Im going to be receiving my 308 build by the end of the week and it has a .299 bartilen which is tighter than the .300. I was reading that a tighter bore can boost fps just curious.
Tighter bore mean faster fps?
- Thread starter tlg308
- Start date
Re: Tighter bore mean faster fps?
it is easier to blow through a wide straw than it is to blow through a thin straw
things i have noticed with projectiles:
a .223 takes a .224 projectile
this interested me as well it comes back to physics
im not a mythbuster but i would say ur theory is correct
im not sure however of how much more this will improve accuracy or how this will effect barrel life.
i spent a long time going over alot of this sort of thing and figured if it shoots well don't worry if it isn't then try some load development.
it is easier to blow through a wide straw than it is to blow through a thin straw
things i have noticed with projectiles:
a .223 takes a .224 projectile
this interested me as well it comes back to physics
im not a mythbuster but i would say ur theory is correct
im not sure however of how much more this will improve accuracy or how this will effect barrel life.
i spent a long time going over alot of this sort of thing and figured if it shoots well don't worry if it isn't then try some load development.
Re: Tighter bore mean faster fps?
I'm thinking more friction, so it would probably also depend on barrel length, powder and bullet, and I'm sure other parameters as well. With all the knowledge on this site surely someone could shed more light, because I know it's not going to be me.
I'm thinking more friction, so it would probably also depend on barrel length, powder and bullet, and I'm sure other parameters as well. With all the knowledge on this site surely someone could shed more light, because I know it's not going to be me.
Re: Tighter bore mean faster fps?
Lowlight has at least one tight bore 308. And it shoots really well according to all reports. The thing with tight bores is that they can offer increased velocity at the expense of creating higher pressure. Due to this most manufacturers will not chamber tight bores in magnum calibers.
Lowlight has at least one tight bore 308. And it shoots really well according to all reports. The thing with tight bores is that they can offer increased velocity at the expense of creating higher pressure. Due to this most manufacturers will not chamber tight bores in magnum calibers.
Re: Tighter bore mean faster fps?
I believe my tight bores are .298 and they do increase the FPS by quite a bit.
I had a brand new 20" bbl that chronographed around 2500 -2550fps depending on the ammo. I immediately replaced it with a tight bore Bartlien the same 20" in length. My fps went to 2635 - 2675fps depending on the ammo. So on average I gained 125+ fps from the same length.
I have not seen a downside to going with a tight bore.
I believe my tight bores are .298 and they do increase the FPS by quite a bit.
I had a brand new 20" bbl that chronographed around 2500 -2550fps depending on the ammo. I immediately replaced it with a tight bore Bartlien the same 20" in length. My fps went to 2635 - 2675fps depending on the ammo. So on average I gained 125+ fps from the same length.
I have not seen a downside to going with a tight bore.
Re: Tighter bore mean faster fps?
125 FPS velocity gain is outstanding.
I wish LMT did something similar with the MWS. The 16" tubes are barely hitting 2500 with several members here running 45 grains of varget in 2.810" 175grain loads. (really pretty hot loads)
125 FPS velocity gain is outstanding.
I wish LMT did something similar with the MWS. The 16" tubes are barely hitting 2500 with several members here running 45 grains of varget in 2.810" 175grain loads. (really pretty hot loads)
Re: Tighter bore mean faster fps?
thats alot for a few thou's
would this multiply by how long the barrel is or would it just add in fps
just pondering the idea for a match grade barrel to go onto my Rem action,
the only other question would be can this action withstand the possible extra psi?
thats alot for a few thou's
would this multiply by how long the barrel is or would it just add in fps
just pondering the idea for a match grade barrel to go onto my Rem action,
the only other question would be can this action withstand the possible extra psi?
Re: Tighter bore mean faster fps?
Hey thanks for the replys I've been away for a couple days, thought this post wasn't gonna get any feed back. Thanks for the replies.
Hey thanks for the replys I've been away for a couple days, thought this post wasn't gonna get any feed back. Thanks for the replies.
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I believe my tight bores are .298 and they do increase the FPS by quite a bit.
I had a brand new 20" bbl that chronographed around 2500 -2550fps depending on the ammo. I immediately replaced it with a tight bore Bartlien the same 20" in length. My fps went to 2635 - 2675fps depending on the ammo. So on average I gained 125+ fps from the same length.
I have not seen a downside to going with a tight bore.
</div></div> Do you have and longer barrel tight bores. And was there a consistant increase in thoughs too? A gain of 125 fps would be awesome.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I believe my tight bores are .298 and they do increase the FPS by quite a bit.
I had a brand new 20" bbl that chronographed around 2500 -2550fps depending on the ammo. I immediately replaced it with a tight bore Bartlien the same 20" in length. My fps went to 2635 - 2675fps depending on the ammo. So on average I gained 125+ fps from the same length.
I have not seen a downside to going with a tight bore.
</div></div> Do you have and longer barrel tight bores. And was there a consistant increase in thoughs too? A gain of 125 fps would be awesome.
Re: Tighter bore mean faster fps?
I just got my new build from my smith this last friday and haven't been able to get it out and compare a standard bore .308 yet, but that will change this week.
I just got my new build from my smith this last friday and haven't been able to get it out and compare a standard bore .308 yet, but that will change this week.
Re: Tighter bore mean faster fps?
Yes my Valkyrie is a tight bore 22" and with the new faster load from Cor Bon I have recorded 2770fps with no pressure signs or issues. It's a laser.
I generally don't run 308 barrels longer than 22".
Yes my Valkyrie is a tight bore 22" and with the new faster load from Cor Bon I have recorded 2770fps with no pressure signs or issues. It's a laser.
I generally don't run 308 barrels longer than 22".
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Yes my Valkyrie is a tight bore 22" and with the new faster load from Cor Bon I have recorded 2770fps with no pressure signs or issues. It's a laser.
I generally don't run 308 barrels longer than 22". </div></div> Was this a custom load or retail? I do all my own reloads, but a round like that I would be interested in.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">Yes my Valkyrie is a tight bore 22" and with the new faster load from Cor Bon I have recorded 2770fps with no pressure signs or issues. It's a laser.
I generally don't run 308 barrels longer than 22". </div></div> Was this a custom load or retail? I do all my own reloads, but a round like that I would be interested in.
Re: Tighter bore mean faster fps?
A tighter chamber will really up velocities as well. Given the same load.
A tighter chamber will really up velocities as well. Given the same load.
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigwheeler</div><div class="ubbcode-body"> A tighter chamber will really up velocities as well. Given the same load.</div></div>
A tighter chamber has no business on a tactical rifle.
Its a field gun, not a Benchrest rifle.
Take your tight chamber out in the rain and let me know how that works for you.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bigwheeler</div><div class="ubbcode-body"> A tighter chamber will really up velocities as well. Given the same load.</div></div>
A tighter chamber has no business on a tactical rifle.
Its a field gun, not a Benchrest rifle.
Take your tight chamber out in the rain and let me know how that works for you.
Re: Tighter bore mean faster fps?
You read something into my statement that is not there. I had a 22-250 set back
and rechambered. It was tight. My speeds jumped from 3400 to 3800+ with the
same exact loads. The chamber has been corrected since by another smith. Unless
your chamber specs are exactly the same they can cause a speed variation, that's
all. No benchrest guns in the house, never has interested me.
You read something into my statement that is not there. I had a 22-250 set back
and rechambered. It was tight. My speeds jumped from 3400 to 3800+ with the
same exact loads. The chamber has been corrected since by another smith. Unless
your chamber specs are exactly the same they can cause a speed variation, that's
all. No benchrest guns in the house, never has interested me.
Re: Tighter bore mean faster fps?
k thanks for the info. Just got done doin some loads that are the same and gonna run them through my new gun and another standard bore .308 and see what happens. If all is right then I should get some easy fps gain. I'll keep an update.
k thanks for the info. Just got done doin some loads that are the same and gonna run them through my new gun and another standard bore .308 and see what happens. If all is right then I should get some easy fps gain. I'll keep an update.
Re: Tighter bore mean faster fps?
Tight bore is a great way to get more velocity out of factory ammo and short barrels. Neither of which I have so I use standard bore barrels. Does anybody know how much more pressure a tight bore produces over an otherwise identical barrel?
Tight bore is a great way to get more velocity out of factory ammo and short barrels. Neither of which I have so I use standard bore barrels. Does anybody know how much more pressure a tight bore produces over an otherwise identical barrel?
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I believe my tight bores are .298 and they do increase the FPS by quite a bit.
I had a brand new 20" bbl that chronographed around 2500 -2550fps depending on the ammo. I immediately replaced it with a tight bore Bartlien the same 20" in length. My fps went to 2635 - 2675fps depending on the ammo. So on average I gained 125+ fps from the same length.
I have not seen a downside to going with a tight bore.
</div></div>
out of curiosity, was the original barrel the same style and manufacture only standard bore diameter or was it a factory rifle? just making sure we are comparing apples to apples here.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I believe my tight bores are .298 and they do increase the FPS by quite a bit.
I had a brand new 20" bbl that chronographed around 2500 -2550fps depending on the ammo. I immediately replaced it with a tight bore Bartlien the same 20" in length. My fps went to 2635 - 2675fps depending on the ammo. So on average I gained 125+ fps from the same length.
I have not seen a downside to going with a tight bore.
</div></div>
out of curiosity, was the original barrel the same style and manufacture only standard bore diameter or was it a factory rifle? just making sure we are comparing apples to apples here.
Re: Tighter bore mean faster fps?
Palma shooters have been running tight boars to enable them to push those 155gr Palma bullets just a little faster. Most of those guys also have 30inch tubes on their rifles. You have to shoot one of those Palma bullets pretty fast to keep them supersonic at 1,000yds. Here in the states we do not have to follow international Palma rules and the 190gr bullets work pretty well out of standard tubes.
Palma shooters have been running tight boars to enable them to push those 155gr Palma bullets just a little faster. Most of those guys also have 30inch tubes on their rifles. You have to shoot one of those Palma bullets pretty fast to keep them supersonic at 1,000yds. Here in the states we do not have to follow international Palma rules and the 190gr bullets work pretty well out of standard tubes.
Re: Tighter bore mean faster fps?
I was wondering the same thing as 300sniper. Lowlights gain in velocity seems so high. Granted Im a nobody in this industry but I just don't see gaining that much from that small reduction in bore size. It would be logical hd gained that much going from a factory Remington barrel to a custom tight bore but custom to custom and picking that much up is a little far fetch to me.
If you could gain that much why wouldn't everybody go tight bores in their 308's? You would have 24-26 tubes running close to 2900 fps with 175 grain projectiles, that's if the gain in velocity stayed consistent.
My best friends 20" tight bore Obermeyer only runs about 60 fps faster then my 17.5" Brux, regular bore. That's Only around 25-30 fps faster per inch, which is very good no doubt but it's not 100-125 fps. Like I said, I'm a nobody here but I study ALOT and try to keep my mouth shut, ears open approach and Lowlights the only person I've ever heard say they gain that much velocity just by switching to a tight bore.
I was wondering the same thing as 300sniper. Lowlights gain in velocity seems so high. Granted Im a nobody in this industry but I just don't see gaining that much from that small reduction in bore size. It would be logical hd gained that much going from a factory Remington barrel to a custom tight bore but custom to custom and picking that much up is a little far fetch to me.
If you could gain that much why wouldn't everybody go tight bores in their 308's? You would have 24-26 tubes running close to 2900 fps with 175 grain projectiles, that's if the gain in velocity stayed consistent.
My best friends 20" tight bore Obermeyer only runs about 60 fps faster then my 17.5" Brux, regular bore. That's Only around 25-30 fps faster per inch, which is very good no doubt but it's not 100-125 fps. Like I said, I'm a nobody here but I study ALOT and try to keep my mouth shut, ears open approach and Lowlights the only person I've ever heard say they gain that much velocity just by switching to a tight bore.
Re: Tighter bore mean faster fps?
It's pretty clear not all barrels are created equal... Some run faster out of the box than others.
In this case, (I know because I just did it less than 30 days ago) it was a factory AI barrel. Which are notoriously slow out of the gate.
Factory Remingtons are slow too, I can usually match a 26" Factory remington with my shorter tight bores.
A Brux might be a bit faster, as well I know Rock Creek barrels are fast out of the gate. But comparing a .298 to a factory AI barrel, I gained 125fps ... your results may vary, especially if you are looking at a custom barrel. A Krieger, Brux, Broughton, etc might only gain half of that... to be expected, they are custom to start with it. But pull a barrel from a new 20" SPS and replace it with a tight bore Bartlien I bet they hit my numbers.
and PS Brux offers a .298 how do you know you don't have that ? It's the first one listed under .30 cal
It's pretty clear not all barrels are created equal... Some run faster out of the box than others.
In this case, (I know because I just did it less than 30 days ago) it was a factory AI barrel. Which are notoriously slow out of the gate.
Factory Remingtons are slow too, I can usually match a 26" Factory remington with my shorter tight bores.
A Brux might be a bit faster, as well I know Rock Creek barrels are fast out of the gate. But comparing a .298 to a factory AI barrel, I gained 125fps ... your results may vary, especially if you are looking at a custom barrel. A Krieger, Brux, Broughton, etc might only gain half of that... to be expected, they are custom to start with it. But pull a barrel from a new 20" SPS and replace it with a tight bore Bartlien I bet they hit my numbers.
and PS Brux offers a .298 how do you know you don't have that ? It's the first one listed under .30 cal
Re: Tighter bore mean faster fps?
If I am not misunderstanding the physics involved (which I may be,) the tight bore increases velocity through increased pressure. So the same load will generate more pressure in the tight bore barrel than the standard barrel, and all other thing being equal, will generate more velocity.
That said, I think that if you handload, you can increase pressure by increasing the powder charge and as such, get the same velocity. A charge which is max in a standard bore most likely will be over max in a tight bore.
If I am not misunderstanding the physics involved (which I may be,) the tight bore increases velocity through increased pressure. So the same load will generate more pressure in the tight bore barrel than the standard barrel, and all other thing being equal, will generate more velocity.
That said, I think that if you handload, you can increase pressure by increasing the powder charge and as such, get the same velocity. A charge which is max in a standard bore most likely will be over max in a tight bore.
Re: Tighter bore mean faster fps?
BM11
I am just going to guess as well, but I am thinking that the real benifit is the supirior gas seal along with higher friction. So, you could also increase bullet size instead of powder charge. I am guessing that the tight bore offers some advantages that increasing the powder charge alone will not gain. I have no proof, but those velocity increases, from known, reliable expirementers are huge. I can say that I will be ordering a tight bore barrel next time.
RTH
BM11
I am just going to guess as well, but I am thinking that the real benifit is the supirior gas seal along with higher friction. So, you could also increase bullet size instead of powder charge. I am guessing that the tight bore offers some advantages that increasing the powder charge alone will not gain. I have no proof, but those velocity increases, from known, reliable expirementers are huge. I can say that I will be ordering a tight bore barrel next time.
RTH
Re: Tighter bore mean faster fps?
Tight bores I have all run faster especially Schneider barrels poly which has been the fastest even compared to other tight bore.
Tight bores I have all run faster especially Schneider barrels poly which has been the fastest even compared to other tight bore.
Re: Tighter bore mean faster fps?
Might have to consider a tight bore bartlein when i replace my .308 barrel.
Might have to consider a tight bore bartlein when i replace my .308 barrel.
Re: Tighter bore mean faster fps?
I purchased my barrel from bugholes who usally list if a barrel is a tightbore, but I suppose it could be. I know velocities I gave gotten so far are not in line with that of a tight bore so that's why I figured I did not have one.
I would like to have a tight bore but with the way this Brux shoots now you would have to pry it out of a cold hand for me to give it up
I purchased my barrel from bugholes who usally list if a barrel is a tightbore, but I suppose it could be. I know velocities I gave gotten so far are not in line with that of a tight bore so that's why I figured I did not have one.
I would like to have a tight bore but with the way this Brux shoots now you would have to pry it out of a cold hand for me to give it up
Re: Tighter bore mean faster fps?
You guys have to be careful what you are talking about and terminology etc....in some cases most people talk about the bore of the barrel but there are two different specific things when it comes to bore size.
You have the actual bore size (tops of the lands)
and
You have the groove size.
So you are talking bore and groove size when talking about the bore of the barrel.
Changing the bore size (tops of the lands) from a .300 bore to a .299 or .298 will not raise or change pressure a ton. It can have a bearing but not as much as we all think it might. Most standard min. dimensions on bore size are .3000" +.0005" tolerance.
Changing the groove size will have a more drastic impact on the pressure curve etc....we're all talking .30cal. so industry standard is mostly .3080" +.0005"
We run at the min. size on standards. So your .308 groove size we try and keep at .3080".
We make and offer bore sizes for .30cal. barrels at .2980", .2985", .2990 and .3000".
Some say looser is faster but than again what are you talking about? Bore size or groove size?
Now lets throw variables into the mix.
Lets start with production made barrels like Remington, Savage, Armalite etc.....it's not uncommon for a factory barrel to be +.001" big on the bore size and groove size. I didn't say .0001" big but +.001" thou. big. Most production barrels I'm going to go on limb and say run big vs. min. sizes. I've seen to many barrel drawings etc...being used and see the dimensions listed. Same with chamber reamers. Even factory chambers when we order reamers they will ask us is it a SAAMI min. spec. or production chamber etc.....
Some of you have said tight chambers? Be more specific on tight chambers. Do you mean a tight case neck? Tight dimensions on the case body? A combination of both? Or do you mean a tight, shorter throat dimensions or a combination of all 5 (body, neck, throat diameter, throat length, angle of throat?
When we look at making an ammunition test barrel we have a bore size to watch, groove size to watch, width of grooves and total surface area of the bore. Yes changing the groove width effects the land width etc...and can total surface area of the whole bore of the barrel.
Now lets throw in the bullet being a variable. Lets say you get a box of bullets or a certain lot of factory loaded ammo and the bullets in that certain batch is running +.0002" bigger than the min. spec.
Now lets throw in the powder, primers etc....
I'm sure there is more that I didn't list than what I could have. This thread can be a can of worms and I hesitated to reply because it will cause more controversy and or raise more questions.
When comparing barrels from one gun to the next even if the barrel was made by the same maker but one guys gun has gunsmith x chamber it with his reamer and the other guy had gunsmith t chamber his with a different reamer are you really comparing apples and apples? Those two barrels from the same maker could vary a little bit.
Palma shooters started using tight bore barrels back in the '70's I believe and the barrel maker that made them (I believe is dead now and I don't remember his name off hand) did it because some countries when they host the International Palma matches was issuing 7.62Nato ball ammo and the bullets where running as small as .3065" in diameter.
A tighter bore (loosely speaking) doesn't guarantee you longer barrel life either. There are a ton of variables that can effect barrel life. I won't even get started on that.
Later for now!
Frank
Bartlein Barrels
You guys have to be careful what you are talking about and terminology etc....in some cases most people talk about the bore of the barrel but there are two different specific things when it comes to bore size.
You have the actual bore size (tops of the lands)
and
You have the groove size.
So you are talking bore and groove size when talking about the bore of the barrel.
Changing the bore size (tops of the lands) from a .300 bore to a .299 or .298 will not raise or change pressure a ton. It can have a bearing but not as much as we all think it might. Most standard min. dimensions on bore size are .3000" +.0005" tolerance.
Changing the groove size will have a more drastic impact on the pressure curve etc....we're all talking .30cal. so industry standard is mostly .3080" +.0005"
We run at the min. size on standards. So your .308 groove size we try and keep at .3080".
We make and offer bore sizes for .30cal. barrels at .2980", .2985", .2990 and .3000".
Some say looser is faster but than again what are you talking about? Bore size or groove size?
Now lets throw variables into the mix.
Lets start with production made barrels like Remington, Savage, Armalite etc.....it's not uncommon for a factory barrel to be +.001" big on the bore size and groove size. I didn't say .0001" big but +.001" thou. big. Most production barrels I'm going to go on limb and say run big vs. min. sizes. I've seen to many barrel drawings etc...being used and see the dimensions listed. Same with chamber reamers. Even factory chambers when we order reamers they will ask us is it a SAAMI min. spec. or production chamber etc.....
Some of you have said tight chambers? Be more specific on tight chambers. Do you mean a tight case neck? Tight dimensions on the case body? A combination of both? Or do you mean a tight, shorter throat dimensions or a combination of all 5 (body, neck, throat diameter, throat length, angle of throat?
When we look at making an ammunition test barrel we have a bore size to watch, groove size to watch, width of grooves and total surface area of the bore. Yes changing the groove width effects the land width etc...and can total surface area of the whole bore of the barrel.
Now lets throw in the bullet being a variable. Lets say you get a box of bullets or a certain lot of factory loaded ammo and the bullets in that certain batch is running +.0002" bigger than the min. spec.
Now lets throw in the powder, primers etc....
I'm sure there is more that I didn't list than what I could have. This thread can be a can of worms and I hesitated to reply because it will cause more controversy and or raise more questions.
When comparing barrels from one gun to the next even if the barrel was made by the same maker but one guys gun has gunsmith x chamber it with his reamer and the other guy had gunsmith t chamber his with a different reamer are you really comparing apples and apples? Those two barrels from the same maker could vary a little bit.
Palma shooters started using tight bore barrels back in the '70's I believe and the barrel maker that made them (I believe is dead now and I don't remember his name off hand) did it because some countries when they host the International Palma matches was issuing 7.62Nato ball ammo and the bullets where running as small as .3065" in diameter.
A tighter bore (loosely speaking) doesn't guarantee you longer barrel life either. There are a ton of variables that can effect barrel life. I won't even get started on that.
Later for now!
Frank
Bartlein Barrels
Re: Tighter bore mean faster fps?
To get good hard data you would need a barrel maker make a couple of barrels or a few etc...
The barrels made out of the same lot of steel.
Chambered with the same chamber reamer.
Tested with the same lot of ammo and or handloaded components i.e. powder, primers, cases, bullets etc...out of the same lot.
Tested in the same temp. conditions etc...
You make one barrel to a set dimension. Fit barrel do testing and record the data.
Now for barrel No.2 you only change one thing! Lets say it's the bore size from a .3000" bore on barrel number one to a .2990" bore size. You fit that up and test and record the data.
Now for barrel No. 3 and 4 do the same bore sizes on each (.3000") but now you change the groove size and use .3080" for one and .3085 for the other.
You can easily see how many barrels and configurations you can get into. Who has all the time and money for testing?
Lowlight I sent you a private message!
Later, Frank
Bartlein Barrels
To get good hard data you would need a barrel maker make a couple of barrels or a few etc...
The barrels made out of the same lot of steel.
Chambered with the same chamber reamer.
Tested with the same lot of ammo and or handloaded components i.e. powder, primers, cases, bullets etc...out of the same lot.
Tested in the same temp. conditions etc...
You make one barrel to a set dimension. Fit barrel do testing and record the data.
Now for barrel No.2 you only change one thing! Lets say it's the bore size from a .3000" bore on barrel number one to a .2990" bore size. You fit that up and test and record the data.
Now for barrel No. 3 and 4 do the same bore sizes on each (.3000") but now you change the groove size and use .3080" for one and .3085 for the other.
You can easily see how many barrels and configurations you can get into. Who has all the time and money for testing?
Lowlight I sent you a private message!
Later, Frank
Bartlein Barrels
Re: Tighter bore mean faster fps?
I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
</div></div>
George kills me! I'll talk to you next week. Going out deer hunting tomorrow and special customer all day Wed. than Thanksgiving after that.
Later, Frank
Bartlein Barrels
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
George kills me! I'll talk to you next week. Going out deer hunting tomorrow and special customer all day Wed. than Thanksgiving after that.
Later, Frank
Bartlein Barrels
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
</div></div>
I knew it!.....Conspiracy theory my ass!
I think Corbon is in on it too.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
I knew it!.....Conspiracy theory my ass!
I think Corbon is in on it too.
Re: Tighter bore mean faster fps?
My GAP Valkyrie / Bartlien / Cor Bon Combo goes 2770fps out of a 22" .298 bore... so eat my vapor trail...
My GAP Valkyrie / Bartlien / Cor Bon Combo goes 2770fps out of a 22" .298 bore... so eat my vapor trail...
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Pusher591</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
</div></div>
I knew it!.....Conspiracy theory my ass!
I think Corbon is in on it too.
</div></div>
Lmao that is funny.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Pusher591</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I heard you made my barrels extra special which is why I got the boost in MV which might be different from the average guy on street.
George said you had a machine there with my name on it just so I had a bit of an advantage over the next guy.
So, thanks...
I knew it!.....Conspiracy theory my ass!
I think Corbon is in on it too.
Lmao that is funny.
Re: Tighter bore mean faster fps?
So I feel pretty stupid asking this, considering everyone seems to not have any questions about it but... How is it possible for the bullet to go through a hole(bore) smaller than its size. Or area you guys talking about chamber/neck area?
So I feel pretty stupid asking this, considering everyone seems to not have any questions about it but... How is it possible for the bullet to go through a hole(bore) smaller than its size. Or area you guys talking about chamber/neck area?
Re: Tighter bore mean faster fps?
Some of you have said tight chambers? Be more specific on tight chambers. Do you mean a tight case neck? Tight dimensions on the case body? A combination of both? Or do you mean a tight, shorter throat dimensions or a combination of all 5 (body, neck, throat diameter, throat length, angle of throat?
Later for now!
Frank
Bartlein Barrels [/quote]
Mine was reamed tight in dia. New Reamer, The smith ran over and borrowed
one from Lilja and took out very little metal to try and correct it. Then it blew cases in half. My guess is because of the tight reamer it was already long and
when he dressed it it could then use that length. I gave up and had it set back by another smith. My point was comparing a new barrel
with an old is not apples to apples. The chambers are different. I should have spelled it all out. Thanks for chiming in.
Some of you have said tight chambers? Be more specific on tight chambers. Do you mean a tight case neck? Tight dimensions on the case body? A combination of both? Or do you mean a tight, shorter throat dimensions or a combination of all 5 (body, neck, throat diameter, throat length, angle of throat?
Later for now!
Frank
Bartlein Barrels [/quote]
Mine was reamed tight in dia. New Reamer, The smith ran over and borrowed
one from Lilja and took out very little metal to try and correct it. Then it blew cases in half. My guess is because of the tight reamer it was already long and
when he dressed it it could then use that length. I gave up and had it set back by another smith. My point was comparing a new barrel
with an old is not apples to apples. The chambers are different. I should have spelled it all out. Thanks for chiming in.
Re: Tighter bore mean faster fps?
To the guy asking how a bullet fits down a hole smaller in diameter than the bullet: it obturates! It gets longer as it is essentially swaged into tge bore with pressure behind it.
I think if the "tight bore" was so special, Sierra/Berger/etc would make oversized bullets available to us.
Also as previously mentioned, if the more difficult obturation raises pressure that increases velocity, you could match that velocity with a looser bore by charging with more powder.....unless you're already limited by case capacity, which is generally rare.
To the guy asking how a bullet fits down a hole smaller in diameter than the bullet: it obturates! It gets longer as it is essentially swaged into tge bore with pressure behind it.
I think if the "tight bore" was so special, Sierra/Berger/etc would make oversized bullets available to us.
Also as previously mentioned, if the more difficult obturation raises pressure that increases velocity, you could match that velocity with a looser bore by charging with more powder.....unless you're already limited by case capacity, which is generally rare.
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">To the guy asking how a bullet fits down a hole smaller in diameter than the bullet: it obturates! It gets longer as it is essentially swaged into tge bore with pressure behind it.
I think if the "tight bore" was so special, Sierra/Berger/etc would make oversized bullets available to us.
Also as previously mentioned, if the more difficult obturation raises pressure that increases velocity, you could match that velocity with a looser bore by charging with more powder.....unless you're already limited by case capacity, which is generally rare.</div></div>
You know, in my head that's the only way I saw it could happen but I just thought I was missing something because it seems like it would distort the bullet. But obviously it doesn't if it works so well for you guys. Thanks for explaining.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">To the guy asking how a bullet fits down a hole smaller in diameter than the bullet: it obturates! It gets longer as it is essentially swaged into tge bore with pressure behind it.
I think if the "tight bore" was so special, Sierra/Berger/etc would make oversized bullets available to us.
Also as previously mentioned, if the more difficult obturation raises pressure that increases velocity, you could match that velocity with a looser bore by charging with more powder.....unless you're already limited by case capacity, which is generally rare.</div></div>
You know, in my head that's the only way I saw it could happen but I just thought I was missing something because it seems like it would distort the bullet. But obviously it doesn't if it works so well for you guys. Thanks for explaining.
Re: Tighter bore mean faster fps?
Dang this thing kinda blew up cool. I had a little time on thanksgiving to do some shooting. Just had two loads one was 175smks at 42gr of Varget and the other was 168smks at 42gr of Varget. Here's the results...
175's (5 shots)
1)2637
2)2653
3)2616
4)2632
5)2680
AVG. 2644
168's (5 shots)
1)2672
2)2636
3)2693
4)2663
5)2672
AVG. 2667
Not bad, the 168's shot really good (dont know how to post pics)but 2 shots were in the same hole and the othere 3 were in the same hole but a 1/2" left. The only thing that I dont get was the average spread which was pretty big. As of now the gun only has 83 rounds down the tube. Made some other loads to test next week so I'll post my results.
Dang this thing kinda blew up cool. I had a little time on thanksgiving to do some shooting. Just had two loads one was 175smks at 42gr of Varget and the other was 168smks at 42gr of Varget. Here's the results...
175's (5 shots)
1)2637
2)2653
3)2616
4)2632
5)2680
AVG. 2644
168's (5 shots)
1)2672
2)2636
3)2693
4)2663
5)2672
AVG. 2667
Not bad, the 168's shot really good (dont know how to post pics)but 2 shots were in the same hole and the othere 3 were in the same hole but a 1/2" left. The only thing that I dont get was the average spread which was pretty big. As of now the gun only has 83 rounds down the tube. Made some other loads to test next week so I'll post my results.
Re: Tighter bore mean faster fps?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">It's pretty clear not all barrels are created equal... Some run faster out of the box than others.
In this case, (I know because I just did it less than 30 days ago) it was a factory AI barrel. Which are notoriously slow out of the gate.
Factory Remingtons are slow too, I can usually match a 26" Factory remington with my shorter tight bores.
A Brux might be a bit faster, as well I know Rock Creek barrels are fast out of the gate. But comparing a .298 to a factory AI barrel, I gained 125fps ... your results may vary, especially if you are looking at a custom barrel. A Krieger, Brux, Broughton, etc might only gain half of that... to be expected, they are custom to start with it. But pull a barrel from a new 20" SPS and replace it with a tight bore Bartlien I bet they hit my numbers.
and PS Brux offers a .298 how do you know you don't have that ? It's the first one listed under .30 cal </div></div>
Any noticeable decrease in barrel life from the tighter bores?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">It's pretty clear not all barrels are created equal... Some run faster out of the box than others.
In this case, (I know because I just did it less than 30 days ago) it was a factory AI barrel. Which are notoriously slow out of the gate.
Factory Remingtons are slow too, I can usually match a 26" Factory remington with my shorter tight bores.
A Brux might be a bit faster, as well I know Rock Creek barrels are fast out of the gate. But comparing a .298 to a factory AI barrel, I gained 125fps ... your results may vary, especially if you are looking at a custom barrel. A Krieger, Brux, Broughton, etc might only gain half of that... to be expected, they are custom to start with it. But pull a barrel from a new 20" SPS and replace it with a tight bore Bartlien I bet they hit my numbers.
and PS Brux offers a .298 how do you know you don't have that ? It's the first one listed under .30 cal </div></div>
Any noticeable decrease in barrel life from the tighter bores?
Re: Tighter bore mean faster fps?
How was your barrel made? Button?, Cut rifled?, Hammer forged? What type of steel is it made from? What lot of steel did it come from?
A tighter bore like a .298 or .299 might help vs. a standard .300 bore because your making the lands how should I say it? Taller/deeper. This might help as the lands start to wear in the throat and when you start to loose the metal in the throat is when the accuracy goes.
But you also have to consider all the other variables in how a barrel is made. There are a lot of things that effect barrel life.
Not to mention the type of load/ammo being shot thru it and the type of powder. Some powders are harder on barrels than others.
Later, Frank
Bartlein Barrels
How was your barrel made? Button?, Cut rifled?, Hammer forged? What type of steel is it made from? What lot of steel did it come from?
A tighter bore like a .298 or .299 might help vs. a standard .300 bore because your making the lands how should I say it? Taller/deeper. This might help as the lands start to wear in the throat and when you start to loose the metal in the throat is when the accuracy goes.
But you also have to consider all the other variables in how a barrel is made. There are a lot of things that effect barrel life.
Not to mention the type of load/ammo being shot thru it and the type of powder. Some powders are harder on barrels than others.
Later, Frank
Bartlein Barrels
