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Joined: Sep 2001
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Campfire Ranger
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Campfire Ranger
Joined: Sep 2001
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I was looking at the heavier bullet ballistics in a 10.5". Looks like 2400 fps is realistic with the 75/77gr bullets. This is a JBM calc on the Sierra 77gr TMK at 2400 fps, in local atmo,
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Joined: Feb 2007
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Campfire Regular
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Campfire Regular
Joined: Feb 2007
Posts: 2,600 |
I am curious if you have a round house figure for rounds down range and have there been any functioning issues.
Whom the gods wish to destroy they first make mad.
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Joined: Sep 2001
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Campfire Ranger
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Campfire Ranger
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Not many rounds at all. Maybe 100 or so.
The only ammo I've used so far is PMC X-TAC 62gr green tip LAP. Roughly an M855 equivalent.
So far no malfunctions or stoppages at all.
When I put it together I did throw in an H3 buffer from the start. Tested it for positive bolt lock-back on the last round and it worked fine, so I ran with it.
A standard carbine buffer probably would be fine too, but I didn't try that.
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Joined: Sep 2004
Posts: 17,417
Campfire Ranger
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Campfire Ranger
Joined: Sep 2004
Posts: 17,417 |
I have a kit on order from PSA with the standard carbine buffer. I’ll report out on any stoppages, if I get stoppages.
“Live free or die. Death is not the worst of evils.” - General John Stark.
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Joined: Sep 2001
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Campfire Ranger
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Campfire Ranger
Joined: Sep 2001
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I think the trouble most commonly associated with the 10.5" with the carbine gas system is the short dwell time, causing an under-gassed condition.
If that is the case, the lighter buffer would probably be better than a heavy buffer.
Anyhoo, I'm going to run with the H3. If I run into any cycling issues down the road I'll share the info. With the H3 and the ammo I'm using, I don't feel any thump from the buffer hitting the back of the extension tube. It's real smooth.
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Joined: Sep 2004
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Campfire Ranger
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Campfire Ranger
Joined: Sep 2004
Posts: 17,417 |
MM,
I going to get the 7.62x39 carbine upper from PSA when they are back in stock.
What buffer do you run in yours?
“Live free or die. Death is not the worst of evils.” - General John Stark.
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Joined: Sep 2001
Posts: 19,072
Campfire Ranger
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Campfire Ranger
Joined: Sep 2001
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I've got an H3 in the 16" 7.62x39.
It ran OK with a standard buffer, but I could definitely feel it hitting the back of the extension tube. The H3 smoothed it out real nice.
Another reason I went to the H3 in the 7.62 was because I figured delaying the unlocking a bit, should help reduce or eliminate the chance of losing a bolt lug. Apparently that has happened with the 7.62x39 in the AR.
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Joined: Sep 2004
Posts: 17,417
Campfire Ranger
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Campfire Ranger
Joined: Sep 2004
Posts: 17,417 |
“Live free or die. Death is not the worst of evils.” - General John Stark.
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Joined: Nov 2003
Posts: 18,310 Likes: 1
Campfire Ranger
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Campfire Ranger
Joined: Nov 2003
Posts: 18,310 Likes: 1 |
some of the pistol uppers are over gassed, the H3 makes some sense. I think the heavier bullets do better at longer ranges.
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Joined: Sep 2001
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Campfire Ranger
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Campfire Ranger
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The heavies with the higher BC always win at distance.
Muzzle velocity numbers impress sometimes, But high BC is the gift that keeps on giving.
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Joined: Nov 2003
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Campfire Ranger
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Campfire Ranger
Joined: Nov 2003
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I see they have a chromed version as well, probably not as accurate.
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Joined: Sep 2001
Posts: 19,072
Campfire Ranger
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Campfire Ranger
Joined: Sep 2001
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The nitride barrels do seem to shoot a little better, on average.
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Joined: Nov 2011
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Campfire 'Bwana
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Campfire 'Bwana
Joined: Nov 2011
Posts: 30,977 |
I see they have a chromed version as well, probably not as accurate. You're assuming the underlying barrels are equal. They are not. Most of PSA's chrome lined barrels are made by FN, their nitrites are made by some second tier producer. I trust FN to make a good barrel.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
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Joined: Nov 2003
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Campfire Ranger
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Campfire Ranger
Joined: Nov 2003
Posts: 18,310 Likes: 1 |
so your saying that an FN chrome lined barrel would be more accurate than a second tier nitrided barrel? I don't dispute that they would be more durable.
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Joined: Nov 2006
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Campfire Outfitter
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Campfire Outfitter
Joined: Nov 2006
Posts: 10,169 |
You can nitride a turd and it's still gonna be a turd.
You need to start out with a good barrel and they seldom come as the cheapest option.
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Joined: Nov 2011
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Campfire 'Bwana
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Campfire 'Bwana
Joined: Nov 2011
Posts: 30,977 |
so your saying that an FN chrome lined barrel would be more accurate than a second tier nitrided barrel? I don't dispute that they would be more durable. Yep. This: You can nitride a turd and it's still gonna be a turd.
You need to start out with a good barrel and they seldom come as the cheapest option.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
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Joined: Nov 2003
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Campfire Ranger
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Campfire Ranger
Joined: Nov 2003
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Yep I owned an FN double chromed barrel, in one of the early Noveske guns, it was a 2.5 MOA barrel with xm193 did not shoot much better than that with Hornady 55 grain Vmax factory ammo. They replaced the barrel with a new one when I complained that the barrel seemed a bit rough and the new one shot about the same. They are milspec barrels. I have spoken to a Knight armament dealer and he said the Knight barrels are about the same until you get 1000 rounds down the tube and they smooth up a bit. Again I am no expert here as many others are, but have owned a few chromed barrels. Colt has made a decent barrel.
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Joined: Dec 2009
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Campfire Tracker
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Campfire Tracker
Joined: Dec 2009
Posts: 3,395 |
Yep I owned an FN double chromed barrel, in one of the early Noveske guns, it was a 2.5 MOA barrel with xm193 did not shoot much better than that with Hornady 55 grain Vmax factory ammo. They replaced the barrel with a new one when I complained that the barrel seemed a bit rough and the new one shot about the same. They are milspec barrels. I have spoken to a Knight armament dealer and he said the Knight barrels are about the same until you get 1000 rounds down the tube and they smooth up a bit. Again I am no expert here as many others are, but have owned a few chromed barrels. Colt has made a decent barrel. Did you try any 75/77gr match ammo? M193 is 3.5 MOA at best, and usually between 4 and 5 MOA. Every FN Double chrome lined barrel I’ve seen (100-125) has been a sub 2 MOA for ten rounds with 77gr Blackhills.
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Joined: Nov 2003
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Campfire Ranger
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Campfire Ranger
Joined: Nov 2003
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It was about 2.5 maybe 3 MOA for 5 shots with an NXS 1-4 in a LaRue Mount.. I never shot any 77’s. It was a reliable gun, sold it for too little. These days a PSA upper with an FN barrel which I assume is the same as what Noveske offers and a PSA premium bolt would be my choice over any intruded barrel
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Joined: Jan 2018
Posts: 2,387
Campfire Regular
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Campfire Regular
Joined: Jan 2018
Posts: 2,387 |
Another reason I went to the H3 in the 7.62 was because I figured delaying the unlocking a bit, should help reduce or eliminate the chance of losing a bolt lug. Apparently that has happened with the 7.62x39 in the AR.
I'm don't understand your logic. I feel the reason as to why 7.62x39 breaks lugs on bolts is that the lugs on the bolt have to be much smaller than the lugs on a .223 sized bolt. Also, The pressure on the 7.62x39 bolt is much higher than the pressure on a .223/5.56 bolt. (7.62 Case has a larger bolt surface area than a .223 bolt area hence more load is applied to the bolt). I understand 7.62x39 does not have an issue with breaking lugs in an AR10 or similar platform. I am not comfortable running 7.62x39 loads in an AR15 sized platform due to the smaller bolt lugs and increased load on the bolt.
Last edited by Lennie; 11/27/18.
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