only cosmetically marked.

Seems to indicate a barrel of .581" groove and .573" bore.
Tight.

Would not the consensus be that you need custom bullets for that double rifle?

Would kind of seem that way! BTW, do you have a pool I can shoot my 577 into?!!

Sorry,
No cement ponds in my yard, and I even have to truck the Homer buckets out to the country and fill them from a frog pond to do my bullet catching.
That is why I do it so infrequently.

Todd,
Easiest thing to do:
Find a pure lead round ball about .585" to .600" diameter,
or a fishing sinker, or lead cylinder or slug of appropriate size,
just so it is over .585" diameter and small enough to drop into the chamber/breech end of the disassembled double rifle bores,
one for each barrel.
Soft lead slug.

Drive it through with a 1/2"-diameter wooden dowel, or brass rod, or mild steel rod, and a mallet,
from chamber to muzzle.

Measure the groove diameter of each barrel thataway,
by applying your calipers to the lead slugs that emerge from the muzzles.
Or shoot that left barrel into a swimming pool.

Will do RIP.

I'm intrigued at this point! I'm thinking the lead slug might be the best method at this point. Do you remember a few threads here where CEB bullets, and maybe some other bore riders such as NF and the Barnes Banded Solid were posted showing almost NO engraving after recovery? IIRC, it seems those bullets appeared to have almost all of the bands sheared off.

I don't remember what the outcome of those discussions were at this point. Is it possible those rifles had a "tight" barrel as well causing the shear / wiping of the bands? Really just thinking out loud here but is there any connection to be drawn between those bullets with the bands wiped off and my bullet / rifle combo?

It would be interesting to see if Sam and Michael have those CEB bullets tested in Sam's VC 577NE. If so, I wonder what they measure? Same bullets, same caliber, same rifle manufacturer. Same measurements?

quote:

It would be interesting to see if Sam and Michael have those CEB bullets tested in Sam's VC 577NE. If so, I wonder what they measure? Same bullets, same caliber, same rifle manufacturer. Same measurements?

Todd

I have all those bullets in the lab, when I return this week I can take a look and some measurements for
you.

Michael

I have some too and a 577 to shoot them in. I'll try to take a look at it.

Todd:

I just think it is those darned VCs. The barrel ain't round inside

Todd,
Your bullets look way different than the case of Ulrik's 500 AccRel bullets, CEB brass,
fired in a very long parallel-sided free-bore throat (plus leade) with a fast twist barrel and higher velocity,
where the bullets got a run at the rifling and possibly sheared bands down to bore size, IIRC, showed no rifling pattern engraving.

Yours show good rifling with only band diameter reduction by .004" inch, and cosmetic marking of the .573" bore-riding nose.
As if it squeezed down and spun properly engaged in a .573-bore/.581-groove barrel.
Or is that .573"/.582"?

While you are at it, check the twist and see if it is a 1:20" like Lothar Walther makes.
Use a long, ball-bearing-handled, cleaning rod that spins freely on the handle with a tight fitting bore brush or tightly patched jag that will follow the rifling.
Put a piece of tape on the cleaning rod (near the handle) and a Sharpie mark on the tape, or a tab of tape standing up radially on the rod as a marker.
Mark the rod (with Sharpie at point near breech) when the spin marker is first starting to rotate (brush/jag engaged).
Mark the rod again at same reference point near breech after one revolution of the rod.
When the tape marker spins one revolution as you push the rod 20" down the bore, you have a 1:20" twist.
I am sure you will get the hang of it, or maybe you have done it before?

Just eyeballing the rifling marks on the bullet, it looks faster than the 1:30" CIP standard,
and that is good, IMHO.
Does VC use LW barrels?
Did any info come with the rifle or can you ask VC for the barrel specs?

I am now wondering if the compression of the bullet going from .585" down to .581" bumps up the .573"-diameter bore-riding nose a few 10-thous',
enough to mark the nose as it squeezes down, until the bands shear, and the bullet relaxes back to .573 in the nose?

Brass cases expand and spring back after firing,
I wonder if brass bullets do a wee bit of that too?
Bump up/obturate under pressure then spring back ... on the order of 1/10,000th inch?

Maybe the "bump-up" of the entire bullet results in the .585" bands shearing down to .582" groove diameter while going down the bore under pressure,
then at rest the band diameter "relaxes" down to .581" diameter,
as the compressed bullet stretches out lengthwise and contracts in diameter when the pressure is off?

Just thinking, don't know if that is possible or not.
Barrel steel rifling might expand and spring back on the same order of magnitude too, steel has some elasticity,
but is harder and less elastic than brass, I guess.
Where is a metallurgist when you need him?

Slugging the bores will be informative.

Get the bores really clean, spotless and dry, then use a saturated patch with a good oil like Break Free CLP
to lubricate the bores lightly before you slug them with a pure lead slug or ball big enough.

Good guidance there RIP. I've done the barrel twist rate test before so I'll check that out as well. If we can get Ken from Kebco to comment, he will probably know the VC barrel information such as who makes them and standard specs. There wasn't any other info with the rifle when I received it. It was owned previously by Aaron Neilson and I'm not sure if he was the original owner or not.

But in any event, some good homework assignments you gave me there.

I couldn't remember what the issue was with the lightly engraved bullets and the sheared bands. Sounds like that was quite different now that you've shed some light on it. All very interesting and I'm anxious to see what Sam's gun did as well.

Todd

when you slug the bore you may use a Dry silicon spray if you can get it.

It dries into invisible, yet slippery surface. More precise slug outcome.

Pyzda

RIP

You should be a well paid Internal ballistic scientist.

I find it quiet amazing, that some rifle manufacturers can have such big differences in the barrel tolerances and get away with it.

I wonder what would/could happen if the solid monolitic bullet had only one full length solid bearing surface. (no bands)

Personally I think that all rifle and barrel manufacturers should be forced by law and have stated they internal (bore/groove) measurements.

On complete rifles from a manufacturer these (bore/groove) measurements should be stamped next to the Proof marks.

Even more so when they are so much below (the normal industry specified measurements)

Pyzda

Pyzda,
If you say silicone lube, OK, but I have used Break Free CLP for lube before slugging bores, worked well.

Todd,
I am wondering what the diameter of a 20-guage Foster slug is?
Cut a factory loaded shell open?
I think those are soft/pure lead so they obturate well and fly like badminton birdies.
The hollow skirt on the bottom might not be reliable for measuring, but at least some of the leading edge diameter should be good to measure.

Any cast lead bullets or balls of +.585" diameter (or fishing sinkers) to be found?

When you find out the groove diameter,
just get a 30-dollar Lee bullet sizer made (base push-through) to that spec and resize your CEB brass bullets.

I am going to experiment with that for sizing .416-cal to .411-cal for the 400 Whelen.

I had to re-size some GSC copper bullets from +.512" to .510" for the 500 Mbogo. That worked well enough for sub-MOA.

RIP,

Haven't had a chance to look for lead just yet. Been too busy trying to kill bambi's grandfather. Can't get the the sight of that big buck standing in the road the other day out of my head!!

I'll get my homework done. I promise. Damn, saying that brings back memories!

RIP

It was just a suggestion. As long as some lube is used it's perfectly OK for slugging a bore.

When we will start talking about 0.000 01" tolerances I would take the Silicon amongst number of other important measures.

Pyzda

One more thing,

We are too spoiled about the High Tec lubricants, that suppose to do everything better than anything we have ever seen,(so to speak).

However a simple PORK FAT from an ordinary pig will do just about anything the other lubricants will do. At a fraction of the cost.

Slugging a bore, no problem, just buy yourself a pork chop on the way home first. LOL

Pyzda