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Discussion Starter #1
I see that Druid Hill Armory is selling Speer Gold Dots capable of almost 3100 fps. I would assume that I can use this ammo in my new upper with an 18” SPCII 3R barrel and super bolt. Am I correct? I have no idea what kind of pressures that they are capable of.
 

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You should be able to shoot any currently manufactured 6.8 ammo from that barrel/bolt with confidence.
 

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I would suggest firing one or two rounds to check for pressure signs before you attempt loading up a magazine and empty it. Your new 18" 3R has a short freebore to get best performance out of standard factory ammo. If this SPC II ammo was developed in a barrel with a more typical freebore, you may show signs of pressure. I would appreciate it if you could post some pictures of your primers/cases after you shoot them. I will be testing some DH Armory ammo next week and would benefit from any information you can share.
 

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Discussion Starter #5
I would suggest firing one or two rounds to check for pressure signs before you attempt loading up a magazine and empty it. Your new 18" 3R has a short freebore to get best performance out of standard factory ammo. If this SPC II ammo was developed in a barrel with a more typical freebore, you may show signs of pressure. I would appreciate it if you could post some pictures of your primers/cases after you shoot them. I will be testing some DH Armory ammo next week and would benefit from any information you can share.
I’ll share whatever I can, but it may not be for a bit. I’m still waiting on my upper to arrive. I will however shoot a few different factory loads first to make sure all is well. When I do get to shoot the DH rounds, I will inspect each case after each shot.
 

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I suspect that any pressure signs due to the leade, may be off-set by the 3R rifling of H's design. His 5R has been so good over the years... his 3R should be just as good, possibly better in that regards. His land to groove ratio just plain works at promoting muzzle velocity. The quicker the acceleration from the case and movement towards the muzzle, the quicker the pressure drops (of course, speed of powder burn also influences things). This is where the 6 groove Enfield and 4 groove Enfield barrels fall behind (in my opinion). The harder it engraves into the bullet, the slower it is to build speed, the slower it is to leave the muzzle, and higher the pressure remains for a longer time in the chamber, and the slower the overall muzzle velocity is. His use of odd numbers of engraving means it's not an opposing force too. It all just makes sense to me.
 

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I suspect that any pressure signs due to the leade, may be off-set by the 3R rifling of H's design. His 5R has been so good over the years... his 3R should be just as good, possibly better in that regards. His land to groove ratio just plain works at promoting muzzle velocity. The quicker the acceleration from the case and movement towards the muzzle, the quicker the pressure drops (of course, speed of powder burn also influences things). This is where the 6 groove Enfield and 4 groove Enfield barrels fall behind (in my opinion). The harder it engraves into the bullet, the slower it is to build speed, the slower it is to leave the muzzle, and higher the pressure remains for a longer time in the chamber, and the slower the overall muzzle velocity is. His use of odd numbers of engraving means it's not an opposing force too. It all just makes sense to me.
Just noticed they had large rifle primer brass. I might get some given our current primer situation. I know small rifle is preferable.
 

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The freebore is the same as it has always been .085". Bison after 10 years just changed his chambers from .100 to .085 like mine.
The only barrels I have ever made with a shorter freebore than that were some 16" barrels marked "match" They were made for shooting the 130gr Bergers when they first came out and it seemed like everyone was testing those. I haven't received any reports of those barrels having pressure issues.
The problem with xmans barrels is some were chambered with PTG reamers so some had a long freebore and now he thinks the normal .085 freebore is short.
Even the 12 and 13 twist 3 groove barrels used in the 2008 performance test had .085 freebore and the DMR chamber.
 
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Discussion Starter #9
I just received my order from Druid Hill. Very fast shipping. Just waiting for my upper to arrive now to try them out. Also heard that he may start loading some CBB’s in the near future! I can’t wait.
 

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Just for posterity, here's what I found on Druid Hill's website (the product page for the 6.8 SPC II 90-grain Gold Dots):

"This Ammunition is designed and tested for the 6.8 SPC II or ARP improved chamber and should not be used in 6.8mm Remington SPC original barrels. If you have questions or concerns regarding the use of this ammunition in your rifle, please contact me or buy commercially available ammunition."
 

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I ordered some as well. Have not had the time to measure, but they are loaded longer compared to xm68gd. He answers emails quickly and ships quickly as well.

Havnt shot any at my new house yet. Hope to this weekend weather permitting.
 

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what is mixxed 6.8 once fired brass going for?
 

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Constructor or others can correct me if I remember the facts wrong, but the freebore was not the only problem with many early 6.8 SPC barrels. In particular, there was a sharp angle at the place where the chamber diameter steps down from the outside of the case neck to the smaller diameter freebore.* Brass/copper from the jackets would sometimes be shaved off the bullets here. In addition, the bores of a significant number of early barrels were undersized. Many early SPCII reamers did not address the sharp angle, but went overboard lengthening the freebore in order to drop pressure. This tended to reduce velocity and definitely did not help with accuracy with factory ammo.

ARP and some others fixed the sharp-angle problem and found that the cartridge worked better with less freebore than in some of the SPCII drawings (yes, there is more than one "SPCII drawing").

*There was an error in the chamber print (two numbers transposed), but some reamers had an even sharper angle, making the problem worse!
 

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Will be shooting at my house. The targets will be set up at 100 yards behind the house and barn. All animals will be safe in the barn. Target will be free of surrounding rocks...the land around here produces rock or stone. It will come into use when making a nice fire pit.

Also will put some rounds through a 6.5 cm tikka ctr.
63275
 

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Will be shooting at my house. The targets will be set up at 100 yards behind the house and barn. All animals will be safe in the barn. Target will be free of surrounding rocks...the land around here produces rock or stone. It will come into use when making a nice fire pit.

Also will put some rounds through a 6.5 cm tikka ctr.
View attachment 63275
His point was meant as humor... shoot on your property... just don't shoot the house (is what he was saying). (y)
 

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Constructor or others can correct me if I remember the facts wrong, but the freebore was not the only problem with many early 6.8 SPC barrels. In particular, there was a sharp angle at the place where the chamber diameter steps down from the outside of the case neck to the smaller diameter freebore.* Brass/copper from the jackets would sometimes be shaved off the bullets here. In addition, the bores of a significant number of early barrels were undersized. Many early SPCII reamers did not address the sharp angle, but went overboard lengthening the freebore in order to drop pressure. This tended to reduce velocity and definitely did not help with accuracy with factory ammo.

ARP and some others fixed the sharp-angle problem and found that the cartridge worked better with less freebore than in some of the SPCII drawings (yes, there is more than one "SPCII drawing").

*There was an error in the chamber print (two numbers transposed), but some reamers had an even sharper angle, making the problem worse!
Correct as I understand it.
 

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Will have to do further tests on druid hills two loads. This 6.8 liked ssa 110 accubond load, and the hornady 110 hpbt. Xm68gd and the druid hill 90gr gold dots were 2+, so were the Lehigh 100gr. Could just tell this barrel didn't like them.
 

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I see that Druid Hill Armory is selling Speer Gold Dots capable of almost 3100 fps. I would assume that I can use this ammo in my new upper with an 18” SPCII 3R barrel and super bolt. Am I correct? I have no idea what kind of pressures that they are capable of.
Thank You Druid Hill Armory
 

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Discussion Starter #20 (Edited)
I would suggest firing one or two rounds to check for pressure signs before you attempt loading up a magazine and empty it. Your new 18" 3R has a short freebore to get best performance out of standard factory ammo. If this SPC II ammo was developed in a barrel with a more typical freebore, you may show signs of pressure. I would appreciate it if you could post some pictures of your primers/cases after you shoot them. I will be testing some DH Armory ammo next week and would benefit from any information you can share.
I finally got around to testing these out. Overall they shot very well. I didn’t see any pressure signs on the case, but there were gouge marks on the bottom, I guess from the ejector? I’m not sure what would cause that. Higher pressure?
4150F074-A0CA-4E1C-BB89-AD55B9FA9413.jpeg
A38AE515-7C97-4795-9793-D040C94F7FF4.jpeg
 
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