|
November 28, 2008, 06:42 PM
|
#1 |
|
Member
Join Date: October 14, 2005
Location: Northwest Arkansas
Posts: 5,871
|
7.62x39mm ammo tested in bbl lengths from short to long
Over on AR15.com I offered to compile a bunch of data concerning how 7.62x39 preforms in diffrent bbl lengths. I figured I'd share it with you guy's first.
The rifles used for this test differed greatly from one another so please don't take this as "one size fits all" data. The rifles used were as follows 1. A norinco 16.5" paratrooper SKS .310bore 2. is a 20" Model 1 Sales AR15 upper .310bore 3. a custom bolt gun with a 1/15 inch twist bbl that's 26" long and has a .308 bore All chrony readings were taken at 12 feet with a model F1 without sky screens against a uniformly Grey overcast sky and an air temp of 55 degrees. Perfect chronographing weather. Part 1 factory loads 154 grain WOLF sp 16' bbl........20" bbl........ 26" bbl 2042............2106............2273 2025............2110............2265 2015............2113............2261 2041............2125............2256 2033............2124............2250 avg velocity 2031............2115............2261 123 grn Monarch FMJ 16' bbl........20" bbl........ 26" bbl 2354............2432............2599 2345............2418............2595 2377............2405............2593 2315............2453............2548 2330............2422............2601 avg velocity 2344............2426............2587 125 grn Remington SP 16' bbl........20" bbl........ 26" bbl 2265............2261............2428 2238............2308............2444 2202............2304............2437 2191............2366............2485 2224............2264............2486 avg velocity 2224............2300............2456 Part 2 hand loads for these loads the 26" rifle was omitted and the SKS had the gas piston removed due to slamfire and cycling concerns 170grn Sierra .308 diameter 30-30 flat point, magtech SR primer, 28.0grs H335 16' bbl........20" bbl 1921............1968 1924............1967 1931............1970 1936............1970 1896............1985 avg velocity 1921............1972 125 grn nosler b-tip, magtech SR primer, 25.5grs AA1680 16' bbl........20" bbl 2256............2359 2226............2355 2243............2361 avg velocity 2241............2358 The only real loser in all this is the anemic Remington ammo, this stuff just reinforces my assertion that anything METRIC factory loaded in this country is going to suck. The most interesting find was just how fast and accurate these loads were when fired from as accurate platform as possible through a 26" tube 5 shot groups for the factory loads in the Stevens 200 were as follows 154grn Wolf 1.2" 123grn Monarch 1.37" 125grn Remington 1.0"
__________________
Have you taken an AR15 hunting recently? Please think of the poor unfortunate EBR's will you? .223 rem Buck 7.62x39mm Doe Last edited by krochus; November 28, 2008 at 10:05 PM. |
|
|
November 28, 2008, 09:34 PM
|
#2 |
|
Member
Join Date: July 14, 2008
Location: TX
Posts: 298
|
Nice data. I just stocked up on some monarch from academy so this is nice data to have. The monarch looks to be pretty hot stuff. Thank for your efforts.
__________________
2+2=4 |
|
|
|
November 28, 2008, 09:45 PM
|
#3 |
|
Member
Join Date: August 10, 2007
Location: Phoenix Arizona
Posts: 2,675
|
Rem is way underloaded! Curious why Wolf Military Classic Ammo wasn't also tested in 122gr or Winchester White Box from Wally World? Would like to have seen those included. Otherwise good info. Thanks.
__________________
Lady Astor: "If I were your wife I'd put poison in your coffee." Winston Churchill: "If I were your husband I'd drink it!" The beatings will continue until Morale improves! |
|
|
|
November 28, 2008, 09:50 PM
|
#4 | |
|
Member
Join Date: October 14, 2005
Location: Northwest Arkansas
Posts: 5,871
|
Quote:
Even though I had a box of mil classic on hand my AR15 will not ignite the stuff. I didn't have any win ammo on hand, the ammo tested was what I happened to have. I'm most impressed with the Monarch fodder especially the combination of accuracy and velocity from the Bench gun. Just over MOA for less than $5 a box and at a smoking velocity too. I wish I had bought another 1K
__________________
Have you taken an AR15 hunting recently? Please think of the poor unfortunate EBR's will you? .223 rem Buck 7.62x39mm Doe |
|
|
|
|
November 28, 2008, 10:11 PM
|
#5 |
|
Member
Join Date: September 6, 2007
Posts: 914
|
With my Yugo SKS, which is a 24" barrel with the grenade launcher, I'm getting 2450-2500 fps with the 122 grain Wolf FMJ and I'm getting 2150-2200 with the 154 grain Wolf SP's. The extra 4" of length is giving me 75-100 fps. The grenade launcher acts like an expansion chamber, its not rifled, but it still contains the gas from the powder.
|
|
|
|
November 28, 2008, 10:42 PM
|
#6 |
|
Member
Join Date: February 22, 2007
Location: Oz, right next door to The Lollipop Guild HQ
Posts: 681
|
I've been hoping someone with a chrony and weapons in 7.62x39 with different barrel lengths would do this type of testing.
Thank you, krochus.  IIRC, someone mentioned in another thread that Monarch is a re-badged version of Sapsan. Anybody know if this is true? Hmmm...haven't been to Arfcom's dark side in a couple of weeks. Better mosey on over and catch up. 
__________________
<~><~><~><~><~><~><~><~><~><~><~><~> Free advice by this author is worth exactly what you paid for it. |
|
|
|
November 28, 2008, 10:43 PM
|
#7 | |
|
Member
Join Date: October 14, 2005
Location: Northwest Arkansas
Posts: 5,871
|
Quote:
__________________
Have you taken an AR15 hunting recently? Please think of the poor unfortunate EBR's will you? .223 rem Buck 7.62x39mm Doe |
|
|
|
|
November 29, 2008, 04:42 PM
|
#8 |
|
Member
Join Date: March 17, 2008
Location: Somewhere.........
Posts: 2,616
|
Nice data krochus. Can you get some ballistics charts up for this info?
|
|
|
|
November 29, 2008, 04:54 PM
|
#9 |
|
Member
Join Date: October 14, 2005
Location: Northwest Arkansas
Posts: 5,871
|
I could calculate them up using my "POINT BLANK" program, but I'd be completely lost as to how to post em in a readable format. I really struggled with the HTML needed for this small collection of numbers.
I'll see what I can do for a simple 100 200 and 300yd energy and trajectory table
__________________
Have you taken an AR15 hunting recently? Please think of the poor unfortunate EBR's will you? .223 rem Buck 7.62x39mm Doe |
|
|
|
November 29, 2008, 05:03 PM
|
#10 |
|
Member
Join Date: March 17, 2008
Location: Somewhere.........
Posts: 2,616
|
Cool, thanks.
|
|
|
|
November 29, 2008, 06:07 PM
|
#11 |
|
Member
Join Date: October 14, 2005
Location: Northwest Arkansas
Posts: 5,871
|
as best I can calculate the ballistics are as follows, based on a 200yd ZERO
154 grain Wolf SP, ballistic coefficient .3302 range........elevation........velocity........energy 16.5" bbl 100yds........+4.64"........1813fps........1124 fpe 200yds........+0.00"........1614fps........890 fpe 300yds........-17.78".......1432fps........701 fpe 20" bbl 100yds........+4.20"........1891fps........1223 fpe 200yds........+0.00"........1685fps........971 fpe 300yds........-16.39".......1497fps........766 fpe 26" bbl 100yds........+3.46"........2029fps........1407 fpe 200yds........+0.00"........1811fps........1121 fpe 300yds........-14.35".......1612fps........888 fpe 123 grain Monarch FMJ, ballistic coefficient .257? range........elevation........velocity........energy 16.5" bbl 100yds........+3.44"........2042fps........1139 fpe 200yds........+0.00"........1765fps........850 fpe 300yds........-14.72".......1517fps........628 fpe 20" bbl 100yds........+3.12"........2118fps........1225 fpe 200yds........+0.00"........1833fps........918 fpe 300yds........-13.74".......1578fps........680 fpe 26" bbl 100yds........+2.66"........2268fps........1404 fpe 200yds........+0.00"........1971fps........1061 fpe 300yds........-11.71".......1701fps........790 fpe 125 grain Remington SP, ballistic coefficient .267 range........elevation........velocity........energy 16.5" bbl 100yds........+3,93"........1941fps........1046 fpe 200yds........+0.00"........1684fps........787 fpe 300yds........-16.15".......1454fps........587 fpe 20" bbl 100yds........+3.57"........2012fps........1124 fpe 200yds........+0.00"........1747fps........847 fpe 300yds........-15.02".......1510fps........633 fpe 26" bbl 100yds........+2.97"........2157fps........1292 fpe 200yds........+0.00"........1879fps........980 fpe 300yds........-13.11".......1629fps........736 fpe
__________________
Have you taken an AR15 hunting recently? Please think of the poor unfortunate EBR's will you? .223 rem Buck 7.62x39mm Doe Last edited by krochus; November 29, 2008 at 06:50 PM. |
|
|
|
November 29, 2008, 07:17 PM
|
#12 |
|
Member
Join Date: March 27, 2008
Location: Queens, NY
Posts: 592
|
Krochus:
Did you see a big difference in your groupings when using 308 diameter bullets in the guns. I ask because I am looking into reloading 7.62x39 for my AK and it would be easiest and cheapest to use the .308 diamter I have for my .308 bolt gun. I heard everything from "it will be a tackdriver in the bolt gun and okay in the AK, hey it's an AK anyway who cares" to "if you do that you will blow your AK up in your face. You seem to be very knowledgable in this department so any info you could share would be appreciatted. |
|
|
|
November 29, 2008, 07:30 PM
|
#13 |
|
Member
Join Date: October 14, 2005
Location: Northwest Arkansas
Posts: 5,871
|
In all the .310 bored rifles I've tried .308 bullets in none showed the slightest reduction in accuracy because of it. Many reloading dies for 7.62x39 come with two expander balls for .308 and .310 diameter bullets just for this reason.
I have however noted that with low pressure loadings the smaller bullets tend to produce somewhat lower velocities, but this disparity all but disappears when full throttle loads are used. many don't realize that .310 bores tend to have deeper rifling than STD american .30 caliber. guns. While the BORE may be .002" larger typically the measurement between the lands will still mic .300 just like any 30 cal. This means that you still have plenty of grip on .308 bullets in a .310 bore. I theorize that between the bullet jacket material displaced by the rifling and bullet obturation there's more than ample bullet seal generated to prevent any significant amount of gas blowby that or...... when it comes right down to it .002 just isn't very darn much
__________________
Have you taken an AR15 hunting recently? Please think of the poor unfortunate EBR's will you? .223 rem Buck 7.62x39mm Doe |
|
|
|
November 29, 2008, 07:44 PM
|
#14 |
|
Member
Join Date: March 27, 2008
Location: Queens, NY
Posts: 592
|
Thanks for the reply and figured you were the one to ask. I never thought about the dies and your right all the ones I looked at had both 308 and 310
|
|
|
|
November 29, 2008, 08:05 PM
|
#15 |
|
Member
Join Date: November 14, 2007
Posts: 12,609
|
Very interesting; thank you!
__________________
ATTENTION: Shooters, hunters, sportsmen & women everywhere -- Please pick up and pack out more trash with you than you created, every time you venture into the great outdoors - Let's show the world that we are more responsible than the average citizen! |
|
|
 |
| Thread Tools | |
| Display Modes | |
|
|
Linear Mode
