Has anyone tried or heard of anyone playing with this cartridge?

[jasent]

In this book Brian talks about how the gain twist barrel causes bullet imbalance(not spinning on its center axis but it's center of gravity) also how it induces spin rate decay.

 

[HARPERC]

http://bulletin.accurateshooter.com/2008/08/boyer-succeeds-with-bartlein-gain-twist-barrel/

 

[RockyMtnMT]

Launching long bullets into rifling at high vel is hard on bullets. Gain or not. Question is, its one harder on the bullet than the other. I think it could go either way depending on bullet length and launch vel.

Steve

 

[gregsjt]

In this book Brian talks about how the gain twist barrel causes bullet imbalance(not spinning on its center axis but it's center of gravity) also how it induces spin rate decay.

That's interesting, he obviously knows what he's talking about but a lot of people are having success with them.

 

[Rich Coyle]

Nothing succeed like success.

 

[jasent]

That's interesting, he obviously knows what he's talking about but a lot of people are having success with them.

they may be getting better. Book is copyright 2014. Has some live fire testing results to back it up but maybe it was just a poor barrel. Idk. He was testing Berger 175 gr hybrid I think and the Sierra mk. Both showed spin rate decay before Mach one

 

[WildRose]

This is true, but the distance between the lands and grooves or the shape of the lands and grooves does not.

The angle and length of the grooves cut into the bullet changes constantly as the twist increases for the length of the barrel.

That is a tremendous shearing force exerted on the jacket.

 

[machgman]

Answer is yes it has been done. Google it, not a lot of info available.

Barrel life gets tossed around like "you'll shoot your eye out kid". A barrel is dead when it no longer perform the tasks it was intended for. Some are dead on arrival, we replace them, dump them, make excuses for them, and move on. Some of what we consider accuracy comes from 5-10 shot groups used in other disciplines. This type of rifle likely should be judged base on first round hits, a second on top of that, and rarely a 3 round group. 3 rounds seems where the ELR folks are going.

Bullets are the real issue. You'll need one heavy enough to develop decent pressure for a consistent burn, and provide a decent BC. Presumably long range is your intended use.

The 155 Berger is coming-it would be interesting to see it severely tested. Steve from Hammer has a pure copper in his head, probably in hand this summer.

Barrels-you'll need one with enough twist, and could be a place to try gain twist.

You'll need a Weatherby sized action.

The end product will be very specialized.

It's about having fun. if it's a process you enjoy go for it.

Thank you for the informative reply as I have never encountered this combo round before.

 

[machgman]

Answer is yes it has been done. Google it, not a lot of info available.

Barrel life gets tossed around like "you'll shoot your eye out kid". A barrel is dead when it no longer perform the tasks it was intended for. Some are dead on arrival, we replace them, dump them, make excuses for them, and move on. Some of what we consider accuracy comes from 5-10 shot groups used in other disciplines. This type of rifle likely should be judged base on first round hits, a second on top of that, and rarely a 3 round group. 3 rounds seems where the ELR folks are going.

Bullets are the real issue. You'll need one heavy enough to develop decent pressure for a consistent burn, and provide a decent BC. Presumably long range is your intended use.

The 155 Berger is coming-it would be interesting to see it severely tested. Steve from Hammer has a pure copper in his head, probably in hand this summer.

Barrels-you'll need one with enough twist, and could be a place to try gain twist.

You'll need a Weatherby sized action.

The end product will be very specialized.

It's about having fun. if it's a process you enjoy go for it.

With regards to the accelerated barrel wear issue, would there be any advantages to using a rifle barrel with Polygonal rifling?

 

[MudRunner2005]

With regards to the accelerated barrel wear issue, would there be any advantages to using a rifle barrel with Polygonal rifling?

Not really... Barrel burning has more to do with the case capacity vs. the bore diameter. The more powder packed behind a smaller bore, will have a longer burning and more concentrated flame, which will burn out the throat quicker than a cartridge with a larger diameter bore, and a smaller capacity case.

For an easy comparison, think .26 Nosler vs. .308 Winchester. .26 Nosler lasts about 500-600 rounds of accurate barrel life. .308 Win will last 8,000+. This is because the .308 Win has a larger diameter bore and a smaller case capacity, so the flame is less concentrated and burns out quicker.

 

[NEMTHunter]

Launching long bullets into rifling at high vel is hard on bullets. Gain or not. Question is, its one harder on the bullet than the other. I think it could go either way depending on bullet length and launch vel.

Steve

Not mention if the bullets a solid cooper bullet a lead core bullet. Not all gain twists are a fast gain. some only gain half a twist the length of the barrel.

I have a gain twist on order. will see how it does. Hope I am not shooting myself in the foot.

 

[HARPERC]

.....I have a gain twist on order. will see how it does. Hope I am not shooting myself in the foot......

I don't think you've shot yourself in the foot, establishing it's better is a bit more difficult.
I'm thinking my next one will use gain twist-I'd be very interested in how it works for you.

 

[Hatrick]

Not mention if the bullets a solid cooper bullet a lead core bullet. Not all gain twists are a fast gain. some only gain half a twist the length of the barrel.

I have a gain twist on order. will see how it does. Hope I am not shooting myself in the foot.

What is the average gain in a gain twist barrel?

 

[HARPERC]

......With regards to the accelerated barrel wear issue, would there be any advantages to using a rifle barrel with Polygonal rifling?..........

I don't think so I think some of the coatings hold promise, but the reality is if you use it you're going to wear it out.

My definition of a dead barrel: When it no longer works for what it was intended to do.
Examples I bought a Howa .223 for the kids to shoot squirrels with. We never found anything that it would shoot minute of squirrel with. I consider that dead on arrival. A Tikka with several days of hard use, (one trip we returned with 18 lbs of brass) is still laying them low. I haven't shot it in a bit but it was a 0.25" rifle in the beginning, even if it's declined to 0.5" it's more than usable.

My .338 RUM is rare to see a 3 shot 0.5" group, but the first 2 are dead on, and it remains my favorite long range rock chuck rifle. Past 400 yards it will yield more dead chucks than the .223. Especially if the wind is up.

Neither of these would win a bench rest match.

Shawn Carlock has posted groups from his LRKM rifles of better than 0.25", 3 shot groups. If after 500 rounds these are 0.5" does that represent a dead barrel? Is reliable 0.75" unusable as a LRH rifle? Sub MOA?
https://www.facebook.com/1117393455...739345552194/1811950742197704/?type=3&theater