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5/28/2020 10:18:12 PM
Posted: 1/7/2003 9:43:52 AM EDT
As reported in Special Weapons Magazine winter 2003
“Most recent information to come to our attention indicates the military is seriously looking at a 6.8x43mm round to ultimately replace the.22. This Special Purpose Carbine that is currently being tested at military labs, which features a muzzle velocity of 2750 feet per second.  The .276 caliber “open tipped match bullet’s” ballistic coefficient is .380, which is the equivalent of the vaunted 168-grain boatailed .308 round.  Terminal ballistic results have been impressive.”
Link Posted: 1/7/2003 10:17:56 AM EDT
Is it just me, or are they merely reinventing the 30 caliber rifle?
Link Posted: 1/7/2003 12:17:17 PM EDT
Link Posted: 1/7/2003 12:27:16 PM EDT
Before WWII there was A LOT of testing of .270 caliber rounds in England.  There was some testing and development in the U.S. as well. It was all dropped due to the war for obvious reasons.

Supposedly the rounds had better performance than military rounds of the time.  This is most likely true, but as for today, it a whole new ball game. Maybe it a good idea, maybe not.
Link Posted: 1/7/2003 12:34:56 PM EDT
Originally Posted By Troy:
Originally Posted By El_Roto:
Is it just me, or are they merely reinventing the 30 caliber rifle?
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How are they "reinventing the 30 caliber rifle" by experimenting with a .270 load?

-Troy
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Perhaps ballistically.  As stated experiments are achieving simular results as with the .308Win.

Given conventional short action brass, this seems to be a slightly smaller package than the 7.62 with near equal terminal ballistics. Most likey the MV is much higher and the mass lower than the traditional 7.62. I wonder what the actual mass is of this new "open tipped match" bullet.

Historically, there has never been the level of attention put into the effectiveness of rifle ammunition that has gone into pistol ammunition. This reminds me of the birth of the .40S&W.
Link Posted: 1/7/2003 1:55:56 PM EDT
Originally Posted By Boomholzer:
As stated experiments are achieving simular results as with the .308Win.
View Quote


No.  It states that the BC is the same.  It never states that any other results are the same.  Big difference.

Different bullet, different characteristics.  BC just happens to be the same.
Link Posted: 1/7/2003 2:02:57 PM EDT
Link Posted: 1/7/2003 2:06:59 PM EDT
Wouldn't they have a conflict with the NATO requirements for all the NATO nations to have the same ammo?
Link Posted: 1/7/2003 2:12:37 PM EDT
The U.S has been good at forcing NATO to do what they want weapons wise.  What was that deal the U.S. screwed the British with? The U.S would buy FAL's and we would adopt their (270 caliber round I think) new ammunition.

This project is a ways off regardless.
Link Posted: 1/7/2003 2:17:13 PM EDT
Oh well if it happens, they will see they are sitting on a crap load of .223 Ammo and decide to sell it off to the civilians. All it takes is for Bush to sign to allow it.
Link Posted: 1/7/2003 2:26:42 PM EDT
[Last Edit: 1/7/2003 2:28:06 PM EDT by Boomholzer]
Brou,
Agreed. I said perhaps as in speculation. The drive for experimentation is still to produce a cartidge more like the old .30 cal to overcome ballistic shortcomings of the 5.56.


Originally Posted By Aimless:
Aren't 7mm and 270 bullets supposed to be pretty accurate because of the width/length characteristics or something like that?
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From what I know: The .308 is inherently more accurate because of the shorter powder column combined with more efficent flame travel due to the dia. The cartidges you noted are also used in "short action" rifles.
All else the same; The .270 is never considered "more accurate" than the .308. I dont recall the reasoning and Im sure this will be rebutted by .270 fans. I think this has to due with the cartidge being loaded with almost as much powder as will fit inside it. Perhaps because it is typically pushed as a "hot" load, even from the factory.
Link Posted: 1/7/2003 2:37:21 PM EDT
Originally Posted By obershutze916:
The U.S has been good at forcing NATO to do what they want weapons wise.  What was that deal the U.S. screwed the British with? The U.S would buy FAL's and we would adopt their (270 caliber round I think) new ammunition.

This project is a ways off regardless.
View Quote


OK, maybe I'm dumb, but I thought that the original intention of the British was to adopt the FAL in a 7mm round with similar ballistics to the .280 Remington.  When the US adopted the 7.62x51mm (.308 Winchester) round in the M1A rifle, the English changed their order to FALs chambered in 7.62x51mm, if memory serves.  Like I said, maybe I'm dumb.  

Either way, I don't see how going to a .270 TCU (or would this be closer to a .270 Whisper?) is really going to be equivalent to .308 Winchester ballistics.  How is it that a heavier bullet out of a smaller case is going to be better than a lighter bullet at a higher velocity.  The larger bullet is unlikely to fragment, will not be designed to expand (I'm assuming here), and is starting at a much slower velocity.  Range will likely be similar to the current 5.56x45mm round, I have my doubts about barrier penetration, not to mention the logistics of deploying it.  I dunno, I'm not a terminal ballistics expert.
Link Posted: 1/7/2003 2:59:12 PM EDT
Originally Posted By Boomholzer:
[snip] The drive for experimentation is still to produce a cartidge more like the old .30 cal to overcome ballistic shortcomings of the 5.56.
[snip]
View Quote


My point exactly.  
Link Posted: 1/7/2003 3:30:52 PM EDT
Originally Posted By Aimless:
Aren't 7mm and 270 bullets supposed to be pretty accurate because of the width/length characteristics or something like that?
View Quote


I'm not sure about the .270 and 7mm, but the 6.5mm has a very high BC, and because of that, it keeps it's energy for a much longer distance than other rounds.  I think that's what you're thinking of.

I'm not sure about the 270 specifically, as I've never paid much attention to it.  But in general, 6mm-7mm rounds display this characteristic.

Then again, I'm more of a terminal performance kind of guy, so maybe someone else can chime in.
Link Posted: 1/7/2003 4:57:05 PM EDT
BTW. I missed it on the original post. The bullet is 125 grains.
Never did learn to type worth a damn.
Link Posted: 1/7/2003 5:49:45 PM EDT
I ran this in my ballistic program.  100yd zero.

6.8 125gr bullet at a muzzle velocity of 2750 fps
ballistic coefficent of .380
100 yds    0.00 in  2523 fps  1767 fpe  0.114 sec
200 yds   -4.96 in  2308 fps  1478 fpe  0.238 sec
300 yds  -16.53 in  2103 fps  1228 fpe  0.375 sec
400 yds  -35.75 in  1908 fps  1011 fpe  0.523 sec
500 yds  -64.91 in  1727 fps   828 fpe  0.690 sec
600 yds -105.83 in  1559 fps   675 fpe  0.873 sec
700 yds -160.93 in  1406 fps   549 fpe  1.075 sec
800 yds -234.60 in  1274 fps   451 fpe  1.300 sec

.308 168gr bullet at a muzzle velocity of 2700 fps.
ballistic coefficent of .462
100 yds    0.00 in  2515 fps  2359 fpe  0.115 sec
200 yds   -4.98 in  2337 fps  2037 fpe  0.238 sec
300 yds  -16.43 in  2167 fps  1751 fpe  0.372 sec
400 yds  -35.15 in  2003 fps  1497 fpe  0.516 sec
500 yds  -62.43 in  1847 fps  1272 fpe  0.671 sec
600 yds -100.51 in  1701 fps  1079 fpe  0.842 sec
700 yds -150.49 in  1563 fps   912 fpe  1.026 sec
800 yds -214.34 in  1436 fps   769 fpe  1.225 sec
Link Posted: 1/7/2003 6:19:46 PM EDT
Originally Posted By Ariel:
Oh well if it happens, they will see they are sitting on a crap load of .223 Ammo and decide to sell it off to the civilians. All it takes is for Bush to sign to allow it.
View Quote


All it takes is his signature on a lot of issues. Unfortunately he does not appear eager to sign away any of Clintons executive orders.
Link Posted: 1/7/2003 6:39:34 PM EDT
Originally Posted By 5pins:
As reported in Special Weapons Magazine winter 2003
“The .276 caliber “open tipped match bullet’s” ballistic coefficient is ...”
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I wonder if they will get around the Hague Convention's prohibition on use of hollow-point rounds in war.  Depending on the expansion of the round, it might not cut the mustard under the law of war.
Link Posted: 1/7/2003 8:01:49 PM EDT
Originally Posted By obershutze916:
Before WWII there was A LOT of testing of .270 caliber rounds in England.  There was some testing and development in the U.S. as well. It was all dropped due to the war for obvious reasons.
View Quote


 Actually the British started testing a .276 cal mauser action to replace the incomparable No1 MkIII SMLE in 1910, with development stopping due to the outbreak of ww1.  They ended up sticking to the .303, simplifying the SMLE somewhat, and shipping the mauser tooling (converted to .303) to the US.  We produced these rifles as the P14 for british home service use until 1917 when we finally decided to get in on the fun.  The Springfield was in short supply, so the P14 was converted again to 30-'06 and renamed the M1917 Enfield for american use.  More of these saw service than Springfields, IIRC.  
 The Canadians actually fielded a .280cal cartridge in their misbegotten son of a sewerpipe, the Ross rifle (later also in .303), though one too many jammed or blew their bolts back at their users and the canadians switched over to the SMLE also.
 No, there won't be a test on this, though if you REALLY want a story, check out the US produced, never-exported, and service-issued Mosin Nagants for a good time.
Link Posted: 1/7/2003 8:36:18 PM EDT
[Last Edit: 1/7/2003 8:36:50 PM EDT by Jetlag]
Originally Posted By spartacus2002:
Originally Posted By 5pins:
As reported in Special Weapons Magazine winter 2003
“The .276 caliber “open tipped match bullet’s” ballistic coefficient is ...”
View Quote


I wonder if they will get around the Hague Convention's prohibition on use of hollow-point rounds in war.  Depending on the expansion of the round, it might not cut the mustard under the law of war.
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An open tip is not a hollow point.
Link Posted: 1/7/2003 9:42:07 PM EDT
The deal was with the new "NATO rifle" of the late 1950's, everyone would adopt the 7.62x51mm NATO round if we would adopt the FAL.

The new caliber does sound interesting....the Czechs adopted a 7.62x45mm round after WWII, and kept it until the Soviet invasion when they had the 7.62x39mm rammed down their throats.
Link Posted: 1/8/2003 7:06:36 AM EDT
Originally Posted By Jetlag:
An open tip is not a hollow point.
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Correct.  An open-tip is a product of the manufacturing process, and is NOT desgned with expansion in mind.
Link Posted: 1/8/2003 8:05:53 AM EDT
My memory might be faulty on this, but wasn't the Garand originally developed for a .270 cartridge?
Link Posted: 1/8/2003 8:28:49 AM EDT
[Last Edit: 1/8/2003 8:32:28 AM EDT by brouhaha]
Originally Posted By eswanson:
My memory might be faulty on this, but wasn't the Garand originally developed for a .270 cartridge?
View Quote


Yes.  The .276 Pederson.  It primarily failed because of timing.  The US has HUGE stocks of .30 cal ammo left over from WW1, and the .276 came at the height of the depression.  Refitting and restocking to a new caliber was deemed too costly, so the Garand was rechambered to the more common .30 cal.
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