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mgouldsr
07-06-2010, 17:09
Just tried the Double Tap 140gr. .40cal Tac-XP. Box shows 1240fps from a 4"
bbl. Web sites states, Expands to .83" and penetrates 13.75" in 10% gelatin.
This round has by far the biggest hollow point I have ever seen, it's all copper and reports are that it performs very well against barriers. It functioned perfectly in my G23 and accuracy was very good, and it was suprisingly mild to shoot. I was also shooting some Win white box for practice and I have to say the Win actually felt hotter. I have fired a lot of double tap and corbon and this is not what I was expecting. Very impressive to get this kind of performance with so little recoil. Price is $50.00 for 50 rounds vs Corbon $35.00 for 20 rounds and you get a little more velocity from the DT's.

UnTainted
07-06-2010, 20:11
Sounds like good ammo. I've looked at buying the 125 grain load for the 40.

Anybody chrono these new loads yet?

mgouldsr
07-06-2010, 20:55
Ballistics : 125gr. @ 1390fps / 536 ft/lbs- Glock 23 (4.0"bbl)

This is new on the web site, looks promising.

gatorboy
07-18-2010, 08:22
I shot the 125 and 140 from a 22, 23, 27 and M+P 40c the other day in addition to the 125 and 155 from a 20. My thoughts on this ammo is it's extremely light recoiling due to the long length of the bullets and the amount of case space left. I did some tests in water jugs, through 2x4's and a thick plastic 55 gallon drum. They penetrated well but not as well as a good bonded 165 or 180. My fiance' was with me and we both agreed better SD loads for the .40 do not exist for recoil shy and weaker or smaller shooters. I find the velocity claims hard to believe because despite the light bullets, there just is'nt the case space. I've got good, young ears and I can shake loaded ammo next to my ear and hear the powder move. Not so with these, the powder is definately packed tight with the Barnes bullets. That is O.K. with me though. I wanted to see the difference in weight between 14 rds. of 180's and 14 rds. of 125's. It's about 2oz. - a noticable difference after 12 hrs. of IWB carry. The 10mm is the best with these IMO because you can still get some good velocity with the heavier bullets. The 125 appears to be the same length as a GD 165 which is why I find it hard to believe the 125's are going 1390 fps from a 23, light recoil aside. I could see 1250 being possible but who knows, I did'nt have a chrono with me.

BOGE
07-18-2010, 10:54
...My thoughts on this ammo is it's extremely light recoiling due to the long length of the bullets and the amount of case space left....

...I find the velocity claims hard to believe because despite the light bullets, there just is'nt(sic) the case space. I've got good, young ears and I can shake loaded ammo next to my ear and hear the powder move. Not so with these, the powder is definately packed tight with the Barnes bullets...

How does bullet length affect recoil? It doesn`t in such a small sample as a handgun bullet. Yes, in a cannon there are friction coefficients but not of any discernible measure in a handgun when the weight is the same as a given lead projectile. Also, what you hear by shaking a cartridge has no relation to velocity whatsover. Manufacturers use proprietary powder blends not available to the consumer. It is not blackpowder.

Glolt20-91
07-18-2010, 11:44
Just tried the Double Tap 140gr. .40cal Tac-XP. Box shows 1240fps from a 4"
bbl. Web sites states, Expands to .83" and penetrates 13.75" in 10% gelatin.
This round has by far the biggest hollow point I have ever seen, it's all copper and reports are that it performs very well against barriers. It functioned perfectly in my G23 and accuracy was very good, and it was suprisingly mild to shoot. I was also shooting some Win white box for practice and I have to say the Win actually felt hotter. I have fired a lot of double tap and corbon and this is not what I was expecting. Very impressive to get this kind of performance with so little recoil. Price is $50.00 for 50 rounds vs Corbon $35.00 for 20 rounds and you get a little more velocity from the DT's.

I would like to see McNett's gel calibration numbers with this ammo. Here are some 9mm and .40S&W Gold Dot numbers McNett posted on GT back on 2.22-2006;

All of these tests were done using 10% ballistic gelatin provided by Vyse gelatin using all FBI protocols and 4 layers of denim and two layers of light cotton T-shirt in front of the gelatin.

DoubleTap 9mm+P
115gr. Gold Dot JHP @ 1415fps - 12.00" / .70"
124gr. Gold Dot JHP @ 1310fps - 13.25" / .70"
147gr. Gold Dot JHP @ 1125fps - 14.00" / .66"

DoubleTap .40 S&W Penetration / expansion
155gr Gold Dot JHP @ 1275fps - 13.00" / .76"
165gr Gold Dot JHP @ 1200fps - 14.0" / .70"
180gr Gold Dot JHP @ 1100fps - 14.75" / .68"


A question I'm unable to reconcile is the comparison between the 140gr Barnes bullet and 155gr Gold Dot. How is it that the slower velocity, wider expanding, lighter weight 140gr Barnes bullet achieves deeper penetration than the faster, heavier, less expanding 155gr Gold Dot?

Bob :cowboy:

gatorboy
07-18-2010, 19:50
How does bullet length affect recoil? It doesn`t in such a small sample as a handgun bullet. Yes, in a cannon there are friction coefficients but not of any discernible measure in a handgun when the weight is the same as a given lead projectile. Also, what you hear by shaking a cartridge has no relation to velocity whatsover. Manufacturers use proprietary powder blends not available to the consumer. It is not blackpowder.

A 125 that is backed by the same amount of powder as a 165 is going to affect recoil. It will recoil less. As for the rest of the points I made, you missed them also. You don't know enough to teach me anything so please stop trying.

The GAP really sucks for the Barnes bullets since theres not enough room for Speer to pack a regular copper jacketed lead 230 in. :whistling:

BOGE
07-19-2010, 00:21
...A question I'm unable to reconcile is the comparison between the 140gr Barnes bullet and 155gr Gold Dot. How is it that the slower velocity, wider expanding, lighter weight 140gr Barnes bullet achieves deeper penetration than the faster, heavier, less expanding 155gr Gold Dot?

Bob :cowboy:

Because it's a solid copper projectile. There are hundreds of gel tests on the Internet showing how the Barnes solid copper bullets penetrate better.

A 125 that is backed by the same amount of powder as a 165 is going to affect recoil. It will recoil less. As for the rest of the points I made, you missed them also. You don't know enough to teach me anything so please stop trying.

The GAP really sucks for the Barnes bullets since theres not enough room for Speer to pack a regular copper jacketed lead 230 in. :whistling:

I misssed nothing. Reread your rambling first post. Just keep shaking your cartridges like a monkey. :upeyes:

thegriz18
07-19-2010, 07:11
There is only one way to solve this question. Someone has to get those DT 125 and 140 loads and chrono them. I mean about 20 rounds each, and then see how far off DT's numbers are, taking into consideration the elevation that DT tests their ammo at. I personally would like to see how a 125 grain 40 penetrates at 1400 fps. It must get 6 inches. I'm hesitant to use that. Shoot, I'm hesitant to use the 135 grain HST load since I can't find any reliable numbers on it.

Glolt20-91
07-19-2010, 15:48
Because it's a solid copper projectile. There are hundreds of gel tests on the Internet showing how the Barnes solid copper bullets penetrate better.



So, a lighter, slower velocity, wider expanding, machined HP copper bullet will penetrate deeper than a heavier, faster velocity, less expansion diameter copper jacketed bullet??? :yawn:

Using McNett's data, the much slower 9mm/147gr Gold Dot penetrated slightly (0.25") deeper in gel than the .40S&W/140gr XPB bullet and his .40S&W/155gr GD slightly less (0.75") than the 'wonder' solid copper design.

Given that differences in gel calibration numbers can yield 2" + penetration depths. Gel calibration numbers are important when making ballistic comparisons, given the high cost of the XPB bullet; other designs perform just as well, if not better, than the Barnes bullet.

Bob :cowboy:

gatorboy
07-19-2010, 17:21
Because it's a solid copper projectile.There are hundreds of gel tests on the Internet showing how the Barnes solid copper bullets penetrate better.

I misssed nothing. Reread your rambling first post. Just keep shaking your cartridges like a monkey. :upeyes:

There are major discrepancies (simple physics) with those "hundreds of gel tests on the internet" as Bob has pointed out below. An ammo company as large as DT, Corbon and others should have the tests available to the consumer to view online.

As for shaking things like a monkey, I save that for a couple other things I have when I read your drivel.

There is only one way to solve this question. Someone has to get those DT 125 and 140 loads and chrono them. I mean about 20 rounds each, and then see how far off DT's numbers are, taking into consideration the elevation that DT tests their ammo at. I personally would like to see how a 125 grain 40 penetrates at 1400 fps. It must get 6 inches. I'm hesitant to use that. Shoot, I'm hesitant to use the 135 grain HST load since I can't find any reliable numbers on it.

I'll chrono these loads in the next two weeks and make an attempt to get video. Your instinct not to trust the 135 HST is a good one. The 155 is very soft shooting also and the 180 expands better than any of them and is as tame as any 180.

So, a lighter, slower velocity, wider expanding, machined HP copper bullet will penetrate deeper than a heavier, faster velocity, less expansion diameter copper jacketed bullet??? :yawn:

Bob :cowboy:

Second stage jet propulsion?

Glock1911
07-19-2010, 18:25
From all the stats being bantered around, I'm almost convinced that DT's 9mm and .40 S&W loads are more effective than my 10mm or .45 Super loads.:cool:

Scoob
07-21-2010, 06:20
A question I'm unable to reconcile is the comparison between the 140gr Barnes bullet and 155gr Gold Dot. How is it that the slower velocity, wider expanding, lighter weight 140gr Barnes bullet achieves deeper penetration than the faster, heavier, less expanding 155gr Gold Dot?

Bob :cowboy:


If you compare only expansion and penitration numbers, it doesn't seem to make sense. I don't think you get something for nothing though.

My opinion...look at a picture of an expanded XP bullet beside a normal expanded JHP. Think about which would have the least resistance pushing through gelatine. It's like comparing a full parachute vs. one that has a star pattern in its canopy with small sections taken out. If it expands to .6, it is not cutting a .6 hole the way a standard jhp would but rather a star shape that is .6 diameter at its tips.

Again that is just my opinion.

Glolt20-91
07-22-2010, 10:52
If you compare only expansion and penitration numbers, it doesn't seem to make sense. I don't think you get something for nothing though.

My opinion...look at a picture of an expanded XP bullet beside a normal expanded JHP. Think about which would have the least resistance pushing through gelatine. It's like comparing a full parachute vs. one that has a star pattern in its canopy with small sections taken out. If it expands to .6, it is not cutting a .6 hole the way a standard jhp would but rather a star shape that is .6 diameter at its tips.

Again that is just my opinion.

After testing the 125gr XPB in .38Super (~1200fps), there are better performing bullets. Testing the XPB through sheetrock, 4-layer denim, water bag, large cow rib, water; 3 of the 6 petals folded down.

http://i119.photobucket.com/albums/o144/aztrekker/At%20the%20range/125grBarnesXPB-1202fpssheetrock--2.jpg

The life span of a bullet in tissue is only a few milliseconds, just a couple revolutions of the bullet.

This 124gr Gold Dot (1268fps) illustrates the star effect you wrote about, bullets cutting through tissue like an outboard's prop through water is a misnomer. Hydraulic pressure acting upon the increased bullet's surface area (0.920") drastically slows the bullet;

http://i119.photobucket.com/albums/o144/aztrekker/At%20the%20range/124GD1268fps003.jpg

Expect about 9" of penetration from the Gold Dot and ~10.7" from the XPB (0.649").

This 230gr Gold Dot 984fps/0.735";

http://i119.photobucket.com/albums/o144/aztrekker/At%20the%20range/45auto230GD984fps006.jpg

gets about 13.5" of penetration, plus one huge crush cavity.

Bullet shapes and cavitation;

http://i119.photobucket.com/albums/o144/aztrekker/At%20the%20range/bulletcavitation-flow.jpg

Bob :cowboy:

UnTainted
07-22-2010, 19:16
Bob, I'd say in my opinion the 38 round on display in your post performed well. Maybe not perfect, but you did say it defeated a bone, and it stayed together and expanded some.

I'm not going to rely on expansion for my hole to hit my target, I'll rely upon placement.

UnTainted
07-22-2010, 19:18
And the 125 grained in 40 may be different than the 38 one

Glolt20-91
07-22-2010, 22:13
Bob, I'd say in my opinion the 38 round on display in your post performed well. Maybe not perfect, but you did say it defeated a bone, and it stayed together and expanded some.

I'm not going to rely on expansion for my hole to hit my target, I'll rely upon placement.

Given placement, there is a point where expansion negates penetration to vitals.

Examples

This
http://i119.photobucket.com/albums/o144/aztrekker/At%20the%20range/Furniture180PDX-4x4-lid-rib0024.jpg

and this 147gr Gold Dot

http://i119.photobucket.com/albums/o144/aztrekker/At%20the%20range/Furniture147GD-4x4-lid-rib016.jpg

both performed very well against large bone, and both penetrate deeper than the 125gr XPB.

YMMV

Bob :cowboy:

UnTainted
07-23-2010, 14:22
Huh? Does that make sense to anybody else?

Given placement, there is a point where expansion negates penetration to vitals.

Snapper2
07-23-2010, 14:38
Huh? Does that make sense to anybody else?

Youre not very likely to have a chance to pick your shot in SD. A shot from a downed position will likely have penetrate further because of the angle. Not only that but whatever else that might be in the way of vitals....forearm etc. Expansion limits penetration.

mickdundie
07-23-2010, 18:29
Just tried the Double Tap 140gr. .40cal Tac-XP. Box shows 1240fps from a 4"
bbl. Web sites states, Expands to .83" and penetrates 13.75" in 10% gelatin.
This round has by far the biggest hollow point I have ever seen, it's all copper and reports are that it performs very well against barriers. It functioned perfectly in my G23 and accuracy was very good, and it was suprisingly mild to shoot. I was also shooting some Win white box for practice and I have to say the Win actually felt hotter. I have fired a lot of double tap and corbon and this is not what I was expecting. Very impressive to get this kind of performance with so little recoil. Price is $50.00 for 50 rounds vs Corbon $35.00 for 20 rounds and you get a little more velocity from the DT's.

Where can I get 50 rounds for $50.00? Link please

Never mind ...found it http://www.doubletapammo.com/php/catalog/index.php?cPath=21_26

That's a good price. Usually runs a buck and a half a round

Mick:thumbsup:

UnTainted
07-23-2010, 21:11
Oh I get what that meant: expansion can prevent penetration to the vitals.

Negate as used led me to think he was saying expansion would negate (the need of) penetration to the vitals.

So if the petals fold slightly back on a barnes round, isn't that less expansion allowing more penetration? Given it is some expansion, and given expansion is an if scenario with all hp rounds, I would be as happy having a barnes round in my mag as gold dot.

Incidentially I have gold dot in all my handguns at this time.

Glolt20-91
07-24-2010, 12:18
Oh I get what that meant: expansion can prevent penetration to the vitals.

Negate as used led me to think he was saying expansion would negate (the need of) penetration to the vitals.

So if the petals fold slightly back on a barnes round, isn't that less expansion allowing more penetration? Given it is some expansion, and given expansion is an if scenario with all hp rounds, I would be as happy having a barnes round in my mag as gold dot.

Incidentially I have gold dot in all my handguns at this time.

Sorry for the confusion using 'negate' in that context, should have said expansion can 'negate' the bullet's ability to penetrate into the vitals.

As an example, there is a direct relationship between a bullet's expansion diameter and its penetration depth to reach vital organs, given same velocities/bullet weights.

Using Eugene Wolberg's data from San Diego PD's Officer Involved Shootings, Win 9mm/147gr JHPs (950fps); 3 examples from a 27 OIS database:

1. 0.584", 140grs, 10.0"
2. 0.542", 140grs, 12.5"
3. 0.462", 146grs, 17.0"

This study demonstrated equality of avergae penetration in live human torso soft tissue and properly prepared and calibrated 10% ordnance gelatin.

Calibration: .177" BB, 590fps, 8.5cm penetraion at 4C (centigrade)
A 590fps BB penetrating, say 10.0cm+ is going to skew penetration depth numbers higher, 7.5cm lower.

Wolberg's data was consistant with Dr. Matin Fackler's ballistic gel design that is used today in ballistic testing, comparing all types of ammo through the same medium and different types of barriers. ATK workshops with various LE agencies is a prime example.

Duncan MacPherson, using properly prepared and calibrated gel shot 400 rounds of ammo and used up about 2,000lbs of 10% gel to derive complex mathematical formulas validating Wolberg's and Fackler's data.

Going back to a 140gr bullet, expansion 0.83" (2.01 x .40cal), at whatever velocity; how does GT achieve 13.75" penetration in properly prepared and calibrated 10% ordnance gelatin?

.357cal/125gr XTP (125gr retained weight), 1436fps, 0.592" (1.67 x .357cal) , 13.3" penetration.

Bob :cowboy: