First K baffle suppressor - comments please

[Enfield577]

Well here it is my first suppressor using K baffles.

It is a Norinco JW-15 22 with full length barrel shroud fitted with 6 K baffles, tube ID is 21mm with about 170mm of tube forward of the muzzle.
I have a spacer for the frist 1/3rd then the baffles and another spacer to take up the gap to the end cap.



Baffles have a 7mm dia hole in and I used a1/4 dia ball nose cutter for the dater hole and the cut out in the large end of the cone.

It all seems to work quite well however I have made/modified many of these 22's, with similar dimensions and just used spacers and thin flat washer type baffles. Today I tried one alongside this new design and found the noise very similar, with slightly more hollow pop from the the Ks.

Any advise comments would be welcome as this is my first more into the Ks.








Cheers

Enfield

[delta9mda]

reduce that spacer and add another 1-2 baffles in there. you do not need a huge expansion chamber. period.

[delta9mda]

there is no dater hole in your baffles. also, i think you ported them wrong. there is supposed to be a port diagonally from the scoop at the entrance of the baffle. im only going by what i can and can not see in the pics.

you can do way better with slight mods to the k's (you will need to make new ones). you can also eliminate the "mouse hole" at the large diameter of the cone.

you did not fail, this is learning. your machining looks fine you just need to have porting in the correct places.

om me for help.

[delta9mda]

the port at the small diameter of the cone needs to be opposite the scoop at the flat. looking at the baffle from the rear think of it like this- scoop at 12 o'clock and on the opposite side where the flat meets the cone will be ported at 6 o'clock.

do this correctly and you will notice a good amount of difference.

[Enfield577]

the port at the small diameter of the cone needs to be opposite the scoop at the flat. looking at the baffle from the rear think of it like this- scoop at 12 o'clock and on the opposite side where the flat meets the cone will be ported at 6 o'clock.

do this correctly and you will notice a good amount of difference.

Hi and thanks for your help

I have redone the photos - hope you can see, now I saw other post including your reply when I asked about mouse holes.

I may have miss understood but thought I copied your cad drawing reply, I used a 1/4 ball nose cutter and dropped it down alongside the main hole (bullet path) from the back until it broke through into the base (small end) of the cone. My thoughts were so that gas could bleed off into the space around the outside of the cone. I also cut the cutout in the wide part of the cone at 180 degres to this hole, my thoughts were that the gas would (as you said in your reply to my mouse hole post ) zig zag

This is just about an exact copy of the post that a chap did on machining K baffles viewtopic.php?f=10&t=17116 apart from insead of dropping the hole through at 45 I sank it in from the back with a ball nose cutter

I thought the dater hole was the one at the base of the cone ?

All that said this thing is bloody quiet (as per my old flat baffle designs) you just hear dull thud - can you get much better than this ?. I am in the process of building a rifle from parts with a very short barrel as it was previously mentioned that pistols are harder to suppress so this may make for a better test bed.

Thanks for your help - I tried to PM this but it would not send

[SRM]

You could also thin the cones a little and get rid of that strait section. The less "tube" you form, the better.

[CThomas]

You need your 45 degree angle at rear to line up with a port where angle of K starts. The outside of K serves as an expansion area.

Picture of Dater hole but I have seen its location has vary

Dater hole in different spot

[delta9mda]

like i said, this is not a fail just a learning experience. to do it better, do the cross bore back to front. most manufacturers are not drilling straight through. they are now using ball ends and plunging approx half the thickness of the flat. one from the rear (making that scoop you see) and one from the front 180 degrees opposite the scoop (creating the port through the cone spacer).

most are not using the mouse hole either from the original Finn patent. gas restriction is the key here.

and yes, remove the tube section of the cone after the flat and thin the wall thk of the cone.

pm me for assistance.

[Schulze]

I like the longer "neck" between the face and the cone. The other guys pretty much covered the changes I would make.

[Bluedog]

Should the dater hole be in all the baffles or just the first one?

[Schulze]

Just the first one.

[SRM]

http://advanced-armament.com/product.aspx?pid=488

This is what you want to duplicate.

[delta9mda]

http://advanced-armament.com/product.aspx?pid=488

This is what you want to duplicate.

the element baffle has a bunch of features that more or less need cnc capabilities to get done.

try doing the pilot baffle that can all be done on a lather and mill.

[Enfield577]

Hi, so I think I have it now the port that I did wrong should be, from the back 45 Deg across the centre hole and should clip a bit out of the flat face (the face that the bullet see first) and continue on through at 45 deg untill it cuts through from the inside of the cone and emerges to the outside. Thus creating a path for a gas jet to cut across the centre hole and feed into the space around the outside of the cone. I don't quite understand your comments regards the manufactures using a ball mill and coming from each side, could i not just set the baffle up at 45 deg with the rear face up (large end of cone down) and sink a cutter through clipping the edge of the bore on one side until it exits throught to the outside of the cone.i.e. hole cutting across the center hole.

Also this Dater hole is just a hole say 1/8 dia in the back face of the first baffle that runs parallel with the bore. I guess this is a quick bleed off for gas into the space around the outside of the cone?

Cheers

[delta9mda]

see PM

[CThomas]

Follow steps in link that Whisperfan shared with us a while back. Just skip step 10
http://www.modernrifle.com/forum/viewto ... e55265597c

[Bendersquint]

Well here it is my first suppressor using K baffles.

It is a Norinco JW-15 22 with full length barrel shroud fitted with 6 K baffles, tube ID is 21mm with about 170mm of tube forward of the muzzle.
I have a spacer for the frist 1/3rd then the baffles and another spacer to take up the gap to the end cap.




Enfield

Make that blast chamber smaller like Delta said and lost that last spacer, have the K's butt up against the endcap.

I am assuming that by your use of MM that you aren't in the US, thats a good thing in this situation because now you can tweak it.

For crying out loud make that endcap thinner, counterbore it and start using that space instead of wasting it.

Looks good for your first K's! Keep up the good work and post more pics!

What materials did you use?

-B

ETA... now I see you are a Kiwi! Lucky you! Wife wants to go back and drag me with this time!.

[Enfield577]

Excellent advice

Thanks for the help guys

[Svenska]

I would use your end spacer for your blast chamber spacer and fill the rest of the space with more baffles. Looks good for your first design.

How did your first design sound compared to the changes you made?

I have done a couple of 22 cans and the k baffles seem to work well in 22 and pistol caliber cans.

[Hoop]

The initial baffle design is fine for the rifle. But do make the end cap thinner to make room and add a baffle to the rear where the spacer is.

Rethink the whole thing when the pistol suppressor is being made. This is where you find out if your design is good or not.

[delta9mda]

The initial baffle design is fine for the rifle. But do make the end cap thinner to make room and add a baffle to the rear where the spacer is.

Rethink the whole thing when the pistol suppressor is being made. This is where you find out if your design is good or not.

maybe good enough for rifle but can be better, much better. wrong porting but that has been addressed.

[Enfield577]

Well gents I tried your suggestions and got a bit of an Improvement so thanks for that. I deliberatly did not introduce all the mods so as to see the (or hear the changes) for each feature. I made new baffles, eight this time not six and added the 45 degree hole as suggested.

As yet I have not included the mouse hole (opinion seems divided on this one) and I also did not include a dater hole in the first baffle.

So I can see that we are headed in the right direction, now with the rifle you just a get a hissy sort of pop - the bullet hitting is by far the loudest sound. Stage two is to make a more suitable test bed, I have an old Winchester single shot and am fitting it with a very short barrel (say about eight inches), as you say the real test is with a pistol so I will use this for further development.

Thanks again for the help, having heaps of fun with this stuff

Enfield

[delta9mda]

i have found no mfgr's as of late that use the mouse hole at the large end of the cone spacer.

i think there is a reason for this.