10mm Ammo

I don't own a chronograph (seems like there's always something else demanding my time, money, and attention), so I can't test this myself. However, I can't help but wonder if the velocity issues reported with Double Tap and others (it seems there are several 10mm loadings which don't live up to their advertised velocities) is due at least in part to pistols which are slightly undersprung by the manufacturers to ensure reliability with the watered-down FBI-spec 10mm ammo.
__________________
Click to expand...

The velocity issues with Double Tap ammo is mostly guys using chronographs that don't understand how to interpret the results. Double Tap tests their ammo in a standard factory G-20. I'm sure it gets the advertised velocity from THAT gun. Most revolver loads in real guns are WAY slower than advertised because they are tested in 8" test barrels with no cylinder gap. Shoot a load advertised at 1400 fps in a 4" revolver and you might not get 1200 fps.

The other problem is that no 2 guns are exactly alike. I've done most of my chronograph work with rifles, but the same things I've noted will apply to handguns as well.

Some guns just shoot faster even though they appear the same. I've seen 2 different 30-06 rifles with 130 fps difference with ammo from the same box even though both rifles had the same 22" barrels.

Altitude and temperature can make a difference. I've shot the same loads through the same rifle and seen 100 fps faster in August when temps are near 100 degrees than when fired in January when it is 20 degrees.

Double Tap advertises their 200 gr hardcast at 1300 fps. My G-20 got 1315 fps when I chronographed it. Someone else's 10mm might be 50 fps or more slower than mine with ammo from the same box. If I were to take my gun out and shoot it in sub-zero temps it may well be much slower than the 1315 I initially got.
 
jmr40, I could understand somebody's gun shooting that Double-Tap 50fps slower than yours, but 200fps slower (1115fps)? Out of a gun that has since fired 200 grain ammo that was advertised at 1290fps at 1267fps? That is not the gun, nor the temperature, not the spring. That is ammo not performing as advertised.

That is exactly the result that this guy on Youtube who has used a G20 to chrono over 50 different 10mm cartridges got btw, 1115fps average over 5 shots of 200grain hardcast. For him all Double-Tap consistently underperformed its claims, usually by more than 100fps, often by almost 200fps. Meanwhile other companies with similar cartridges and claims performed as advertised, or very close to as advertised (no more than 25fps under), from the same gun, and even on the same day.

I don't know what is going on. Maybe it is just that this guys gun and DT ammo somehow hate each other, but if that is the case it still shouldn't go to such extremes as his tests show. I think right now those tests are really hurting DT's rep, a rep built on hot 10mm ammo, and if they want to get it back they need to find a way to prove there isn't an under (claimed) performance issue with their rounds. Until they do (and likely after) I am going with Underwood for the great performance and lower price.
 
What loadings, specifically, did you test and what were your velocity results?
Click to expand...

Don't have the info in front of me right now, but I'll dig it out tonight if I remember.

I did use Underwood Ammunition, Remington, Norma, Winchester, and a few handloads. I'll find the numbers tonight...
 
Arentol - The thing is, it's not just a handful of guys that chrono'd DT ammo and got poor results. It's nearly EVERYONE that chrono's it and gets bad results.

I could see 50 fps difference being ok...but when it's 100 - 200 fps low, that's not just the guns (when it's EVERYONE's guns).

The velocity issues with Double Tap ammo is mostly guys using chronographs that don't understand how to interpret the results.
Click to expand...

Lets say DT is advertising his 180gr ammo at 1300 fps. Lets say someone chrono's it, and gets 1100 fps. How is there any possible way to inerpret this wrong? If it chrono's 200 fps low, it's 200 fps low.
 
jmr40, I could understand somebody's gun shooting that Double-Tap 50fps slower than yours, but 200fps slower (1115fps)? Out of a gun that has since fired 200 grain ammo that was advertised at 1290fps at 1267fps? That is not the gun, nor the temperature, not the spring. That is ammo not performing as advertised.

That is exactly the result that this guy on Youtube who has used a G20 to chrono over 50 different 10mm cartridges got btw, 1115fps average over 5 shots of 200grain hardcast. For him all Double-Tap consistently underperformed its claims, usually by more than 100fps, often by almost 200fps. Meanwhile other companies with similar cartridges and claims performed as advertised, or very close to as advertised (no more than 25fps under), from the same gun, and even on the same day.
Click to expand...

Again, I don't know the answer here which is why I'm trying to collect data, but I could see powder burn rate possibly affecting velocity discrepancies with an undersprung gun. For example, if Buffalo Bore uses a faster buring powder than Double Tap does, then I would think that premature slide opening (the issue supposedly caused by a weak recoil spring) would have less effect on Buffalo Bore's velocities than it would Double Tap's since more of the powder used in Buffalo Bore's ammunition has burnt up before the slide opens.

Also, Double Tap isn't the only company to have reports of disappointing velocities with 10mm ammo. I've seen similar reports about Grizzly, Winchester, and Reed's as well. The only "full power" 10mm makers that don't seem to have reports of disappointing velocities are Buffalo Bore, Swamp Fox, and Underwood although data on Swamp Fox and Underwood is somewhat scant right now.
 
TRaGiK, we are on the same side on this one. I was just trying to be polite about it and acknowledge their may be limited validity to some of jmr40's point, while also pointing out that there is plenty of clear evidence he is probably almost entirely wrong.
 
Arentol - Didn't mean to reply to you...meant to reply to jmr. Oops.

Forgot about posting data. I'll get it up tonight when I get home.


Webley - Swampfox owner had a heart attack and died a couple months ago.

Also, I've tested a lot of factory loads. Almost every ammo maker is a bunch of liars with their 10mm (and this includes the original Norma ammo in my experience), EXCEPT Underwood, Georgia Arms, and...umm...I think that's it (of what I've tested).

I'll post up before and after recoil spring swap data, as well as all the factory loads I've tested.
 
Here's my data on a stock recoil spring (17 pound) vs. 20 pound, out of a otherwise completely stock Glock 20.


String 1A:
200gr Hornday FMJ
8.5 Longshot
1.26 OAL
New Starline brass
Stock recoil spring
1117
1109
1126
1119
1101
1123
1129
1147
1115
1113

Average: 1120 FPS
ES: 46
String 1B:
Specs identical to above, but with 20 pound recoil spring
1140
1140
1139
1116
1138
1149
1117
1128
1098
1132

Average: 1130
ES: 51

Sting 2A:
200gr FMJ
8.8 Longshot
1.26 OAL
New Starline brass
Stock recoil spring
1191
1193
1200
1185
1166
1164
1171
1189
1206
1152

Average: 1182
ES: 54

String 2B:
Same specs as above, but with 20 pound spring
1157
1160
1152
1148
1119
1165
1145
1152
1145
1128

Average: 1147
ES: 37

String 3A:
Norma 170gr JHP
Stock recoil spring
1241
1232
1192
1215
1211

Average: 1218
ES: 49

String 3B:
Norma 170gr JHP
20 pound recoil spring
1282
1200
1260
1202
1260

Average: 1240
ES: 82

String 4A:
Winchester Silvertips
Stock recoil spring
1154
1161
1161
1166
1163

Average: 1161
ES: 9

String 4B:
1128
1145
1167
1144
1160

Average: 1149
ES: 39
 
Here's my chrono data on factory ammunition. Again, stock Glock 20.

-PMC 200gr FMJ averaged 1025 fps. Advertised 1050 fps.

-Blazer 200gr TMJ averaged 928 fps. Advertised 1050 fps.

-Remington 180gr FMJ averaged 1055 fps. Advertised 1150 fps.

-Winchester Silvertips averaged 1161 fps. Advertised 1290 fps.

-Winchester Silvertips (an OLD lot...made around 1990) averaged 1190 fps.

-Norma 170gr JHP averaged 1218 fps. Advertised 1300 fps.

-Norma 200gr FMJ averaged 1007 fps. Advertised 1200 fps.

-Georgia Arms 180gr JHP averaged 1123 fps. Advertised 1150.

-Underwood Ammunition 180gr JHP (both XTP's and his standard JHP) averaged 1280 and 1300 fps. Tried both on two different days. One day they averaged 1300, the next day out was 1280. My results on this nearly mirror everybody else that has chrono'd it from a stock Glock 20.
 
Here's some data using the same Glock 20, but with a Storm Lake 5.3 inch barrel, with factory ammo.

-Winchester Silvertips averaged 1227 fps.

-Underwood Ammunition 180gr XTP averaged 1355 fps.

-Remington 180gr FMJ averaged 1125 (still 25 fps shy of their 1150 claim!)

-Georgia Arms 180gr JHP averaged 1204 fps.

-PMC 200gr FMJ averaged 1066.


Some of "Glock barrel safe" hand loads, absolutely scream out of this barrel, in comparison to the stock barrel. With handloads, I get anywhere from a 70 to 110 fps increase in velocity!
 
TRaGiK, thank you for posting that, it was most helpful. If anyone else has similar data, particularly with different loadings and/or different weight recoil springs than that posted by TRaGiK, I would be most appreciative if you would share it.
 
Looks like Underwood may be burning a little faster than other ammo in order to get the most power out in the first 4" that they can.

I am fine with that as I will primarily be using Underwood from my Fusion 10mm Commander Bobtail which has a 4.25" barrel.
 
You must log in or register to reply here.
Back
Top