imr 8208 vs Tac (5.56 nato loads)

[freestylmx]

Ive loaded up several 75 bthp and 77 noslers with Tac and imr 8208. They both have almost identical burn speeds and they both are excellent in my 20" BCM AR-15, but Im getting much higher velocities with tac
24.5 grains of tac and Im getting 2865 fps with 77's and 3000 fps with 75's which according to most over sensitive people my rifle should have exploded (nonsense)
With 8208 my velocities are about 150-200 fps less but I think my loads with imr are not max like tac, Im loading around 23.3 gr with a 75 BTHP getting 2700 FPS
which is what I was expecting and dont need much more, but if tac is going to give me just as good accuracy but with much more velocity Ill take it.
Whats been your guys experience with these two? Im getting consistent groups of 0.5-0.8 moa with both and anything under 1moa for an ar-15 is outstanding imo. Id be happy with 1-1.5moa (can hit anything where it needs to be hit out to 200 yards or more with that)

 

[pdice]

Re: imr 8208 vs Tac (5.56 nato loads)

I saw nearly identical results. I picked up the 8208 as soon as it came out looked and compared it to my TAC loads and wasn't satisfied. I pushed it up to book max.

 

[freestylmx]

Re: imr 8208 vs Tac (5.56 nato loads)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pdice</div><div class="ubbcode-body">I saw nearly identical results. I picked up the 8208 as soon as it came out looked and compared it to my TAC loads and wasn't satisfied. I pushed it up to book max. </div></div>
Its working better in my AR-10 but its still excellent in the ar-15. I still need to try a lot more different charges and bullets but so far Im leaning toward tac for the 5.56 and 8208 for the 308 even though one is good for both. Tac works out great in the 308 as well
BUt one issue I have is I live in Phoenix and Im afraid these max loads wont be a great idea with the tac in temps over 100 degrees. I know the 8208 is temperature stable

 

[Woodlanddude]

Re: imr 8208 vs Tac (5.56 nato loads)

TAC shows actual5.56 pressure loads. IMR is too pansy to publish or release this data, even by email. Therefore if you wish similar performance, you must go on your own devices to work up a load at your own risk. I would love to see a quickload for 77s/75s for 8208 xbr. I have it almost to mk 262 velocities a smidgeon over book max, but hesitate to go further without addtl. info. I have seen some using it super hot with good results. IMR will lose some sales to TAC without comparible load data soon IMHO. Mine is about to turn there for 5.56, at the least.

 

[freestylmx]

Re: imr 8208 vs Tac (5.56 nato loads)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Woodlanddude</div><div class="ubbcode-body">TAC shows actual5.56 pressure loads. IMR is too pansy to publish or release this data, even by email. Therefore if you wish similar performance, you must go on your own devices to work up a load at your own risk. I would love to see a quickload for 77s/75s for 8208 xbr. I have it almost to mk 262 velocities a smidgeon over book max, but hesitate to go further without addtl. info. I have seen some using it super hot with good results. IMR will lose some sales to TAC without comparible load data soon IMHO. Mine is about to turn there for 5.56, at the least. </div></div>
Ya Ramshot and Accurate both show 5.56 nato loadings. It would be nice if others would do the same. Im going to start working over book max on 8208 xbr and see if I can get around 2800-2900 fps with good accuracy with the 77's out of my 20" barrel. I get that easily with Tac. Honestly Im happy sticking with Tac, I just dont know how well its going to be in hot temps around 110 degrees. Ill find out in a few months

 

[biner626]

Re: imr 8208 vs Tac (5.56 nato loads)

See my post. I like this load a lot
http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=351023&page=5

 

[leid]

Re: imr 8208 vs Tac (5.56 nato loads)

This is a 2008 email I received from Keith Anderson (cut n pasted with Keith's written permission) back when I was first working up high pressure TAC loads prior to 5.56MM NATO data being made public:

>> From: Keith Anderson
>> Subject: powder temperature stability
>> To: carey
>> Date: Friday, June 13, 2008, 12:36 PM
>> Carey,
>>
>> First I would like to thank you for your interest in
>> Ramshot powders.
>>
>> All of the powders sold under the Ramshot or Accurate
>> brands meet or exceed the military specification for hot
>> and cold stability. As with anything some powders are
>> better than others. Single base powders such as Varget can
>> be made more temperature stable than double based powders
>> such as Accurate 2520 although there are trade offs to
>> anything. While the nitroglycerin in a double based powder
>> makes it less temperature stable it is the component that
>> makes double based powders cleaner burning and allows them
>> to attain higher velocities than their single based
>> cousins.
>>
>> In both the single base and double base lines of powders
>> some powders have better temperature stability than others.
>> Ramshot "TAC" is one of the most temperature
>> stable double based powders available. It is this very
>> reason that so much of it is being used for military
>> applications in both Iraq and Afghanistan. Even under
>> extreme temperatures Ramshot "TAC" will vary less
>> than half of what the military will allow.
>>
>> I hope this helps you out.
>>
>> Good shooting!
>>
>> Keith Anderson
>> Western Powders Ballistic Lab

 

[freestylmx]

Re: imr 8208 vs Tac (5.56 nato loads)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: leid</div><div class="ubbcode-body">This is a 2008 email I received from Keith Anderson (cut n pasted with Keith's written permission) back when I was first working up high pressure TAC loads prior to 5.56MM NATO data being made public:

>> From: Keith Anderson
>> Subject: powder temperature stability
>> To: carey
>> Date: Friday, June 13, 2008, 12:36 PM
>> Carey,
>>
>> First I would like to thank you for your interest in
>> Ramshot powders.
>>
>> All of the powders sold under the Ramshot or Accurate
>> brands meet or exceed the military specification for hot
>> and cold stability. As with anything some powders are
>> better than others. Single base powders such as Varget can
>> be made more temperature stable than double based powders
>> such as Accurate 2520 although there are trade offs to
>> anything. While the nitroglycerin in a double based powder
>> makes it less temperature stable it is the component that
>> makes double based powders cleaner burning and allows them
>> to attain higher velocities than their single based
>> cousins.
>>
>> In both the single base and double base lines of powders
>> some powders have better temperature stability than others.
>> Ramshot "TAC" is one of the most temperature
>> stable double based powders available. It is this very
>> reason that so much of it is being used for military
>> applications in both Iraq and Afghanistan. Even under
>> extreme temperatures Ramshot "TAC" will vary less
>> than half of what the military will allow.
>>
>> I hope this helps you out.
>>
>> Good shooting!
>>
>> Keith Anderson
>> Western Powders Ballistic Lab
</div></div>

Thanks for posting that up. Ive always wondered if all these people saying how temp sensitive powders are that are ball powders are really correct. Ive thought this because all 5.56 military loads are hot loads. If there was such a fine line between your rifle "exploding" vs it running just fine from just dropping your charge a couple tenths of a grain, then rifles in combat would be blowing up left and right. I think everyone blows things way out of proportion just because they heard someone else say something on a forum and it gets spread as gospel.
The only thing I think would happen with a "temp sensitive" powder is your point of impact will shift...not your rifle going Kaboom (if its built to spec, which just about all commercial AR-15's are)
Usually "kabooms" are from something obstructing the barrel

 

[leid]

Re: imr 8208 vs Tac (5.56 nato loads)

Old data but still a very good read on SMALL ARMS PROPELLANT THERMAL STABILITY: http://www.dtic.mil/ndia/2006smallarms/marsh.pdf

Edit: Info only: Maximum 5.56MM NATO pressure is 62,350 PSI but USGI 5.56MM ammunition can only be loaded to 58,700 PSI according to the mil-spec AFAIK.

 

[freeflight]

Re: imr 8208 vs Tac (5.56 nato loads)

Good info.