300 Whisper/Fireball Project Part 4 [Archive] - The Guns Network LLC ~ Discussion Forums

L1A1Rocker

10-29-2010, 01:37 AM

Obligatory disclaimer: Do not start your own silencer project without first obtaining the ATF Form 1 approval back in hand plus any state paperwork that may be required in your state. Silencers a legal in 30 some odd states - please stay legal.

Ok, IIRC I left off with ordering a section of T3 aluminum and finishing the internals. Well, the T3 aluminum showed up and it sure looks strange compared to the T6 I'm used to. It has a kind of sheen to it that changes color depending on the angle you look at it. It seems to shift from a purple sheen to Fuchsia. Looks kind of sci-fi to me. Here is a pic but it does not do it justice of what it looks like in person. VERY strange.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0414.jpg

OK so after cutting down the new T3 tube to 15.5 inches and threading it I made the cutters to cut out the polyurethane baffles. I'll need to make two cutters for two different sizes. Three large ones will go in the tube and two smaller ones will go in the endcap. The large cutter I made from some left over section of the stainless steel tubing.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0415.jpg

Wow that stainless was HARD to cut down. This is just a matter of taking down the outside at a nice angle and boring out a bit from the inside to make sure that when the baffle is cut it fits nice and snug.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0416.jpg

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0417.jpg

The last part is to sharpen the cutting edge. I use a file first, then finer and finer sand paper, then finish it off with stones. Gets damn sharp, and yes I've cut myself a few times miss-handling them.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0418.jpg

Now I needed something to make the smaller cutter out of. Off to the scrap pile.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0419.jpg

Note: BEWARE the scrap pile.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0429.jpg

Unfortunately I did not find anything that would work. I ran into the same problem with the Mauser project and wound up ordering some extra thick high pressure tubing. I was hoping to avoid that this time so off to Lowe's I went.

I picked up a couple of "couplers" that seemed like they may work. A 1/2 inch to 1 1/4 inch couple seemed to work ok.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0424.jpg

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0426.jpg

And another mock-up to show all the internals with the tube.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0427.jpg

Now with all the internals complete I decided to do some sand blasting.

You'll notice that the disks and the inside of the expansion chambers are also sand blasted. I did this with the the consideration that a dirty silencer works better than a clean silencer. By sandblasting the internals I'm trying to pre-dirty the silencer.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0434.jpg

Well, it was time to turn my attention to the gas port. I had done a lot of research on this and found that for a sub sonic gun I needed to drill this out to be the same diameter as the gas tube. A number 32 drill bit seemed the best fit here.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0432.jpg

Please take note to the left along the barrel. Notice the grind mark? I had to do that in order to clear the gas tube coming out the endcap going into the upper receiver.

Well, back to the internals because I have not done one very important thing yet. The tube support is blocking all the volume of the tube that is over the barrel. I needed to drill some holes in it so that that space was opened up for gas expansion.

Ya know, I can remember in my high school math class saying "I'll never need to use this stuff in real life." How little did I know.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0439.jpg

Then I just cut out my template and taped it onto the tube support to pin punch it.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0440.jpg

And the finished product.

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0441.jpg

http://i79.photobucket.com/albums/j154/L1A1Rocker/300%20Fireball%20project/HPIM0442.jpg

Ok, that's enough for now. I'll continue with part 5 sometime tomorrow. Please stay tuned.

L1A1Rocker

10-30-2010, 09:00 PM

Wow. A lot of work goes into this. I guess a basic supressor that screws onto the end of the barrel would be less involved? This overlapps the barrel some doesn't it?

And what are the ballistics of the 300 wisper - and you can load it up to be a fireball? Cool.

Oops, sorry I missed this responce. Yes, a screw on silencer could be made a little easier. I like to do the integrals for mostly personal reasons. First you can get a lot more volume with an intagral by "lapping over the barrel" like you asked, (this one goes over the barrel 7.5 inches) and that's important when you are going old school like mine. It's also easier to keep everything in alignment and reduce to odds of a bullet hitting the end cap with an intagral. And, I just like the looks of an intagral.

Screw on silencers do have one BIG advantage though. You can use one suppressor on multiple guns. I've even read where some people will use a screw on for calibers smaller than it was made for.

Ballistics for the 300 whisper are rather impressive (to me anyway).
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 1050.9 0.941 539.4 0.000 0.0 ***
100 -0.0 -0.0 1.2 1.1 1003.7 0.899 492.1 0.292 51.4 49.1
200 -33.0 -15.7 4.7 2.2 964.3 0.864 454.2 0.597 105.1 50.2
300 -103.3 -32.9 10.2 3.2 930.2 0.833 422.7 0.914 160.9 51.2

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

I haven't looked into the supersonic loadings but have read that they are almost identical to the 7.62 X 39. That sounds very appealing in an AR platform.