In general I agree with everything in this thread. BUT - I have always believed large bullet jump erodes a throat more but really have no hard evidence for this.
'Ned Kelly' wrote
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As for seating depth, DEFINATELY either jumping or well into the lands but NOT kissing the lands. At least that way you know one way or the other and throat erosion isn't a problem that it might be if your kissing the lands.
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I can see accuracy reasons for not 'kissing the lands', especially when using commercial projectiles. Variability will be magnified.
But I cannot see why it promotes more throat erosion over BOTH alternatives - ie large jump OR negative bullet jump.
What is the rationale for this - or alternatively have you any evidence to support your statement.
Peter Smith.
Barrel Tunning a 556
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ned kelly
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G'Day Peter,
the only real reason I do not recommend "kissing" the lands is when the seater is first set, the bullet is touching the lands and as the throat erodes due to normal wear and tear at some point it will go from "kissing" to "jumping" with the risk of accuracy changing possibly for the worse.
I feel it is far better to be one or the other i.e. jumping or hard into the lands as the throat erosion is essentially negated. If you jump a bullet, another 5 thou wear shouldn't make that much difference but it just might.
Jamming the bullet into the lands, on the other hand, does help to align the bullet with the bore axis and depending on case neck tension, usually the bullet is pushed back into the case for a very consistent bullet to rifling relationship, regardless of throat wear.
Naturally, accuracy minded shooters, will monitor and adjust their bullet seating depth as the throat erodes to maintain the optimum seating depth that the load and rifle requires for competition.
Hopefully this clarifies my point (or opinions
) on bullet seating.
Cheerio Ned
the only real reason I do not recommend "kissing" the lands is when the seater is first set, the bullet is touching the lands and as the throat erodes due to normal wear and tear at some point it will go from "kissing" to "jumping" with the risk of accuracy changing possibly for the worse.
I feel it is far better to be one or the other i.e. jumping or hard into the lands as the throat erosion is essentially negated. If you jump a bullet, another 5 thou wear shouldn't make that much difference but it just might.
Jamming the bullet into the lands, on the other hand, does help to align the bullet with the bore axis and depending on case neck tension, usually the bullet is pushed back into the case for a very consistent bullet to rifling relationship, regardless of throat wear.
Naturally, accuracy minded shooters, will monitor and adjust their bullet seating depth as the throat erodes to maintain the optimum seating depth that the load and rifle requires for competition.
Hopefully this clarifies my point (or opinions
) on bullet seating.
Cheerio Ned
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pjifl
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Ned,
OK. I misinterpreted what you meant. I thought you meant that kissing actually causes more throat erosion. So I agree that throat erosion which inevitably results will have more impact on accuracy and tuning.
To return to long bullet jump. I suspect it actually causes more throat erosion. Has anyone information or evidence on this one way or the other.
Peter Smith.
OK. I misinterpreted what you meant. I thought you meant that kissing actually causes more throat erosion. So I agree that throat erosion which inevitably results will have more impact on accuracy and tuning.
To return to long bullet jump. I suspect it actually causes more throat erosion. Has anyone information or evidence on this one way or the other.
Peter Smith.
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richmac
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Barrel Tunning a 556
Hi Again Ned
I have to go along with you on that statement as the barrell that I have had in my rifles all wear out in the throat very quickly.
I have always had them Kissing the lanse and my barrel life has not been good.(1500 rounds tops)
I will give my pills a 12 to 15 thou jump and try this out this weekend as I have a team shoot and also a prize meeting on Sunday.
That will be at least 60 rounds that will be a fair test.
Catch U soon
I have to go along with you on that statement as the barrell that I have had in my rifles all wear out in the throat very quickly.
I have always had them Kissing the lanse and my barrel life has not been good.(1500 rounds tops)
I will give my pills a 12 to 15 thou jump and try this out this weekend as I have a team shoot and also a prize meeting on Sunday.
That will be at least 60 rounds that will be a fair test.
Catch U soon
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mike H
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Richmac,
Perhaps I am getting confused, after all it is Saturday evening. But 1500 rounds for a .223 barrel, no way. Should be double that, at least.
Mine wear, and probably every 500 rounds, I seat bullets out a bit more. I always have about 20 to 40 thou jump. Probably because I was never a benchrest shooter, and have seen the problems of bullets left in the throat and powder jamming up triggers, and actions.
Also with wear, and longer throats, I seem to need to increase powder loads. The current load of 2208, I am using, to me four years ago, I would have thought ridiculous, even dangerous. But some wear gives more clearance, and seems to reduce pressure, probably at some point, erosion, and roughening of the lead, will balance out. By then you should notice accuracy has diminished.
It is difficult to carry on about these matters, as I am a B-grade F/class shooter, Have never thought I could shoot 1" groups at 300 Metres, but really I believe wind reading miscalculations hold me back, not the ammo, or rifle.
I have two 1-8 barrels, the next one will be a 1-7, as I think it will be better at the longer ranges.If it is not, or I am not, so what. The people you meet rifle shooting, are what is important to me, not the gongs, not that I don`t enjoy getting one , now and then.
Best of luck,
Mike.
Perhaps I am getting confused, after all it is Saturday evening. But 1500 rounds for a .223 barrel, no way. Should be double that, at least.
Mine wear, and probably every 500 rounds, I seat bullets out a bit more. I always have about 20 to 40 thou jump. Probably because I was never a benchrest shooter, and have seen the problems of bullets left in the throat and powder jamming up triggers, and actions.
Also with wear, and longer throats, I seem to need to increase powder loads. The current load of 2208, I am using, to me four years ago, I would have thought ridiculous, even dangerous. But some wear gives more clearance, and seems to reduce pressure, probably at some point, erosion, and roughening of the lead, will balance out. By then you should notice accuracy has diminished.
It is difficult to carry on about these matters, as I am a B-grade F/class shooter, Have never thought I could shoot 1" groups at 300 Metres, but really I believe wind reading miscalculations hold me back, not the ammo, or rifle.
I have two 1-8 barrels, the next one will be a 1-7, as I think it will be better at the longer ranges.If it is not, or I am not, so what. The people you meet rifle shooting, are what is important to me, not the gongs, not that I don`t enjoy getting one , now and then.
Best of luck,
Mike.
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pjifl
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You should have more like 3000 shots from a 223. I have one now with about this through it - some roughness now felt - but it recently shot 60 (FS) and 98 on the open target. Somehow I expect it to collapse soon but who knows. Usual velocity is about 2840.
Unless you are really stoking up the loads, I would be retrying a 223 barrel with only 1500 through it looking for some other reason for accuracy to fall off.
Even with misadventures in windreading, elevation consistency is always a good test of accuracy.
Peter Smith.
Unless you are really stoking up the loads, I would be retrying a 223 barrel with only 1500 through it looking for some other reason for accuracy to fall off.
Even with misadventures in windreading, elevation consistency is always a good test of accuracy.
Peter Smith.
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Guest
Cannot comment on 223's as I ( we ) do not use them, but 1500 rounds sounds a bit light to me unless of course you are using "hot " loads.
Our 308's are all aproaching 4500 rounds and recent wins by Jenny and Adam bear testimony as to the accuracy of both rifles. They have never been rechambered or recrowned and seating depth is only 10 thou or so longer that new. Of course we do not use hot loads--no need, all you need is sufficient speed to reach 1000yds with accuracy. Incidently all of our barrels are 14 twist which certainly appears to extend life. I rechambered one of the 14 twist barrels at 4500 rounds and the new seating depth actually measured 5 thou shorter than an identical new barrel. This barrel will be good for another 4500 rounds.
Seems to me people who cannot get good life from their barrels either use loads that are too " hot " or wear them out with a cleaning rod thinking that the bad score is due to faulty cleaning rather than one of the many " other " factors that go to make an accurate rifle.
Barry
Our 308's are all aproaching 4500 rounds and recent wins by Jenny and Adam bear testimony as to the accuracy of both rifles. They have never been rechambered or recrowned and seating depth is only 10 thou or so longer that new. Of course we do not use hot loads--no need, all you need is sufficient speed to reach 1000yds with accuracy. Incidently all of our barrels are 14 twist which certainly appears to extend life. I rechambered one of the 14 twist barrels at 4500 rounds and the new seating depth actually measured 5 thou shorter than an identical new barrel. This barrel will be good for another 4500 rounds.
Seems to me people who cannot get good life from their barrels either use loads that are too " hot " or wear them out with a cleaning rod thinking that the bad score is due to faulty cleaning rather than one of the many " other " factors that go to make an accurate rifle.
Barry
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pjifl
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Relating the life of a 223 to a 308 will help put it in perspective.
I agree with Barry's estimate of the life of a 308 and have found a 223 definitely has - relatively - a little less life. But not dramatically so. I have always used 2208 powder.
It may be tied in with the higher twist rate but in general the smaller the caliber the faster the throat wears away. Especially with large relative cases - which is not typical of the 223 so this saves the 223 from rediculously small barrel life. Now a 22-250 is another kettle of fish.
The slightly reduced life would NOT turn me away from a 223 - maybe other factors could.
Some people stoke up a 223 to the max but I have never found it really needed - even at 1000. But if you do, can I suggest people use a seperate 1000 y load for 223s and just use 'normal' loads for every other range. I normally use 2840 fps but can achieve 2950 if needed with 2208 using Sierra 80's.
Like most cartridges - I have always found best accuracy at less than max load anyway.
P{eter Smith.
I agree with Barry's estimate of the life of a 308 and have found a 223 definitely has - relatively - a little less life. But not dramatically so. I have always used 2208 powder.
It may be tied in with the higher twist rate but in general the smaller the caliber the faster the throat wears away. Especially with large relative cases - which is not typical of the 223 so this saves the 223 from rediculously small barrel life. Now a 22-250 is another kettle of fish.
The slightly reduced life would NOT turn me away from a 223 - maybe other factors could.
Some people stoke up a 223 to the max but I have never found it really needed - even at 1000. But if you do, can I suggest people use a seperate 1000 y load for 223s and just use 'normal' loads for every other range. I normally use 2840 fps but can achieve 2950 if needed with 2208 using Sierra 80's.
Like most cartridges - I have always found best accuracy at less than max load anyway.
P{eter Smith.
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RobH
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On barrel life of a 223.
Have a trueflite barrel in my rem 700 that has 3800 rounds. Load was 25 gns 08 does 2900 fps. Recently changed to 24 gns 06h does 2915 fps. this load will still hold .5" elevation at 200 yds. Am currently rechambering as appears to be heaps of life left in it yet. I am astounded when a barrel life of 1500 rounds is floated. I use moly and seat at or into the lands.
RobH.
Have a trueflite barrel in my rem 700 that has 3800 rounds. Load was 25 gns 08 does 2900 fps. Recently changed to 24 gns 06h does 2915 fps. this load will still hold .5" elevation at 200 yds. Am currently rechambering as appears to be heaps of life left in it yet. I am astounded when a barrel life of 1500 rounds is floated. I use moly and seat at or into the lands.
RobH.
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richmac
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barrel tuning a 556
Well I think we should get back to what I originally posted about barrel tunning a 556.
I went to the range the other day and tried to tune the barrel by using different loads.
The 2 loads I tried were 24.7 of 2206h Danzac coated with 12 to 15 thou jump...also 25.2 2208 with the same jump.
The groups I shot were still hollow.
I also ran a chron over them to check the speeds 2206h =2890 ave and 2208 = 2930 Ave
The Rifle is bedded on a V block with a full floating barrel.
While driving home from the range I had thoughts...
A 556 barrel is a lot heavier than a 762 barrel hence a smaller hole.
This means a lot more weight which I now think it needs to be supported under the barrel to cut down the vibrations.
I think this could be the answer to good groups.
I will try it out on Saturday and see if I am right with my therory
I went to the range the other day and tried to tune the barrel by using different loads.
The 2 loads I tried were 24.7 of 2206h Danzac coated with 12 to 15 thou jump...also 25.2 2208 with the same jump.
The groups I shot were still hollow.
I also ran a chron over them to check the speeds 2206h =2890 ave and 2208 = 2930 Ave
The Rifle is bedded on a V block with a full floating barrel.
While driving home from the range I had thoughts...
A 556 barrel is a lot heavier than a 762 barrel hence a smaller hole.
This means a lot more weight which I now think it needs to be supported under the barrel to cut down the vibrations.
I think this could be the answer to good groups.
I will try it out on Saturday and see if I am right with my therory
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pjifl
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The extra weight of a long 223 barrel over a 308 barrel of similar profile usually amounts to about 3 - 4 oz.
The extra stiffness will be quite small.
Personally I haver never liked bedding on the barrel but that proves nothing. (presumably you mean just in front of the receiver). On barrel tuning I have no idea so any experiments you do will be of interest.
As a matter of interest, what length and profile barrel ???
Peter Smith.
The extra stiffness will be quite small.
Personally I haver never liked bedding on the barrel but that proves nothing. (presumably you mean just in front of the receiver). On barrel tuning I have no idea so any experiments you do will be of interest.
As a matter of interest, what length and profile barrel ???
Peter Smith.
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richmac
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barrel tunning a 556
Hi Pete
I am running a true Flite 30inch 7 in 1 twist.
I think it is a Palma profile
Cheers Rich
I am running a true Flite 30inch 7 in 1 twist.
I think it is a Palma profile
Cheers Rich
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richmac
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barrel tunning a 556
G/Day Ned
Yep I have tried this as well.
I had great results doing it with the Krieger barrels but this was wearing out the throat and I was using 2206 powder.
I am still set on trying a bed under the barrel.
I think this will act like a tuner so the barrel vibrates consistantly
Cheers Rich
Yep I have tried this as well.
I had great results doing it with the Krieger barrels but this was wearing out the throat and I was using 2206 powder.
I am still set on trying a bed under the barrel.
I think this will act like a tuner so the barrel vibrates consistantly
Cheers Rich
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KHGS
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How are you cleaning this barrel?
What screw tension are you using on your takedown screws? Vee block bedding requires more tension than conventional epoxy bedding.
I doubt that bedding under the barrel will do very much with a Barnard, they are one very stiff receiver and are able to support a barrel much heavier than a Palma contour barrel with no problems.
Jamming bullets does not hasten throat erosion, my experience indicates the opposite if anything. I usually run my 5.56's into the lands or .010" off, both work well, I use CCI primers.
I use moly, but I clean regularly, my Matchmaster, Schneider & True-Flite barrels all clean easily. All shoot very well & are in Barnard actions on vee bedding blocks.
Keith H.
What screw tension are you using on your takedown screws? Vee block bedding requires more tension than conventional epoxy bedding.
I doubt that bedding under the barrel will do very much with a Barnard, they are one very stiff receiver and are able to support a barrel much heavier than a Palma contour barrel with no problems.
Jamming bullets does not hasten throat erosion, my experience indicates the opposite if anything. I usually run my 5.56's into the lands or .010" off, both work well, I use CCI primers.
I use moly, but I clean regularly, my Matchmaster, Schneider & True-Flite barrels all clean easily. All shoot very well & are in Barnard actions on vee bedding blocks.
Keith H.
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