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Posted: 2/12/2006 5:35:06 AM EDT
As the title implies, has anybody taken a look at the 6.8 SPC Ammo in the Hornady booth?

If so, was it the 110 gr polymer tipped loading? Did the reps offer any performance data (i.e., mean velocities from different barrel lengths, etc...)?

Thanks.

Justin
Link Posted: 2/12/2006 7:10:11 AM EDT
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes. The lable says 2550 fps out of a 16 inch barrel. I have not chronoed it but it is about as accurate as my best hand load.
Link Posted: 2/12/2006 8:31:59 AM EDT

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes. The lable says 2550 fps out of a 16 inch barrel. I have not chronoed it but it is about as accurate as my best hand load.



Damn. I spoke with Zak Smith and he's able to handload VMAX up to 2670 from an 18" barrel.

I was hoping that Hornady could push it to 2650/2700 FPS from a 16" barrel.
Link Posted: 2/12/2006 9:08:06 AM EDT
[Last Edit: 2/12/2006 9:08:29 AM EDT by inkaybee]

Originally Posted By CitySlicker:

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes. The lable says 2550 fps out of a 16 inch barrel. I have not chronoed it but it is about as accurate as my best hand load.



Damn. I spoke with Zak Smith and he's able to handload VMAX up to 2670 from an 18" barrel.

I was hoping that Hornady could push it to 2650/2700 FPS from a 16" barrel.



Why are we so worried about sqeezing that extra 100 fps out of the 6.8.

I shot two coyotes last weekend with the Vmaxes both about 250 yards. First one was right through the vitals. It was dead before it hit the ground and the exit hole was the size of a softball. The second one was running and I hit it back in the guts. The Vmax almost tore it in half -- compleatly disemboweled.

For me, another 100 fps is not going to make a difference.
Link Posted: 2/12/2006 10:02:31 AM EDT
inkaybee--good post!
Link Posted: 2/12/2006 11:37:06 AM EDT

Originally Posted By DocGKR:
inkaybee--good post!



If you've got your eye on this thread that must mean you have some interest. And in my deduction that means that it is alive and well, unlike what some other posters have tried to proclaim.

Am I assuming correctly?
Link Posted: 2/12/2006 3:49:00 PM EDT
did anybody notice what size primers are in the hornady 6.8 brass?
Link Posted: 2/12/2006 4:07:25 PM EDT
Mine are small.
Link Posted: 2/12/2006 6:05:33 PM EDT

Originally Posted By inkaybee:

Originally Posted By CitySlicker:

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes. The lable says 2550 fps out of a 16 inch barrel. I have not chronoed it but it is about as accurate as my best hand load.



Damn. I spoke with Zak Smith and he's able to handload VMAX up to 2670 from an 18" barrel.

I was hoping that Hornady could push it to 2650/2700 FPS from a 16" barrel.



Why are we so worried about sqeezing that extra 100 fps out of the 6.8.

I shot two coyotes last weekend with the Vmaxes both about 250 yards. First one was right through the vitals. It was dead before it hit the ground and the exit hole was the size of a softball. The second one was running and I hit it back in the guts. The Vmax almost tore it in half -- compleatly disemboweled.

For me, another 100 fps is not going to make a difference.



If you must know, it's because I wanted to one up the 6.5 Grendel advocates!

In all seriousness, the reason is simple; I want to see 6.8 SPC meeting the MV figures presented during the inital hype.
Link Posted: 2/12/2006 6:19:18 PM EDT

Originally Posted By CitySlicker:
If you must know, it's because I wanted to one up the 6.5 Grendel advocates!




I try to ignore them.
Link Posted: 2/14/2006 11:41:37 AM EDT
Originally Posted By stiles:
did anybody notice what size primers are in the hornady 6.8 brass?[/quote



The 6.8 uses Large Rifle primers
Link Posted: 2/14/2006 11:53:46 AM EDT
Doc Roberts,

Do you think we will ever see 6.8 SPC at the original mean velocity figures quoted at the outset?

Thanks.

Justin
Link Posted: 2/14/2006 12:32:28 PM EDT

Originally Posted By Grizzly556:
Originally Posted By stiles:
did anybody notice what size primers are in the hornady 6.8 brass?[/quote



The 6.8 uses Large Rifle primers




But Hornady has chosen to use SMALL rifle primers and has changed their brass accordingly.

Tom
Link Posted: 2/14/2006 12:35:30 PM EDT

Originally Posted By CitySlicker:
Doc Roberts,

Do you think we will ever see 6.8 SPC at the original mean velocity figures quoted at the outset?

Thanks.

Justin


It would appear that most 6.8 is being underloaded to compensate for the barrels with incorrect bore diameter.
Link Posted: 2/14/2006 2:14:22 PM EDT

Originally Posted By Gamma762:

Originally Posted By CitySlicker:
Doc Roberts,

Do you think we will ever see 6.8 SPC at the original mean velocity figures quoted at the outset?

Thanks.

Justin


It would appear that most 6.8 is being underloaded to compensate for the barrels with incorrect bore diameter.



I had heard that Silver State lowered the pressure for one of their loadings of the 6.8 SPC. Has this become more wide spread so that all the Ammo manufactures are now lowering the pressure levels for their loadings of this cartridge.

Joe
Link Posted: 2/14/2006 2:39:13 PM EDT
the lead/throat length's having different specifications from a few mfg's is the main issue. change the shape of the bullet ogive or the COAL and the pressures in this situation will be very different from one mfg to another.
Link Posted: 2/14/2006 3:18:25 PM EDT
Ok lets look at this cartridge. Remington comes out with the 6.8 SPC they submit the cartridge specs to SAAMI and it is accepted, from this we can now get reamers made. Remington cannot get their process to conform to the pressure levels that have been established and so ends up with lower than originally stated velocities.

The perceived need to get the most velocity out of this cartridge and max out the fragmentation range has probably caused some to load it on the really hot side to begin with. Then we have a barrel that is a chrome plated chamber and bore that is on the small side, and pressures climb even higher. Because of this ammo manufactures now load to even lower pressures so that these few barrels are not a problem.

Now the chamber pressure and the velocities are on the low side so we introduce more free bore to compensate and can again raise pressure levels for more velocity.

But what about the undersized barrels that caused the problem to begin with.
Link Posted: 2/14/2006 4:15:46 PM EDT
[Last Edit: 2/14/2006 4:17:13 PM EDT by inkaybee]
I think Remington down loaded long before anybody knew Model one Sales had a few tight bores -- probably even before those barrels were made. I don't think that is the cause of reducced velocity from the orriginal specs.

BTW I have one of those supposedly f#$@ up Shaw / Model One sales and have not seen any problems. I have loaded to Hodgdon's published Max without seeing anything but the slightest of primer flatening. I have seen real real flat primers when shooting Silver State with the Xtream bullet.
I think that is a hot load and then there is an issue with the blunt, soft plated bullet.

Silver State said it was a combo of that bullet and that barrel, and that is why the backed the Xtream down while leaving all their other loads the same.

In short, I dont think Remington or Hornady have built their ammo around a few tight barrels.
Link Posted: 2/14/2006 5:35:51 PM EDT
The original military requirement was for the SPC velocity to exceed that of a standard AKM/AK-47 by 200 fps from 16" barrels.

The early AMU loaded 6.8 mm 110 gr ammo was running 2700-2750 f/s out of a 16" barrel. AMU loaded ammo tends to run on the hot side--compare the difference between a commercial .223 load and an AMU load. Commerical ammo vendors are a bit more conservative and we see current 6.8 mm velocities running about 100 fps or so lower--note that this still meets the original specification.
Link Posted: 2/14/2006 6:16:12 PM EDT

Originally Posted By DocGKR:
The original military requirement was for the SPC velocity to exceed that of a standard AKM/AK-47 by 200 fps from 16" barrels.

The early AMU loaded 6.8 mm 110 gr ammo was running 2700-2750 f/s out of a 16" barrel. AMU loaded ammo tends to run on the hot side--compare the difference between a commercial .223 load and an AMU load. Commerical ammo vendors are a bit more conservative and we see current 6.8 mm velocities running about 100 fps or so lower--note that this still meets the original specification.



With all due respect Dr. Roberts, isn't it more like 200 FPS lower (reference 2750 FPS to Hornady's published MV of 2550 from a 16" barrel)?

Justin
Link Posted: 2/14/2006 8:12:19 PM EDT
Cityslicker--you can say whatever feels best for you. We're shooting SSA ammo that is running between 2600-2650 f/s in 16" barrels; that seems to be about 100 fps slower than the first AMU loads. The Hornady ammo is running about 150-200 fps slower than the original AMU--I suspect Hornady could bump that up 50 fps without any problems--just like Federal could bump up their .223 77 gr OTM GM load about 200 fps so it would run like Mk262...
Link Posted: 2/15/2006 12:32:06 AM EDT

Originally Posted By inkaybee:
I think Remington down loaded long before anybody knew Model one Sales had a few tight bores -- probably even before those barrels were made. I don't think that is the cause of reducced velocity from the orriginal specs.

BTW I have one of those supposedly f#$@ up Shaw / Model One sales and have not seen any problems. I have loaded to Hodgdon's published Max without seeing anything but the slightest of primer flatening. I have seen real real flat primers when shooting Silver State with the Xtream bullet.
I think that is a hot load and then there is an issue with the blunt, soft plated bullet.

Silver State said it was a combo of that bullet and that barrel, and that is why the backed the Xtream down while leaving all their other loads the same.

In short, I dont think Remington or Hornady have built their ammo around a few tight barrels.



I agree with everything you said, I just wanted everyone to think about the real reason way the ammo has been down load to a lower pressure. The 6.8 is a fine cartridge for the AR15 platform the way it is. It will however never be a .270 super short magnum master blaster cartridge. Is this so bad, I think not .

Joe
Link Posted: 2/15/2006 6:01:20 AM EDT
Art with SSA

We had to drop the charge on the 115 grain X-Treme because some guns were having pressure issues that were unacceptable, ie blowing primers. We were running the X-Treme around 2,620 FPS, our pressure test indicated 55,000 PSI. We have several guns here and we would have some flattening of primers to a varying degree but no blown primers.

When the reports started coming in we sent samples of the X-Treme to our powder manufacture to varify pressures, in their test barrel they were getting pressures in the 60's from the same lot. To error on the safe side we had to drop the charge and loss velocity.

Our Sierra loads are still at 2,620 FPS, our pressure barrel as well as our powder manufacture test indicate 55,000 PSI with no signs of pressure. We ran test on both these loads and we can get them to go faster but we would be exceeding SAMMI MAX pressure of 55,000.

Art - Silver State Armory
Link Posted: 2/15/2006 6:06:21 AM EDT
I was at the Long Mountain Outfitters DOE shoot in Las Vegas on Sunday. Carl Lewis of LMT was there to demo his guns and had one set up in 6.8mm with a 16" barrel. He also had no less than 5 or 6000 rounds of the Hornady 110gr OTM. It was cool seeing that much 6.8 ammo all in one place after the months and months of waiting. It was also a hell of a lot of fun to finally try some select fire 6.8mm shooting. It has a much better recoil impulse than the 5.56mm when firing bursts. Instead of of muzzle flip and rise, it was more of a nudge in the shoulder and it allowed the shooter to lay down fairly accurate automatic fire.

Stephen
Link Posted: 2/15/2006 6:38:28 AM EDT

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes.



Do you mind telling us which vendor you got them from?

Thanks!
Link Posted: 2/15/2006 9:55:52 AM EDT

Originally Posted By Forest:

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes.



Do you mind telling us which vendor you got them from?

Thanks!



www.midwayusa.com has it (or at least HAD it) in stock.

Stephen
Link Posted: 2/15/2006 11:00:55 AM EDT

Originally Posted By kalwasart:
Art with SSA

We had to drop the charge on the 115 grain X-Treme because some guns were having pressure issues that were unacceptable, ie blowing primers. We were running the X-Treme around 2,620 FPS, our pressure test indicated 55,000 PSI. We have several guns here and we would have some flattening of primers to a varying degree but no blown primers.

When the reports started coming in we sent samples of the X-Treme to our powder manufacture to varify pressures, in their test barrel they were getting pressures in the 60's from the same lot. To error on the safe side we had to drop the charge and loss velocity.

Our Sierra loads are still at 2,620 FPS, our pressure barrel as well as our powder manufacture test indicate 55,000 PSI with no signs of pressure. We ran test on both these loads and we can get them to go faster but we would be exceeding SAMMI MAX pressure of 55,000.

Art - Silver State Armory



Art:
This is what we should all expect from any ammo manufacturer, your quick response in addressing this problem shows the dedication of your company to produce safe performance based ammo. I hope your 6.8 SPC sales are doing well, and that you will be producing this cartridge for a long time to come.

Joe
Link Posted: 2/15/2006 11:30:53 AM EDT

Originally Posted By CitySlicker:
I want to see 6.8 SPC meeting the MV figures presented during the inital hype.



+1

Still waiting for factory ammo that meets the claims made by the 6.8SPC promoters circa late 2002.


Either that or retraction of all the early Data and new testing of actual factory ammo.
Link Posted: 2/15/2006 11:35:23 AM EDT

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes. The lable says 2550 fps out of a 16 inch barrel. I have not chronoed it but it is about as accurate as my best hand load.



I get 2675 +/- 25 FPS out of my 16 inch barrel with Silver State Armory 115gr FMJ. 2550FPS is about right I should think.
Link Posted: 2/15/2006 11:37:19 AM EDT

Originally Posted By stephen_101st:
I was at the Long Mountain Outfitters DOE shoot in Las Vegas on Sunday. Carl Lewis of LMT was there to demo his guns and had one set up in 6.8mm with a 16" barrel. He also had no less than 5 or 6000 rounds of the Hornady 110gr OTM. It was cool seeing that much 6.8 ammo all in one place after the months and months of waiting. It was also a hell of a lot of fun to finally try some select fire 6.8mm shooting. It has a much better recoil impulse than the 5.56mm when firing bursts. Instead of of muzzle flip and rise, it was more of a nudge in the shoulder and it allowed the shooter to lay down fairly accurate automatic fire.

Stephen



Really? I found the opposite to be true. I found the 6.8SPC much harder to keep on target. The muzzle brakes on the Barett M468 Carbines are there for a reason. Maybe the 2003 Remington ammo was loaded hotter than the 2006 Hornady? Of course recoil, is subjective but i never heard a shooter claim the 6.8SPC is more controllable that the same weapon firing 5.56mm before.
Link Posted: 2/15/2006 12:02:09 PM EDT
Well it has been a long time since I looked at the data for the 6.8 SPC on Remington's web page and do not remember the original specs. They list a max velocity of 2800 FPS out of a 24" test barrel. So if 1" less of barrel equals 25 FPS drop in velocity then a 20' barrel would deliver 2700 FPS and a 16" would be around 2600.

Looks good to me but if these numbers are not what you are looking for there are other calibers available to choose from. I posted a long time back that the 6.8 is what it is and wanting it to be something else is not going to change that. And having said that I also believe it to be a good choice for the AR15.

Joe
Link Posted: 2/15/2006 12:05:51 PM EDT

Originally Posted By Forest:

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes.



Do you mind telling us which vendor you got them from?

Thanks!



Midway
Link Posted: 2/15/2006 12:08:51 PM EDT
[Last Edit: 2/15/2006 12:35:16 PM EDT by inkaybee]
.
Link Posted: 2/15/2006 2:32:39 PM EDT

Originally Posted By g136653:

Originally Posted By inkaybee:
I did not go to SHOT but I have a box of it right here in my hot hand. It has 110 Vmaxes. The lable says 2550 fps out of a 16 inch barrel. I have not chronoed it but it is about as accurate as my best hand load.



I get 2675 +/- 25 FPS out of my 16 inch barrel with Silver State Armory 115gr FMJ. 2550FPS is about right I should think.




g136653

What upper are you using, and are you seeing any pressure signs?

Art - SSA
Link Posted: 2/16/2006 7:43:45 AM EDT
I am using a Model 1 Sales chrome lined upper with a 16 inch barrel. I had popped primers and flattened primers. I took the spent cases to a gunsmith who is supposed to be a local guru. Hetold me that this was a result of having oil in the barrel, which made me laugh.

The ammo is SSA 115gr xtreme bullets. The accuracy is excellent, but the pressure issues worry me. After function testing and sighting the rifle in I have not fired it since I was waiting for more ammo to become available. Should I not use this ammo Art?
Link Posted: 2/16/2006 10:16:45 AM EDT
I just spoke to Art. What a great guy. He wanted to send me free ammo to replace what I have. Instead I think I will go ahead and get a Noveski Barrel.

Wow. Above and beyond, Art. Thank you.
Link Posted: 2/16/2006 10:21:09 AM EDT
I won't go into any specifics, but I will say that from a 12" barrel I've gotten velocities from Hornady's 110 VMAX (factory loaded) that SHOULD allow for fragmentation in excess of 125M. I won't know exactly what it will do until Vyse gets my gel here, so the preliminaries are based on numbers that I have received from a reliable source. When I do get my gel, I'll give a cursory report based on my impressions, and those from a few folks much more qualified than myself.

BTW, this is with a Douglas 12" middy barrel running on regular old direct gas.
Link Posted: 2/16/2006 10:54:53 AM EDT

Originally Posted By g136653:
I am using a Model 1 Sales chrome lined upper with a 16 inch barrel. I had popped primers and flattened primers.


That's the problem barrel, (in combination with the problem bullet) and much of the reason we are now getting "downloaded" 6.8 ammo, if what I have read is correct.
Link Posted: 2/16/2006 11:22:34 AM EDT

Originally Posted By Gamma762:

Originally Posted By g136653:
I am using a Model 1 Sales chrome lined upper with a 16 inch barrel. I had popped primers and flattened primers.


That's the problem barrel, (in combination with the problem bullet) and much of the reason we are now getting "downloaded" 6.8 ammo, if what I have read is correct.



What ammo besides SSA/Xtream has been down loaded for this reason? Where are you getting this info?
Link Posted: 2/16/2006 12:42:25 PM EDT
Can someone tell me all the different mfgrs of 6.8SPC chrome-lined barrels out there?

Any reports of quality/issues, etc. (I've heard something about Model 1's early bbls).

Right now I know of...
- Barrett
- Model1Sales (apparently with some early teething problems?)

And apparently CMMG _may_ be coming out with one.

Any others?

I'm esp interested in an 18" one with midlength (non-CAR, non-rifle) gas system.



Bill Wiese
San Jose, CA
Link Posted: 2/16/2006 3:34:51 PM EDT

Originally Posted By inkaybee:

Originally Posted By Gamma762:

Originally Posted By g136653:
I am using a Model 1 Sales chrome lined upper with a 16 inch barrel. I had popped primers and flattened primers.


That's the problem barrel, (in combination with the problem bullet) and much of the reason we are now getting "downloaded" 6.8 ammo, if what I have read is correct.



What ammo besides SSA/Xtream has been down loaded for this reason? Where are you getting this info?



Some guns can handle the X-Treme at the higher velocities but many can not. Our Barrett and TC handles the higher velocities with no pressure issues. Leitner-Wise was out here prior to the Shot show and their 6.8 handled the higher velocity X-Treme very well.

Remington has down loaded there FMJ a while back because of the same problem.Their published numbers are 2,800 FPS (24" barrel) quote on Midway's site. Go to Midways site and read the reviews on the X-Treme, and then read the reviews on Remingtons FMJ. velocities for Remington in the low 2,500's out of a 20" barrel.

Now that we down loaded the X-Treme we are getting some negative feed back from the guy's who have guns that can handle the higher velocities, just can't win.

If its velocity you want go to our Sierra's because to my knowledge (correct me if I am wrong) we (SSA) are the only ones currently loading rounds that run 2,620 + FPS (Closer to 2,650) out of 16" barrel. Hornady's site on their VMAX is 2,550 FPS.

We have made some proto types on the X-Treme and will be running tests next week, we want to get the velocities back up. We want to keep it as an less expensive plinking round which has good accuracy.

Art - Silver State Armory
Link Posted: 2/16/2006 4:13:03 PM EDT
Thanks Art.

Hey I am going to going to make a cerrosafe chamber cast. What should the throat measure? Do you have any tips for making the cast?

Thanks
Link Posted: 2/16/2006 4:17:52 PM EDT
Link Posted: 2/16/2006 4:29:53 PM EDT

Originally Posted By inkaybee:
Thanks Art.

Hey I am going to going to make a cerrosafe chamber cast. What should the throat measure? Do you have any tips for making the cast?

Thanks



Min throat dia for the chamber is .3085, some guns are running below that, one manufacture is at .303 my cartridge can be as large as .306. The last time I looked a .306 does not fit into a .303 hole! I will dig up a chamber reamer drawing tomorrow and give the diemensions.


Art - Silver State Armory
Link Posted: 2/20/2006 1:49:36 AM EDT
So who makes a good upper for the AR? How about DPMS? Others?
Link Posted: 2/20/2006 9:49:02 AM EDT

Originally Posted By army_eod:
So who makes a good upper for the AR? How about DPMS? Others?


For what it's worth, the only AR15 uppers I'll buy with my own money are those from MSTN and John Noveske.
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