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Posted: 11/16/2008 12:13:20 PM EDT
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Is this stuff sealed at both ends?
What is the general consensus between this VS. Hornady T2? Molon, if it isn't too much trouble, can you tell me the trajectory difference between this and M855 out to 800m (I am trying to match the BDC of an RCO A4 ACOG). Thanks in advance! |
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Its more accurate by about .1 MOA, it has much later yaw so its not as good from a terminal ballistics standpoint. It has a temperature stabiliser so it wont gain so much pressure and velocity in desert conditions which the TAP lacks. It has a tiny bit better external ballistics than T2 TAP because of the better BC.
If the RCO ACOG has a M855 BDC you will get better results using a 7.62 BDC ACOG. The ballistics are not very close. The only way you will "match" a M855 BDC for an M4 is to use 68/69 grain ammo and a long ass barrel. |
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Quoted:
Its more accurate by about .1 MOA, it has much later yaw so its not as good from a terminal ballistics standpoint. It has a temperature stabiliser so it wont gain so much pressure and velocity in desert conditions which the TAP lacks. It has a tiny bit better external ballistics than T2 TAP because of the better BC. If the RCO ACOG has a M855 BDC you will get better results using a 7.62 BDC ACOG. The ballistics are not very close. The only way you will "match" a M855 BDC for an M4 is to use 68/69 grain ammo and a long ass barrel. Your IM box is full. |
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Quoted:
Its more accurate by about .1 MOA, it has much later yaw so its not as good from a terminal ballistics standpoint. It has a temperature stabiliser so it wont gain so much pressure and velocity in desert conditions which the TAP lacks. It has a tiny bit better external ballistics than T2 TAP because of the better BC. If the RCO ACOG has a M855 BDC you will get better results using a 7.62 BDC ACOG. The ballistics are not very close. The only way you will "match" a M855 BDC for an M4 is to use 68/69 grain ammo and a long ass barrel. I ran some numbers using T2 ballistics and it is within 20" drop of M855 at 800m At 600m it is within 6-10" Am I running the numbers wrong? |
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Quoted:
Quoted:
Its more accurate by about .1 MOA, it has much later yaw so its not as good from a terminal ballistics standpoint. It has a temperature stabiliser so it wont gain so much pressure and velocity in desert conditions which the TAP lacks. It has a tiny bit better external ballistics than T2 TAP because of the better BC. If the RCO ACOG has a M855 BDC you will get better results using a 7.62 BDC ACOG. The ballistics are not very close. The only way you will "match" a M855 BDC for an M4 is to use 68/69 grain ammo and a long ass barrel. I ran some numbers using T2 ballistics and it is within 20" drop of M855 at 800m At 600m it is within 6-10" Am I running the numbers wrong? Run the numbers against a 7.62 reticle. I dont know what BC or velocity figures you are using. Over 1 MOA off is not close IMO but you may disagree. What zero are you running for both? From what barrel length? The difference in the rounds overall trajectory is not the only thing effecting the closeness of the BDC. If its zeroed at 100m like many ACOGs that changes things. The M855 will have less elevation dialed in than MK262 or TAP at 100m zero. It has less drop at 100m but way more out at 800m. This can create even more difference in the BDC vs bullet impact than just how much the bullets are off if you actually zero the 75/77 grain ammo at 100 and dont just "let it be" to maintain just the difference. Then you can tune the 100 yard zero high or low to help reduce the BDC difference. THere is a tackes thread in the optics section on ACOG BDS or at least there used to be. |
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Its more accurate by about .1 MOA, it has much later yaw so its not as good from a terminal ballistics standpoint. It has a temperature stabiliser so it wont gain so much pressure and velocity in desert conditions which the TAP lacks. It has a tiny bit better external ballistics than T2 TAP because of the better BC. If the RCO ACOG has a M855 BDC you will get better results using a 7.62 BDC ACOG. The ballistics are not very close. The only way you will "match" a M855 BDC for an M4 is to use 68/69 grain ammo and a long ass barrel. I ran some numbers using T2 ballistics and it is within 20" drop of M855 at 800m At 600m it is within 6-10" Am I running the numbers wrong? Run the numbers against a 7.62 reticle. I dont know what BC or velocity figures you are using. Over 1 MOA off is not close IMO. What zero are you running for both? From what barrel length? .350BC@2800fps (20" barrel) for the T2 .304BC@3100fps (20") for the M855. I just punched 100m zero in for both. at 7 and 800m there is about a 2' difference or so (19X" vs. 22X" drop), but at 600m it is close to 1-2MOA and 500m in is 1moa or so IIRC. I don't have the print out in front of me. For all but the longest shots, T2 should be pretty dead on with the M855 and for the longer shots, hold 1-2 BDC lines over. |
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This is how close the .308 BDC is
For a Flattop 16" firing 75gr OTM @2615fps (.223 pressure but about the same for a 14.5" with 5.56 TAP) Sight in at 100 per manual. This is a real close match. Max deviation is 2" at 600m and you'll be within 1" at all other ranges. To me close is relative. You can always just laser range and see what the differences are. Also the ACOG is in meters. You can also get a nice alternative range by calling all the distances yards. This, in effect, changes the BC of the BDC reticle. Just deciding and remembering to change your inital sight in point by 1 MOA... 1" at 100 yards can close the gap by 8" at 800. You just have to play with it to get it as close as you feel you need. You can get a reticle "closer" but you wont "match" it is all I am trying to convey. |
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Is this stuff sealed at both ends? MK262 has sealed primers but is not sealed at the case mouth. Newer lots of 5.56 TAP have sealed primers and case mouths. What is the general consensus between this VS. Hornady T2? click here Molon, if it isn't too much trouble, can you tell me the trajectory difference between this and M855 out to 800m (I am trying to match the BDC of an RCO A4 ACOG). see below Thanks in advance! 
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Quoted:
This is how close the .308 BDC is For a Flattop 16" firing 75gr OTM @2615fps (.223 pressure but about the same for a 14.5" with 5.56 TAP) Sight in at 100 per manual. This is a real close match. Max deviation is 2" at 600m and you'll be within 1" at all other ranges. To me close is relative. You can always just laser range and see what the differences are. Also the ACOG is in meters. You can also get a nice alternative range by calling all the distances yards. This, in effect, changes the BC of the BDC reticle. Just deciding and remembering to change your inital sight in point by 1 MOA... 1" at 100 yards can close the gap by 8" at 800. You just have to play with it to get it as close as you feel you need. You can get a reticle "closer" but you wont "match" it is all I am trying to convey. I understand completely, I meant "match" in a very general sense. I should have used the term "approximate". DEVL, is this a "normal" neck for MOD1, or is it shorter/longer than avg.? Looks pretty nasty to me. 
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Is this stuff sealed at both ends? MK262 has sealed primers but is not sealed at the case mouth. Newer lots of 5.56 TAP have sealed primers and case mouths. What is the general consensus between this VS. Hornady T2? click here Molon, if it isn't too much trouble, can you tell me the trajectory difference between this and M855 out to 800m (I am trying to match the BDC of an RCO A4 ACOG). see below Thanks in advance! http://www.box.net/shared/static/zlzxc1836s.jpg Thankyou Molon, your reply is more than up to your usual golden standard for accurate and concise information! DevL said the neck is much longer for the MK262MOD1, does it fragment at the same range as T2 though? What is the range of reliable fragmentiation, same 2300fps rule? |
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