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Posted: 8/1/2016 4:21:39 PM EDT
I have a 5.45x39 16" barrel M4 upper, Think it is a S&W upper bought it years ago when these first came out from AIM surplus. Anyways, I have shot maybe 1200rnds through it in it's life, never had a problem with the 7n6 surplus, Russian or Bulgy. Anyways I have tried a box here or there of the commercial stuff, to see if I could find something better than surplus, since it has dried up. Think I shot some silver bear a while back, and today a old box of wolf white box from the 80's-90's. I have noticed I get a few rounds from the commercial ammo that always keyholes. Today it was 3-4rnds out of 20 that I shot.
So, is it how the bullets in commercial 5.45 are made, or the weight or what that makes them keyhole, never had one issue with surplus 7n6.... Here's the cross of a 7n6, what does the commercial stuff look like?? 
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Posted: 8/1/2016 9:22:01 PM EDT
[#1]
The wolf and bear ammo is much heavier. But I wouldnt think it would cause keyhole. May not be accurate, but not keyhole. You sure the barrel hasnt been shot out? You could always give S&W a call. If I remember right, they have a life time warranty.
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Posted: 8/1/2016 9:34:18 PM EDT
[#2]
After a little research I found S&W 5.45 barrels notoriously wear quicker and are prone to keyholing. S&W has discontinued the 5.45 uppers. They wont do anything for you except maybe offer a similar 5.56 replacement.
I bought a used S&W 5.45 barrel off the EE from someone who said it had only a few K rounds through it. The upper I built with it was keyholing. Of course I didnt get around to it for quite a while and later found the previous owner had done many mag dumps on full auto with it by finding youtube videos with a similar username. I could tell there was scoring in the barrel. Should have looked at it more closely when I first got it. Shortly after that the 7n6 ban happened and it was a good excuse to get out of the game. Sold the barrel for super cheap and made a bunch of extra money on my 5.45 stash. I would buy a Ballistic Advantage barrel if you want to stay with 5.45x39. |
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Posted: 8/1/2016 10:14:18 PM EDT
[#3]
My S&W 5.45X39 barrel is chrome lined. Why would it wear out faster than anything else?
So far I've only shot Russian surplus. Shoots damn good, too. 2 MOA out to 300 yds. anyway. |
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Posted: 8/1/2016 10:19:47 PM EDT
[#4]
Quote HistoryQuoted:
My S&W 5.45X39 barrel is chrome lined. Why would it wear out faster than anything else? So far I've only shot Russian surplus. Shoots damn good, too. 2 MOA out to 300 yds. anyway. This, my barrel is chromed, and from looking down it looks clean as a whistle. Anyone know s&w twist rate? That might give more info why or why not it like certain ammo? |
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Posted: 8/1/2016 10:20:50 PM EDT
[#5]
Quote HistoryQuoted:
After a little research I found S&W 5.45 barrels notoriously wear quicker and are prone to keyholing. S&W has discontinued the 5.45 uppers. They wont do anything for you except maybe offer a similar 5.56 replacement. If that is the case go for it if yours is shot out, might as well get a 5.56 barrel if nothing else and then buy one from a different company if you want to stay with that caliber. |
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Posted: 8/2/2016 10:07:15 AM EDT
[#6]
My 5.45x39 AR doesn't keyhole with anything I've shot BUT 7N6 is by far the most accurate round with Monarch & Silver Bear being the best commercial ammo. RAS 69 gr ammo is by far the worst performer. I'd like to try some Golden Tiger or Wolf green box in 5.45x39 but for now I've got enough 7N6 stockpiled I won't be buying any commercial for a while.
My twist rate is 1 in 9 but based on what I've read the 1 in 8 is the better choice for bullets in 60 grain & up. |
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Posted: 8/2/2016 12:14:33 PM EDT
[#7]
Quote HistoryQuoted:
My 5.45x39 AR doesn't keyhole with anything I've shot BUT 7N6 is by far the most accurate round with Monarch & Silver Bear being the best commercial ammo. RAS 69 gr ammo is by far the worst performer. I'd like to try some Golden Tiger or Wolf green box in 5.45x39 but for now I've got enough 7N6 stockpiled I won't be buying any commercial for a while. My twist rate is 1 in 9 but based on what I've read the 1 in 8 is the better choice for bullets in 60 grain & up. Is yours a S&W barrel? |
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Posted: 8/3/2016 7:24:28 AM EDT
[#8]
No, Alpha Shooting Sports barrel.
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Posted: 8/3/2016 7:55:24 AM EDT
[#9]
My S&W CL bbl started to keyhole around 8-10K rounds. This is not an isolated incident, even being chromed. Not as bad as the Tantal debacle, but definately a S&W issue.
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Posted: 8/3/2016 8:46:34 AM EDT
[#10]
Quote HistoryQuoted:
<snip> I would buy a Ballistic Advantage barrel if you want to stay with 5.45x39. If you can find one. They had a few in stock at the beginning of the year (with 12 options). None in stock now and only two options. I've made a few inquiries about them and was told they plan to release barrels when they can get 5.45 bolts. Got the same reply at NRA Louisville when I visited their booth. |
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Posted: 8/3/2016 5:42:33 PM EDT
[#11]
Get the bore slugged and see if it's out of spec. or just shoot the ammo that doesn't tumble.
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Posted: 8/3/2016 9:21:54 PM EDT
[#12]
Quoted:
I have a 5.45x39 16" barrel M4 upper, Think it is a S&W upper bought it years ago when these first came out from AIM surplus. Anyways, I have shot maybe 1200rnds through it in it's life, never had a problem with the 7n6 surplus, Russian or Bulgy. Anyways I have tried a box here or there of the commercial stuff, to see if I could find something better than surplus, since it has dried up. Think I shot some silver bear a while back, and today a old box of wolf white box from the 80's-90's. I have noticed I get a few rounds from the commercial ammo that always keyholes. Today it was 3-4rnds out of 20 that I shot. So, is it how the bullets in commercial 5.45 are made, or the weight or what that makes them keyhole, never had one issue with surplus 7n6.... Here's the cross of a 7n6, what does the commercial stuff look like?? http://www.armslocker.com/pics/545ammo.jpg The commercial stuff should look exactly the same except with a lead inner core where the 7n6 has a steel inner core. |
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Posted: 8/4/2016 8:20:38 AM EDT
[#13]
I've not measured it, but I've read a few posts claiming the 52 gr steel core bullets are a little larger/longer than the commercial lead core 60 grain. Other users of 5.45x39 will claim the 7N6 is almost always the most accurate round on average.
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Posted: 8/4/2016 8:53:12 AM EDT
[#14]
Quote HistoryQuoted:
I've not measured it, but I've read a few posts claiming the 52 gr steel core bullets are a little larger/longer than the commercial lead core 60 grain. Other users of 5.45x39 will claim the 7N6 is almost always the most accurate round on average. I think that may be my issue, 52gr does fine, 60gr not so much. I recon they can't make a clone of the surplus, cause they'd say it was AP cause it has a steel core 
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Posted: 8/4/2016 11:17:31 AM EDT
[#15]
Quote HistoryI think that may be my issue, 52gr does fine, 60gr not so much. I recon they can't make a clone of the surplus, cause they'd say it was AP cause it has a steel core Seems they could copy the outer dimensions of the original projectile while still using lead core. |
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Posted: 8/4/2016 7:12:24 PM EDT
[#16]
Quoted:
Quoted:
<snip> I would buy a Ballistic Advantage barrel if you want to stay with 5.45x39. If you can find one. They had a few in stock at the beginning of the year (with 12 options). None in stock now and only two options. I've made a few inquiries about them and was told they plan to release barrels when they can get 5.45 bolts. Got the same reply at NRA Louisville when I visited their booth. You can still get Adams Arms/Voodoo 5.45 barrels. http://www.adamsarms.net/16-mid-length-government-contour-5-45 |
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Posted: 8/4/2016 7:19:09 PM EDT
[#17]
Quote HistoryQuoted:
This, my barrel is chromed, and from looking down it looks clean as a whistle. Anyone know s&w twist rate? That might give more info why or why not it like certain ammo? Quote HistoryQuoted:
Quoted:
My S&W 5.45X39 barrel is chrome lined. Why would it wear out faster than anything else? So far I've only shot Russian surplus. Shoots damn good, too. 2 MOA out to 300 yds. anyway. This, my barrel is chromed, and from looking down it looks clean as a whistle. Anyone know s&w twist rate? That might give more info why or why not it like certain ammo? Or, I guess it could be a chamber issue with the Wolf ammo? This is from Ballistic Advantage's website here: http://ballisticadvantage.com/faq What 5.45 ammo works with your barrel? The only ammo that we have found to have function problems is Wolf 5.45×39 WPA Polyformance 55 grain HP ammo. The spec of this round will not match the spec of our chamber so we strongly recommend you do not use it. |
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Posted: 8/4/2016 8:32:16 PM EDT
[#18]
Quote HistoryQuoted:
Or, I guess it could be a chamber issue with the Wolf ammo? This is from Ballistic Advantage's website here: http://ballisticadvantage.com/faq What 5.45 ammo works with your barrel? The only ammo that we have found to have function problems is Wolf 5.45×39 WPA Polyformance 55 grain HP ammo. The spec of this round will not match the spec of our chamber so we strongly recommend you do not use it. Quote HistoryQuoted:
Quoted:
Quoted:
My S&W 5.45X39 barrel is chrome lined. Why would it wear out faster than anything else? So far I've only shot Russian surplus. Shoots damn good, too. 2 MOA out to 300 yds. anyway. This, my barrel is chromed, and from looking down it looks clean as a whistle. Anyone know s&w twist rate? That might give more info why or why not it like certain ammo? Or, I guess it could be a chamber issue with the Wolf ammo? This is from Ballistic Advantage's website here: http://ballisticadvantage.com/faq What 5.45 ammo works with your barrel? The only ammo that we have found to have function problems is Wolf 5.45×39 WPA Polyformance 55 grain HP ammo. The spec of this round will not match the spec of our chamber so we strongly recommend you do not use it. And wolf is pretty much the only commercial 5.45, other than the rare golden tiger, or silver bear. I do have some of the hornady made stuff, I shot it way back and never had any problems that I remember. A new barrel may be in the works down the road, as of now I'm rolling with it, as I don't have the funds for a new barrel, plus have someone drill and install the gas block. I think if I went that route, I'd go piston anyways. You know how one thing always leads to another 
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Posted: 8/4/2016 9:07:48 PM EDT
[#19]
Quote HistoryQuoted:
And wolf is pretty much the only commercial 5.45, other than the rare golden tiger, or silver bear. I do have some of the hornady made stuff, I shot it way back and never had any problems that I remember. A new barrel may be in the works down the road, as of now I'm rolling with it, as I don't have the funds for a new barrel, plus have someone drill and install the gas block. I think if I went that route, I'd go piston anyways. You know how one thing always leads to another SGAmmo pretty consistently has Silver Bear which is the favorite after Golden Tiger which is never available. http://www.sgammo.com/product/545x39-ammo/750-round-case-545x39-fmj-60-grain-silver-bear-non-corrosive-ammo |
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Posted: 8/4/2016 9:19:47 PM EDT
[#20]
Quote HistoryQuoted:
I think if I went that route, I'd go piston anyways. You know how one thing always leads to another You could try and find this at a Fleet Farm: http://www.fleetfarm.com/detail/huldra-mark-iv-5-45-x-39-complete-upper/0000000069737 And there are these (don't know how legit the sites are though): http://www.tacticalcoordination.com/All%20AR15%20Parts%20Accessories%20Specs/Adams_Arms/Adams_Arms_545x39_Conversion_Kit.html https://skyarms.net/conversion-kits |
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Posted: 8/4/2016 10:11:03 PM EDT
[#21]
Quote HistoryQuoted:
SGAmmo pretty consistently has Silver Bear which is the favorite after Golden Tiger which is never available. http://www.sgammo.com/product/545x39-ammo/750-round-case-545x39-fmj-60-grain-silver-bear-non-corrosive-ammo Quote HistoryQuoted:
Quoted:
And wolf is pretty much the only commercial 5.45, other than the rare golden tiger, or silver bear. I do have some of the hornady made stuff, I shot it way back and never had any problems that I remember. A new barrel may be in the works down the road, as of now I'm rolling with it, as I don't have the funds for a new barrel, plus have someone drill and install the gas block. I think if I went that route, I'd go piston anyways. You know how one thing always leads to another SGAmmo pretty consistently has Silver Bear which is the favorite after Golden Tiger which is never available. http://www.sgammo.com/product/545x39-ammo/750-round-case-545x39-fmj-60-grain-silver-bear-non-corrosive-ammo Might try a box of silver bear sometime, but something tells me its the same bullet as the wolf... |
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Posted: 8/5/2016 2:26:09 PM EDT
[#22]
I purchased a complete Smith & Wesson MP15R in 5.45x39 new several years ago. I never shot 7n6 through it, however I did shoot about 5,000 rounds of Hornady, Wolf, Monarch, Silver Bear, Brown Bear and Tula through it.
At first it grouped good and tight, absolutely no keyholing. As it approached the 5000 round mark it started keyholing intermittantly. I initially thought I had gotten a bad batch of ammo, so I would change up the brands. It started to intermittently keyhole then eventually all 30 founds in a mag would keyhole at 30 yards. The target would look like you shot it with a shotgun. It did seem to keyhole less with certain brands of ammo, but initially it had absolutely no keyholing with any ammo I used. The rifle was cleaned regularly and was not subjected to repeated mag dumps, and normally had no more than 240 rounds or so sent through it in a session. I assumed that the barrel was shot out at this point. I know some calibers can be harder on the barrel causing a shorter barrel life, but if I remember correctly I think that eh MP15R had a chrome lined barrel. You would think that it would last longer than that. I have read reports that Smith & Wesson had used .223/5.56 barrel blanks instead of one's properly sized for the 5.45. I cannot remember for sure but I think the twist rate was 1/9. I currently own a Huldra 5.45 upper and it has performed flawlessly with the same ammo. It has 1/8 twist. |
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Posted: 8/5/2016 4:57:34 PM EDT
[#23]
I dont think they used 5.56 blanks, century did that with the tantals, and were utter failures. I think s&w just used the wrong twist 1 in 9 and not 1 in 8?
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Posted: 8/5/2016 6:14:50 PM EDT
[#24]
Quote HistoryQuoted:
I dont think they used 5.56 blanks, century did that with the tantals, and were utter failures. I think s&w just used the wrong twist 1 in 9 and not 1 in 8? Probably is the twist rate then, it shot so good for a while and then was worthless. I didn't think it would have shot as good as it did at first if the barrel was wrong. I never noticed any irregularities with the flash hider or barrel crown either. |
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Posted: 8/6/2016 12:27:01 AM EDT
[#25]
I just bought a 5.45 barrel and bolt because of this thread.
I thought I had missed the boat. |
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Posted: 8/6/2016 10:21:54 AM EDT
[#26]
Barrels on Adams Arms, bolts by Lehigh.
This thread reminded me to swap out my keyholing s&w barrel. |
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Posted: 8/6/2016 11:10:27 AM EDT
[#27]
Quote HistoryQuoted:
I dont think they used 5.56 blanks, century did that with the tantals, and were utter failures. I think s&w just used the wrong twist 1 in 9 and not 1 in 8? I still have a tantal with several thousand round tins of the banned stuff in the bottom of a closet. Maybe, one day when I get time, I'll investigate if someone re barrels the keyhole queen. 
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Posted: 8/6/2016 1:10:11 PM EDT
[#28]
Quote HistoryQuoted:
I still have a tantal with several thousand round tins of the banned stuff in the bottom of a closet. Maybe, one day when I get time, I'll investigate if someone re barrels the keyhole queen. Quote HistoryQuoted:
Quoted:
I dont think they used 5.56 blanks, century did that with the tantals, and were utter failures. I think s&w just used the wrong twist 1 in 9 and not 1 in 8? I still have a tantal with several thousand round tins of the banned stuff in the bottom of a closet. Maybe, one day when I get time, I'll investigate if someone re barrels the keyhole queen. Yeah, tons of folks who had those sent them back for Century to fix, but there is still a few out there, that were not fixed I guess 
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Posted: 8/6/2016 11:03:06 PM EDT
[#29]
With that few rounds I would guess the 1/9 twist to be the problem based on what ive read. I love my voodoo barrel it 1/8 no problems.
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Posted: 8/7/2016 2:31:32 AM EDT
[#30]
I have a LWRC 5.45 that works really well. I had a smith wesson one before it did not work very well at all
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Posted: 8/9/2016 1:36:31 AM EDT
[#31]
Quote HistoryQuoted:
I just bought a 5.45 barrel and bolt because of this thread. I thought I had missed the boat. Adams Arms/Voodoo barrel I assume? Who's bolt? |
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Posted: 8/9/2016 1:45:51 AM EDT
[#32]
Quote HistoryQuoted:
My S&W CL bbl started to keyhole around 8-10K rounds. This is not an isolated incident, even being chromed. Not as bad as the Tantal debacle, but definately a S&W issue. Most 5.56 barrels will keyhole at that round count |
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Posted: 8/9/2016 2:21:41 AM EDT
[#33]
One of my SW barrels started keyholing at about 3k rounds. Got to about 8k before every single round keyholed. It was still reasonably accurate out to about 25, and I was using it as a training rifle.
Later SW barrel made it to around 9k before i started seeing keyholes, and 12k before it needed replacing. I think they got the land and groove diameter/depths wrong. |
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Posted: 8/9/2016 11:09:27 AM EDT
[#34]
Quote HistoryQuoted:
Barrels on Adams Arms, bolts by Lehigh. Given the different 5.45 headspace specs between manufacturers, is this a known good combination? |
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Posted: 8/9/2016 12:51:45 PM EDT
[#35]
Quote HistoryQuoted:
Given the different 5.45 headspace specs between manufacturers, is this a known good combination? Quote HistoryQuoted:
Quoted:
Barrels on Adams Arms, bolts by Lehigh. Given the different 5.45 headspace specs between manufacturers, is this a known good combination? I was wondering that as well since on Ballistic Advantage's FAQ it says this: Will my 5.45 bolt work with a BA barrel? Headspace correct for BA barrel: - Smith & Wesson - Spike’s Tactical - Adam’s Arms Headspace NOT correct for BA barrel: - Model 1 Sales - Red X Arms Since Adams Arms/Voodoo barrel would be similar to the Ballistic Advantage's barrels headspace then the bolt would need to be the same as the ones that work with the BA barrel. If the Lehigh bolt is the same as Spikes, S&W, and Adams it will be fine; if it is like the Model 1 and Red X I can only assume problems. There was a thread explaining the differences in the depth of the bolt faces between the manufacturers and it having to do with the firing pin, but I can't find it. |
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Posted: 8/9/2016 3:38:20 PM EDT
[#36]
Quote HistoryQuoted:
Given the different 5.45 headspace specs between manufacturers, is this a known good combination? Quote HistoryQuoted:
Quoted:
Barrels on Adams Arms, bolts by Lehigh. Given the different 5.45 headspace specs between manufacturers, is this a known good combination? Limited examples, but my research says Lehigh bolts headspace correctly in BA barrels. |
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Posted: 8/9/2016 5:42:41 PM EDT
[#37]
There is also this one: https://rubbercityarmory.com/shop/5-45x39-complete-bolt/ More expensive but I am sure is a solid option. Or, for a little more you can get the entire BCG: http://www.tntesales.com/rubber-city-armory-5-45x39-m16-bcg/
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Posted: 8/9/2016 6:04:48 PM EDT
[#38]
And, another barrel option: https://ar15depot.com/ard-ar-15-stainless-str-fluted-h-bar-5-45-barrel-16-inch-r545 Who knows what bolt will go with it though.
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Posted: 8/9/2016 7:43:40 PM EDT
[#39]
Quote HistoryQuoted:
Most 5.56 barrels will keyhole at that round count Quote HistoryQuoted:
Quoted:
My S&W CL bbl started to keyhole around 8-10K rounds. This is not an isolated incident, even being chromed. Not as bad as the Tantal debacle, but definately a S&W issue. Most 5.56 barrels will keyhole at that round count I have plenty of other CL barrels just as many, and one with twice as many, hard life rounds, and they don't keyhole. |
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Posted: 8/9/2016 9:33:04 PM EDT
[#40]
Quote HistoryQuoted:
I still have a tantal with several thousand round tins of the banned stuff in the bottom of a closet. Maybe, one day when I get time, I'll investigate if someone re barrels the keyhole queen. Quote HistoryQuoted:
Quoted:
I dont think they used 5.56 blanks, century did that with the tantals, and were utter failures. I think s&w just used the wrong twist 1 in 9 and not 1 in 8? I still have a tantal with several thousand round tins of the banned stuff in the bottom of a closet. Maybe, one day when I get time, I'll investigate if someone re barrels the keyhole queen. http://www.gmriflebarrel.com/5-45-x-39mm-polish-tantal-replacement-barrel/ $152 directly from GM |
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Posted: 8/10/2016 10:40:07 AM EDT
[#41]
Might be a dumb question, but we talk about bolts headspacing on certain barrels. How in the hell could they be different?? Is it because 5.45 isn't a SAAMI spec round, so folks are just using the commie figures or what?? I'd think you have a round made to certain specs, you would headspace it to certain specs?
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Posted: 8/10/2016 11:12:30 AM EDT
[#42]
Quote HistoryQuoted:
Might be a dumb question, but we talk about bolts headspacing on certain barrels. How in the hell could they be different?? Is it because 5.45 isn't a SAAMI spec round, so folks are just using the commie figures or what?? I'd think you have a round made to certain specs, you would headspace it to certain specs? Quote HistoryQuoted:
Might be a dumb question, but we talk about bolts headspacing on certain barrels. How in the hell could they be different?? Is it because 5.45 isn't a SAAMI spec round, so folks are just using the commie figures or what?? I'd think you have a round made to certain specs, you would headspace it to certain specs? from what Ive read on the AK forums, US made headspace gauges aren't dimensionally the same as Combloc headspace gauges or live ammo for that matter. #1 Re: 5.45x39 Headspace Gauge Confusion
I called Manson Reamers to order a barrel crowning tool for my Arsenal SLR-107UR SBR project. What I had the lady on the phone I asked her about 5.45x39 gauges. She said that I needed to speak with Dave. She then came back and asked if he could call me. I said sure, half expecting not to get a call back. True to her word, he called me back. We discussed this issue. He seemed very interested. He said that the gauges are made to CIP drawings and he's 100% confident that they're made to the correct dimensions. However, he said that it's possible that the factories use some other sort of gauge standard. Based on everything that I've seen, I believe this is the most likely scenario. He said that he can make me a custom gauge to the specifications that I want. I think that I may have a gauge made to the Go dimensions -0.002" or -0.003". I'll test my new 5.45x39 Vepr when it arrives. If it's also tighter than the Go, I'll do this. If it's not, then I'll just be even more confused. BTW, I'll give a big +1 to Dave Manson for his attention to customer service. I'm an amature and he still took the time to speak with me in great detail. #2 I picked up a new 5.45x39 Vepr today. I disassembled the bolt and tried both gauges. I won't close on a No-Go. It will close on a Go with a little pressure. It closes on live rounds with no pressure at all. #3 I picked up a new 5.45x39 Saiga yesterday. It won't close on a Go gauge, even with a good amount of pressure to the back of the carrier. So my Vepr and Saiga are headspaced differently. Call me confused. |
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Posted: 8/10/2016 12:50:00 PM EDT
[#43]
Quote HistoryQuoted:
Might be a dumb question, but we talk about bolts headspacing on certain barrels. How in the hell could they be different?? Is it because 5.45 isn't a SAAMI spec round, so folks are just using the commie figures or what?? I'd think you have a round made to certain specs, you would headspace it to certain specs? http://www.ar15.com/archive/topic.html?b=3&f=121&t=612446 http://www.ar15.com/archive/topic.html?b=3&f=121&t=592379 |
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Posted: 8/10/2016 12:53:22 PM EDT
[#44]
Quote HistoryQuote HistoryQuoted:
Quoted:
Might be a dumb question, but we talk about bolts headspacing on certain barrels. How in the hell could they be different?? Is it because 5.45 isn't a SAAMI spec round, so folks are just using the commie figures or what?? I'd think you have a round made to certain specs, you would headspace it to certain specs? http://www.ar15.com/archive/topic.html?b=3&f=121&t=612446 http://www.ar15.com/archive/topic.html?b=3&f=121&t=592379 I got it now, so basically some 5,45 AR bolts have the faces reamed deeper than others, and thus headspace different. I guess since there's no real standard on the 5.45 specific stuff, manufacturers can have parts made as they wish. |
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Posted: 8/10/2016 5:54:23 PM EDT
[#45]
1/9 twist is too slow for the long 5.45 bullets. The 7N6 with it's higher velocity was probably just on the edge of stability out of the 1/9. The slower heavier commercial bullets would be more likely to be unstable if you're right on the stability edge with that long bullet. The commercial 5.45 ammo uses the same jacket as 7N6, except it's filled with lead and a pretty long air gap instead of the steel core. Arsenal (Bulgarian) 5.45mm rifles list the twist rate at 1/195mm. That is approx. 1/7 +/-.
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Posted: 8/10/2016 8:41:16 PM EDT
[#46]
My Huldra upper from Fleet Farm (made by Adams with a Voodoo barrel) is nice and accurate, eats commercial and 7N6 ammo, and is a blast to shoot.
It should be noted that though 5.45x39 isn't SAAMI standardized, it IS CIP standardized. Here is the CIP standard document for 5.45x39.. Instead of a datum circle, as used in SAAMI specs, CIP uses the top of the shoulder as the headspace reference. It's not rocket science to see how long the chamber should be at that point. The shoulder of the chamber should end at a 6.46mm diameter that is 33.65mm from the breech face. The document has all the pertinent data. PT&G makes both a GO and a NO GO gage for this cartridge. Since my upper came with a correct bolt - and there's no sign of headspace issues - I haven't worried about gages, so I haven't contacted them to ask what dimensions they use. Since PT&G is "kinda good" at making gages, reamers, etc., I sort of expect that they know what they're doing... |
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Posted: 8/20/2016 6:08:32 PM EDT
[#47]
Bore was cleaned with sweets a few weeks ago, for the first time that I remmeber. Took it out today, shoots great still with surplus. 50yds with my vortex red dot. Not bad for no magnification in a 4MOA dot. That group is one 30rnd mag
Ignore the odd holes down low, that was a 6.5 carcano I was toying with shitty ammo with.
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Posted: 8/27/2016 7:42:08 AM EDT
[#48]
As mentioned earlier, they burn out faster. I also believe that some of the surplus rounds aren't made right and keyhole no matter what but the main culprit is the barrel burnout. I've burned out two S&W barrels and am on a Ballstic Advantage barrel now. I wrote the below article.
http://rationalgun.blogspot.com/2013/01/my-definitive-545x39mm-ar15-article.html |
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Posted: 8/27/2016 11:55:44 AM EDT
[#49]
I do remember a lot of reports of the S&W barrels keyholing at 10-12K, but the bigger question was why they did, whereas an AK74 barrel would go 3 times that (not counting CIA Tantal fiasco).
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Posted: 8/27/2016 11:58:58 AM EDT
[#50]
Quote HistoryQuoted:
I do remember a lot of reports of the S&W barrels keyholing at 10-12K, but the bigger question was why they did, whereas an AK74 barrel would go 3 times that (not counting CIA Tantal fiasco). I believe it was the rifling but definitely barrel construction related. My BA barrel shoots well but the nitride coating is no match for the corrosive salts in the surplus primers. |
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