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#1194856 - 05/06/17 06:05 PM 510 Whisper 12.7x48
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
As some know, I have ventured into subsonic Wildcats. This thread will be dedicated to the build of my 510 Whisper.

5 years ago, this project started as a dream. My goals were 1000 grains of projectile at 1000 fps. This was initially driven by getting into 50 Beowulf, however after a few years I figured out the platform would not support my goals.




More to come in terms of loading. As always, use any loads in this thread at your own risk. I accept no responsibility for use of any loads in this thread in your gun. These loads are perfectly safe in my firearm.

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#1195445 - 05/08/17 06:56 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
Here's a teaser of the upcoming loads.

From left to right

1016 Grain Lead Cast Powder coated Round Nose Gas Checked

690 Grain AP

690 Grain South African Ball

150 Grain FMJBT in a 50 to 30cal Sabot


Attachments
2017-05-08 06.54.20.png



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#1195471 - 05/08/17 08:44 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
Cash is King Offline
Nice guy... NO MORE

Registered: 09/15/11
Posts: 5741
Loc: Woodbridge/Stafford/Gloucester...
City or County: Prince William, Stafford & Gloucester monthly.
VERY NICE!!!

Try some 168s, 190s, 200s and 220s in the one on the right. Curious what the speeds will be.

BTW... you are a Madman!
_________________________
IF you spend your lifetime acting the victim, your Participation Trophy will ALWAYS be a Busted Nose.

I-95 "Fast Lanes" solved NOTHING!!!




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#1195828 - 05/08/17 11:20 PM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
We are going to start off this quest by making the brass. 510 Whisper uses 338 Lapua Magnum Brass as the parent case. To convert the brass I use the following process.

I use a K&M Micro Neck Turning tool for 50BMG to machine the case necks. After speaking more with Roger at K&M, the maximum cutter angle he could grind me is 77. The chamber print for 510 Whisper shows a 83 angle. I got the K&M Expander as well to ensure the necks were expanded enough so the brass doesn't gall on the pilot. It took me a little bit to get the neck turner set up like I wanted, but it works great. The finished brass looks incredible, and have minimal machining marks. I polish with steel wool after turning. I got the 50bmg setup with a steel pilot and carbide cutter with the custom grind. I also got a 0.005" depth micrometer which installs on the neck turner to get good measurements. I'm pretty happy with it so far, but it is time intensive. I'd say 10+ minutes per case in neck turning, it is time intensive. It helps a lot to tighten the shell holder with a wrench, it eliminates any spinning of the case in the shell holder.

My process ended up like this:
1) Rough cut brass behind the neck. I use a Harbor Freight Chop Saw to do this step. Afterwards I debur and chamfer the case mouth, which helps the next step.
2) Trim brass to 1.885". Debur and chamfer case mouth again. (I chose 1.885" due to it is 0.115" shorter than my chambers neck, and lets me crimp the neck later just inside the cannelure of my 690 grain milsurp projectiles)
3) Use 338 Lapua Mag FL sizing die to full length size brass to minimum dimensions
4) Use K&M Expander die to expand case mouth to fit on pilot of neck turner
5) Lube case mouth and pilot on neck turner with good case wax.
6) Turn down neck to .012" thick, in 4 passes. I set the shoulder at 1.440" from the base of the rim, as my go gage's dimension was 1.437" and the no go was 1.443" from the base of the rim. This should put me right in the middle of the headspace I was having my chamber cut to. I chose 0.012" thick neck for flexibility in projectile choices. I initially chose 0.0135", however this only worked with .510" projectiles. My .512" lead cast would not chamber.
7) Use 510 Whisper dies to full length resize case ( Shouldn't be much happening here)

From here on it is normal loading.


Attachments
chop saw.png

chop saw2.png

chop saw3.png

trimmer 1.png

measurements.png



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#1195832 - 05/09/17 12:00 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
Big Red aka Lipstick Rounds as Mrs_Dirjumper895 calls them....


This round is the one that drove my dream to pursue the big whisper. The dream of 1000 Grains at 1000 fps. We will discuss it first. This round is still heavily in load development, to this point I have not figured out what shoots best in my setup. Lots of variables to play with. Lead Alloy which will result in change in bullet mass, to gas check or not gas check, seating depth, single or double layer powder coat, load density, and powder type.

Mold Specs:

Cast Bullet Engineering 512-975GC
Mold is made of brass, and is a single cavity. The mold quality is amazing. It took a while to order it from Australia, but it was worth it.

What I have figured out so far:

1)Using Lyman #2, this mold casts approximately a 950 grain projectile. Using pure lead, this mold will cast approximately a 1005 grain projectile. Both of these weights are prior to gas checking which is approximately 10 grains.

2)My gun likes a 3.075" seating depth. Anything over 3.085" is into the lands.

3) The powder coating adds approximately .0015" per coat. One coat gives decent coverage, however a second coat is preferred.

4) Using a Lee Push through sizing ram and the seating die works great for seating gas checks on the bullet shank. After gas checking, these get sized through a custom Lee 0.512" sizing die.


24.5 GR of Accurate #9 has yielded approximately 950 FPS. 28 GR of Accurate #9 has yielded approximately 1080 fps. I would not go much above this, the recoil starts to become pretty harsh.

I have not got to do much for accuracy tests yet. These rounds have made my scope slide in the rings, even with the rings torqued and set in rosin. Cash Is King set me up with some lead tape to help remedy the situation, however I have not got to get the scope reset onto the lead tape. It should not need to be said, but due to such a heavily recoiling round do not use a cheap scope. I am glad I have a few VX3/VXIII/VariX-III with Lifetime Warranties, just in case.

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#1196467 - 05/10/17 03:17 PM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
MetroBluing Offline
Bolt action

Registered: 03/10/13
Posts: 164
Loc: Va
City or County: Loudoun
Definitely have some great information here. It will surely help out when I dive into the deep end of this pool.
_________________________
Built not Bought

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#1223490 - 07/11/17 09:01 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
Well time to keep this thread alive.

I had come Case gages made using my chamber reamer. ( Thanks to Cash Is King for the POC) Attached are the pictures. These will really help when swapping to other projectile sizes, to determine if the neck diameter is the tight area or if the shoulder is not set in the right place.

And yes, this is a teaser picture of a new projectile not yet discussed. The projectile is a 750 grain Hornady AMAX with a BC of 1.050, loaded at 3.600" OAL. More to come on this....


Attachments
22975.jpg




Edited by dirtjumper895 (07/11/17 09:09 AM)

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#1224054 - 07/12/17 02:17 PM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
Cash is King Offline
Nice guy... NO MORE

Registered: 09/15/11
Posts: 5741
Loc: Woodbridge/Stafford/Gloucester...
City or County: Prince William, Stafford & Gloucester monthly.
That came out nice. Gotta love a 3D case gauge.
_________________________
IF you spend your lifetime acting the victim, your Participation Trophy will ALWAYS be a Busted Nose.

I-95 "Fast Lanes" solved NOTHING!!!




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#1224801 - 07/14/17 10:11 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
Cash is King Offline
Nice guy... NO MORE

Registered: 09/15/11
Posts: 5741
Loc: Woodbridge/Stafford/Gloucester...
City or County: Prince William, Stafford & Gloucester monthly.
[img]https://i.screenshot.net/s/jpn16se[/img]

https://i.screenshot.net/s/jpn16se

...well that failed

Photobucket still has me by the short hairs.


Edited by Cash is King (07/14/17 10:27 AM)
_________________________
IF you spend your lifetime acting the victim, your Participation Trophy will ALWAYS be a Busted Nose.

I-95 "Fast Lanes" solved NOTHING!!!




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#1224850 - 07/14/17 11:23 AM Re: 510 Whisper 12.7x48 [Re: Cash is King]
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
Originally Posted By: Cash is King
[img]https://i.screenshot.net/s/jpn16se[/img]

https://i.screenshot.net/s/jpn16se

...well that failed

Photobucket still has me by the short hairs.


Whoa! Those look very simular to mine. I think they may be from Feb 12th, I recognize the brown tarp....and my wife's hand.


Attachments
FB_IMG_1500046974162.jpg

FB_IMG_1500047001579.jpg



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#1277457 - 11/10/17 06:16 PM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
dirtjumper895 Offline
Addicted

Registered: 08/10/12
Posts: 440
Loc: Virginia
City or County: Suffolk
Well, I've been absent with this project for a while. Between getting cast 9mm and 50 beowulf running this project took the back burner.

This post is going to be dedicated to things I've learned with my CBE 512-975 GC mold.


I used to think that my gun liked a oal of 3.075". This was what reliably chambered, but I failed to understand how to properly use a long bore riding boolit. Alot of reading on the Internet and I learned my mold was throwing a slightly larger nose than I needed, and powder coating increased the size even more. The Lee push through sizers only size the bands, not the nose.

I picked up a old Lyman 45 sizing press and a Lyman .501 sizing die. With some slight mods to the press, I was able to size the nose with the bullet upside down to 0.501". At this size, the bore riding portion of the boolit is doing what is is supposed to. The nose very lightly engraved the rifling, and supports the first 1.5" of the boolit. The last 0.630" is still sized to .512, and is the gas seal. I can now run an oal of 3.290", which QL has predicted lowered my pressures with the same load by about 18000psi.

So far these dummy rounds have chambered with 100% reliability, which is way better than before. I hope to have some accuracy tests soon, and then I will be playing with different alloys for this gun.

Alos ran some weight and recoil #'s.

Loaded mag with 5 rds is 1.5lbs
Scope and Rings are 1.7lbs

Gun with suppressor, scope, and full mag are 15.5lbs.

Should be about 24lbs of recoil energy, shooting a 1005gr projectile at 980fps.


Attachments
whisper.jpg




Edited by dirtjumper895 (11/10/17 07:11 PM)

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#1278625 - 11/13/17 07:58 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
Cash is King Offline
Nice guy... NO MORE

Registered: 09/15/11
Posts: 5741
Loc: Woodbridge/Stafford/Gloucester...
City or County: Prince William, Stafford & Gloucester monthly.
Originally Posted By: dirtjumper895

Gun with suppressor...


I thought Maxwell House only made coffee... didn't realize they also made XL suppressors.

-------------------------------

As for cutting off brass, I use a different method for my .458 CAT ((aka Catastrophe)... belted magnum brass cut to "bottom of shoulder"... loaded with .458 pill.)

First I tried the mini-chop...

Then the 6" chop from HF...

Then 60 grit paper on 4.5" hand grinder... does very well to simply vaporize material.

The fastest and best I have found is the stepped drill bits (pyramid shaped)... with final trim after.

-------------------------------

Gotta love an 18k psi drop.

NICE PROJECT!!!

P.S. Watch stability (study it hard... and look for keyholing hits on paper BEFORE mounting your can)... you don't need 1,005 grains going short axis inside a can.

Not happened to me, but my 730s (.458s) fly like a duck with one wing... so just saying.


Edited by Cash is King (11/13/17 08:05 AM)
Edit Reason: typos... as always
_________________________
IF you spend your lifetime acting the victim, your Participation Trophy will ALWAYS be a Busted Nose.

I-95 "Fast Lanes" solved NOTHING!!!




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#1510765 - 07/06/19 08:08 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
MetroBluing Offline
Bolt action

Registered: 03/10/13
Posts: 164
Loc: Va
City or County: Loudoun
Been awhile, any new break thru? Just keeping the dream alive.


Attachments
IMG_0136.jpg




Edited by MetroBluing (07/06/19 04:41 PM)
_________________________
Built not Bought

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#1559935 - 11/13/19 11:01 AM Re: 510 Whisper 12.7x48 [Re: dirtjumper895]
OXN Offline
Reagan Bush '84

Registered: 10/25/10
Posts: 1148
Loc: Virginia
City or County: Richmond
Originally Posted By: dirtjumper895
Well, I've been absent with this project for a while. Between getting cast 9mm and 50 beowulf running this project took the back burner.

This post is going to be dedicated to things I've learned with my CBE 512-975 GC mold.


I used to think that my gun liked a oal of 3.075". This was what reliably chambered, but I failed to understand how to properly use a long bore riding boolit. Alot of reading on the Internet and I learned my mold was throwing a slightly larger nose than I needed, and powder coating increased the size even more. The Lee push through sizers only size the bands, not the nose.

I picked up a old Lyman 45 sizing press and a Lyman .501 sizing die. With some slight mods to the press, I was able to size the nose with the bullet upside down to 0.501". At this size, the bore riding portion of the boolit is doing what is is supposed to. The nose very lightly engraved the rifling, and supports the first 1.5" of the boolit. The last 0.630" is still sized to .512, and is the gas seal. I can now run an oal of 3.290", which QL has predicted lowered my pressures with the same load by about 18000psi.

So far these dummy rounds have chambered with 100% reliability, which is way better than before. I hope to have some accuracy tests soon, and then I will be playing with different alloys for this gun.

Alos ran some weight and recoil #'s.

Loaded mag with 5 rds is 1.5lbs
Scope and Rings are 1.7lbs

Gun with suppressor, scope, and full mag are 15.5lbs.

Should be about 24lbs of recoil energy, shooting a 1005gr projectile at 980fps.


Dude this is a really wild thread. Please keep us updated on how things turned out if you're still on here.
_________________________
Why carry? Because 1911 > 911.

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