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Old 11-03-2008, 08:57 PM   #1
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Default Subsonic 7.62x39

I just got my Form 1 for a suppressor. It'll be going on an AMD-65, threaded on with a blind pin to make the barrel legal length. I want to load some sunsonic ammo for it. The ultra quiet shooting will be great for pest controle.

First off I have been reloading for over a decade and understand all the saftey precautions with subsonic ammo by itself, let alone through a suppressor. Testing will be done unsuppressed first with targets ranging from 1yd. out to 25yd. to make sure the load is stable and prevent baffle contact.

Ok, on to the ammo. I have the brass preped and ready for loading. Flash holes are drilled out to 9/64th. I'm using Win. mag large rifle primers. I'll be starting out with Red Dot powder, I have some loading data but its hard to find.

The bullet slection is where I have questions. Will a round nose feed in an AK? I made a few dummy rounds with 150 FMJ BT loaded backwards and they won't feed, they'll get up on the feed ramp but hit the end of the barrel. I would like to shoot somewhere around 180-220 grain bullets.

Any input?
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Old 11-03-2008, 09:03 PM   #2
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Bullet weight might best in the 180 to 200 grain range. Maybe even a bit less. Using Red Dot in the small case will be less than 308. I had a bunch of subsonic data somewhere. I'll see if I can locate it. As for the Winchester primers, if they are the older nickel plated ones they MIGHT be safe in an AK. The newer copper colored ones are more sensitive. The nickel plated were originally made to be safer in semi auto's. Winchester dsaid they got too many complaints of light primer strikes and off center strikes misfires, so they redesigned the copper colored ones to be more sensitive.
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Old 11-03-2008, 09:04 PM   #3
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Default One more thing

On the bullet selection .308 bullets are fine for me. I'm one of those "crazy" people who reload .308's for my AK's. I shot hundreds of reloads in the past year using .308's and see no danger or loss of accuracy, my Romy G will shoot 1.25 MOA with them.
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Old 11-03-2008, 09:07 PM   #4
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Quote:
Originally Posted by allesennogwat
Bullet weight might best in the 180 to 200 grain range. Maybe even a bit less. Using Red Dot in the small case will be less than 308. I had a bunch of subsonic data somewhere. I'll see if I can locate it. As for the Winchester primers, if they are the older nickel plated ones they MIGHT be safe in an AK. The newer copper colored ones are more sensitive. The nickel plated were originally made to be safer in semi auto's. Winchester dsaid they got too many complaints of light primer strikes and off center strikes misfires, so they redesigned the copper colored ones to be more sensitive.
I only have problems with them when the rifle is REAL hot, I'll get a slam fire erery now and then. But good to know and thanks.
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Old 11-03-2008, 09:11 PM   #5
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I get decent accuracy with .308" bullets. I do get higher velocity and pressure with .311" bullets of the same weight with the same powder charge.
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Old 11-03-2008, 09:22 PM   #6
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Quote:
Originally Posted by allesennogwat
Bullet weight might best in the 180 to 200 grain range. Maybe even a bit less. Using Red Dot in the small case will be less than 308. I had a bunch of subsonic data somewhere. I'll see if I can locate it. As for the Winchester primers, if they are the older nickel plated ones they MIGHT be safe in an AK. The newer copper colored ones are more sensitive. The nickel plated were originally made to be safer in semi auto's. Winchester dsaid they got too many complaints of light primer strikes and off center strikes misfires, so they redesigned the copper colored ones to be more sensitive.

What kind of primers do you use? If you could find your load data that would be very appreciated.
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Old 11-03-2008, 09:37 PM   #7
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It will take a while to locate my subsonic data but I might be able locate some of my notes that I emailed myself a long time ago so I wouldn't lose them. I used to use Remington primers. These are (were) safer than CCI primers. I have heard quality may not be what it used to be but I never had a problem with them. When the CCI mil spec primers came out I went to them. They are magnum rated and the safest. Avoid Federal primers and copper Winchesters. I remember when the nickel Winchesters camr out. Before then they were as sensitive as the Federals. CCI are quality but may be a bit more sensitive than Remington.The Remington's are (were) as close to mil spec as you could get.
1st choice would be CCI mil spec's #34, 2nd choice would be Remington 9 1/2 M and 3rd choice would be CCI 250. I wouldn't mess with Winchesters or Federals.
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Old 11-03-2008, 10:42 PM   #8
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catsneeze loads..try some 180 grain speer with 6.5 grns. of IMR SR7625 or 200 grain with 7.8 grains of SR7625..but I think with the fast burning powders you would have to remove the operating rod to keep from bending it.might be wrong..
try this place to..
http://guns.connect.fi/gow/arcane2.html
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Old 11-03-2008, 11:08 PM   #9
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Default subsonic loads

I'm suggestin the 160 gr cast lead. from Lee.Mine drops em at 165 gr and right diameter ...312.

Cleanin is no biggy, and less powder required since they are cast....might be just the ticket and they are cheap

they feed real well,...right length ..heavy enuff for what you want to do.

I'll be real surprised if you can find a bullet that will work in the 180 gr range...even in 308
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Old 11-04-2008, 02:00 AM   #10
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Swabbie I've been using the same Lee .311 sized down to .309 in my K31 Schmidt Rubin 7.5X55 with 19.0 Grs. of 4759 and it shoots well. Would be ideal to SubSonic I feel also.

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Old 11-04-2008, 10:54 AM   #11
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Default Lazy

John......

I'm even lazier than that ..I bought 2 of the tumble lube molds and decided that they were too slow casting, so I'm heading up a group buy for a custm 6 cavity Lee mold which will drop them in 314 diameter

This will allow use in Mosins,Enfields,Japs,etc.
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Old 11-04-2008, 11:34 AM   #12
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I can't find my data right away but here is some old data from internet that seems about right.

200gr cast - Red Dot 4.5gr = 900 fps

200gr cast - Trail Boss 5.5gr (better load density) = 900 fps

180gr RN - Red Dot 6.0gr = 930 fps

150gr RN - Red Dot 5.5gr = 980 fps

Not sure I'd worry too much about round nose vs pointed bullets. Pointed bullets should feed better and I've used mostly pointed bullets.
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Old 11-04-2008, 01:10 PM   #13
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Thanks everybody, getting some good info here.

I thought about cast bullets. I think the softer material will give better terminal ballistics at such a slow speed. I have never casted my own but it could be another thing for me to do to me out of trouble. Bought a copy of Handloader mag. and they have a big artical about casting bullets.

allesennogwat:
Ever have stabilty issues using pointed bullets in a subsonic load?
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Old 11-04-2008, 01:15 PM   #14
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No I haven't had much trouble with bullets being stable. I think that pointed bullets are suppose to make more noise than flat or round nose bullets. I kept my velocities right at subsonic. A faster twist rifling is suppose to help to stabilize the bullets. I just didn't go full heavy on bullet weight. Sometimes my loads would go supersonic as I was working with them.
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Old 11-04-2008, 02:01 PM   #15
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Default wanna try some

I've got some out in the Man Cave now(I think)....if not ,I'll be castin within the next week.

I just loaded approx 500 of them..250 for my SKS and 250 for my AK...the SKS cycles with less powder charge

Let me know..I'll send ya 25 or so before you decide.....


BTW...you did mark those subsonic cases with a blue marker didn't you????
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Old 11-04-2008, 04:54 PM   #16
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The Bulgarian Heavy Ball lead core bullet might be a nice projectile to work with. 184g, proper diameter and shaped right to feed in your AK. Seating to proper level may be risky as the ogive of the bullet may end up in the case neck.
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Old 11-04-2008, 05:08 PM   #17
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Default Heavy ball...

Haven't tried them in7.62x39...it's for sure the light ball won't crimp.
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Old 11-04-2008, 08:00 PM   #18
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Quote:
Originally Posted by allesennogwat
No I haven't had much trouble with bullets being stable. I think that pointed bullets are suppose to make more noise than flat or round nose bullets. I kept my velocities right at subsonic. A faster twist rifling is suppose to help to stabilize the bullets. I just didn't go full heavy on bullet weight. Sometimes my loads would go supersonic as I was working with them.
Are you shooting these through an AK? If not whats your twist?

Quote:
Originally Posted by swabbie
I've got some out in the Man Cave now(I think)....if not ,I'll be castin within the next week.

I just loaded approx 500 of them..250 for my SKS and 250 for my AK...the SKS cycles with less powder charge

Let me know..I'll send ya 25 or so before you decide.....


BTW...you did mark those subsonic cases with a blue marker didn't you????
Purple in the extractor grove. Incoming PM.
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Old 11-04-2008, 08:59 PM   #19
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Default PM box is full

Grrr

I had a nice message composed
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Old 11-04-2008, 09:02 PM   #20
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Casting Is Fun And Easy With A Little Outlay
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Old 11-04-2008, 09:56 PM   #21
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Whats the cost to get started in casting? Can lead wheel weights be used? I'm a mechanic and have access to them for free.
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Old 11-05-2008, 10:09 AM   #22
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Default extra time involved

the cost is not overwhelming,but casting is a Sloooooow business.It's kinda like watching paint dry..with the added danger of killing urself

I'm using custom 6 cavity molds to speed up the process.

If you've got more money than time,you don't want to get into it.
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Old 11-05-2008, 06:32 PM   #23
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Just use ragler ammo, and jamm the bore fulla loominum ferl. It will slow down 'at 'air bullet afore it gets outta the end.
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Old 11-05-2008, 07:02 PM   #24
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Quote:
Originally Posted by Slade797
Just use ragler ammo, and jamm the bore fulla loominum ferl. It will slow down 'at 'air bullet afore it gets outta the end.
Dude, it must have taken me 5 min. to figure out what the hell you were talking about.

The rifle exploding might defeat the whole trying to be quiet idea!
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Old 11-05-2008, 07:39 PM   #25
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I understood him perfectly

It's time to move a bit farther North
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Old 11-05-2008, 09:17 PM   #26
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Quote:
Originally Posted by allesennogwat
I can't find my data right away but here is some old data from internet that seems about right.

200gr cast - Red Dot 4.5gr = 900 fps

200gr cast - Trail Boss 5.5gr (better load density) = 900 fps

180gr RN - Red Dot 6.0gr = 930 fps

150gr RN - Red Dot 5.5gr = 980 fps

Not sure I'd worry too much about round nose vs pointed bullets. Pointed bullets should feed better and I've used mostly pointed bullets.
That Is Playing With Fire Plain And Simple. Primer Flame Overtravel Igniting The Front And Back Of These Small Charges Is A Recipe Of Detonataion.
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Old 11-05-2008, 11:30 PM   #27
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Default load info

I can't speak to that particular load although I have tried something similar in 7.62x51 for my Ishie

I beleive that drilling out the primer hole and using Magnum rifle primers is what the original poster had done

That said,before I ruined a perfectly good AK,I'd be tryin this in a Handi rifle chambered in 7.62x39(or a Rossi)

No disrespect to Alles's data but I'd want to see some more published info
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Old 11-06-2008, 07:29 AM   #28
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Quote:
Originally Posted by swabbie
I can't speak to that particular load although I have tried something similar in 7.62x51 for my Ishie

I beleive that drilling out the primer hole and using Magnum rifle primers is what the original poster had done

That said,before I ruined a perfectly good AK,I'd be tryin this in a Handi rifle chambered in 7.62x39(or a Rossi)

No disrespect to Alles's data but I'd want to see some more published info

There is no published info. I have been studying subsonic for a while now and yea it's dangerous, but no dangerous than working up a max load IF you do it right. You MUST use a chronograph, start high and work your way down. Always paying attention to pressure signs, and hangfires. With the primer hole drilled out it allows faster ignition, use something as a "wad" before seating the bullet to keep the powder at the bottom of the case. Bullet lube is your friend. I might never get a safe load that'll run in my AK and be subsonic, but I want to try.
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Old 11-06-2008, 09:07 AM   #29
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Quote:
Originally Posted by John@JCDLESales
That Is Playing With Fire Plain And Simple. Primer Flame Overtravel Igniting The Front And Back Of These Small Charges Is A Recipe Of Detonataion.
That's why Red Dot and Trail Boss are used. They have a lot of volume.
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Old 04-02-2009, 07:24 PM   #30
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I would like to see more posts this thread. I have a AMD65 SBR and I am waiting for the holy paper to process for a YHM 308.

The AMD65 has a 1:8.5-ish twist rate and I think the heavy bullets will do great.

I started SS loads with 180gr and 168gr spitzers in a 308 1:11 24" rifle and I am not getting good results (all 180gr rounds keyholed, and the slower 168gr keyholed, too). And I did not even get fully subsonic, mostly transonic. So I want to move away from the 1:11 bolt and into the Russians 1:8.5-ish twists bolts and autoloaders. I love my ADM65 and would love to supress it above anything else.

I read somewhere AMD65 with subsonic had terrible accuracy and I would like to prove them wrong.
http://www.sunblest.net/gun/AMD65.htm
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Old 04-02-2009, 09:13 PM   #31
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pr787lv,

I got em down around 1200 fps without any signs of danger. Problem is once I go lower she wont run right, every other round will fail to cycle the bolt all the way back. I could start to shorten the recoil spring or enlarge the gas port, then it a sub or nothing gun.

This is all without the suppressor on, the can might raise the pressure enough to help it cycle but I doubt it. The bullets are stable at this point but not as accurate as I hoped for. 4-6" @ 35 yds off a bench. Than again once I get a load that will cycle in the subsonic range I can play around with it to find the best accuracy.

My biggest mistake is not having the rifle SBR'd, I have to work without the suppressor off for now b/c it has to be fixed in place, no on and off allowed.

I have not messed with this rifle in a while do to trying to afford a ring, yes the evil ring most men fear. It is time.

I'm sending you a PM.
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Old 04-03-2009, 12:37 AM   #32
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I have been loading sub sonic 7.62X39 since around 1996.

I found the best bullet to use is the Sierra 180 gr. Spitzer made for the .303 Brit.
When you load it to the same OAL as factory ball it feeds very well.
I always used Winchester brass and primers.
I did not drill out the flash holes.
I found by useing a powder like Winchester 748 I could get enough gas pressure to work the action of the Colt AR in 7.62X30.

I did not try it in a AK.

The load I like best and was most accurate was 16.5 gr. of Win. 748 with the 180 .311 spitzer.

I went up to 18 grains of 748 and it averaged around 1098 FPS, still accurate.

Here is a link to the bullet.
https://www.sierrabullets.com/index....stock_num=2310

AS WITH ANY RELOADING DATA USE AT YOUR OWN RISK.

Court in FL.

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Old 04-05-2009, 09:19 PM   #33
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Not really into the Sub-Sonic stuff but I do load the heavy bullets. A couple week ago I load up a few test rds. using some surplus .310.5 dia. 187 gr. FMJ bullets I had pulled for Bulgarian 54r ammo. I loaded up three rounds each,using Reloader#7 with 18,19 and 20 grs. ever and seated the bullet to 2.200". I was doing this more as a function test more than accuracy but I was pleasantly surprised.

The 18.0 gr load shot a three shot 2" group at 50 yds off the bench in the Chinese SKS with iron sights. Cases all cycled in and out of the action fine,primers looked normal no cratering or flattening of any kind,groups we about 6" low due to the extra bullet weight and the sights being set up for 123 gr bullets.
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Old 05-14-2009, 07:45 PM   #34
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Default AMD65 subsonic

cjaholic,

While you prepare to tie the knot, maybe you can spare some time and spare me some trial and error. I tied the not many years ago and have more spare time than you, I guess.

Can you include the specific loads you experimented with (powder, bullet wt, powder wt?

My guess is you used a fast burning handgun powder (i.e. Trai Boss, etc.) which is good because they burn completely before the bullet leaves the barrel (good for suppressor longevity is my guess), and produce a high and safe Pmax.

The problem is by the time the bullet reaches the gas port, there is little pressure left to work the bolt. We need a slower burning powder, like what Court in Fl suggested. Since your powder did not work, help me rule it out.

Also a heavier bullet may help build that pressure better. My theory is the heavier the bullet, the easier it is to build pressure at the gass port to work that bolt carrier.

I am working a 220gr RN (yes, jacketed) just like the one used by EBR Jackhammer. I even ramped my little SBRed AMD a little as they suggested. (by the way, you need to ramp the trunnion, too, or else they will pipe stove).

Court in Fl has been using Win. 748 with 16 to 18gr and it worked the bolt on a AR platform. The AMD bolt carrier is a lot heavier and I am not sure it will work. Quickload (QL) predicts Win 748 produces a 20kpsi Pmax and ~ 6kpsi at bbl 10", where the gas port approx is located at in an AMD.

If I know what powder you used I can have an approx idea of the min pressure needed to work the bolt carrier. I suspect we need more than 6kpsi, but can't tell how much more.

I am guesstimating Win 296 will do the job. Will start with 15gr, and work it down. (QL predicts 15gr yields 7.5kpsi @ 10", 1445fps mv, and 99% propellant burnt, plus a healthy 35kpsi Pmax). Of course, thanks to the gas port, the mv will be much less, or at least thats what I expect. In fact, if QL where any good at predicting subsonic performance, 12gr would be our ticket with 5.6kpsi @10", 21kpsi Pmax, 1150fps mv, 95% propellant burnt and a 1.5ms barrel time, which is ideal as per Chris Long barrel time white paper for a 13" barrel. QL predicts Court in FL Win 748 load mv to be 1194fps and 6kpsi at 10" so I think we are in the ball park. 14.5gr of RL7 yields pretty similar predictions, but with only 90% propellant burnt.
(Note: for all QL number crunching above I turned on bbl friction option).

I think no subsonic load developed for another platform will be nowhere close to work on a 13" SBRed AMD65. I think the closest is EBR's. Wished I could get my hands on a few of them Jackhammers.

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Old 05-17-2009, 11:59 PM   #35
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I know a little bit about this from an aerodynamic point of view (mainly from the point of view of designing rocket nosecones for subsonic and supersonic flight regimes).

For subsonic flight, a nosecone with a blunt, rounded parabolic shape will offer less drag. For supersonic flight, sharply pointed noses such as conic or bi-conic shapes will offer reduced drag. These are the most simple shapes, there are more complex designs that are highly dependent on exactly what velocities and altitudes the vehicle flight plan will encounter. For rockets that operate in both flight regimes (generally starting at subsonic velocities and accelerating to supersonic velocities) there are all sorts of compromise designs that will depend on how much of the flight is spent subsonic versus supersonic and the altitude at which the transition occurs at .

For a subsonic bullet fired out of a gun the situation is greatly simplified. The bullet will exit the barrel at a subsonic velocity, at a relatively constant altitude (i.e. constant atmospheric density) and will begin to slow from the moment it exits the barrel (i.e. we don't have to worry about it transitioning to supersonic later in the flight as would occur in a rocket). For this application, a somewhat blunt, slightly rounded nose, parabolic shape is going to be best from a purely aerodynamic drag point of view. By contrast, the fairly sharp nose spitzer was designed for reduced drag at supersonic velocities where the bullet will spent most of the useful portion of it's flight in a typical supersonic round.

In addition, the blunt nosed parabolic shaped bullet would seem to give you an advantage in that you should be able to use a more sensitive primer with less fear that the nose of the bullet of the preceding round will strike the primer of the round in front of it with enough force to cause an inadvertent primer ignition, since the rounded blunt nose will require more force to generate the peak pressure required to ignite the primer, as compared to the spitzer nose which concentrates it's force over a much smaller area.

That said, I don't have any information on how well the AK design feeds blunt rounded nose bullets as compared to the spitzers which are the norm for most 7.62x39 rounds. If it helps, I would think a round nose bullet will feed better than a hollow point design. I know several people that shoot hollow points without issue, but some have reported issues. A rounded nose bullet would almost certainly feed better than any hollow point. If I were you I'd make up a quantity of subsonic rounds with a rounded parabolic profile bullet and just fire a few hundred to see how well they feed. If this design doesn't have any feeding issues it will retain velocity better than a spitzer given a subsonic muzzle velocity.

Last edited by General Disarray; 05-18-2009 at 12:09 AM.
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