StraightJacket Litmus test.

[dogmush]

In other words, unless the Straightjacket folks say every load will be made more accurate, your test will be inconclusive.

That's pretty much what they say though.

The invention dealt with the heat and harmonics so well that the old battle rifle was corrected from shooting like a shotgun with buckshot to keeping the Military surplus ammo in two inch groups!

Didn't get to the range yestertday for the heat testing, I had a sick dog come up. Looks like Wed.

[Smokey Joe]

Dogmush--I've been following the postings about the Straightjacket system with some interest. All along, its main proponent on this forum, Wristtwister, has been a little tight with actual results to back up his claims.

You're obviously attempting to put the system to a controlled test, as would any good scientist.

For this I salute you, and will be looking with great interest at the results.

Given your handle, it's no surprise that a sick dog had priority. Hope the pooch does all right.

[wristtwister]

All along, its main proponent on this forum, Wristtwister, has been a little tight with actual results to back up his claims.

Hmmm... I thought I'd been up front with everything about the Straitjacket system. It started off with me telling the forum that it existed... and then I was put through about a month and a half of "no it doesn't", "it can't work", "you don't have any proof"... just about every scenario that the skeptics could think up... even to the point that the company that was manufacturing it didn't exist, simply because some of you internet wizards couldn't find their location "on the net".

Then, after they got their website up, the tenor changed to "all these claims are bogus"... "they haven't been written up in the gun rags, so none of this is true"... Stay tuned for that one... the articles are on the way from one of the leading gun writers in the country... but, of course, they haven't been printed yet, so I'm sure to be lying about that too...

The company opened January 1st of this year, so they have been operational for a whole 3 months... I'm surprised that you guys haven't bothered to stop by and go shoot the guns, but I'm sure it's easier to just sit at your desk and rail at me about them. YOU'RE WELCOME TO COME SHOOT A STRAITJACKETED RIFLE AT ANY TIME... AND IF THE COMPANY DOESN'T HAVE ONE AVAILABLE, YOU CAN SHOOT MINE. It's a 30-06 Mossberg ATR, so bring your own ammo. I shoot Winchester and Core Lokt 165 gr for the best results... box ammo right off the shelf. Stop by Wal Mart on the way to the house... I'll print you a target.

If you aren't satisfied with a "100 yard" test, we can drive the 65 miles to my gun club and you can shoot up to 1000 yards. My eyes aren't that good, but feel free to do as you will. Call Teludyne at 864-334-5300 and tell Paul or Mark to give me the message of when you'll be here. I'll meet you at their shop and give you a tour, then... we'll go shooting.

Skeptics always talk a good game, but when they have to prove their own skills, etc. they usually appear to have "issues". I've been open about everything related to Straitjacketed rifles. The sticking point is that the company won't reveal what their heat-hungry infill material is, and it's proprietary information, so I don't even know... What I do know is that the system works, and works well. If you can't shoot worth a damn, it doesn't matter if they gave you a $50,000 rifle, you'd still suck... but if you are a marksman, this system will improve the capabilities of the rifle well beyond whatever you imagined. I'm lucky enough to own one...

WT

[Absintheur]

I would point out I never claimed you were lying nor did I say the claims were bogus, I merely pointed out that when something new that makes the claims the StraightJacket system does that if it is true then it will be written up by one of the well known gun magazines. I believe independent testers far more than I believe advertising hype...sorry but that is the way it is. If you can show me were I called you a liar I will apologize but don't say I said things I didn't.

I would happily pay to have a rifle done if the claims prove true.

[Smokey Joe]

WT--I'd LOVE to take you up on your generous offer, and personally test the SJ system! Unfortunately, Teludyne's location in SC is a little far from mine, for a weekend jaunt. Believe me, if I find myself in that neck of the woods for any reason, you'll hear from me. That's a promise. BTW, I CAN shoot worth a damn.

Absintheur basically answered for me--I didn't call you a liar either, but we have yet to see photos of a "before & after" target shot by a "pre then post" SJ'd rifle. We have yet to read a write-up from one of your unnamed major gun magazine writers. We have yet to hear of a competitor of note, using the SJ system and reporting--favorably or unfavorable--on it. We have yet to see a diagram of exactly WHAT the SJ system is, or does, to a rifle.

I'm looking forward to Dogmush's results as well.

Honest, I'm not hostile to you nor to the StraightJacket system, nor to anything that helps riflemen shoot more accurately. (Hey, I'll take all the help I can get!) As I said in my original post re the SJ system, if it's good enough for the likes of David Tubb, it's good enough for me. Take it to Camp Perry and demonstrate how good it is. Let us read an "outsider's" write-up. (These I am eagerly awaiting!) Show us some RESULTS.

[dogmush]

Anyone ever had a week just end up way more crowded then planned?

Finally got back to the range on Thursday, and now big surprise the barrel gets hotter when you shoot.

She'll get sent of to TTI next week sometime, I have to dig up a box.

Data below:

Test rig:

Results:



A note on chamber temps, when taking that temp, I put the thermocouple in the chamber for 30 secs, and noted begining and end temps. I then subtracted the end from the begining temp giving me the amount of temperature change over a set time. I'll call this the temp factor. Since the mass of the brass is a constant, and it's not actually that wide a range of temps, I can draw a rough idea of the temperature of the chamber by the amount of heat transfered to the brass insert. It should be enough to let me know if the chamber temp is noticably different (either higher or lower) after the Straight Jacket.

Stay tuned for the exciting part!! (in two or three weeks)

Also, I can no longer edit the acurracy post but I put together this table comparing group size and barrel temp. Neat info:

[2aHawaii]

Great job dogmush!!!

[Dewey 123]

Interesting stuff. However, the line graph is a little misleading as the intervals on the X-axis aren't uniform. Also, how's your dog? (and I think I have that same pen, is it a Zebra)

[dogmush]

Dewey, The dog's better, thanks. She picked up a stomach virus somewhere, lots of carpet cleaning and getting her fluids and she's OK.

On the graph, I didn't take measyements every shot, as it takes a non-zero time to write stuff down, and I didn't wanted to get at least a couple of heat measurements from multiple shot groups. Excel's not quite smart enough to extrapolate automatically.

Hang on a sec.

[dogmush]

Dewey has a real point there too.

Because I used increasingly large intervals between measurements, ans Excel didn't acount for that on the X-axis for me, the heat graph has an almost exponential curve look to it. Because it's my data, and I knew of this I was sub-conciousilly ignore that curve. I knew it wasn't there. But I can see how that might be misleading.

After some judicous use of the TREND function, try these on for size. I think they give a better graphical representation anyway. It's a nearly linear rise that tapers off towards the end as the barrel starts to heat-soak a little.

On the first graph, the wierd points are artifacts of mathamatically trending, and then forceing it back to a new data point when needed. It's close, but not exact.

On the time graph remember that I didn't measure at set time intervals, as reloading had to happen somewhere in there to. The dot's are actual data points, and the lines are two period average trendlines.

[wristtwister]

Dogmush... you guys are quite obsessed with the temperature deal, so I'll throw you something that was said to us by a gunsmith this past week. I rode with my buddy who's an owner of the company to this gunsmith's shop, and he examined one of the rifles Mark took to Kansas for the gun writer's shoot.

The conversation went pretty much like this... (almost verbatim)
He took out his borescope and very carefully inspected the inside of the rifle. "How many rounds have been through this gun?.. he asked. "About 2000, as far as we can guess" Mark answered.
"Are you sure?" he asked.
"Well, we shot 600 rounds through it last week at the Kansas shoot... it's one of our old "beater guns" that we let anybody shoot that wants to... 2,000 is probably a conservative estimate... it's probably more than that."
"I find that hard to believe" said the gunsmith... "there's no appreciable throat erosion in the gun... if it had been shot that many times, there should be considerable erosion, and I can't see any..."
Playing stupid, I asked... "what causes throat erosion"?
"Heat... and the friction of the bullet mating up with the rifling when it's fired"... he said.
"So if there's no heat, then there's no throat erosion?"...
"There would be some from friction, but I don't find any. If your guns keep the action cooled enough to stop this, you're on to something..."



WT

[Dewey 123]

Dogmush, thanks for redoing those graphs, and I'm glad to hear that your dog's better. Judging by your name. I was going to ask if you are a dog sledder, but then I noticed your location... It's interesting to see the midpoint and muzzle temperatures plateau between shots 25? and 30 and then again from shot 33 or 34. And I would have thought that the chamber would be hotter, but then most of the heat is probably transferred to the case, not the chamber wall...

[dogmush]

Actually, Throat Erosion is caused by the high velocity, high temperature propellant gas jet cutting before the bullet seals in the rifling.

Dewey, I used to be a musher, before I got moved to the overpopulated swamp.

The first plateau is (i think) an artifact of reloading times and temps. As the barrel gets hotter the difference between it and ambient temp gets greater. As a result of that it cools down more during the relaoding stops, and that dip translates to the graph where it didn't on earlier loads. The later plateau is, I think, the start of heatsoak on the barrel.

I guess I should also mention planned results. Whatever else the straight jacket does, it shrouds the barrel, so I fully expect lower external barrel temps. For me to consider the system successful at controling heat I'd want to see the slope of those three lines drop. If they just translate down 50 or so degrees, all we're seeing is good insulation. A sucessful system will show three lines much closer to flat then those are and a chamber temp bar graph that has all the bars pretty much the same height. I think an improvment in accuraccy will be self evident, if it happens.

[dogmush]

Also redid the chamber temp graph to go to a linear axis. That trend line is what we'd like to see come more towards horizontal.

[RecoilRob]

Nice work so far! One thing that wonders me is how long it will take the SJ'd barrel to cool back down again? With simple addition of mass, we'd expect to see the flattening of the graphs and will certainly see this once you get the rifle back.

But, the mass+insulation will cause increased internal temperatures eventually vs the naked barrel...at least I would think so.

Is there any way to measure the hottest barrel point after a set time post shooting to try to get a feel for how long the new barrel system will cool down?

One of the original claims was that you could shoot the rifle rapidly and never over-heat it. They mentioned Military applications specifically so that is at least what I thought they meant to say.

Some test of how long it takes to cool would lend some insight into whether the barrel will eventually overheat despite mass addition.

You are doing fine work Dogmush! If you run short of ammo, I've got a couple hundred FN FMJAP surplus laying around that I could donate to the cause.

[dogmush]

One thing that wonders me is how long it will take the SJ'd barrel to cool back down again? With simple addition of mass, we'd expect to see the flattening of the graphs and will certainly see this once you get the rifle back.

You're killing me, where were these suggestions while I was planning the experiment?

Let me see if I can come up with a repeatable way to measure cooling.

[wristtwister]

Actually, Throat Erosion is caused by the high velocity, high temperature propellant gas jet cutting before the bullet seals in the rifling.

"Heat... and the friction of the bullet mating up with the rifling when it's fired"...

Think you guys can at least agree to agree when we say the same thing two different ways? All this anal diagnosis isn't necessary, and your opinions are worth the same as those offered by other experts. The "my expert can whip your expert" is a little childish, but... have at it.

Since you're making all these "measurements", tell me how they relate to anything about the accuracy of the barrel system? When the bullet is fired, the barrel gets hot... given... where does the heat go? In a "normal" barrel, it's radiated off the outside diameter of the barrel... in the straitjacketed barrel, it's radiated off a 1.25" diameter tube with about 10 times the surface area of the barrel through a heat absorption material. Okay... now, what does that prove about the accuracy provided in the system?... absolutely nothing.

To be honest, I'm interested in seeing how you put all this together, and what actual conclusions you can draw from having the information. I think it's going to end up like a chart of steam tables, where you can tell what temperature steam is at what pressure, and unless you know how it's applied to the problem you're trying to solve, it's a useless puddle of information that means nothing. I shot my 30-06 today, and fired about 35 rounds through it. The barrel got warm, and stayed about the same temperature the whole time I was shooting... but it was about 80-85 degrees outside. How are you going to account for outside source heat?... such as sunlight... outside ambient temperature... etc. Just wondering... are you shooting in a temperature controlled atmosphere?

I was shooting outside today.. under a shed, 7 mph wind... here's the results of my test...
most of the rest of my ammo was spent letting other people shoot my gun or zeroing my new scope. That's about an inch and a half group, but I have bad eyes (cataracts)...

[JWF III]

Quote:
Actually, Throat Erosion is caused by the high velocity, high temperature propellant gas jet cutting before the bullet seals in the rifling.

Quote:
"Heat... and the friction of the bullet mating up with the rifling when it's fired"...

Think you guys can at least agree to agree when we say the same thing two different ways?

That's two ways of saying two totally different things. You're saying that the temperarures and the friction from the bullet cause throat erosion. (WRONG.) dogmush is saying that throat erosion is caused by the burning powder and resultant gases. (CORRECT.)

Do some research on "flame cutting" pertaining to revolvers. "Flame cutting" is a revolver's version of throat erosion (though some revolvers experience that too). But "flame cutting" happens nowhere near the barrel, but on the top strap of the frame.

Since you're making all these "measurements", tell me how they relate to anything about the accuracy of the barrel system? When the bullet is fired, the barrel gets hot... given... where does the heat go? In a "normal" barrel, it's radiated off the outside diameter of the barrel... in the straitjacketed barrel, it's radiated off a 1.25" diameter tube with about 10 times the surface area of the barrel through a heat absorption material. Okay... now, what does that prove about the accuracy provided in the system?... absolutely nothing.

Now I'll start by saying I'm not performing these tests. So I could be off base here. But this is my opinion after reading dogmush's porposal of this test.

It sounds to me like you're (WT) looking at the barrel like a standard bullbarrel...

it's radiated off a 1.25" diameter tube with about 10 times the surface area of the barrel through a heat absorption material.

That statement descibes nothing more than a bull barrel. (Granted this product is a tube with something between the barrel and the outer surface. But all a bull barrel is the same design with steel inbetween the outer surface and the inner surface. And steel absorbs heat very well.)

What it sounds like to me, what dogmush is trying to do, is find out about heat dispersal from the barrel (bore namely). If this system proves to remove heat from the bore of the barrel, that is the only way I would consider TTI claims correct.

It's common knowledge that if you put a bull barrel on a rifle, it will take longer for the barrel to heat up. This would flatten the heat curve. But (with the minor difference of the additional heat sink) this does nothing to change the bore temperatures.

Accuracy means not one dang thing to me in these tests. For the cost of this system, I could get a match grade barrel threaded and chambered for dogmush's Savage, and install it myself.

External temperature of the barrel means nothing to me. I could get real Bubba on it, and glue a PVC pipe to a rifle, and stuff this "shroud" with fiberglass insulation. I could then tell everyone what a difference in barrel temperature it makes. Patent it and sell it for $xxx a system. But I know that that doesn't change the temperature of the barrel. All it does is insulate the heat to the barrel, and not let it radiat from the barrel.

Which that brings me to another variable that I hope dogmush has considered. (Though reading his posts, I haven't seen any stats on this. And it may be too late if he has already sent off the gun.)

Cool down time. IF the barrel (bore) cools down faster, I could call it successful. Because it dissipates heat faster. If it cools down slower, I'd call it a failure (gimmick, etc.). Because all it's doing is insulating the heat to the (inner) barrel and not letting it dissapate.

After such a long post, I'll sum it up to make it easily understandable...

I want to see the changes in bore temperature in both as the gun's being fired through it's string, and as it's cooling down. The only way I myself could call it a success (and such I would get a rifle done) would be if the bore heated up slower AND cooled down faster. This would prove that the system was dissapating the heat.

Accuracy and external barrel temperature is nothing more than smoke and mirrors. Just "facts" to prove another snake oil works. Same thing the antis do when they pull out their "statistics".

Wyman

[Sheik Yerbouti]

All this anal diagnosis isn't necessary, and your opinions are worth the same as those offered by other experts. The "my expert can whip your expert" is a little childish, but... have at it.

You protest too much.

For me, that's a red flag. What are you trying to hide?

Let the guy run his tests, and if they prove out your assertions, we can all listen to you say "I told you so", while we enjoy some crow pie.

[RecoilRob]

And, going to make a prediction! Seeing as most competitive rifle shooting events have some sort of weight limit, if this 'system' was truly 'revolutionary', the shooters would be lined up three deep getting their competition rifles rebarrelled with the SJ.

But....I'm predicting that they aren't lined up because at the specified weight limit, nothing is better than STEEL in the barrel to get you to that limit. One caviat...when desperately trying to make some very light spec, carbon fiber composit tubes seem to work well for their weight.

This reminds me of the discussions about whether fluting makes a barrel stiffer or not? A fluted barrel IS stiffer than a non-fluted one of the same weight. But, the stiffness come from the increased diameter....not the fluting. Taking mass from the barrel decreases the stiffness....every time.

Ok....I'll freely admit to being a nay-sayer and don't believe that this SJ deal does anything any better than an equal weight heavier barrel would do. There....I'm on record now.

If crow gets eaten in the end (and I HAVE eaten some in my days!), count me in for a heaping helping. Nay-sayers are always popping up when something new arrives, especially one that 'changes how we look' at something. Like people up until now are stupid and this hasn't been tried....and abandoned.

My bib is on (as crow is very messy when eaten) and I'm ready to dine.

[dogmush]

Nope, Haven't sent the rifle off yet. I plan on calling TTI on Monday to make the arraingments, I was just too busy last week.

I'm working on some kind of experimental rig that will let me test bore cooling. The eureka moment came last night when I realized that I didn't have to shoot the rifle to test cooling. My current plan is to place thermocouples on the inside of the bore and heat the whole barrel to 200*F or so, then time the return to ambient. I can do this at home in my leisure time so that'll help scheduling. It should get me a good feel for how well both barrels radiate heat.

I'm trying to figure out a way to heat the bore from the inside out as I think that'll give me a better feel for shooting conditions as well as omit any insulation variables that the SJ system might add to the exterior surface. This might end up being uneconomical however.

I have to mow the grass and do some gardening today, then I'll see what kind of rig I can come up with.

As always sugestions are appreciated, and will be considered.

WT, JWF covered it nicely but I wasn't being anal, you're incorrect about the cause of throat (and muzzle) erosion. Think oxy/act torch(high velocity gas) vs. file (heat and friction).

And the whole point of this is that it's not my expert vs. your expert, it'll be (for me at least) this is what I saw first hand. At that point your expert is irrelevent.

[jim147]

http://www.springfield-wire.com/cate...fm?Category=21

I might try running a couple pairs of this wire down the bore to heat it up.

jim

[wristtwister]

http://www.exteriorballistics.com/re...rifleinout.cfm

Check out this article... I think you'll find that corrosive primers, heat of combustion, friction, propellants, improper cleaning, metal fouling and powder fouling all contribute to throat erosion. The phenomena of hot gas scoring metal is called "wire drawing", and is common in high pressure, high temperature fluid calculations. It, however, is not the primary culprit in a situation where corrosive addititives and compounds, friction, and high pressure gases coexist and move together through a conduit (barrel). The rounding of the surfaces where the bullet mates into the rifling becomes worn down as much by all the other elements as by the hot gas wire drawing the rifling. The more rounds fired, the greater influence of each factor.

Something else that can affect erosion is ignition of residual powder left in the chamber from incomplete ignitions or "blowback" from the barrel due to slightly excessive barrel pressure at the mating surface of the throat. Just as you want to claim the high pressures are wire drawing the throat, they might equally be pushing unburned powder and microscopic residue along the cartridge case.

WT

[dogmush]

Ummm. Dude......from your own article

With the passing of corrosive primers, erosion from the propellant itself is undoubtedly your barrel’s greatest enemy. When the powder is ignited, it creates extremely hot gases under tremendous pressure. These two factors combine to create erosion, particularly in the throat area of the barrel.

....


Bullet friction, as it pertains to barrel wear, is frequently a topic of discussion among shooters. While this friction causes some wear, it is the least measurable factor in barrel life. In Small Arms Design Vol. II, Col. Townsend Whelen mentions a Springfield 22 rimfire barrel that had been gauged when it was installed, and again after having fired in excess of 80,000 rounds. A uniform wear of .0004” was observed throughout the length of the bore, undoubtedly caused by bullet friction. Granted, this was referring to lead bullets, not jacketed. However, when we consider that most centerfire barrels are completely shot out due to throat erosion in less than 10,000 rounds, bullet friction becomes utterly meaningless as a factor in barrel wear.

[wristtwister]

Ummm... yourself.... from your own quote...

erosion from the propellant itself is undoubtedly your barrel’s greatest enemy

As a mere mortal mechanical designer, that indicates to me chemical impingement and corrosive activity. The wire drawing of the throat is a secondary effect, even though it might be damaging.

I certainly agree that burning the powder creates the gas effects you're touting, but it's not the single cause of erosion. As for friction being irrelevant, that can be related to the types of ammunition you're shooting, the frequency of cleaning, cleaning methods, residual deposits of copper (which also cause electrolytic corrosion on the molecular level)... just all kinds of things that don't have a thing to do with "blast gas" effects.

I used to design high pressure piping in chemical plants, so chemical erosion, hot gas impingement, wire drawing, etc. are all familiar to me. The effects you're touting are very common in steam piping and damage to valve seats... but just like making a general statement that one thing causes all evil, there are a multitude of causes for a lot of common problems... even in rifle shooting. A lot of things that cause "visible" damage are actually caused by things that go on at the molecular level, and the softening of the metal allowing it to be eroded and blown off the finished surface is more likely a chemical erosion than a hot gas effect. The gas may blow the tiny pieces out and down the barrel, but the erosion itself would be a chemical effect.

Again, from your own post:

These two factors combine to create erosion, particularly in the throat area of the barrel.

I'm not trying to be a jerk here, just give you a different perspective on what mechanical engineering has taught me over the past 45 years. "Rifle barrel" problems are very similar to piping design problems, and there are a lot of misconceptions about what actually causes a lot of things. Chemicals cause things to happen to steel... heat cause things to happen to steel... and the effects aren't always "linear calculations" to see the effects. It can be as simple as the addition of condensation to cause the effect you're talking about, but my choice would be chemical impingement from the corrosive elements in the rifle powders, and then revealed by the hot gas blow-by to carry off the particles loosened by it. As the author of the article I quoted said... these two factors combine to create erosion... but it's still like arguing over which flea owns the dog.

WT