Warning

 

Close

Confirm Action

Are you sure you wish to do this?

Confirm Cancel
BCM
User Panel

Page AR-15 » Ammunition
AR Sponsor: bravocompany
Arrow Left Previous Page
Page / 4
Posted: 3/5/2009 10:58:43 AM EDT
[Last Edit: Molon]
Prvi Partizan 75 grain OTM



Thanks to the efforts of the esteemed Dr. G.K. Roberts, we now have some excellent information on the terminal ballistic properties of the Prvi Partizan 75 grain OTM load.


Privi Partizan 75 gr OTM

Velocity:  2468 fps from a 16" 1:7” twist barrel

penetration in bare ballistic gel: 12.6"

neck length:  0.8”

maximum temporary cavity: 3.2” at a depth of 4.7”

recovered diameter:  0.36”

recovered length:  0.15”

recovered weight:  30.1gr

percentage of fragmentation:  60%



The same lot of Prvi Partizan 75 grain OTM ammunition that Dr. Roberts used in testing had a nearly identical velocity when I chronographed it from a 16" Colt barrel.



atmospheric conditions:

Average temperature- 83 degrees F
Humidity - 64%
Barometric pressure – 30.04
Elevation- 960 feet above sea level
Link Posted: 3/5/2009 11:17:08 AM EDT
[Last Edit: N2CH_556] [#1]


Subscribing for further study.


ETA:  very nice.  Thanks again.  I was wondering if this PRVI 75gr would do as a "poorman's TAP" and it looks like it might be closer to a poorman's TAP FPD (.223).
Link Posted: 3/5/2009 11:20:06 AM EDT
[#2]
Molon,

Good to see the information on this load.  Once again, your efforts are very much appreciated. Thank You.
Link Posted: 3/5/2009 11:23:00 AM EDT
[#3]
Link Posted: 3/5/2009 11:26:17 AM EDT
[Last Edit: cowboy7242001] [#4]
Link Posted: 3/5/2009 11:27:39 AM EDT
[Last Edit: Molon] [#5]
Originally Posted By R6731:
Molon,

Good to see the information on this load.  Once again, your efforts are very much appreciated. Thank You.


The thanks all goes to Dr. Roberts.  He was gracious enough to offer to test this load.

Link Posted: 3/5/2009 11:33:03 AM EDT
[#6]
200 FPS slower, less penetration, smaller temporary cavity than TAP.  Wonder how POI varies ??
Link Posted: 3/5/2009 11:36:20 AM EDT
[#7]
Originally posted by Zhukov:

Seems like the Prvi is running just a tad slow, even for a .223 load.



Originally posted by cowboy7242001:

But geez...you'd think they could get it to fly a little faster.



It seems that more recent lots are being loaded to a slightly higher velocity.

Link Posted: 3/5/2009 11:51:35 AM EDT
[Last Edit: Winn] [#8]

How does all of this translate to estimated distances for consistent fragmentation ...

IOW, what's the expected fragmentation threshold out of a 16" bbl.  

Link Posted: 3/5/2009 1:09:10 PM EDT
[#9]
Great info.

By chance are there any pics from the ballistic gel test. I'd love to see how the round fragments.
Link Posted: 3/5/2009 1:25:45 PM EDT
[#10]
I have ordered some of this PPU 75 from Wideners.  I haven't received it yet, but how do I tell if it's 2007 or 2008 vintage?
Link Posted: 3/5/2009 1:44:21 PM EDT
[Last Edit: BushMeister] [#11]
So 2007 Prvi 75 was tested by DocGKR?

It seems the frag test indicates that the ammo is better than M193-type rounds for self-defense (especially given the amazingly short neck length of 0.8 in., and 60% fragmentation).  What would you say, Molon?

I guess we can assume that this ammo would be even more effective from a 20" barrel.



Link Posted: 3/5/2009 4:02:35 PM EDT
[#12]
Wondering if there have been any reports of setbacks in SBR's ??  

2008 (the faster) loading still using the same bullet without cannelure ??
Link Posted: 3/5/2009 4:21:28 PM EDT
[#13]



Originally Posted By R6731:



2008 (the faster) loading still using the same bullet without cannelure ??


My batch of '08 has no cannelure.



 
Link Posted: 3/5/2009 4:39:36 PM EDT
[#14]
I love it when he does his thing!  Thanks Molon!
Link Posted: 3/5/2009 7:10:24 PM EDT
[Last Edit: phoenix27] [#15]
Dupe
Link Posted: 3/5/2009 7:18:41 PM EDT
[#16]
Yeah, I'd love to know how to differentiate the sloooow '07 ammo from the faster '08 75-gr OTM lots. The boxes appear the same and so do the bullets. Any ideas out there on how to tell 'em apart?

I would also like to see how fast the newer 69-gr PRVI OTM ammo is compared to the 75-gr OTM stuff. I think Molon has that one on the radar screen for testing in the Spring when the weather breaks up in MI, but I'd like to get some info before the price goes up or they run out of stock and would really like to know what I'm getting. Seems like no one has any info on the PRVI 69-gr OTM ammo, other than it kills hogs effectively as per another post.
Link Posted: 3/9/2009 3:47:10 PM EDT
[#17]
Good info, thanks.
Link Posted: 3/9/2009 3:52:33 PM EDT
[Last Edit: vicious_cb] [#18]
To tell which lot you have you just have to look at the strip of paper thats in each box of ammo. Its gives the year month and inspector number. For example it would say 0803 63 meaning 2008/03 inspector 63

Anyway the new hotter lots look to be on par with TAP FPD or Black Hills 75gr. From my personal testing it seems that Prvi 75gr and Black Hills 75gr shoot to the same point of impact at 50 yards.
Link Posted: 3/9/2009 5:29:34 PM EDT
[#19]

"maximum temporary cavity: 3.2” at a depth of 4.7”

Seems like this would be pretty darn effective on Zombies.
Link Posted: 3/11/2009 12:27:24 AM EDT
[Last Edit: Molon] [#20]
Originally Posted By BushMeister:


It seems the frag test indicates that the ammo is better than M193-type rounds for self-defense (especially given the amazingly short neck length of 0.8 in., and 60% fragmentation).  What would you say, Molon?



You pretty much answered this question for yourself.  The ballistic neck of M193 is typically about six times longer than that of the Prvi round.  This aspect alone, gives the Prvi load greatly superior terminal ballistic properties compared to M193.
Link Posted: 3/11/2009 5:19:33 AM EDT
[#21]
I wonder if we bumped the velocity we would see a larger temp. cavity. TAP and Mk242 are going more than 200 fps faster. Perhaps this is the causing the more than 1" larger cavity.
Link Posted: 3/11/2009 11:33:00 AM EDT
[#22]
Originally Posted By phoenix27:
Yeah, I'd love to know how to differentiate the sloooow '07 ammo from the faster '08 75-gr OTM lots. The boxes appear the same and so do the bullets. Any ideas out there on how to tell 'em apart?

I would also like to see how fast the newer 69-gr PRVI OTM ammo is compared to the 75-gr OTM stuff. I think Molon has that one on the radar screen for testing in the Spring when the weather breaks up in MI, but I'd like to get some info before the price goes up or they run out of stock and would really like to know what I'm getting. Seems like no one has any info on the PRVI 69-gr OTM ammo, other than it kills hogs effectively as per another post.


When you open the box of ammo, there is a piece of paper in the right hand side of the box (when facing the front) that says what the lot number is.  The first two numbers are the year of the lot number.  2007 is going to start with 07xx, and 2008 is going to start with 08xx.  That's the easiest way to tell.
Link Posted: 3/12/2009 1:22:39 AM EDT
[Last Edit: Duggan] [#23]
hmm, tempting.

Has a full range/accuracy report been done on this yet?

Is this "match" ammo actually "match" quality, aka sub MOA capable?

ETA - answered my own question

http://www.ar15.com/forums/topic.html?b=3&f=16&t=372350
Link Posted: 3/12/2009 2:44:31 PM EDT
[Last Edit: BadassWeakling] [#24]

Originally Posted By Molon:
Originally Posted By BushMeister:


It seems the frag test indicates that the ammo is better than M193-type rounds for self-defense (especially given the amazingly short neck length of 0.8 in., and 60% fragmentation). What would you say, Molon?



You pretty much answered this question for yourself. The ballistic neck of M193 is typically about six times longer than that of the Prvi round. This aspect alone, gives the Prvi load greatly superior terminal ballistic properties compared to M193.

M-193's fragmentation chart from the Ammo Oracle, for reference




The above M-193 chart seems to be using centimeters instead of inches.  Remember that ~2.2 cm = 1 inch.

Now use this chart provided by DocGKR to interpret the data he also provided.  



Originally Posted By Molon:

penetration in bare ballistic gel: 12.6"

neck length:  0.8”

maximum temporary cavity: 3.2” at a depth of 4.7”

recovered diameter:  0.36”

recovered length:  0.15”

recovered weight:  30.1gr

percentage of fragmentation:  60%


I prefer visual representation of information  

If anyone had the picture of 77 Gr or 75 gr fragnmentation handy, it would be much appreciated
Link Posted: 3/15/2009 9:55:46 AM EDT
[#25]
Do all 08 lots have the faster velocities? I have several hundred 0803 and a 1000 of 0808, just curious if I will see any large velocity difference between them.
Link Posted: 3/15/2009 12:33:19 PM EDT
[#26]
Link Posted: 3/15/2009 9:22:12 PM EDT
[#27]
Originally Posted By cerberus212:
Do all 08 lots have the faster velocities? I have several hundred 0803 and a 1000 of 0808, just curious if I will see any large velocity difference between them.


Those are both 2008 lot numbers...

Link Posted: 3/31/2009 8:28:18 PM EDT
[#28]
Originally Posted By BadassWeakling:

Originally Posted By Molon:
Originally Posted By BushMeister:


It seems the frag test indicates that the ammo is better than M193-type rounds for self-defense (especially given the amazingly short neck length of 0.8 in., and 60% fragmentation). What would you say, Molon?



You pretty much answered this question for yourself. The ballistic neck of M193 is typically about six times longer than that of the Prvi round. This aspect alone, gives the Prvi load greatly superior terminal ballistic properties compared to M193.

M-193's fragmentation chart from the Ammo Oracle, for reference


http://ammo.ar15.com/ammo/project/ammoOraclePics/m193.jpg

The above M-193 chart seems to be using centimeters instead of inches.  Remember that ~2.2 cm = 1 inch.

Now use this chart provided by DocGKR to interpret the data he also provided.  

http://www.tridentconcepts.com/alumni/Portals/0/NTForums_Attach/1424105328171.jpg

Originally Posted By Molon:

penetration in bare ballistic gel: 12.6"

neck length:  0.8”

maximum temporary cavity: 3.2” at a depth of 4.7”

recovered diameter:  0.36”

recovered length:  0.15”

recovered weight:  30.1gr

percentage of fragmentation:  60%


I prefer visual representation of information  

If anyone had the picture of 77 Gr or 75 gr fragnmentation handy, it would be much appreciated


NATO pressure Nosler 77 grain OTM from a 20" barrel

courtesy of Dr. G.K. Roberts



SAAMI pressure Hornady 75 grain OTM from a 16" barrel

courtesy of Dr. G.K. Roberts
Link Posted: 4/3/2009 12:07:10 PM EDT
[#29]
Originally Posted By QuicksilverJPR:
Originally Posted By cerberus212:
Do all 08 lots have the faster velocities? I have several hundred 0803 and a 1000 of 0808, just curious if I will see any large velocity difference between them.


Those are both 2008 lot numbers...



It depends, even the best ammo mfgs have small lot to lot variations. I guess its just another thing to test.
Link Posted: 4/3/2009 5:55:07 PM EDT
[#30]
I am glad I found this post. I have 200rds of the 08 got in a trade.  I was thinking of tradeing or selling. I won't be doing that now.
Link Posted: 4/3/2009 6:12:58 PM EDT
[#31]



Originally Posted By Molon:

NATO pressure Nosler 77 grain OTM from a 20" barrel

http://home.comcast.net/~gocartmozart/NATO_pressure_Nosler_77_OTM_gel_shot_from_20_inch_barrel.jpg

courtesy of Dr. G.K. Roberts
SAAMI pressure Hornady 75 grain OTM from a 16" barrel

http://home.comcast.net/~gocartmozart/SAMMI_pressure_Hornady_75_gel_shot_from_16_inch_barrel.jpg

courtesy of Dr. G.K. Roberts



Beautiful, thanks!

 





Link Posted: 4/3/2009 7:47:01 PM EDT
[#32]
I'm still trying to grasp the concept of the varying neck dimensions. I must be missing something. Can anyone out there translate? Thanks.
Link Posted: 4/3/2009 8:05:02 PM EDT
[Last Edit: Molon] [#33]

courtesy of DocGKR




The “ballistic neck” length or initial upset depth is a critical component in evaluating the terminal ballistic properties of a round of ammunition.  It is the length that the bullet travels in the body before it begins to upset (expand, yaw/fragment.)  Keep in mind that on an average adult male, the surface of the heart is roughly 1.5” below the surface of the chest.  Basically, the shorter the ballistic neck, the better.








The difference between a round with a long ballistic neck and a short ballistic neck can be the difference between the bullet sailing through the target without having expanded/yawed/fragmented and only creating the “ice pick” wound versus a bullet that yaws, fragments and creates a large temporary cavity with large amounts of tissue damage within the target.


This . . .



versus this.




This . . .



versus this.


courtesy of DocGKR



Link Posted: 4/3/2009 8:05:05 PM EDT
[Last Edit: BadassWeakling] [#34]
ETA: nevermind
 
Link Posted: 4/4/2009 8:33:33 PM EDT
[#35]
Molon-
Very graphic stuff...I guess the picture really is worth 1,000-words, thanks.

Hey, did you ever get a chance to test out the 69-gr OTM Prvi or the corbon 5.56mm 69 and 77-gr SMK ammo? Those results would be very intriguing.

phoenix27
Link Posted: 4/4/2009 8:47:44 PM EDT
[#36]
Originally Posted By phoenix27:
Molon-
Very graphic stuff...I guess the picture really is worth 1,000-words, thanks.

Hey, did you ever get a chance to test out the 69-gr OTM Prvi or the corbon 5.56mm 69 and 77-gr SMK ammo? Those results would be very intriguing.

phoenix27


It was in the 50s here this week, so we're getting closer.








Link Posted: 4/5/2009 12:12:00 AM EDT
[#37]
Does the Doc give any indication of wether the bullet yaws before fragmenting or expand like a soft point staying nose forward. All the info from hog hunters, the photo from the water jug test and other reports up till now has led me to beleive the bullet is acting as a soft point and expanding rather than yawing and fragmenting. The short neck length also indicates the bullet may be acting as an expansion rnd. I've finally got my hands on a couple of boxes and will do a back yard test in wet news print and report here soon. The news print gives a difinitive view of a bullet yawing so I can see if it yaws or expands.
Link Posted: 4/5/2009 1:44:22 AM EDT
[#38]
Originally Posted By HP40:
Does the Doc give any indication of wether the bullet yaws before fragmenting or expand like a soft point staying nose forward. All the info from hog hunters, the photo from the water jug test and other reports up till now has led me to beleive the bullet is acting as a soft point and expanding rather than yawing and fragmenting. The short neck length also indicates the bullet may be acting as an expansion rnd. I've finally got my hands on a couple of boxes and will do a back yard test in wet news print and report here soon. The news print gives a difinitive view of a bullet yawing so I can see if it yaws or expands.


When I shot news-print with T2 it just punched a massive hole. I could not tell you what happened definitively. It just blew a hole the size of my fist into it after about 1-2".
Link Posted: 4/5/2009 2:42:22 AM EDT
[#39]
Originally Posted By 12_gauge:
Originally Posted By HP40:
Does the Doc give any indication of wether the bullet yaws before fragmenting or expand like a soft point staying nose forward. All the info from hog hunters, the photo from the water jug test and other reports up till now has led me to beleive the bullet is acting as a soft point and expanding rather than yawing and fragmenting. The short neck length also indicates the bullet may be acting as an expansion rnd. I've finally got my hands on a couple of boxes and will do a back yard test in wet news print and report here soon. The news print gives a difinitive view of a bullet yawing so I can see if it yaws or expands.


When I shot news-print with T2 it just punched a massive hole. I could not tell you what happened definitively. It just blew a hole the size of my fist into it after about 1-2".


Maybe my definitive test won't won't be so definitive after all, I know know my tests of various M193 and M855 rnds all showed the yaw very clearly  as the bullet profile shape of the hole prior to the main wound cavity.The only soft points I've tested were Remington 55 gr. PSP wich showed expansion begining at 1" and being fully expanded at 2" wich was the begining of a massive cavity extending to 6" with 11" total penetration. I've always been impressed with how closely wet newsprint corrosponds to ballistic gel though I've heard of deviations others have had.
Link Posted: 4/5/2009 8:29:54 PM EDT
[#40]
Originally Posted By HP40:
Does the Doc give any indication of wether the bullet yaws before fragmenting or expand like a soft point staying nose forward.



The Doc stated, "They yaw, then fragment."  (He's not one to waste words.)

Link Posted: 4/5/2009 10:57:35 PM EDT
[#41]




Originally Posted By Molon:



Originally Posted By HP40:

Does the Doc give any indication of wether the bullet yaws before fragmenting or expand like a soft point staying nose forward.






The Doc stated, "They yaw, then fragment." (He's not one to waste words.)




You're right, he's pretty quiet most of the time.
Link Posted: 4/6/2009 3:31:34 PM EDT
[#42]




Originally Posted By Molon:



Originally Posted By phoenix27:

Molon-

Very graphic stuff...I guess the picture really is worth 1,000-words, thanks.



Hey, did you ever get a chance to test out the 69-gr OTM Prvi or the corbon 5.56mm 69 and 77-gr SMK ammo? Those results would be very intriguing.



phoenix27




It was in the 50s here this week, so we're getting closer.





http://www.box.net/shared/static/v7004ph42k.jpg



http://www.box.net/shared/static/70h027aae4.jpg





We just got clobbered with blizzard-like snow and sleet




I'm looking forward to the 69gr Privi test [and warmer weather!]

Link Posted: 5/2/2009 5:06:16 PM EDT
[#43]
Originally Posted By Rampant_Colt:

Originally Posted By Molon:
Originally Posted By phoenix27:
Molon-
Very graphic stuff...I guess the picture really is worth 1,000-words, thanks.

Hey, did you ever get a chance to test out the 69-gr OTM Prvi or the corbon 5.56mm 69 and 77-gr SMK ammo? Those results would be very intriguing.

phoenix27


It was in the 50s here this week, so we're getting closer.


http://www.box.net/shared/static/v7004ph42k.jpg

http://www.box.net/shared/static/70h027aae4.jpg


We just got clobbered with blizzard-like snow and sleet

I'm looking forward to the 69gr Privi test [and warmer weather!]


It's in the 60's today, so it should be sometime soon.
Link Posted: 5/3/2009 8:42:47 AM EDT
[#44]
Originally Posted By cowboy7242001:
Great results, thanks for posting!

But geez...you'd think they could get it to fly a little faster.


they probably could I bet they did it to keep the presures well with in the safe range of 223. MK262 dose a bit faster than this I think but I hear it's considered a fairly hot load as well.
Link Posted: 5/3/2009 9:02:46 AM EDT
[#45]
thanks!

Question: Isn't 13" perfect?
Link Posted: 5/5/2009 7:07:05 PM EDT
[#46]
Originally Posted By chapperjoe:
thanks!

Question: Isn't 13" perfect?


Perfect?

I guess it depends. Are you shooting a 6 foot, 135 lb emaciated turd or a 6 foot, 550 lb fat ass. In one case 13" might be to much in another 13" might not be enough.
Link Posted: 5/5/2009 7:34:23 PM EDT
[#47]
Originally Posted By Molon:
Originally Posted By Rampant_Colt:

Originally Posted By Molon:
Originally Posted By phoenix27:
Molon-
Very graphic stuff...I guess the picture really is worth 1,000-words, thanks.

Hey, did you ever get a chance to test out the 69-gr OTM Prvi or the corbon 5.56mm 69 and 77-gr SMK ammo? Those results would be very intriguing.

phoenix27


It was in the 50s here this week, so we're getting closer.


http://www.box.net/shared/static/v7004ph42k.jpg

http://www.box.net/shared/static/70h027aae4.jpg


We just got clobbered with blizzard-like snow and sleet

I'm looking forward to the 69gr Privi test [and warmer weather!]


It's in the 60's today, so it should be sometime soon.


Molon-

You're such a tease, ha-ha.
Link Posted: 5/6/2009 12:45:15 AM EDT
[#48]
Originally Posted By fdkay:
Originally Posted By chapperjoe:
thanks!

Question: Isn't 13" perfect?


Perfect?

I guess it depends. Are you shooting a 6 foot, 135 lb emaciated turd or a 6 foot, 550 lb fat ass. In one case 13" might be to much in another 13" might not be enough.


Which is why you want lots of penetration with a short neck before yaw/fragmentation.
Link Posted: 5/6/2009 6:51:33 AM EDT
[#49]
got it, I though the 'goal' of a good round was 13-18 inches
Link Posted: 5/6/2009 9:56:49 AM EDT
[#50]
Originally Posted By chapperjoe:
got it, I though the 'goal' of a good round was 13-18 inches


The FBI standard is 12"-18".

Arrow Left Previous Page
Page / 4
Page AR-15 » Ammunition
AR Sponsor: bravocompany
Close Join Our Mail List to Stay Up To Date! Win a FREE Membership!

Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!

You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.


By signing up you agree to our User Agreement. *Must have a registered ARFCOM account to win.
Top Top