[Charles]

Hey, Henry. Thanks for these results ... very useful as always. I am wondering how those tubes handle heavier ammo: .38 lead, .44 lead, even .50 lead. How badly does the velocity deteriorate with increasing mass of the projectile?

Cheers ..... Charles

 

[Henry the Hermit]

Hey, Henry. Thanks for these results ... very useful as always. I am wondering how those tubes handle heavier ammo: .38 lead, .44 lead, even .50 lead. How badly does the velocity deteriorate with increasing mass of the projectile?

Cheers ..... Charles

I'll get to that, Charles, but here's a teaser. I'm seeing 197 fps average with pseudo taper 1842 and .429 lead ball at full draw.

Today's results with 3/8 steel (53 grains)
2040 single - at 30 inch pull, average velocity 205.30 fps, at full draw 239.58 fps
1842 single - at 30 inch pull, average velocity 203.87 fps, at full draw 243.93 fps
These results are so close that I believe this projectile weight is very close to the crossing point where 1842 becomes more efficient than 2040.

 

[Charles]

Thanks, Henry. I look forward to your results. I like to shoot the heavier stuff.

I think you are right that the 3/8 steel looks like the cross over point for 1842 and 2040.

Can you remind me what the slack length of those bands is ... from pouch tie to the end of the loop?

Cheers ..... Charles

 

[Henry the Hermit]

Thanks, Henry. I look forward to your results. I like to shoot the heavier stuff.

I think you are right that the 3/8 steel looks like the cross over point for 1842 and 2040.

Can you remind me what the slack length of those bands is ... from pouch tie to the end of the loop?

Cheers ..... Charles

Sure thing, 7 1/4 inches.

 

[M.J]

Chinese tubes always keep me guessing.
I mean, it just doesn't seem possible for a 7.25" single 2040 setup to yield 200 fps drawn to 30". I know from experience that this can be the case though because I changed my anchor and my draw length went from 34" to 31" and I'm almost positive my Performance Catapults tubes are faster now than before.
Tubes definately seem to have a sweet spot in terms of stretch. They're not like Theraband where you stretch them to 700% and they work best.

 

[crapshot]

some body should compare china tubes loops withtexs small latex tubing he now sells

 

[M.J]

some body should compare china tubes loops withtexs small latex tubing he now sells

I've got some coming. I don't have a chrony but I do have a bunch of ammo and steel cans

 

[cheese]

interesting

 

[Henry the Hermit]

Just have a minute before my wife and I leave to drive to the Atlantic coast, but I hit 302.7 fps with pseudo tapered 2040 tubes and .30 lead ball a few minutes ago. More tomorrow.

 

[Alex Jacob]

Thanks for all the work you're doing on this, Henry. Fascinating stuff. Particularly the equalizing ammo weight.

 

[August West]

It's been 5 days and I am still shooting the same band set with the cuffs. I'm gonna go ahead and say that pseudo tapers definitely last much longer with the 17/45 cuffs. I used a trick I learned putting bicycle grips on to help put the cuffs on, I used a little dish soap in some water to lubricate the bands. The water will evaporate leaving a tiny bit of soap residue that will really lock everything in place. The only drawback is you have to make your bandsets a couple of days in advance so they can dry, if you don't they will slip for sure. Chris

 

[Henry the Hermit]

Here are the first set of completed tests, on 2040 and 1842 single tube per side band sets. All tests were made using my Natural Ringshooter #5. The shots labeled 30 inches were using an anchor with my knuckle in the hollow just behind my ear lobe and a slight forward tilt to the forks. The full draw shots were simply pulling the bands as far as I could.

I started the tests with .30 caliber (7.6mm) lead balls weighing 39.7 grains, and used increasingly heavy ammo until the power started decreasing. With these two band sets, peak power of 10.43 lb/ft (14.1 joules) was reached with a 125 grain .429 (11mm) cal lead ball at 194 fps. Maximum recorded velocity was 256.7 fps with 2040 and .30 cal lead. The chart below shows averages.

I don't know about you guys, but I am astonished at how much power I got out of such skinny tubes.

 

[Charles]

Great info, Henry ... Thanks!

Cheers .... Charles

 

[Henry the Hermit]

Great info, Henry ... Thanks!

Cheers .... Charles

Hey Charles, just so you will know where this is headed, I just fired a test shot with a 285 grain sinker at 168.4 fps for 18 lb/ft energy using the standard loop configuration of 1842. I plan to go all the way up to 500 grains when I get to 4 tube sets.

 

[Charles]

I find it interesting that the energy of both sorts of tubes, and both types of draw, began to drop off at the same weight of ammo. I would have expected a bit more variation. I am anxious to see your results for the heavier stuff.

Cheers ..... Charles

 

[pgandy]

Henry those results closely approximate what I recorded with a 31" draw. The 2040 was on my want list, but after reviewing your results I'll save the money. Thanks.
Henry's
.30 Pb-3.62 fpe
.375 steel-4.89
.36 Pb-5.81
.429 Pb-6.53
Mine
.31 Pb-3.72 fpe
.375 steel-4.97 fpe
.375 Pb-5.83 fpe
.429 Pb-6.43 fpe

I had the comparison in side by side columns but the forum skewed them badly.

 

[Henry the Hermit]

Henry those results closely approximate what I recorded with a 31" draw. The 2040 was on my want list, but after reviewing your results I'll save the money. Thanks.

Henry's Mine
.30 Pb-3.62 fpe .31 Pb-3.72 fpe
.375 steel-4.89 .375 steel-4.97 fpe
.36 Pb-5.81 .375 Pb-5.83 fpe
.429 Pb-6.53 .429 Pb-6.43 fpe

At the lighter pull weights, there is little reason to purchase either if you already have one size. The 2040 is a bit easier to draw. Some people may find one preferable to the other, but it isn't until we get into the heavier pull weights and heavier projectiles that I'm finding any significant difference between 1842 and 2040 tubes. I hope to have the numbers completed for pseudo-tapered sets tomorrow.

Thanks for posting your results.

 

[Henry the Hermit]

Here are the completed tests on 2040 and 1842 pseudo-taper band sets, same methods as in previous post.

Again, I started the tests with .30 caliber (7.6mm) lead balls weighing 39.7 grains, and used increasingly heavy ammo until the power started decreasing. Note that with the 1842 set at full draw, there was still a slight power increase with .495 ball, but since there was a decrease at 30 inch pull, I stopped at that weight.

Peak power of 12.46 lb/ft (16.9 joules) was reached with a 125 grain .429 (11mm) cal lead ball at 212 fps. Maximum recorded velocity was 302.7 fps with 2040 and .30 cal lead. The chart below shows averages.

Edited to correct graphic.

 

[Henry the Hermit]

As an aside, my first set of 2040 pseudo-tapers, assembled using the cuff method and my cushioned jaws hemostat, failed at 625 shots by breaking at the pouch. I retied and will see how long they last. The retie only reduced length by about 1/2 inch.

 

[Charles]

Thanks again for posting these results, Henry. Any idea what the weight of that .357 bullet is?

Cheers ........ Charles