Cutting 16'' Barrel down fo a krink build
1 - 12 of 12 Posts
Joined
·
91 Posts
I've heard several quotes on the russian Krink twist rate that were taken from literature. Has anyone checked their barrel for actual twist rate?
I just checked the twist on my Bulgarian Krink and it was about 1 in 10!
I checked the rate in the Russian Krink stub and it was about 1 in 8.
I have one of the E. German virgin 16" barrels and it measured about 1 in 8 so it looks like the E. German barrel is what I will go with if the Rguns barrels are too pricey. The only dimension that will be off will be the front forearm hanger, by about .005 which can be mostly nullified by cutting the lock pin slot about that same amount too shallow.
I'd be interested to hear from some others if they get about the same twist rate reading that I got on the russian krink barrel.
The way I measured it was with a 22 cal bronze brush on a cleaning rod with a swivel handle. I wrapped a piece of masking tape around the rod about 7 inches up from the end and left a little flap sticking out like a flag. I inserted the brush into the barrel a short amount until the flag started to rotate. I then took a measurement from the end of the barrel to the flag. At that point I slowly pushed the rod thru the bore to see how far the flag rotated. Since the barrel stub is so short, I could not get a full rotation of the flag, but was able to get a 1/3 rotation. At that point I remeasured the distance from the barrel end to the flag and subtracted that from the original measurement. That figure times 3 gave me a close estimate of the twist rate.
I just checked the twist on my Bulgarian Krink and it was about 1 in 10!
I checked the rate in the Russian Krink stub and it was about 1 in 8.
I have one of the E. German virgin 16" barrels and it measured about 1 in 8 so it looks like the E. German barrel is what I will go with if the Rguns barrels are too pricey. The only dimension that will be off will be the front forearm hanger, by about .005 which can be mostly nullified by cutting the lock pin slot about that same amount too shallow.
I'd be interested to hear from some others if they get about the same twist rate reading that I got on the russian krink barrel.
The way I measured it was with a 22 cal bronze brush on a cleaning rod with a swivel handle. I wrapped a piece of masking tape around the rod about 7 inches up from the end and left a little flap sticking out like a flag. I inserted the brush into the barrel a short amount until the flag started to rotate. I then took a measurement from the end of the barrel to the flag. At that point I slowly pushed the rod thru the bore to see how far the flag rotated. Since the barrel stub is so short, I could not get a full rotation of the flag, but was able to get a 1/3 rotation. At that point I remeasured the distance from the barrel end to the flag and subtracted that from the original measurement. That figure times 3 gave me a close estimate of the twist rate.
Joined
·
1,318 Posts
east german was 1 in 8? hmmm
Joined
·
1,157 Posts
does the twist rate really matter?if the gun goes bang every time you pull the trigger and it shoots M.O.M that is good enough for me.
Joined
·
1,802 Posts
For a shooter, if it stabilizes the bullet then it would be fine. For a collector, well, as close to original matters.
I am not sure how accurate the above mentioned test method for twist determination is; to be honest it seems to leave a bit too much to chance for me.
I have re-checked my literature and the factory twist for an AKS74U is supposed to be a 1:6.3" twist. Will your gun be decently accurate with a barrel with a factory twist of 1:8"?
I am not sure to be honest. It would seem probably to be on a case by case basis but more than likely I would say you probably have a good chance it would be acceptable on accuracy for the M.O.M. needs but I am not more than about 60% sure on anything else. The 5.45 bullet can be a slippery thing at times with twist, velocity and temperature. You might get some keyholing or thrown shots; also if things are not quite right in the twist department at further ranges (50+yds) with certain typs of ammo you could be way out there accuracywise.
(Caveat) But admittedly I don't know any of this for sure either- I guess we will see when we get some range reports from folks who have built them. From past experience I have learned to be cautious with the 5.45mm cartridge in matters concerning barrel length and twist.
I have re-checked my literature and the factory twist for an AKS74U is supposed to be a 1:6.3" twist. Will your gun be decently accurate with a barrel with a factory twist of 1:8"?
I am not sure to be honest. It would seem probably to be on a case by case basis but more than likely I would say you probably have a good chance it would be acceptable on accuracy for the M.O.M. needs but I am not more than about 60% sure on anything else. The 5.45 bullet can be a slippery thing at times with twist, velocity and temperature. You might get some keyholing or thrown shots; also if things are not quite right in the twist department at further ranges (50+yds) with certain typs of ammo you could be way out there accuracywise.
(Caveat) But admittedly I don't know any of this for sure either- I guess we will see when we get some range reports from folks who have built them. From past experience I have learned to be cautious with the 5.45mm cartridge in matters concerning barrel length and twist.
Joined
·
4,029 Posts
dude you and me both are on the same side of the fence.KMFDM said:
correct, 1:6 is more like it. I also acquired a Russian AKSU bareless kit, and stuck as well.
I will go and start looking around (which is empty by the way
) for an actual AKSU barrel. good luck with that one right....
Joined
·
91 Posts
Well, I've heard and read several different twist rates including the 1:63, but I think the only for sure way to know what was used is to test the actual barrel that came with the kit. My method is admittedly crude but I have used it for years to check twist rate on AR type barrels and it has been fairly accurate.KMFDM said:
I still would like others to test their barrels, using whatever method they can devise and lets compare notes. Just accepting what you read is certainly not as accurate as an actual measurement. You can't believe everything you read.
Joined
·
1,318 Posts
well, we already have reports from people who built bulgy krinks, and they seem to be ok. your measurement might not be accurate, but thanks for trying, telling us how you tried and what your approximate measures are... helps out those of us who're deployed and have to resort to the wife taking pics and sending them to me... :bow:
Joined
·
1,157 Posts
my full size bugly chrome lined barrel is on the way.as soon as it gets here it is going to be cut down to normal krink size.if you guys want to wait for a range report you can.i cannot give you a specific time frame but it will be sooner than later.as for me i am a shooter,not a collector.yes it is a russian krink,which is the ultimante in cool factor,but all my rifles MUST function every time and be M.O.M,that makes me happy.just bringing back to life these cold war relics and shooting them gives me a sence of accomplishment.i have target rifles that will shoot 1 moa,and most of my rifles will outshoot my old eyes,but NOTHING beats blazing away with a AK that I built.my.$02
I got my information out the Soviet era military issued AKS74U operators manual (p 145). Now it is possible it is incorrect or was changed at some point-definately granted there.
Voknirk:
Yes, I would like to see some more testing done for sure- no flame intended. I am aware of the technique you used but I am not satisified with "fairly accurate". Especially if fairly accurate possibly means + 1.3" on twist miscalculation. After paying 750.00 for a kit (as we all have here) and a possible $100.00+ for a barrel recontouring job, plus build fees and a possible later SBR stamp. I am uncharacteristically a little anal on this one. Usually I don't care but I know the 5.45 bullet can be tricky to work with also and have seen what can happen when things don't go quite as expected: When one cuts a 16" barrel to 12" and starts running into problems with bullet stability in some barrels then take another almost 4" off and I would guess you might have the potential for more issues. But I just don't know.... Hopefully as I said some here who have already built rifles will chime in and say what their findings are-I admit freely I could be making a tempest in a teacup here.
The gun I will be building is for my wife and I want her to have a good experience with what will be her first rifle. I would like it as close to a factory rifle as possible in the accuracy for shooting department for her to help her build confidence. Plus she may have to use it one day for other purposes. I see no point in building a weapon that isn't at least in the same ballpark as something from the factory when it come to shooting accuracy.
My main problem is I am deployed at the moment and have not even seen the kit and won't for a few more months but would just like to know...
edited for clarity and content
Voknirk:
Yes, I would like to see some more testing done for sure- no flame intended. I am aware of the technique you used but I am not satisified with "fairly accurate". Especially if fairly accurate possibly means + 1.3" on twist miscalculation. After paying 750.00 for a kit (as we all have here) and a possible $100.00+ for a barrel recontouring job, plus build fees and a possible later SBR stamp. I am uncharacteristically a little anal on this one. Usually I don't care but I know the 5.45 bullet can be tricky to work with also and have seen what can happen when things don't go quite as expected: When one cuts a 16" barrel to 12" and starts running into problems with bullet stability in some barrels then take another almost 4" off and I would guess you might have the potential for more issues. But I just don't know.... Hopefully as I said some here who have already built rifles will chime in and say what their findings are-I admit freely I could be making a tempest in a teacup here.
The gun I will be building is for my wife and I want her to have a good experience with what will be her first rifle. I would like it as close to a factory rifle as possible in the accuracy for shooting department for her to help her build confidence. Plus she may have to use it one day for other purposes. I see no point in building a weapon that isn't at least in the same ballpark as something from the factory when it come to shooting accuracy.
My main problem is I am deployed at the moment and have not even seen the kit and won't for a few more months but would just like to know...
edited for clarity and content
Joined
·
1,157 Posts
KMFDM
i understand your concerns.this is the most money i have ever paid for a kit.i also got a correct russian marked receiver for it.when it is all done my krink will look factory and will be the most exspenisve ak i will own.that is the problem with this russian thing as i am finding out.i have a all matching tula akm also.it is just a different preference for different guys.as for collectors,i think that their are way to many of these kits to be rare.i think that collecting russians is a small group of guys compared to the ak circle.i think their are more kits than russian collectors around and their will be plenty enough to satisfy anyone who wants one of these.all the aks i build are shot and are not safe queens.are they shot alot?,not really but they are taken out for a 100rd spin every one in awhile.if i can hit a man size target at 50 yards with my krink i will be happy because i believe these weapons were designed for CQB,and that is what i use it for.i hope it comes out ok,but i will have to wait and see.
i understand your concerns.this is the most money i have ever paid for a kit.i also got a correct russian marked receiver for it.when it is all done my krink will look factory and will be the most exspenisve ak i will own.that is the problem with this russian thing as i am finding out.i have a all matching tula akm also.it is just a different preference for different guys.as for collectors,i think that their are way to many of these kits to be rare.i think that collecting russians is a small group of guys compared to the ak circle.i think their are more kits than russian collectors around and their will be plenty enough to satisfy anyone who wants one of these.all the aks i build are shot and are not safe queens.are they shot alot?,not really but they are taken out for a 100rd spin every one in awhile.if i can hit a man size target at 50 yards with my krink i will be happy because i believe these weapons were designed for CQB,and that is what i use it for.i hope it comes out ok,but i will have to wait and see.
1 - 12 of 12 Posts
