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The StraightJacket Barrel System

Teludyne had a compelling pitch at the SHOT show: the StraightJacket Barrel System will lighten the weight of your rifle, increase its accuracy, and prolong the life of your barrel.  This sounded great, but it also sounded too good to be true, which is generally an indicator that the product I’m looking at is just snake oil.

When Teludyne’s CEO invited me up to have a barrel modified, I used that as an opportunity to test Teludyne’s claims directly.  Read on to learn if the system really does what they say it does.

Disclaimer:  some of the work performed was free.  The offer was to convert my rifle using their standard steel jacket for free, but I opted to pay extra for titanium instead.  The base rifle for the conversion was a Remington 700 5R that I had previously migrated to an AICS stock.

Teludyne’s claims about their StraightJacket system (which you can find on their web site) are:

  1. It significantly improves accuracy
  2. It dramatically reduces heat
  3. It delivers an “outstanding” reduction in recoil
  4. It will extend the life of your barrel

The Process

The folks that run Teludyne are craftsmen.  This isn’t flattery; rather it’s the descriptive term I use for the sort of people that build muskets and sailboats from scratch, which the man behind the company does.  The advantage of craftsmanship is that the work is done correctly each and every time, even with one-off jobs.  The disadvantage is that craftsmanship doesn’t scale — it is much easier to triple your order volume if most of your process is automated than if everything is hand made.  (At the time this article was published Teludyne’s web site indicated they were working at capacity and were no longer taking new orders.  The craftsmanship issue is something I hope Teludyne figures out how to work around.)

When you order from Teludyne the process goes something like this:

  • You choose the material to use for the jacket (steel which cheap and heavy, aluminum that is light but can dent, all the way up to titanium as the premium option) and drop off the rifle.
  • The barreled action is removed from the stock, and the process starts.  In my case they reduced the barrel length from 24″ to 20″, a recommendation they made because with .308 the additional velocity those last few inches contributed was minimal.
  • The original barrel has its wall thickness reduced as much as possible while still meeting SAAMI specifications.  Rigidity is provided by the StraightJacket system rather than the barrel itself, so any barrel thickness above that required for safety is simply additional weight on the rifle.
  • Now the jacket is installed over the barrel.  The gap between jacket and barrel is then filled with Teludyne’s proprietary media.
  • The stock is modified so that the new jacketed barrel fits.  This means that if you’re going to install your rifle in an after-market stock (like the AICS I used, with its aluminum block construction) then you want to install the stock first.  Otherwise you’ll end up paying your local gunsmith to make it fit.

What you get back is a rifle with a thicker barrel (actually the jacket) that weighs less than a comparable bull-barreled rifle:

Compare the diameter of the SJ system (on the right) with a traditional bull barrel (in the rear.)

The Product

The jacketed barrel has a number of interesting properties:

  • It’s strong.  I asked about the strength of the product and the employee I was talking to left and returned with a dented jacketed barrel along with a twenty-pound sledge hammer.  He’d gone to town on the barrel to see what kind of damage he could do and the answer was “not much.”  If you hold the rifle like a baseball bat and swing it against a wall a few times the rest of the rifle will suffer catastrophic damage before the barrel does.  It’s really that strong.
  • It’s light weight.  I’ll need to get this on a scale, but I’ll come back and add in the difference in weight later on.  A SJ barreled system is significantly lighter than a bull-barreled rifle, even though it’s thicker.  Teludyne has an M24 Sniper System that has been modified, and the modified rifle ended up four pounds lighter.  Quite an improvement if you’ll be carrying the rifle all day.
  • The proprietary material Teludyne fills the jacket with is surprisingly conductive.  According to the designer it conducts heat better than any metal.  (This surprised me, so I asked my wife (an MD) and a friend with an engineering degree and the claim isn’t unreasonable.  There are a number of composite materials that are much more conductive than, say, copper.  Materials science has come up with some cool stuff.)
  • It may be safer than a normal barrel.  In the case of over-pressure rounds the SJ system will prevent the barrel from bursting which should be much safer for the shooter.

 

Addressing Teludyne’s Performance Claims

 

Improved Accuracy

Group Size

The StraightJacket system improved the measured groups from my rifle.  It went from 0.75″ groups straight from the factory, to 0.6″ groups after installing the AICS chassis system, and is now grouping at 0.5″ or better after having the StraightJacket installed.  I’m not consistent enough at shooting paper targets to quantify better results than that with the 10 power scope I have mounted.  I can say this though: I successfully engaged 1 MOA targets at greater than 1,000 yards with first round hits using this barrel system.  The only disadvantage this rifle had versus the top-end custom rifles at the course was its caliber — .260 Remington has it all over .308 once you start looking at the effects of wind.

Teludyne has this target on display in the shop.  I was told it was shot by a former SEAL sniper with his personal Ruger 77 after the StraightJacket modification.   I didn’t measure the group, but for reference the Post-It at the bottom of the frame is 5 inches wide.  This is quite a bit better than I expect from a Ruger 77 at 800 yards.

The best 800 yard from a Ruger 77 ever?

Teludyne tells me that any barrel will show increased accuracy due to the increase in rigidity the jacket system offers over an unjacketed barrel.  From what I’ve seen, I believe them.

Shifting point of impact

Of more importance is how the rifle shoots to point of aim regardless of the temperature of the barrel.  Teludyne can show you testing performed by HP White that quantifies this, but it’s fair to say that point of aim/point of impact remains fairly constant with the SJ system, even when shooting so much that the outside of the barrel will burn uncovered skin.

Don’t worry about a cold bore shot — they’ll all go to the same place.  If you’re grouping a rifle and the first and second rounds touch, then shots 3-5 go to a slightly different spot, then you might be seeing a change in impact due to a hotter barrel.  The SJ won’t show this effect though you’re still capable of throwing shots for other reasons.

At the long range course I took this rifle to I never ran into a situation where I needed to let the barrel cool down because my point of impact shifted enough to keep me from hitting 0.5 to 1 MOA targets.

Reduced Heat

This system is amazing with regard to heat reduction (actually heat transfer).  The demonstration I went through with a Teludyne-modified 16″ AR-15. was as follows:

This AR has been modified with the Straight Jacket system – note the thicker “barrel” and the compensator

  • I emptied a magazine as fast as I could pull the trigger.
  • I immediately broke open the rifle and pulled out the bolt carrier.  The bolt and the carrier were room temperature.
  • I stuck my pinkie in the chamber and it was probably 90 degrees Fahrenheit.
  • At the same time, the outside of the “barrel” (actually the “jacket” of the Straight Jacket system) was hot enough to burn.
  • My hands got messy when taking the bolt out, but in a good way.  It turns out that the carbon and soot that the direct impingement system throws into the chamber really sticks well to hot metal, but stays powdery and unattached at lower temperatures.  Teludyne has an M4 demo system that has about 10,000 rounds through it, shot 300 rounds at a time on full auto.  They say that to date the only cleaning it’s received has been a wipe down with a dry cloth, and that’s all it’s needed.  After my brief time with this AR at the range, I believe them.

I don’t know that I would call this heat reduction, though — it’s more like heat transfer.  The heat appears to be pulled away from the chamber and barrel of the rifle, transferred to the outside of the jacket, and kept from returning.  It acts as if there’s a one-way layer in the jacket that allows heat to transfer away from the barrel, and not back.

This is all speculation though.  What I saw was a system where the outside of the jacketed barrel got really hot, while the chamber and barrel stayed much cooler.  I don’t know how it works, so judge the system based on the observations, not the guesswork.

Recoil Reduction

Felt recoil is reduced considerably.  This is to be expected, as the installation includes a large muzzle brake:

That’s a big muzzle brake.

There may be some improvements in felt recoil that are attributable to the StraightJacket system rather than just the brake, but if so I’m not the right person to try and measure it.

Barrel Life

This section is the hardest for me to write, and it’s the main reason it’s taken so long to get this review out.  When it comes down to it, it’s just about impossible to answer the question of increased barrel life without shooting out a couple of barrels in the process.  With a .308 like I submitted for modification, it’s probably reasonable to expect the barrel to last 8,000 to 10,000 rounds before accuracy degrades measurably.  To properly verify Teludyne’s claims, one would need to shoot this many rounds from the modified barrel, and do the same with an unmodified barrel, in order to do the comparison.  Once accuracy dropped on the unmodified barrel, then we could keep shooting the SJ to try and understand the advantages that Teludyne offers.  This test would still be flawed (barrel life varies from barrel to barrel, the shooting would likely be faster than most people would choose to shoot so the SJ system would have an unfair advantage and it’s not a reasonable test, and so on.)

At the end of the day, I’m not going to shoot 20,000 – 30,000 rounds to try and quantify this.  I asked Teludyne about barrels that had extreme lifespans and they couldn’t put me in touch with anyone.  They have their M4 test unit which has seen around 10,000 rounds through it, but the accuracy expectations for a carbine (and allowable accuracy degradation) are significantly less than for a rifle designed to be shot at targets that are nearly a kilometer distant.

So the best I can do is this: I’ll offer the arguments on each side of the debate, and leave it to the reader for further investigation.  I’m not an engineer, and I’m not a materials scientist, and the best I can do is offer the explanations I’ve read elsewhere.

Please note there is a lot of opinion out there on this subject, and not a lot of scientific testing that’s readily available.

So what causes a barrel to wear out?

The standard explanation is that heat is the enemy of barrel life, and the faster the round you’re firing, the fewer rounds the barrel can take before it needs to be replaced.  The less time you leave between shots, the shorter the lifespan of the barrel will be.  Some argue that a barrel has a life tied to the amount of heat put through it (say 20 pounds of powder), and that shooting a rifle faster will reduce this life more than if one allowed the barrel to cool off between shots.  Others argue that the real enemy of accuracy is throat erosion – as the bullet has to jump a longer distance due to erosion at the throat, the ability of the rifling to stabilize the bullet is compromised.  This effect gets worse with additional wear.

The best authoritative source on barrel wear I could find was Understanding and Predicting Gun Barrel Erosion, put out by the Weapon System Division of the Australian DOD.  While focused on big guns (artillery pieces and tank guns), its conclusions are probably still relevant.  It found three sources of erosion that all act in concert to affect barrel life:

  • Chemical Erosion: reactions at the surface of the bore that degrade the material of the barrel
  • Thermal Erosion: changes to the bore, including softening, melting, and cracking
  • Mechanical Erosion: removal of bore materials due to gas and particulate flow

Regardless of cause, Teludyne believes its system minimizes the damage and will keep a barrel shooting accurately for much longer than you would otherwise see.

Teludyne’s Take

The inventor of the SJ system told me that barrel wear isn’t caused by the velocity of the rounds, and it isn’t caused by throat wear.  The real problem is:

  1. The temperature of the propellant will cause the metal to lose its temper over time, at which point it will whip more than normal and destroy accuracy. (The wording here is dumbed down by my understanding — don’t take this as a technical description.)
  2. The pressure a barrel is subjected to when launching a bullet down the bore will cause microscopic cracks in the bore, which also reduces the rigidity of the barrel over time, resulting in decreased accuracy.

The StraightJacket minimizes the damage from heat due to its thermal properties, but in the end the StraightJacket system does not require any rigidity from the barrel for accuracy.  The StraightJacket system does not allow the barrel to move, so the accuracy of the rifle is determined by the rigidity of the jacket, not the barrel, and the rigidity of the Straight Jacket is unaffected by these causes.  As long as the rifling is sufficient to cause the bullet to spin properly, the StraightJacket system will remain sub-minute-of-angle accurate.

As evidence to support this claim, I was told that more than 25 rifles chambered in 22-250 with “shot-out barrels” have had the SJ system installed.  In each case, if the barrels still had working rifling, then the rifle that went back out was producing .75 MOA groups or better.  In all of these cases the barrel was unchanged other than having excess metal removed from the outside of the barrel as part of the process.  To date, none of these barrels have been sent back because they have subsequently lost accuracy.

Criticisms

Dedicated long-range shooters have told me that in cases of shot out barrels it is generally possible to have a gunsmith remove a couple of inches of the barrel near the action and re-chamber it, restoring accuracy for another thousand rounds or so.  This suggests that an eroded throat is the cause of the problem.  In Teludyne’s defense, the above-referenced paper tells us that barrel wear is most severe where the rifling starts, so it’s possible that rechambering the barrel just removes the part of the barrel that was most affected by the mechanisms that the SJ system protects against.

Preliminary Conclusion

I’m not competent to evaluate the claims regarding barrel life, but as far as I can tell Teludyne’s claims seem reasonable.  Even if we discount their explanation of the cause of barrels wear entirely and fall back to the “heat kills barrels” argument, then it is reasonable to conclude that a StraightJacketed barrel, with its improved heat management abilities, should outlive a normal barrel.  If we assume that barrel rigidity degrades over time due to loss of temper (due to heat) and microscopic cracks (due to pressure) then we can assume the StraightJacket system should offer significantly enhanced barrel life (if the rifling still works, the rifle is still accurate.)

So, is it worth it?

I like the system quite a bit.  Let’s look at use cases for particular recommendations:

An AR-style rifle

The StraightJacket system is a definite improvement over stock.  Their AR demo system has fired in excess of 10,000 rounds, 300 rounds at a time and generally full auto.  It is still a sub-MOA rifle, and the only cleaning it has been subjected to is removing the bolt carrier and wiping it down with a cloth.  To date the bolt has not been disassembled and cleaned, and it has not been experienced any failures.

This is a huge improvement over a stock AR-style weapon in my opinion.  The only downside I can find is a failure experienced by one of the staff members on THR where the jacket itself failed, but Teludyne has informed me that the current model is not susceptible to that kind of failure.

If I were buying an M16 lower (or planned on subjecting my carbine to high rates of fire regularly) then I would install a StraightJacket in a heartbeat.  It’s just that much of an improvement.

Unfortunately those of us with SCAR 16s and other AR alternatives are out of luck; there isn’t enough demand for carbines other than the AR for StraightJackets to be offered.  .

A Hunting Rifle

I think the StraightJacket is overkill for a regular hunting rifle.  It results in a lighter rifle than a standard profile barrel offers, but a thin profile barrel would be as good for all-day carry.  The additional advantages of the StraightJacket system are wasted on a rifle that it shot as infrequently as most hunting rifles seem to be.

Long Range Rifles

Here I am going to give a qualified “yes.”

Comparison with a more traditional long range rifle. The StraightJacket equipped rifle is the one in the front, and offers significant weight advantages, as well as no shift in point of impact over long days of heavy shooting

My reasoning is as follows:

  • You can shoot all day without having to slow down because your barrel is getting hot and it is affecting the point of impact.
  • The SJ equipped rifle is noticeably lighter, so it is easier to carry all day.  If you simply shoot from prone then this is not a huge advantage, but if you compete in something like the Sniper’s Hide cup then the benefit is much greater.
  • On a rifle that will be shot frequently you should see enhanced barrel life, which will mean less cost to shoot over time.
  • The downside here is this: the SJ system’s cost is comparable to having a precision barrel installed.  I would not be shocked to learn that an custom match-grade barrel is more accurate than a factory barrel that is subjected to the SJ treatment.  In cases where you have a precision barrel sent off to Teludyne to install the system, the barrel will have to have twice the expected life in order to justify the cost, and barrel life will need to exceed that in order for the system to make financial sense.  I have not seen any evidence that this level of improvement is possible (though it may very well be — we just need more evidence.)

 

Overall this is a very interesting system that is worthy or additional testing.  I hope Teludyne gets their production issues worked out so more of us can experience the system.

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