Re: .375" on a CheyTac
Gerard does good work. I am sure you will be happy with the performance.
- Noel
Gerard does good work. I am sure you will be happy with the performance.
- Noel
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Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">Gerard does good work. I am sure you will be happy with the performance.
- Noel </div></div>
I hope so
.
Fact is that finding a bullet that is max stabile at +2000m is like diving in uncharted waters. Trial and error is properly the best thing
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">Gerard does good work. I am sure you will be happy with the performance.
- Noel </div></div>
I hope so
Fact is that finding a bullet that is max stabile at +2000m is like diving in uncharted waters. Trial and error is properly the best thing
Cheers,
Master Diver
Re: .375" on a CheyTac
I did not catch the range at which you want to operate.
What is the caliber length of the particular GS Custom bullet you intend on using?
I did not catch the range at which you want to operate.
What is the caliber length of the particular GS Custom bullet you intend on using?
Re: .375" on a CheyTac
I would like to be able to shoot beyound 2000 meters.
The 291 grn lathe turned copper bullet is 46mm (1.81")
I am however hoping that Gerard will make the best bullet suitable for my barrel. I know longer and heavier would be better then the 291 grn one he is offering now. I dream of a 330 or 350 grn GS bullet
with a SUPER HIGH BC.
Now I am thinking, was I stupid not getting my barrel cut with the "Lost river Bore"?
Cheers,
Master Diver
I would like to be able to shoot beyound 2000 meters.
The 291 grn lathe turned copper bullet is 46mm (1.81")
I am however hoping that Gerard will make the best bullet suitable for my barrel. I know longer and heavier would be better then the 291 grn one he is offering now. I dream of a 330 or 350 grn GS bullet
Now I am thinking, was I stupid not getting my barrel cut with the "Lost river Bore"?
Cheers,
Master Diver
Re: .375" on a CheyTac
MD,
You are asking too much of that bullet. I start at a 6.5 caliber, 400 grain, engraving-band copper solid for high performance at those ranges.
I am sure Gerard will give you the correct bullet if you allow him some flexibility with exit-twist rates.
MD,
You are asking too much of that bullet. I start at a 6.5 caliber, 400 grain, engraving-band copper solid for high performance at those ranges.
I am sure Gerard will give you the correct bullet if you allow him some flexibility with exit-twist rates.
Re: .375" on a CheyTac
NAG, no. I think they were subsonic before they got to me. We were shooting at 3000 yds when I was downrange and never hit anything.
Ross
NAG, no. I think they were subsonic before they got to me. We were shooting at 3000 yds when I was downrange and never hit anything.
Ross
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">MD,
You are asking too much of that bullet. I start at a 6.5 caliber, 400 grain, engraving-band copper solid for high performance at those ranges.
I am sure Gerard will give you the correct bullet if you allow him some flexibility with exit-twist rates.
</div></div>
I hope so to, I will order 1000 pcs when the design is right. The lost River bore is 1:11.5 right? I was thinking that 1:10.5 would be a good platform for a long bullet made by Gerard.
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">MD,
You are asking too much of that bullet. I start at a 6.5 caliber, 400 grain, engraving-band copper solid for high performance at those ranges.
I am sure Gerard will give you the correct bullet if you allow him some flexibility with exit-twist rates.
</div></div>
I hope so to, I will order 1000 pcs when the design is right. The lost River bore is 1:11.5 right? I was thinking that 1:10.5 would be a good platform for a long bullet made by Gerard.
Cheers,
Master Diver
Re: .375" on a CheyTac
MD,
You are looking for, a minimum, 1: 7.5" exit-twist to adequately stabilize an appropriate bullet design.
You must make a decision between a SMK compatable rifle, or an extreme performance rifle. Your range aspirations indicate the latter. Tighter twist-rates come with the territory.
Like you said... "everything is a compromise".
MD,
You are looking for, a minimum, 1: 7.5" exit-twist to adequately stabilize an appropriate bullet design.
You must make a decision between a SMK compatable rifle, or an extreme performance rifle. Your range aspirations indicate the latter. Tighter twist-rates come with the territory.
Like you said... "everything is a compromise".
Re: .375" on a CheyTac
Yes that would be a good place to start. The LR bore has different dimensions then a standard bore.
Yes that would be a good place to start. The LR bore has different dimensions then a standard bore.
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">MD,
You are looking for, a minimum, 1: 7.5" exit-twist to adequately stabilize an appropriate bullet design.
You must make a decision between a SMK compatable rifle, or an extreme performance rifle. Your range aspirations indicate the latter. Tighter twist-rates come with the territory.
Like you said... "everything is a compromise". </div></div>
Ja, you are right. I guess SMK 350 grn bullets and whatever Gerard can coock up for my standard 1:10.5 twist will have to do for now.....OR I could get another barrel cut with a LRB?
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">MD,
You are looking for, a minimum, 1: 7.5" exit-twist to adequately stabilize an appropriate bullet design.
You must make a decision between a SMK compatable rifle, or an extreme performance rifle. Your range aspirations indicate the latter. Tighter twist-rates come with the territory.
Like you said... "everything is a compromise". </div></div>
Ja, you are right. I guess SMK 350 grn bullets and whatever Gerard can coock up for my standard 1:10.5 twist will have to do for now.....OR I could get another barrel cut with a LRB?
Cheers,
Master Diver
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Yes that would be a good place to start. The LR bore has different dimensions then a standard bore. </div></div>
How does the LRB handle the 350 SMK at +2000m?
PS I sent you an e-mail
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru</div><div class="ubbcode-body">Yes that would be a good place to start. The LR bore has different dimensions then a standard bore. </div></div>
How does the LRB handle the 350 SMK at +2000m?
PS I sent you an e-mail
Cheers,
Master Diver
Re: .375" on a CheyTac
The 375291SP is designed for a standard 1:12" twist (375H&H, 378 Weatherby etc.) Due to the change in firearms laws in SA, it has become an advantage to be a member of a club to avoid hassles with licensing rifles. This has prompted clubs to "formalise" a new format of competition that caters for hunting rifles. Many of our SP range are configured for standard SAAMI and CIP spec rifles.
In 375 there will be a GSC SP for 1:10" and 1:8" ready by mid April.
Going to an odd set of bore/groove dimensions is not an option that I like because it limits one to a particular make / style of bullet. If the rifle does not like that special bullet, you are between a rock and a hard place regarding other brand choices that are designed around standard specs.
It is better for the bullet manufacturer to accommodate existing radial dimensions. It makes for more consistency in barrel manufacturing, I think (but I am not a barrel maker).
What do you say, Noel?
The 375291SP is designed for a standard 1:12" twist (375H&H, 378 Weatherby etc.) Due to the change in firearms laws in SA, it has become an advantage to be a member of a club to avoid hassles with licensing rifles. This has prompted clubs to "formalise" a new format of competition that caters for hunting rifles. Many of our SP range are configured for standard SAAMI and CIP spec rifles.
In 375 there will be a GSC SP for 1:10" and 1:8" ready by mid April.
Going to an odd set of bore/groove dimensions is not an option that I like because it limits one to a particular make / style of bullet. If the rifle does not like that special bullet, you are between a rock and a hard place regarding other brand choices that are designed around standard specs.
It is better for the bullet manufacturer to accommodate existing radial dimensions. It makes for more consistency in barrel manufacturing, I think (but I am not a barrel maker).
What do you say, Noel?
Re: .375" on a CheyTac
GREAT NEWS
I am looking forward to those bullets, do you have a weight on the two models?
I have a standard bore 1:10.5 and sure hope it will stabalize a longer bullet at distances beyond 2K
Cheers,
Master Diver
GREAT NEWS
I am looking forward to those bullets, do you have a weight on the two models?
I have a standard bore 1:10.5 and sure hope it will stabalize a longer bullet at distances beyond 2K
Cheers,
Master Diver
Re: .375" on a CheyTac
The 1:8" bullet is still in development with very little fixed but the 1:10" SP is 355gr. Stability from a 1:10" is 1.4 at the muzzle and from a 1:10.5 it is 1.3. Tractability will be good all the way to subsonic. Calculated BC is around 1 at 3000fps, dropping to mid .700 at 1200fps.
What speed do you figure on getting from your rifle?
The 1:8" bullet is still in development with very little fixed but the 1:10" SP is 355gr. Stability from a 1:10" is 1.4 at the muzzle and from a 1:10.5 it is 1.3. Tractability will be good all the way to subsonic. Calculated BC is around 1 at 3000fps, dropping to mid .700 at 1200fps.
What speed do you figure on getting from your rifle?
Re: .375" on a CheyTac
@ Master Diver,
please send me PM, need some more Info about the GC -Bullets+price.
Best
2RECON
@ Master Diver,
please send me PM, need some more Info about the GC -Bullets+price.
Best
2RECON
Re: .375" on a CheyTac
Hello Gerard!
I am glad you found this thread.
For the benefit of anyone following these comments, Gerard originated the sacrificial forward band design, which makes possible the use of these 6+ caliber bullets in conjunction with EGT rifling geometry.
To your question on conformity with standard bore/groove dimensions...
I believe you have started something fully appreciated by only a few as yet. With the extreme projectile lengths, made possible by your invention, three other things have changed. First, current action designs are not suitable for efficiency optimized case configurations which, when compounded with a much longer projectile nose, means new actions are in order. Second, with new dedicated cases comes the opportunity design to pressure capacities significantly exceeding 65 kpsi to utilize modern, higher energy propellants. Third, since these propellants will eat 416 for lunch, new barrel alloys are required.
Obviously, these very specialized rifles will come into being slowly, and will always be used by only a limited portion of the shooting community. Overwhelmingly, it is the conventional systems which will benefit from tamer applications of your work, but extreme long-range targeting will never be the same.
The chambering, and barrel bore/groove dimensions of these coming rifles will need to be non-interchangable with existing firearms for safety considerations... if for no other reason, in my opinion.
Gerard, I have a question which arose when someone confronted me on this site some time ago. You and I have had this discussion before, but I was never clear on the answer, and had to speculate in my response. The basic assertion this (anonoymous) person made, was that the Moeller projectile "innovated" the first, and only true engraving band ( Defined as engraving only within the major, and minor band diameters.). I assured them that you were not only aware of, but could easily implement the design feature into your bullets, and that the idea is nearly 100 years old in any case, but I still do not understand why your projectile shaft diameter is the same as the bore diameter. Is it to accomodate production barrel tolerances, a softer copper alloy, both, or neither?
Hello Gerard!
I am glad you found this thread.
For the benefit of anyone following these comments, Gerard originated the sacrificial forward band design, which makes possible the use of these 6+ caliber bullets in conjunction with EGT rifling geometry.
To your question on conformity with standard bore/groove dimensions...
I believe you have started something fully appreciated by only a few as yet. With the extreme projectile lengths, made possible by your invention, three other things have changed. First, current action designs are not suitable for efficiency optimized case configurations which, when compounded with a much longer projectile nose, means new actions are in order. Second, with new dedicated cases comes the opportunity design to pressure capacities significantly exceeding 65 kpsi to utilize modern, higher energy propellants. Third, since these propellants will eat 416 for lunch, new barrel alloys are required.
Obviously, these very specialized rifles will come into being slowly, and will always be used by only a limited portion of the shooting community. Overwhelmingly, it is the conventional systems which will benefit from tamer applications of your work, but extreme long-range targeting will never be the same.
The chambering, and barrel bore/groove dimensions of these coming rifles will need to be non-interchangable with existing firearms for safety considerations... if for no other reason, in my opinion.
Gerard, I have a question which arose when someone confronted me on this site some time ago. You and I have had this discussion before, but I was never clear on the answer, and had to speculate in my response. The basic assertion this (anonoymous) person made, was that the Moeller projectile "innovated" the first, and only true engraving band ( Defined as engraving only within the major, and minor band diameters.). I assured them that you were not only aware of, but could easily implement the design feature into your bullets, and that the idea is nearly 100 years old in any case, but I still do not understand why your projectile shaft diameter is the same as the bore diameter. Is it to accomodate production barrel tolerances, a softer copper alloy, both, or neither?
Re: .375" on a CheyTac
Hi Noel,
It is to give the best accuracy in production barrels. I experimented with a variety of configurations during 1996 and found the best accuracy with some bore/shaft contact. During 2005 I revisited that research with additional information and experience and found that my initial conclusions were still valid.
The biggest hurdle in deciding which configuration to use, is that a new barrel only remain so for a short while. The land diameter wears faster than the groove diameter. Also, a large number of barrels are not what they are supposed to be from the start. It seems that it is easier to get the bore diameter right than the groove diameter. Hammer forged barrels excluded.
It is not practical to make a custom sized bullet for every barrel and I had to find solutions that would work across a spectrum of manufacturer's tolerances and degrees of wear, as barrels are used.
That said, it is sometimes not an option to rebarrel a rifle, even if it is badly off. In such cases we will do a custom run. I am doing a custom bullet at the moment for a 5.6x57 where a new barrel is not an option. This one is 0.055mm under on the lands and 0.110mm under in the groove diameters.
Mr. Moeller's first bullets, 5 years after ours, were similar to early GSC bullets as they also showed more shaft contact, albeit a little erratic.
Lately I see that the KJG bullets engrave the drive bands only. It is not the solution we see as optimal. The research done by Brownell and written up in "Rifle Pressure Factors" pointed GSC in a different direction, hence our more complex drive band / bullet shaft configuration.
Hi Noel,
It is to give the best accuracy in production barrels. I experimented with a variety of configurations during 1996 and found the best accuracy with some bore/shaft contact. During 2005 I revisited that research with additional information and experience and found that my initial conclusions were still valid.
The biggest hurdle in deciding which configuration to use, is that a new barrel only remain so for a short while. The land diameter wears faster than the groove diameter. Also, a large number of barrels are not what they are supposed to be from the start. It seems that it is easier to get the bore diameter right than the groove diameter. Hammer forged barrels excluded.
It is not practical to make a custom sized bullet for every barrel and I had to find solutions that would work across a spectrum of manufacturer's tolerances and degrees of wear, as barrels are used.
That said, it is sometimes not an option to rebarrel a rifle, even if it is badly off. In such cases we will do a custom run. I am doing a custom bullet at the moment for a 5.6x57 where a new barrel is not an option. This one is 0.055mm under on the lands and 0.110mm under in the groove diameters.
Mr. Moeller's first bullets, 5 years after ours, were similar to early GSC bullets as they also showed more shaft contact, albeit a little erratic.
Lately I see that the KJG bullets engrave the drive bands only. It is not the solution we see as optimal. The research done by Brownell and written up in "Rifle Pressure Factors" pointed GSC in a different direction, hence our more complex drive band / bullet shaft configuration.
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gerard Schultz</div><div class="ubbcode-body">The 1:8" bullet is still in development with very little fixed but the 1:10" SP is 355gr. Stability from a 1:10" is 1.4 at the muzzle and from a 1:10.5 it is 1.3. Tractability will be good all the way to subsonic. Calculated BC is around 1 at 3000fps, dropping to mid .700 at 1200fps.
What speed do you figure on getting from your rifle? </div></div>
Gerard,
Getting 3250 with the 350 grn Sierra Match King is no problem for the .375 Snipe-Tac, I am hoping a bith faster due to the drive bands
355 grn sure sounds fine for my barrel, and with a SF of 1.3 I should be good for longer distances to.
It is great that you will now offer longer and heavier bullets for the 375 extreme cartridges, it is after all the NEW KING of Extreem Long Range shooting/Hunting.
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Gerard Schultz</div><div class="ubbcode-body">The 1:8" bullet is still in development with very little fixed but the 1:10" SP is 355gr. Stability from a 1:10" is 1.4 at the muzzle and from a 1:10.5 it is 1.3. Tractability will be good all the way to subsonic. Calculated BC is around 1 at 3000fps, dropping to mid .700 at 1200fps.
What speed do you figure on getting from your rifle? </div></div>
Gerard,
Getting 3250 with the 350 grn Sierra Match King is no problem for the .375 Snipe-Tac, I am hoping a bith faster due to the drive bands
355 grn sure sounds fine for my barrel, and with a SF of 1.3 I should be good for longer distances to.
It is great that you will now offer longer and heavier bullets for the 375 extreme cartridges, it is after all the NEW KING of Extreem Long Range shooting/Hunting.
Cheers,
Master Diver
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 2RECON</div><div class="ubbcode-body">@ Master Diver,
please send me PM, need some more Info about the GC -Bullets+price.
Best
2RECON </div></div>
2RECON
I am the dealer for Scandinavia and can NOT sell bullets in Germany, Sorry.
BUT here is the link to the German dealer
http://www.gsgroup.co.za/11dealergermany.html
Mfg,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 2RECON</div><div class="ubbcode-body">@ Master Diver,
please send me PM, need some more Info about the GC -Bullets+price.
Best
2RECON </div></div>
2RECON
I am the dealer for Scandinavia and can NOT sell bullets in Germany, Sorry.
BUT here is the link to the German dealer
http://www.gsgroup.co.za/11dealergermany.html
Mfg,
Master Diver
Re: .375" on a CheyTac
Gerard,
I thought as much. It is a good engineering solution.
How soon do you think it will take to get your 8" twist 375 into production?
Best,
Noel
Gerard,
I thought as much. It is a good engineering solution.
How soon do you think it will take to get your 8" twist 375 into production?
Best,
Noel
Re: .375" on a CheyTac
So far we are on track for completion mid April. The first run of the 1:8" will probably be 1st week in May. We are trying to figure how many of the 355gr SPs to do as we will run them back to back with the 1:8" SPs. It will depend on the demand plus some for stock with both. First runs are always small because guys want to try before committing.
So far we are on track for completion mid April. The first run of the 1:8" will probably be 1st week in May. We are trying to figure how many of the 355gr SPs to do as we will run them back to back with the 1:8" SPs. It will depend on the demand plus some for stock with both. First runs are always small because guys want to try before committing.
Re: .375" on a CheyTac
...also, I just noticed that the two bullet styles displayed in your picture post have a gain-twist band layout, and the engraving pattern is from a constant-twist barrel.
Do you have any bullet samples which were recovered following firing from a gain-twist barrel?
...also, I just noticed that the two bullet styles displayed in your picture post have a gain-twist band layout, and the engraving pattern is from a constant-twist barrel.
Do you have any bullet samples which were recovered following firing from a gain-twist barrel?
Re: .375" on a CheyTac
Sorry, dump question, but what is the differencs between a "standard" and a "lost´river bore"...?
And, will a 330grs.Lehigh shoot from a 1 in 12" at 2800fps ?
Thanks
2RECON
Sorry, dump question, but what is the differencs between a "standard" and a "lost´river bore"...?
And, will a 330grs.Lehigh shoot from a 1 in 12" at 2800fps ?
Thanks
2RECON
Re: .375" on a CheyTac
I know NotAGuru can answer this far better than I, but the land/groove/bore dimensions are different from a standard barrel designed to shoot a .375 diameter bullet. The solid, full diameter copper alloy Lost River/Hooker Tactical/Jamison bullets tend NOT to shoot well in a standard bore:groove dimensioned barrel. Solid bullets with driving bands shoot fine out of standard barrels.
I know NotAGuru can answer this far better than I, but the land/groove/bore dimensions are different from a standard barrel designed to shoot a .375 diameter bullet. The solid, full diameter copper alloy Lost River/Hooker Tactical/Jamison bullets tend NOT to shoot well in a standard bore:groove dimensioned barrel. Solid bullets with driving bands shoot fine out of standard barrels.
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 2RECON</div><div class="ubbcode-body">Sorry, dump question, but what is the differencs between a "standard" and a "lost´river bore"...?
And, will a 330grs.Lehigh shoot from a 1 in 12" at 2800fps ?
Thanks
2RECON </div></div>
The 330 Lehigh is best stabalized in a "Lost River Bore" they are 1:11.5 twist.
Your 1:12 standard twist would be best of with a 291 grn GS Custom SP bullet or maybe the 350 grn SMK or thge 300 grn SMK. Just my five cents
Do you have a 378 Weatherby?
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 2RECON</div><div class="ubbcode-body">Sorry, dump question, but what is the differencs between a "standard" and a "lost´river bore"...?
And, will a 330grs.Lehigh shoot from a 1 in 12" at 2800fps ?
Thanks
2RECON </div></div>
The 330 Lehigh is best stabalized in a "Lost River Bore" they are 1:11.5 twist.
Your 1:12 standard twist would be best of with a 291 grn GS Custom SP bullet or maybe the 350 grn SMK or thge 300 grn SMK. Just my five cents
Do you have a 378 Weatherby?
Cheers,
Master Diver
Re: .375" on a CheyTac
MD,
The "Lost River Bore" is not about twist rate, it is about groove depth.
Groove diameter exceedes projectile shaft diameter, in this system, to afford a somewhat crude solution to a basic design flaw in bullet/barrel configuration.
MD,
The "Lost River Bore" is not about twist rate, it is about groove depth.
Groove diameter exceedes projectile shaft diameter, in this system, to afford a somewhat crude solution to a basic design flaw in bullet/barrel configuration.
Re: .375" on a CheyTac
Yes I know, but is the 375 CT Barrel not a 1:11.5 LRB if you buy a CheyTac m310?
How does the LRB handle normal bullets? Does the barrel wear faster?
Noel what is the twist on your barrel?
Cheers,
Master Diver
Yes I know, but is the 375 CT Barrel not a 1:11.5 LRB if you buy a CheyTac m310?
How does the LRB handle normal bullets? Does the barrel wear faster?
Noel what is the twist on your barrel?
Cheers,
Master Diver
Re: .375" on a CheyTac
MD,
Bobby can fill you in on the detail of what is coming out of Lawton Machine, but there is much greater flexibility in bore/groove tolerances when using jacketed bullets. There is no flexibility in the use of the system's non-banded solid... and even that will be sensitive to barrel temperature, and attendant fouling.
We have had (anticipated) limited success with the 1: 8" twist, as you can discern from earlier posts. As I am sure you already know, Gerard's band design can be made compatable with either groove depth. Eight-inch twist is the minimum which the Lawton rifling machine is capable of. To fully capture the velocity potential of our 6.5, and 7.0 caliber projectiles, it will be necessary to use a 1: 7.0". Results from this combination will be showing up on this thread.
Best,
Noel
MD,
Bobby can fill you in on the detail of what is coming out of Lawton Machine, but there is much greater flexibility in bore/groove tolerances when using jacketed bullets. There is no flexibility in the use of the system's non-banded solid... and even that will be sensitive to barrel temperature, and attendant fouling.
We have had (anticipated) limited success with the 1: 8" twist, as you can discern from earlier posts. As I am sure you already know, Gerard's band design can be made compatable with either groove depth. Eight-inch twist is the minimum which the Lawton rifling machine is capable of. To fully capture the velocity potential of our 6.5, and 7.0 caliber projectiles, it will be necessary to use a 1: 7.0". Results from this combination will be showing up on this thread.
Best,
Noel
Re: .375" on a CheyTac
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">MD,
Bobby can fill you in on the detail of what is coming out of Lawton Machine, but there is much greater flexibility in bore/groove tolerances when using jacketed bullets. There is no flexibility in the use of the system's non-banded solid... and even that will be sensitive to barrel temperature, and attendant fouling.
We have had (anticipated) limited success with the 1: 8" twist, as you can discern from earlier posts. As I am sure you already know, Gerard's band design can be made compatable with either groove depth. Eight-inch twist is the minimum which the Lawton rifling machine is capable of. To fully capture the velocity potential of our 6.5, and 7.0 caliber projectiles, it will be necessary to use a 1: 7.0". Results from this combination will be showing up on this thread.
Best,
Noel </div></div>
OK I follow you.
I would be interesting to see how the new 1:8 GS SP Bullet will perform in 1:8 LRB barrel. Getting beyond 2500 Meters is tough I guess
Cheers,
Master Diver
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Noel Carlson</div><div class="ubbcode-body">MD,
Bobby can fill you in on the detail of what is coming out of Lawton Machine, but there is much greater flexibility in bore/groove tolerances when using jacketed bullets. There is no flexibility in the use of the system's non-banded solid... and even that will be sensitive to barrel temperature, and attendant fouling.
We have had (anticipated) limited success with the 1: 8" twist, as you can discern from earlier posts. As I am sure you already know, Gerard's band design can be made compatable with either groove depth. Eight-inch twist is the minimum which the Lawton rifling machine is capable of. To fully capture the velocity potential of our 6.5, and 7.0 caliber projectiles, it will be necessary to use a 1: 7.0". Results from this combination will be showing up on this thread.
Best,
Noel </div></div>
OK I follow you.
I would be interesting to see how the new 1:8 GS SP Bullet will perform in 1:8 LRB barrel. Getting beyond 2500 Meters is tough I guess
Cheers,
Master Diver
Re: .375" on a CheyTac
Sir if you are really getting a 1:12 twist barrel those lehighs should work great out of that barrel.
Mr. lrs's explanation is a good enough one for me on lost rifle bore configuration.
Sir if you are really getting a 1:12 twist barrel those lehighs should work great out of that barrel.
Mr. lrs's explanation is a good enough one for me on lost rifle bore configuration.
Re: .375" on a CheyTac
Are you Guys using coated Bullets...Moly?
Has anyone ever tried hBN-coating on mayby 330Lehight´s??
Best
2RECON
Are you Guys using coated Bullets...Moly?
Has anyone ever tried hBN-coating on mayby 330Lehight´s??
Best
2RECON
Re: .375" on a CheyTac
2Recon,
There is no coating on any of my bullets, only the engraving bands contact the barrel. You may want to lube the bore with a WS2/Isopropyl Alcohol(99.9%) suspension for break-in. Let the initial application dry completely, and then burnish with dry WS2.
2Recon,
There is no coating on any of my bullets, only the engraving bands contact the barrel. You may want to lube the bore with a WS2/Isopropyl Alcohol(99.9%) suspension for break-in. Let the initial application dry completely, and then burnish with dry WS2.
Re: .375" on a CheyTac
Noel,
Do you have a source for the WS2? Anyone have experience coating the bore? The reason I ask, is that I tried WS2 coated brass solid projectiles in FCSA competition years ago, but found that with the solids, it was "too" slippery, and caused pronounced vertical stringing secondary to velocity variance. It eliminated all of the brass fouling associated with shooting uncoated or moly'd bullets. Had to send them out for vapor deposition process to be coated.
FWIW, I have not found the fouling to be bad at all shooting your bullets so far. There is some, but it doesn't seem to build up like the brass alloys do, especially > 2800 fps.
Scott
Noel,
Do you have a source for the WS2? Anyone have experience coating the bore? The reason I ask, is that I tried WS2 coated brass solid projectiles in FCSA competition years ago, but found that with the solids, it was "too" slippery, and caused pronounced vertical stringing secondary to velocity variance. It eliminated all of the brass fouling associated with shooting uncoated or moly'd bullets. Had to send them out for vapor deposition process to be coated.
FWIW, I have not found the fouling to be bad at all shooting your bullets so far. There is some, but it doesn't seem to build up like the brass alloys do, especially > 2800 fps.
Scott
Re: .375" on a CheyTac
LRS,
I get it from Canada, but I can send you some. A small amount goes a long way.
-Noel
LRS,
I get it from Canada, but I can send you some. A small amount goes a long way.
-Noel
Re: .375" on a CheyTac
krlemas,
The stability factor at 3000fps mv with a 1:11" is 1.19. That would be on to the limit for the combination but it will work. With a 1:10" twist the stability factor is 1.45 at 3000fps mv.
We attended the Aim Show in JHB this past weekend and left on the 1st of April and returned yesterday. Hence the slow reply.
krlemas,
The stability factor at 3000fps mv with a 1:11" is 1.19. That would be on to the limit for the combination but it will work. With a 1:10" twist the stability factor is 1.45 at 3000fps mv.
We attended the Aim Show in JHB this past weekend and left on the 1st of April and returned yesterday. Hence the slow reply.
Re: .375" on a CheyTac
Gerard,
Thank you for the reply I just received my new Brux barrel yesterday with the 1:11 so I will want to try your new 375/355gr bullets. When will they be available with your USA dealer and any idea on cost?
Ken
Gerard,
Thank you for the reply I just received my new Brux barrel yesterday with the 1:11 so I will want to try your new 375/355gr bullets. When will they be available with your USA dealer and any idea on cost?
Ken
Re: .375" on a CheyTac
They will be on the USA price list early next week around US$85 for 50 plus USPS flat rate. The catalog number is 375355SP173. It will be a special order item, as most SPs are, and we are in process with the next order for Northern Light Trading. We ship to him about every four weeks.
They will be on the USA price list early next week around US$85 for 50 plus USPS flat rate. The catalog number is 375355SP173. It will be a special order item, as most SPs are, and we are in process with the next order for Northern Light Trading. We ship to him about every four weeks.
Re: .375" on a CheyTac
Gerard
Any results on the 1:8 or 1:10 projectiles yet?
I have an upcoming .375 Cheytac IMP (Snipetac) build and I am trying to determine barrel specs. I am sure others are just as excited and anxious for results as I am. I am looking to 'max' out the range and go 2500+ meters.
After reading (and reading again) every thread and post I can on the 375 Cheytac and all other ELR cartridges I found myself agreeing with your rationale on using standard bore deminsions instead of LRB/Hooker bores so the user has more accesiblity to other projectiles. The standard bore or LRB/Hooker bore has been my most difficult decision with my upcoming project.
To the Sniper's Hide community:
This is my first post but I have been studying and researching for awhile now...
There is a wealth of information on Sniper's Hide as well as "Later's" website and with David Veirs of Veirsco. Later and David Vier have both been very helpful in educating me and I look forward to hopefully meeting some of the other experts on here.
Thank You
Gerard
Any results on the 1:8 or 1:10 projectiles yet?
I have an upcoming .375 Cheytac IMP (Snipetac) build and I am trying to determine barrel specs. I am sure others are just as excited and anxious for results as I am. I am looking to 'max' out the range and go 2500+ meters.
After reading (and reading again) every thread and post I can on the 375 Cheytac and all other ELR cartridges I found myself agreeing with your rationale on using standard bore deminsions instead of LRB/Hooker bores so the user has more accesiblity to other projectiles. The standard bore or LRB/Hooker bore has been my most difficult decision with my upcoming project.
To the Sniper's Hide community:
This is my first post but I have been studying and researching for awhile now...
There is a wealth of information on Sniper's Hide as well as "Later's" website and with David Veirs of Veirsco. Later and David Vier have both been very helpful in educating me and I look forward to hopefully meeting some of the other experts on here.
Thank You
Re: .375" on a CheyTac
This seems to be a decision of what Bullet then build the rifle for it .
A lot of development has been happening , will sit on the sidelines and see what happens in the next 6 months , gathering parts that I need for the build.
Bill
This seems to be a decision of what Bullet then build the rifle for it .
A lot of development has been happening , will sit on the sidelines and see what happens in the next 6 months , gathering parts that I need for the build.
Bill
