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DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 2:42 am
by riude
Greetings
First, sorry for my bad grammary, I´m from Finland :oops:

Anyway, I needed expanding/fragmenting .30 subsonic bullets for varmint hunting. Target is quite small "Racoon dog", typically they weight 5-9 kg.
They are quite strong little critters, if you shoot them with FMJ, they will run far away unless you hit head or heart.
Bullet should "open" very fast, lethal area of these animals is just 4-6" thick.

That time, Lehigh bullets (or others like that) were not available in europe. Now I could get them from Germany, but price is still quite high.
So I though there must be some way to modify "normal" bullets to archieve at least somehow controlled fragmentation or expansion.
I spent lot of time in internet to find information, but didn´t find much. What is surprising.
Modified ammunition should also have decent subsonic accuracy, so I set my goal to consistent 1 moa.

I have bolt action rifle, so I didn´t need to take care of cycling etc. ar problems.

I did quite much testing, and it was very difficult to get subsonic 1 moa, even with not modified bullets.
In fact only accurate enough was H&N 165gr coated lead cast bullet.
Obviously it did not expand at all when tested to water jugs.
I tried many modifications, example drill very deep hollow point etc, but it didn´t help. They still acted like FMJ.

At last, I decided to radically split point of bullet in two. First I chamfered point of flat nose bullet slightly with normal drill.
Then made jig to center bullets to my milling machine, and split them with slitting saw.
See pic

Image

When you shoot 1 gallon plastic jug with that bullet modified like that, those splitted "wings" will be break off (black line in pic shows where they crack).
Wings path will deviate about 30 degrees from rest of bullets path. Wings almost break 1 gallon jug backside, but not allways. Rest of bullet usually starts tumble in impact.
I have tried this maybe 7-8 times from 100yds, 100% succes.

From my small sample so far (abt 10 critters) this works as I planned.
None of them have run more than 1-2 feets after hit.
However, there has been some motion for 3-15 seconds. When I shoot them with supersonic V-max, motion normally ends righ away.



Has someone else done such research? Like I said, I didn´t find much more than hollowpoint drilling from internet.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 9:58 am
by Boolit_Head
I had to look up a Racoon Dog, wow that is a strange looking critter. It looks like you are following the path of the Lehigh and other fracturing bullets so it is not surprising that you had similar results. It sounds like you only split yours in two while they quarter them. You might try making a second cut to see how that responds.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 1:08 pm
by riude
I've tried that, but it's not working with such soft lead bullet. Remaining "wings" are too weak.
Infact i had some fragmented in my suppressor :P
I think centrifugal force created in 1:7.5 twist barrel ripped wings off.
But beware, same thing happens if you make too deep cut when split in two.
10mm was too much, 8mm is ok. Of course it depends about alloy etc.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 1:11 pm
by riude
Double

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 2:08 pm
by rpk47
Maybe try drilling into the bullet and doing your cut? My thought is that the drilled hole will weaken the bullet allowing your wings to break off a larger chunk than what you currently are seeing.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 2:36 pm
by riude
Also tried that 8) but didn't make many tests.
That alloy is pain in the ass to drill, it sticks to drill like glue.
To make 15mm deep hole you need to take drill back and mechanically clean it 3-4 times.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 3:05 pm
by Walkers Bay
I've got friends over your ways.
Question I have is if they are so tough why use sub sonic. Why not hit them with a full house load.

As for modifying bullets. I know after WW2 the old boys had an excess of 303fmj ammo so they had jigs to drill into the tips.
They worked well on deer for probably 50 years.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Fri Sep 23, 2016 4:59 pm
by riude
Noise. Most of time I use full house v-max loads, but I have couple places (farms) where subsonic is only option.
Anyway, I'm satisfied with my solution, I'm just curious if someone have done it different way.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Sun Sep 25, 2016 11:04 am
by threedogs
I would use Hornady 90gr XTP bullet if available, I load them with trail boss to about 1000 fps and they shoot very well out of my ruger bolt action.

Re: DIY Expanding/fracturing subsonic bullets

Posted: Sun Sep 25, 2016 11:54 am
by anotherkelley
riude wrote:I've tried that, but it's not working with such soft lead bullet. Remaining "wings" are too weak.
Infact i had some fragmented in my suppressor :P
I think centrifugal force created in 1:7.5 twist barrel ripped wings off.
But beware, same thing happens if you make too deep cut when split in two.
10mm was too much, 8mm is ok. Of course it depends about alloy etc.

8mm is the deepest you've went without the petals breaking off as bullet exists the muzzle? Is this with both copper jacketed and cast bullets?

I saw mention of a 165gr cast - what other bullets have you modified and been pleased with the results?