RIP,
You beat me to posting the photographs. You are correct that the three bullets will work with plenty of room within the 0.250” parallel sided freebore specification of the 500 AccRel ST…

I had to leave for a while or I’d have already posted the photographs. Before departing, I’d enlarged these photographs to 8½”x11” in size and measured closely where the bullet taper began as well as where the engraving ended. I ran the approximate dimensions for the simulated bullet in QD and determined that yes they all fit with plenty of clearance in the 500 AccRel ST. Also chasing through Michael’s DR notes, the 500 NE strain gauge compilation sheet identified the Woodleigh bullets as being 0.509” in diameter.

Ulrik and Hatting,
I applogize for any angst or other problems I may have caused either of you.

again, gents, i strongly suggest a minimum of one caliber .. we are changing a perfectly functional design for one bullet -- i just think its over reacting to do that far

quote:

Originally posted by jeffeosso:
again, gents, i strongly suggest a minimum of one caliber .. we are changing a perfectly functional design for one bullet -- i just think its over reacting to do that far

Jeffe,

Although I do not have the exact dimensions of the 570gr Woodleigh FMJ I did do photographic 8½”x11” enlargements of Michael's bullet postings from page 49 TBP thread. If I'm even close with my bullet measurements and where ogive radius begins then there is plenty of throat clearance for the FMJ with a zero-inch parallel sided freebore...just using the 0.0135" length of the 45º neck chamfer and the 0.210” length of the 1º30’ throat angle for a 0.2235” total length… So using the 0.250” parallel sided freebore of Ulrik’s current specification we have 0.2635” freebore + neck chamfer plus the 0.210” length of the 1º30’ throat angle for a 0.4735” total length.

If you possess the 570gr Woodleigh FMJ and SN and are willing to measure those up I’d be pleased to redo my simulated 570gr Woodleigh bullets in QD and rerun the chamber/cartridge clearance collision points.

I do agree with you though, if one intends to use the long/heavy milsurp 50 BMG bullets then a one caliber (0.510") parallel sided freebore would be required.

quote:

Originally posted by capoward:
RIP,
You beat me to posting the photographs. You are correct that the three bullets will work with plenty of room within the 0.250” parallel sided freebore specification of the 500 AccRel ST…

I had to leave for a while or I’d have already posted the photographs. Before departing, I’d enlarged these photographs to 8½”x11” in size and measured closely where the bullet taper began as well as where the engraving ended. I ran the approximate dimensions for the simulated bullet in QD and determined that yes they all fit with plenty of clearance in the 500 AccRel ST. Also chasing through Michael’s DR notes, the 500 NE strain gauge compilation sheet identified the Woodleigh bullets as being 0.509” in diameter.

Ulrik and Hatting,
I applogize for any angst or other problems I may have caused either of you.

Jim,
We been puzzling at the same time.
I may not have properly considered the neck/collar chamfer, but you have, apparently, and,
thanks for looking up that .509" diameter.

Gilding metal-washed steel jackets are hard on double rifle barrels at full .510" diameter, hence the .509", I guess.

Shorter throat definitely works better with the brass bullets available.

Looks like .250" of freebore is good to optimize brass bullet use.

On a related topic: Why would anyone want to use the Woodleigh FMJ bullets?

quote:

Originally posted by RIP:

quote:

Originally posted by capoward:
RIP,
You beat me to posting the photographs. You are correct that the three bullets will work with plenty of room within the 0.250” parallel sided freebore specification of the 500 AccRel ST…

I had to leave for a while or I’d have already posted the photographs. Before departing, I’d enlarged these photographs to 8½”x11” in size and measured closely where the bullet taper began as well as where the engraving ended. I ran the approximate dimensions for the simulated bullet in QD and determined that yes they all fit with plenty of clearance in the 500 AccRel ST. Also chasing through Michael’s DR notes, the 500 NE strain gauge compilation sheet identified the Woodleigh bullets as being 0.509” in diameter.

Ulrik and Hatting,
I applogize for any angst or other problems I may have caused either of you.

Jim,
We been puzzling at the same time.

Thanks for looking up that .509" diameter.

Shorter throat definitely works better with the brass bullets available.

Looks like .250" of freebore is good to optimize brass bullet use.

On a related topic: Why would anyone want to use the Woodleigh FMJ bullets?

RIP,

Yes we have; I just wish I'd have remembered to ask Michael early yesterday to measure up those Woodleigh bullets for us then we'd have exact measurements to puzzle with.

quote:

On a related topic: Why would anyone want to use the Woodleigh FMJ bullets?

I don't know! Perhaps someone has access to .510 Woodleigh blems at sale price to use for practice; similar to our periodic access to the Hornady 500gr .500 FP-XTP blems bullets on sale for practice with our .500s.

Hum...reminds me, I need to chuck up my point die and start making RN bullets out of my FN FP-STP bullets for practice. One of the few times RN bullets are worth using.

I agree, shorter throat is definately good...though we must remember that Michael's rifles do just fine accuracy wise with their 0.375" p-s freebore. I think between the two cartridges series we've identified the min/max specification range for parallel-sided freebore for the .500 caliber as well as any closely related calibers. Heck I even used 0.252" as my p-s freebore specification on my .423/338 Lapua Magnum and it works great with my CEB BBW#13s and MTH bullets - plenty of bullet clearance!

quote:

Originally posted by RIP:

Shorter throat definitely works better with the brass bullets available.

Looks like .250" of freebore is good to optimize brass bullet use.

On a related topic: Why would anyone want to use the Woodleigh FMJ bullets?

AGREE !!

Actually guys, you will be giving up seating milsurp bullets on the crimp and more than likely forgoing barnes tsx and banded solids at .250.

THIS IS NOT A BENCH ROUND. There I said it. Seating a big bite round close to the rifling is not the brightest path. This is a higher pressure round than the ones it is being compared to. We all know this going in as the case is smaller. Jamming the bullet into the lands WILL cause pressure spikes


I am not deadset against a shorter neck. I think changin the round to allow ONE bullet type to shoot MARGINALLY better (feet of penetration and all) isn't what is normally done. The round defeated the construction of the bullet. Or the bullet showed a flaw in the design. Doesn't matter.

.250 will more than likely leave this throated for less bullets than you could use. Want to seat longer than 3.35 well now you could have pressure problems


The ONLY two cases this should be compared to for throat are the 50 peacekeeper and 495 asquare.

Have a look at the peacekeeper


I am not saying the throat is correct. It's not wrong, but it could function shorter. I don't believe going to the radical short end is the answer. But please mark the barrel and reamer with an identifier therefore we would know all loads in the st will be safe in the normal. But not always the other way


Funny thing is most people want longer throats into faster when they modify guns. And ALL ackley improved and weatherby rounds have longer throats than the "parent" round

Jeffe-
Just remember that it was not just one bullet type... - the Barnes Banded solids stripped as well down to .500" diameter / bore size - not only the CEB#13`s...

I think we will end up with the .375" freebore, but we will see.. We will start with .250" and increase until satisfied. I want to be able to use all available hunting bullets in my 500 AccRel (ST) though 99,9% will be CEB and Barnes bullets...

Screw changing the throat; it sounds like a job for gain-twist rifling. Then all these ands, ifs or buts become non-issues.

Ok… Today’s discussion regarding the optimum, or perhaps the optimum range, of parallel-sided freebore for the new 500 AccRel ST cartridge…

And question of the day, “Will a 0.250” P-S freebore eliminate the ability to use the Barnes .510 BND SLD and TSX bullets?”

As I do not have the data points to create the Barnes .510 BND SLD and TSX bullets, I cannot answer that particular question. I have generated a 570gr .510 Woodleigh FMJ bullet (actual diameter of 0.509”)

So only having that specific bullet I’ll attempt to answer this question, “What is the maximum COAL (cartridge overall length) before the bullet ogive/barrel land collision point (defined as when the 0.509”-0.500” section of the bullet ogive touches the 1º30’ throat angle grooving): occurs?”

Here’s what I come up with:
500 AccRel with 570gr .510 Woodleigh FMJ bullet (only facsimile .510 caliber bullet that I have in QD)
Zero” Freebore:
1) 0.0135” Neck Chamfer Length
2) 0.0000” Freebore Length
3) 0.2100” 1º30’ Throat Angle Length
4) 0.2235” Total Length Neck Chamfer to Bore Diameter
5) 2.6500” Case Overall Length
6)3.5853” COAL Before Bullet Nose Touches Lands
7) 0.4007” Bullet Seated Within Case Neck

0.250” Freebore:
1) 0.0135” Neck Chamfer Height
2) 0.2500” Freebore Length
3) 0.2100” 1º30’ Throat Angle Length
4) 0.4735” Total Length Neck Chamfer to Bore Diameter
5) 2.6500” Case Overall Length
6)3.8353” COAL Before Bullet Nose Touches Lands
7) 0.1507” Bullet Seated Within Case Neck

I would love to generate facsimile 570gr .510 Barnes BND SLD and TSX bullets but I do not own any .510 caliber bullets… So anyone willing to PM me the .510 caliber Barnes bullet measurements?

In fact, though I possess CEB BBW#13 FN Solid and HP NonCon bullets in .585 and .620 caliber I do not possess any CEB .510 caliber bullets either so cannot generate those either. So anyone willing to PM me the .510 caliber CEB bullet measurements?

Before I sign off to continue on today’s chores… Perhaps a few comment are in order…

RIP’s .500/338 Lapua Magnum (aka: 49-10, aka: 12.7x68 Magnum) is a .500 caliber cartridge with a 0.252” parallel-sided freebore specification.
Case Specification = 2.65”
Case Trimmed Length = 2.647” (case length used for RIP’s shooting and photographs)



Something to note… The heavy weight .500 caliber CEB BBW#13 bullets are designed with a 0.563”* smooth nose length. The heavy weight non-.500 caliber CEB BBW#13 bullets typically have a smooth nose length right at 0.682”* in length – a typical 0.029” longer smooth nose surface length. And the bullet OAL and location of the upper band between the CEB BBW#13 bullets and the Barnes BND SLD bullets are extremely close in dimensions. So if the CEB BBW#13 bullet cartridge combo has sufficient throat clearance then the Barnes BND SLD cartridge combo will also have sufficient throat clearance.

*Note: Best measurements I could do with my digital calipers…

quote:

Originally posted by capoward:

RIP’s .500/338 Lapua Magnum (aka: 49-10, aka: 12.7x68 Magnum) is a .500 caliber cartridge with a 0.252” parallel-sided freebore specification.
Case Specification = 2.65”
Case Trimmed Length = 2.647” (case length used for RIP’s shooting and photographs)

Jim,

Thanks for posting that pretty picture of 49-10 dummies above.
No help from me today on bullet measurements, sorry,
just clarification of specs on the "other 500."

Max brass length is 2.657", trim-to length is 2.647".

The cartridge is properly named only like this: 12.7X68 49-10
No Magnum.
No Tornado.
But anyone can call it whatever they like, just so they know that they are talking about perfection.

Some artiste's like to change the names of their creations to a simple symbolic representation:

why are we being "dumb" about this??

load some TSX bullets -0.25, -0.35, -0.51, -0.65, and -0.85 off the lands and see if they still strip out....

not a penny has to be spent on reamers or barrels, and we get the results in one day, rather than weeks

that make sense?

quote:

Originally posted by jeffeosso:
why are we being "dumb" about this??

load some TSX bullets -0.25, -0.35, -0.51, -0.65, and -0.85 off the lands and see if they still strip out....

not a penny has to be spent on reamers or barrels, and we get the results in one day, rather than weeks

that make sense?

Dumb you say, jeffeosso?
Speak for yourself!


Jeez!
Copper TSX's don't "strip out" even in the "dumb" excessive free bore length!!!!!

They just shoot with degraded accuracy and velocity.

They "crap out."

The more slippery brass bullets are the ones that "strip out" AND "crap out" even worse in the "DUMB" 1.250" freebore length.

It is OK to learn something here.

OK to admit error.

I do it all the time.

jeffeosso's advice on throat:

quote:

Originally posted by jeffeosso:
why are we being "dumb" about this??

load some TSX bullets -0.25, -0.35, -0.51, -0.65, and -0.85 off the lands and see if they still strip out....

not a penny has to be spent on reamers or barrels, and we get the results in one day, rather than weeks

that make sense?

How does one load a TSX 0.25" off of the lands?

I could even try retesting some brass non-cons, but there're all out the neck.

quote:

Originally posted by 416Tanzan:

quote:

Originally posted by jeffeosso:
why are we being "dumb" about this??

load some TSX bullets -0.25, -0.35, -0.51, -0.65, and -0.85 off the lands and see if they still strip out....

not a penny has to be spent on reamers or barrels, and we get the results in one day, rather than weeks

that make sense?

How does one load a TSX 0.25" off of the lands?

I could even try retesting some brass non-cons, but there're all out the neck.

416Tanzan,
Thanks for pointing out another jackass comment from jeffeosso.
I guess you are supposed to carefully push the TSX separately into that 1.25" freebore until the ogive of the nose gets about halfway into the leade.
Use a 3/8" wooden dowel to do this.
Sort of a jackass ramrod.
That ought to be about 0.25" off the lands.
Then careful not to move the level rifle at the bench while you load the primed and charged case (foam plug to keep the powder in place),
into the chamber behind the bullet.

More precise method:
Point muzzle of "500 AccRel Jackass Throat" rifle downward.
Open action and drop bullet down into barrel.
It will come to rest on lands.
Tap bullet lightly into lands with jackass ramrod.
Then level the rifle at bench.
Then push jackass ramrod down the muzzle end of the bore.
Measure length of rod in bore.
Push rod 1/4" further into the bore from muzzle end.
The TSX is now 0.25" off the lands.
Don't forget to remove jackass ramrod from bore before loading a charged, bullet-less case into the chamber for test fire.
Do not jiggle the rifle too much as bullet will slide out of location .25" from lands,
thus invalidating the scientific value of the test.
Lock and load the jackass way.

RIP

While I appreciate the humor, and I'm sure Jeffeoso does,

you've got to admit that the 500AccR is a beautiful and efficient case design.

There's even a 49-10 look alike.

We'll get the .510" version working.

Hey Tan,

The 500 AccRel definately is a great case design and yes the RIP's 49-10 is extremely close dimensionally... Only dispute is what the proper freebore should be...hunting bullet w/o milsurp bullets and milsurp bullets w/hunting bullets and (I guess) the question of freebore beyond that necessary for milsurp bullets. Personally I believe had Jeffe stayed with a 1-caliber freebore for the 500 AccRel we'd not be having any of these conversations...

On the other end of things, I've no idea the background behind the sniping between Jeffe and RIP nor do I believe I want to know as I figure it's none of my business so I stay out do it.

No background, just common sense ignored by jeffeosso.

Truly, the 500 Accurate Reloading is a great cartridge design.

jeffeosso made a booboo on the throat, and does not want to admit it,
and calls us dumb?

Existing reamers can be fixed for $30 by reamer maker?


Hence the jackass picture has been dredged up.

quote:

Existing reamers can be fixed for $30 by reamer maker?

That is what I was quoted earlier this year...might be a little more now but certainly not an astronomical amount...

$30 dollars for touching up a reamer is not the big expense although it does require the agreement of a reamer owner!

the big expense is for those of us who may rebarrel. I'm guessing that it will run $600-700 after the barrel lug and sights are installed.

I'm going to be doing some accuracy testing over the next 2-3 weeks and when done I'll decide on whether or not to rebarrel or use the yet to be produced light, tipped, non-con .510" or Raptor, or just stay with traditional .510" loads and maybe push for a sleek copper replacement for the old GSC.

You will be plagued by inaccuracy and lower than possible velocity
no matter what bullets and no matter how much of what powders you try.
You will waste a lot of expensive bullets testing for naught.
Cut your losses.
Rebarrel.

quote:

Originally posted by RIP:
You will be plagued by inaccuracy and lower than possible velocity
no matter what bullets and no matter how much of what powders you try.
You will waste a lot of expensive bullets testing for naught.
Cut your losses.
Rebarrel.

Well, I do want to do a little more shooting before rebarreling.

AND it would be nice if McGowen had a reamer before I rebarrel.

Actually there is no actual proof of loss of accuracy or velocity or penetration Ron. I would appreciate it if you could stick to facts. What is trying to be resolved is the apparent stripping of certain banded bore riding bullets. That behavior is not seen in any other type of bullet

I realize you have several axes to grind with me but why don't you stop attacking the cartridge ? The design may not work great with a great design of a bullet. Fine. Let's verify. However you have the role of critic in this experiment being neither owner of one of the rifles or designer of the cartridge. You don't have a dog in the right so why are you flinging insults?

I am attacking only the throat on the reamer of an otherwise fine cartridge.
It is totally ridiculous.
No good reason for it.
Two and one-half times bore diameter of parallel-sided free bore length:
Deserves attack.

Actually, people often went up to three diameters 50 years ago when trying to boost a cartridge's power.

They noted that sometimes accuracy would start to fall off after double calibre and more frequently after three calibre freebore, so that 3-diameter was considered the practical limit.

Tan,

It definately is an expensive proposition to rebarrel with adding the cost of a barrel lug and sights. Check your long range accuracy with available copper spitzer bullets and if satisfactory then just get a few guys together for a bulk order of the CEB BBW#13 bullets cut from copper... Michael used copper Lehigh bullets for many years in his .500s up until he and Sam developed the brass BBW#13s...

Or if you don't want the extra expense of copper, and don't want to rebarrel, you can always slow the 570gr velocity down to 500 NE velocities - I don't believe Ulrik had abraided bands at that velocity...

quote:

Originally posted by 416Tanzan:
Actually, people often went up to three diameters 50 years ago when trying to boost a cartridge's power.

They noted that sometimes accuracy would start to fall off after double calibre and more frequently after three calibre freebore, so that 3-diameter was considered the practical limit.

Betcha they weren't using brass bullets in those 3-caliber freebore barrels...

Tan,

Why not phone the folks at NF to determine if they still offer their bonded semi-spitzer SS bullets in .510 caliber... They no list on their website the CPS and FPS bullets in 535gr, 570gr, and 600gr weights - all in copper construction - so if they do offer a matching SS in the 1st two bullet weights you should be good to go.

Just a thought...

Oh yes - just remembered... I seem to recollect reading a couple of years ago that they were redoing their .510 caliber SS dies so that the bullets would be bore-riding like the CPS and FPS bullets but that their original nose shape SS would be available during the change over. I don't recollect ever reading anything about the new SS dies being put into use so perhaps that'd be something to discuss with them...

quote:

Originally posted by capoward:
Tan,

Why not phone the folks at NF to determine if they still offer their bonded semi-spitzer SS bullets in .510 caliber... They no list on their website the CPS and FPS bullets in 535gr, 570gr, and 600gr weights - all in copper construction - so if they do offer a matching SS in the 1st two bullet weights you should be good to go.

Just a thought...

Oh yes - just remembered... I seem to recollect reading a couple of years ago that they were redoing their .510 caliber SS dies so that the bullets would be bore-riding like the CPS and FPS bullets but that their original nose shape SS would be available during the change over. I don't recollect ever reading anything about the new SS dies being put into use so perhaps that'd be something to discuss with them...

As my son said in discussing this whole problem, the question is not just getting the rifle into shape where it is usable.

After all the extra work of building a non-factory round we want it to do something truly beyond what we could otherwise have done. We can buy a CZ Lott and shoot Raptors. That is pretty good, though we already have hot-loaded 416 Rigbys.

We can certainly shoot 570 gr TSX in 500 AccR. If it is really accurate, we might smile and plan a 450 grain copper bullet and be happy with the freebore. But unless it does something exceptional accuracy-wise, we will want to re-barrel. We also have a charcoal-pepper laminate Boyd's wood-stock to replace the Hogue, should we doubt the stability of the Hogue stock for accuracy. I just bedded the barrel-lug on the 500Accr 'freebore' in the Hogue stock so the next shooting session should give us some data.

I totally understand...

quote:

Originally posted by RIP:
I am attacking only the throat on the reamer of an otherwise fine cartridge.
It is totally ridiculous.
No good reason for it.
Two and one-half times bore diameter of parallel-sided free bore length:
Deserves attack.

IIRC the purpose of the long throat was very specific to the MRC 1999 PH action or others with similar magazine internal length. The long throat allows one to seat 50 cal APTI out far enough to preserve case capacity and still feed from the magazine box, as opposed to being limited to single shots like most other 50 caliber sporting rounds with APTI projectiles. So it's not as if Jeff woke up one morning and made the decision without purpose. It is well documented in early posts describing the round.

I might add that there were no bore riding brass CEB bullets during that early development stage, so beating it up at this late date doesn't accomplish much. If one can afford to build a toy of this nature one can surely afford to get the exact reamer and throat they want.

I wasnt aware of the 1,25" freebore before ordering the reamer.. Didnt check it.. My fault I guess... I would never have proceeded with 1,25" - maximum would be one caliber.. But now I will get an optimum .250" to .375" freebore instead - optimum for all hunting bullets... Mine will never shoot a single milsurp projectile...

Ulrik

quote:

Originally posted by tiggertate:
I might add that there were no bore riding brass CEB bullets during that early development stage, so beating it up at this late date doesn't accomplish much. If one can afford to build a toy of this nature one can surely afford to get the exact reamer and throat they want.

Well - the Barnes Banded Solids are not exactly "bore riding brass bullets" ... And they failed in the 1,25" freebore barrel..

quote:

If one can afford to build a toy of this nature one can surely afford to get the exact reamer and throat they want.

Actually, I was trying to build a low-cost stopping rifle. Available headstamped brass was part of that equation, though negotiable.

Like buffalo, if I knew that the freebore was 1.25" I would have gone with the 49-10 and reforming brass, or asked for a shorter throat reamer from whereever.

What needs to be done these days, is that 49-10 brass should be available and normal throated 500AccR reamers should be available.

quote:

Originally posted by 416Tanzan: normal throated 500AccR reamers should be available.

It soon will be...

I'm sorry if you gents missed the throat dimensions during the early discussions of this cartridge. That was actually the only reason I built mine (as an "entry level" BMG repeater) so different strokes, I guess. I can understand why some people would assume that the throat would be more conventional but the fact was well discussed early on and clearly shown on the reamer drawings. I'm not trying to attack anyone or their decisions. I just think it a bit unfair to attack Jeff when the design and the decisions behind it had a specific purpose different than some others' later purposes.

Point taken on the Barnes bullets.

Well - I will for sure not attack anyone .. I just rebarrel and stay happy... - no problem...

TT,
I admit that although I have Jeff's AR cartridge thread in a PDF file and have read it a few times I most definately missed the discussion regarding the 1.25" P-S freebore. I will re-read the entire tread again today. Definately a good reminder to thoroughly research a cartridge beforehand.

Regarding the 'toys'... I don't believe anyone building a .510 caliber rifle considers it to be a toy...but mistakes can be made. Unfortunately the repair in this circumstance is not a simple hand cutting a longer throat to accomodate a specific bullet it requires a complete re-barrel...

Tan,
My .500 will be barrel marked one side 12.7x68 and the offside with .500/338 Lapua Magnum to assure that I'll always have a semblance of proper headstamped brass. Still not sure were I'll the barrel marked with the 49-10...

Ulrik,
Definately not good to hear that the Barnes BND SLD (copper construction) banding is also abraiding at +2300fps as that just knows the knees out from under potential solution sans re-barrel...

Ok… I went through the following threads today…

416, 458, 470, and 500 AR - the line of AR rounds - dialup warning
http://forums.accuratereloadin.../4711043/m/769108843

500 AR (because calling it the 500 BS wouldn't sell a single one)
http://forums.accuratereloadin...=647105034#647105034

pics added - 500 AR – revisited
http://forums.accuratereloadin.../4711043/m/681106016

500 AR . Thinking about a new Deer Rifle
http://forums.accuratereloadin...961008941#7961008941

…and only found two references to parallel sided freebore – one recommendation by RIP for a .510” P-S freebore – and one comment by Jeffe for a 1.000” P-S freebore… No mention in any of the above threads, or for that matter in any of the threads in the 32-pages of thread references where the 500 AR was mentioned (advanced search).

So guess I didn’t find the historical thread where the 1.25” P-S freebore was specified for the 500 AR… Oh well...

Jim - thanks for the info.. No I wasnt in any way aware of the 1,25" freebore before we ordered the reamer... Thought I had overlooked that info, but maybe not...?