The firearm thread

[jono035]

I only know what I've read on forums with people talking about doing similar things and one of the problems mentioned was getting the bullet to stabilise properly. For the same target velocity the barrel twist rates that can be used are different. If a bullet is supposed to be used at 3000fps then at 1000fps it will be spinning at 1/3rd of the speed which can mean that it may not fly straight. I don't know if this is a major problem or not, I only know that a lot of people have reported having to try various different combinations of bullet and barrel twist rate to avoid keyholing on the targets.

Flip: Sounds like you've got some actual experience with this stuff, what kind of powders/projectiles do you use? Do you use anything as a case filler? Have you had any problems with rounds losing stability?

[Swoop]

Anyone with a clone M-14?
Can you confirm that it has the gas-port shut off between the barrell and the gas tube please? My old one used to, so it could be turned off to create a straight-pull rifle.
Also, the B-square mounts have small grub screws in them and may move around a bit. Spending decent money on the mount would be a wise investment on an M-14.

[Mr Merde]

.....

One word "Wisper 50".

When I saw this thread I imediately thought of the .300 Whisper. Strange that someone else also thought of this line of cartridges also.

The Whisper Family

Cartridge	Parent Case
6mm Whisper	.221 Fireball
6.5mm Whisper	.221 Fireball
7mm Whisper	.221 Fireball
.300 Whisper	.221 Fireball
.338 Whisper #2	.221 Fireball
.338 Whisper	7mm Bench Rest
.375 Whisper	7mm Bench Rest
.416 Whisper	7mm Bench Rest
.458 Whisper	.458 Winchester magnum
.500 Whisper
.510 Whisper	.338 Lapua Mag

As you can see from the following chart the .308 boltface will accomadate a number of the whisper cartridge family as it is the same as the 7mm Bench rest bolt face.

[Mr Merde]

.338 Whisper and .338 Whisper #2

There are actually two versions of the .338 Whisper. The original .338 Whisper is based on the 7mm Remington Benchrest case, which simplifies conversion of rifles that use .308 Winchester case head dimensions (.470").
The .338 Whisper #2 is based on the .221 Fireball case. This allows easier conversion from rifles originally chambered in .223 Remington, such as the AR-15 and variants.

.375 Whisper

The .375 Whisper is based on the 7mm Remington Benchrest case, which simplifies conversion of rifles that use .308 Winchester case head dimensions (.470"). The .375 Whisper may fare a little better as a hunting round than its .338 sibling, but in just about any other area, the .338 has it beat largely because of the wider variety of bullet types available for it.

http://www.quarterbore.com/300whisper/sskwhisper.html

Try this site in NZ

http://home.xtra.co.nz/hosts/suppress/whisper.htm

[Mr Merde]

Actually this whole concept has arroused my interest.

I used to shoot a Contender in 7mmTCU.

I always lusted after a barrel from JD Jones' company. In particular ther .375 JDJ

I remember the Whisper round when it was first announced. Not a really long distance shooter but capable of being real quiet when needed.

I wonder what it would entail in building a bolt action rifle or having a Mini 14 built in one of these calibres.

The Mini 14 would be very interesting but I think that a case catcher would have to be a required attachment as the brass is specialised ( I cant afford to throw my money away)

[jono035]

Yeah, I did run across quite a few references to the .300 whisper when looking at the .308 stuff. According to the wikipedia page, .223 rifles can simply be rebarrelled to make up a .300 whisper rifle given that you can make the cases from trimmed .223 cases (solution to the throwing money away issue?) and the OAL for both .300 whisper and .223 would seem to be the same.

I have seen people discussing how to get semi-autos working with subsonic rounds and there seem to be quite a few different variables. Gas port size and location seem to be key and there are comments about them working in AR-15s with adjustable gas blocks.

Just noticed the .510 Whisper, designed to be used with .50 BMG bullets... That would be particularly awesome.

[Mr Merde]

Check this out then

14.5mm JDJ ...
SSK has non Destructive Device exemption for a 14.5 MM (.585") cartridge.

The 14.5 MM JDJ is based on the 50 BMG case. The neck is opened to accept the SSK 1173 grain bullet loaded over 235 grains of 5010 to fire form the case. Other bullets may become available in the near future.

In the test rifle 100 yard accuracy hovers between .3 and .5" with this fireform load. Velocity is chronographed at 26--2700 feet per second with the 1173 grain bullet. My worst 300 yard three shot group with it is 1.509". The 750 Barnes is a real performer at 3000 FPS. Dies are in stock. Actions suitable for the 50 BMG are the ONLY ones that will take this cartridge. We recommend McMillan actions. Guns are all custom built according to customer preferences. It is doubtful that it will be possible to build one for less than $5,500. Please do not email questions---if seriously interested call--740-264-0176.

SSK's 14.5mm JDJ rifle is based on a 50BMG bolt action. The cartridge has a
Destructive Device exemption. Scope is a 5x22 Nightforce. Barrel on this one
is 36" plus muzzle brake and weighs 42 pounds.

SSK's 14.5mm Brake

McMillan "Fisher" type action as used in the SSK 14.5mm JDJ rifle.
Case shown has been fire-formed with the SSK 1173 grain 14.5 bullet.

SSK 1173 grain 14.5mm bullet, fire formed 14.5 JDJ case.
50 BMG case loaded and ready to fire form with 235 grains of 5010.
Downrange ballistic performance of the heavy, streamlined projectile is exceptional.

[jono035]

28kJ of energy at the muzzle. Thats a good 1.5x the beefier .50 BMG loads... yikes.

I'm going to take a wild guess that it probably doesn't suppress all that well, though...

[jono035]

From those same nutjobs (SSK Industries)...

http://en.wikipedia.org/wiki/.950_JDJ

3600 grain (250 gram) bullet at 2200 fps for 52 kJ at the muzzle.

Cartridge is a shortened and necked up 20mm vulcan case, Rifles weigh around 50kg with an 8.2kg muzzle brake. Cost around USD$8000 with factory rounds at $40 each and lathe-turned bronze bullets for $10 each.

"the rifle should not be held to the shoulder unless the shooter is prepared for severe recoil and possible injury."

[Mr Merde]

Each to their own i suppose.

I too have been slacking off at work. Reading up on the Mini 14 and 300 Whisper combination. I am getting more interested as I read into this subject.

Most septics are using the AR platform for the conversion rather than the Mini 14. They also seem to be using the Remington 700 as a base for a bolt action.

Interesting

[jono035]

Yeah, that was the impression that I got, too. There seem to be quite a few people dismissing the mini-14 as 'incurably inaccurate by design' but again having no experience with them I don't know if this is truth, exaggerated truth or total bs.

Is there anything specific about the mini-14 that makes it a good choice or just the fact that it is common enough to make a cheap project gun?

It would seem that anything chambered in .223 would do so maybe looking for a semi-auto with an adjustable gas system would be a good place to start?

A Remington 700 would be a good default choice if accuracy was a large factor.

Edit: Yeah, both of those big rifles from SSK seem to be a little bit excessive to me. Most of my toys don't get used for much more than punching paper anyway but I'm not particularly interested in anything that non-functional.

[Mr Merde]

Gun City have one for sale Their code GB0129. Selling for $2399

[jono035]

'With silencer and scope'... I wonder how good the suppressor and scope are, though. The fact that they are unnamed isn't encouraging.

Assuming a cheap scope and gunworks suppressor, $2k for the mini-14 and .300 whisper barrel.

I wonder if they have done anything beyond re-barelling it?

[wbks]

From those same nutjobs (SSK Industries)...

http://en.wikipedia.org/wiki/.950_JDJ

3600 grain (250 gram) bullet at 2200 fps for 52 kJ at the muzzle.

Cartridge is a shortened and necked up 20mm vulcan case, Rifles weigh around 50kg with an 8.2kg muzzle brake. Cost around USD$8000 with factory rounds at $40 each and lathe-turned bronze bullets for $10 each.

"the rifle should not be held to the shoulder unless the shooter is prepared for severe recoil and possible injury."

I can't particularly see much point in something so expensive that needs to be fixed to shoot...

Yeah, that was the impression that I got, too. There seem to be quite a few people dismissing the mini-14 as 'incurably inaccurate by design' but again having no experience with them I don't know if this is truth, exaggerated truth or total bs.

Is there anything specific about the mini-14 that makes it a good choice or just the fact that it is common enough to make a cheap project gun?

It would seem that anything chambered in .223 would do so maybe looking for a semi-auto with an adjustable gas system would be a good place to start?

A Remington 700 would be a good default choice if accuracy was a large factor.

Edit: Yeah, both of those big rifles from SSK seem to be a little bit excessive to me. Most of my toys don't get used for much more than punching paper anyway but I'm not particularly interested in anything that non-functional.

The guy in this video uses a 1/8 barrel and says he gets as low as 1/2" with .300 whisper. Quiet, too.
Don't know what the ballistics look like for this round but looks like they all have aftermarket barrels, I'm assuming for the stabilization you were talking about
http://www.youtube.com/watch?v=M7Pbyf-eLW4
And this AR seems to work great.
http://www.youtube.com/watch?v=rT2U6NdkwFk

[Mr Merde]

'With silencer and scope'... I wonder how good the suppressor and scope are, though. The fact that they are unnamed isn't encouraging.

Assuming a cheap scope and gunworks suppressor, $2k for the mini-14 and .300 whisper barrel.

I wonder if they have done anything beyond re-barelling it?

I wondered that. New barrel probably around the $500 mark plus the cost of reaming the chamber and fitting another $200

You apparently dont have to do any other work to the receiver or the magazine.

Could do with a nicer looking stock, properly bedded of course.