Pistol Caliber Carbine- bullet velocity

You can only go so slow with powder in the 9mm. Power Pistol, HS-6 will do well in a carbine. Lyman #49 has good data for comparing pistol to carbine loads.

...ballisticsbytheinch.com, has some very interesting stuff done that seems to indicate that (so far), at least in 9mm, the length that velocity seems to drop off is actually right around 15-17 inches

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The ballisticsbytheinch (BBI) people have done some very unique and interesting work on the relationship between barrel length and velocity, but please take the time to look at the many caveats they mention on their FAQ page.

In general, BBI used factory loadings for their tests. This means they had no idea what powder was used in the tested load so they had no basis for correlating relative burn rate with their observed results.

For rifle-length barrels, my suggestion is that you consult a burn rate chart (all the reloading manuals have one) and then looking at the loads given in the manual, pick a slower burning powder from the published load data. In other words, if the data you consult has a load for HP-38 and HS-6, then you would want to consider starting with the HS-6 loading since it is the slower burning powder.

Burn rate charts show relative burn rates, so they should NEVER be used as the sole basis for developing a load, but in the limited situation here, where we are considering performance out of a longer barrel than used in the published data, using the burn rate chart to select a slower burning powder FROM THE PUBLISHED DATA as a starting point is perfectly logical.

Used in this way, powders like HS-6 and CFEPistol may be better places to start than HP-38 or TiteGroup.

My loads for 9MM, all 124 grain jacketed and plated, only gains from 200 to 250 fps more velocity in a 16" Kel-Tec sub 2000 compared to the same loads in a Glock 19. I think the 200-250 fps is all to expect in a carbine. Slower powders for 9MM won't increase velocity much. Some have played with light .380 88-90 grain bullets with the slowest of 9mm powders and have gotten higher velocities. One of my loads that shoots 124 gr. bullets in my 4.1/4" Glock 19 that gives a pleasant 1050 fps gets 1225 fps in the 16" carbine. I believe your chrono is going to show 200-250 fps with factory or reloads? It's surprising how accurate the stocked carbine with longer sight radius is compared to the pistol. Love shooting the 16" carbine out to 50-75 yards or farther.

on BBTI, it looks like most 9mm loads they test only gain 100-125fps going from 4" to 16". A few light loads gain 200fps. I think that seeing a 70-80fps increase per inch is probably pretty unrealistic. There is only so much performance you can squeeze out of a 9mm cartridge. Ive never owned a 9mm carbine but I had a 45 carbine and the performance increase was about the same. most loads 100fps faster from the 16" tube. 357 mag I see a 450-500fps difference going 6" to 16".

In the 9mm shot from a carbine I would also use a slower powder like HS-6 or Longshot. Slower powders can take advantage of the extended barrel. (to a point)

It's not a 9mm but I did test .357 Magnum ammo in a Marlin levergun. I sent many different loads over the chrono attempting to find the most suitable hunting bullet weight. Here is some if what I found:

I loaded up some 180gr Hornady XTP bullets and from a 4" barrel the AV was 1056 fps and in the levergun the AV was 1495 fps. The powder was W296 with a CCI550 primer. Both were tested different days.

For some reason it's the only load I sent over the Chrono with both guns. All the carbine data was collected on the same day.

Just for interest, here is the data for other weight bullets shot in the carbine.

180gr Hornady XTP
1495 fps with W296
1584 fps with Lil'Gun

125gr Hornady XTP
2239 fps with H110
2055 fps with 2400

170gr Sierra JHC
1699 fps with H110
1793 fps with Lil'Gun

150gr Sierra JHC
1826 fps with H110
1801 fps with 2400

140gr Sierra JHC
1976 fps with H110
1930 fps,with 2400

180gr Cast Performance WFNGC
1547 fps with H110
1657 fps with Lil'Gun

I was surprise to see the 170gr .357 Magnum ammo shot from the Marlin were in line with 170gr 30-30 ammo shot in a levergun. The AV from the 30-30 ammo is usually 1930 fps to 1957 fps.

+1 to rg1/Reefinmike. Depending on the bullet weight (100/115/124/147), I am seeing around 100-200 fps gain from 16" PSA (1:10 twist rate) and 17" Just Right (1:16 twist rate) carbines for 9mm loads.

On the Carbine loads with plated bullets and the THR mythbusting plated bullet comparison threads, I am documenting chrono data from 16"/17" barrels and ambient temperature difference (to show temperature sensitivity of powders) - http://www.thehighroad.org/showthread.php?p=10338994#post10338994

100 gr RMR HM RN 5.2 gr W231/HP-38 @ 1.050": 1459-1424-1423-1465-1413 fps (56 F - JR carbine)
100 gr RMR HM RN 5.5 gr W231/HP-38 @ 1.050": 1493-1468-1432-1479-1454 fps (58 F - JR carbine)

100 gr RMR HM RN 4.5 gr Promo @ 1.050": 1442-1428-1478-1431-1462 fps (58 F - JR carbine)
100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1478-1475-1480-1471-1467 fps (58 F - JR carbine)
100 gr RMR HM RN 4.5-4.7 gr Promo @ 1.050": 1458-1450-1445-1442-1448 fps (71 F - JR carbine)

115 gr Hornady HAP 4.8 gr W231/HP-38 @ 1.075": 1342-1202-1339-1327-1304 (65 F - JR carbine)
115 gr RMR FMJ 4.8 gr W231/HP-38 @ 1.130": 1256-1214-1240-1316-1252 (65 F - JR carbine)
115 gr RMR FMJ 4.8 gr W231/HP-38 @ 1.130": 1251-1279-1257-1254-1272 fps (79 F - JR carbine)
115 gr Winchester FMJ 4.8 gr W231/HP-38 @ 1.135": 1315-1234-1334-1307-1296 fps (59 F - PSA carbine)
115 gr Zero FMJ 4.8 gr W231/HP-38 @ 1.130": 1259-1243-1268-1343-1326 fps (65 F - JR carbine)

115 gr Berry's HBRN 4.6 gr W231/HP-38 @ 1.135": 1264-1270-1233-1246-1288 fps (59 F - PSA carbine)
115 gr Berry's HBRN 4.8 gr W231/HP-38 @ 1.130": 1306-1328-1322-1313-1317 (75 F - JR carbine)

115 gr Berry's HBRN 3.9-4.0 gr Promo @ 1.135": 1275-1261-1316-1287-1294 fps (59 F - PSA carbine)
115 gr Berry's HBRN 4.5-4.6 gr Promo @ 1.130": 1414-1377-1375-1420-1372 (75 F - JR carbine)

115 gr RMR HM RN 4.6 gr W231/HP-38 @ 1.135": 1187-1240-1290-1239-1260 fps (59 F - PSA carbine)
115 gr RMR HM RN 4.8 gr W231/HP-38 @ 1.130": 1275-1263-1253-1290-1248 fps (56 F - JR carbine)
115 gr RMR HM RN 4.8 gr W231/HP-38 @ 1.130": 1303-1289-1298-1311-1323 fps (79 F - JR carbine)
115 gr RMR HM RN 5.0 gr W231/HP-38 @ 1.135: 1380-1368-1378-1387-1399 fps (71 F - JR carbine)

115 gr RMR HM RN 3.9-4.0 gr Promo @ 1.135": 1204-1276-1259-1273-1247 fps (59 F - PSA carbine)
115 gr RMR HM RN 4.0-4.2 gr Promo @ 1.135": 1331-1358-1346 fps (59 F - PSA carbine - ran out of test rounds)
115 gr RMR HM RN 4.5-4.7 gr Promo @ 1.135": 1351-1364-1363-1357-1342 (71 F - JR carbine)

124 gr RMR JHP 3.2 gr W231/HP-38 @ 1.125": 820-838-784-807-860 fps (59 F - PSA carbine)

124 gr RMR HM RN 4.3 gr HP-38 @ 1.160": 1078-1116-1124-1104-1103 fps (59 F - PSA carbine)

124 gr RMR HM RN 3.9-4.0 gr Promo @ 1.160": 1231-1201-1210-1227-1193 fps (59 F - PSA carbine)
124 gr RMR HM RN 4.2-4.3 gr Promo @ 1.160": 1258-1263-1251-1244-1266 fps (68 F - PSA carbine)
124 gr RMR HM RN 4.2-4.3 gr Promo @ 1.160": 1298-1277-1261-1276-1293 fps (68 F - JR carbine)

124 gr RMR HM RN 5.2 gr BE-86 @ 1.160": 1179-1149-1178-1170-1197 fps (59 F - PSA carbine)

I used to shoot a warmish PowerPistol load that launched 115 grainers to 1500 fps back when I had a HiPoint carbine. It did 1250 - 1300ish in my full size pistols. I am certain that it could have been worked up farther, but the blowback action may have started to become an issue.

Later on I thought it would be fun to try 90 gr. bullets due to the lighter weight and, perhaps more importantly, the increased case capacity. I never made it that far though. And I have since heard mixed reports about stability in those bullets at high velocity.

CZ9shooter said:

I thought it would be fun to try 90 gr. bullets ... I have since heard mixed reports about stability in those bullets at high velocity.

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That's what I thought and for my carbine loads, I was planning to use 115 gr bullets as the lowest weight bullets.

But Walkalong suggested I consider using lighter bullets as he got more accurate loads with them. What I found when doing 50/100 yard plated load testing with 115/124 gr bullets is 100/200 fps drop in velocity that resulted in vertical stringing on target that exceeded 6-9 inches.

With 100 gr bullet (RMR HM RN and only 100 gr plated bullet I found with 1500 fps rating) pushed to 1450+ fps, vertical stringing was less (as bullet got to 100 yard target faster than 1250-1350 fps 115/124 gr loads) and I did not see elongation or keyholing of bullets but instead nice round holes even on 100 yard targets (see target pictures below) - http://www.thehighroad.org/showthread.php?p=10286159#post10286159

When Walkalong suggested lighter than 115 gr bullets for 9mm carbine loads, I considered going down to 95 gr Montana Gold JHP bullets I use for 380Auto loads.

At the time, I was doing load development for "cheaper" plated carbine loads and decided on RMR Hardcore Match thick plated bullets as their 100 gr RN is rated to 1500 fps (BTW, you'll likely find 100 gr bullet weights for plated 380Auto bullets instead of 90 gr) and W231/HP-38 and Promo loads reached velocities around 1450 fps. Keep in mind that most other brand 100 gr plated bullets are rated to around 1200 fps.

BDS and Walkalong, do you find it "worth it" to buy the lighter bullets and load specifically for the PCC? Is there enough of a difference in accuracy over the loads you usually shoot in your pistols?
I shoot steel challenge,uspsa and some idpa. I just shot my first uspsa match with the pcc today-very fun!
Hint--practice opposite shoulder shots.

I find it's a lot easier just to shoot the same pistol loads in the carbine. Not having to keep them separate. If you've got a good pistol load you'll be surprised on how accurate they are from the longer stocked carbine. But, the fun of reloading is experimenting.

Thanks. I've got loads worked up with several powders, all 124 gr. for my pistol. I' think I'll just keep using them in the rifle too.

My contribution is for bullets on the heavy side and with a barrel that is about half as long as your 16" carbine barrel; 147 grain Xtreme CPRN and Unique powder (similar to HS-6 and Power Pistol on the burn rate chart). I'm developing a load that is just subsonic out of my CZ Scorpion Evo pistol (soon to be SBR) and Omega can. I compared velocities through the Scorpion (7.75" barrel) with those from an XD service model (4" barrel).

Here's my data:

3.6 grains of Unique
XD: 851 fps, SD 25
Scorpion: 950 fps, SD 43

3.8 grains
XD: 884 fps, SD 17
Scorpion: 974 fps, SD 44

4.0 grains
XD: 913 fps, SD 11
Scorpion: 991 fps, SD 38

4.2 grains
XD: 947 fps, SD 10
Scorpion: 1032 fps, SD 19

Powder charges are as-dropped through my Dillon powder measure (+/- 0.1 grain even with tough-to-meter Unique) and an OAL of 1.162". Mixed brass. No accuracy data because I can't attach a buttstock to the Scorpion yet (haven't received the tax stamp).

Action Matters

The blowback action of semi auto 9mm rifles limits the amount of additional velocity you can achieve in these guns.

A few years ago I was working with a 9mm AR15, I tested factory ammo from 4", 8", 12" and 16" barrels and found the velocity slowed down in 16" vs 8"

I think the fact that the blow back bolt opens and all the acceleration is done when that happens. Therefore the only action on the bullet at that point is friction of the rifling.

The bullet then slows down in that last few inches.

Walkalong said:

RMR 90 Gr JHP 7.2 Grs 3N37 1.065 OAL 83 degrees

1313 Avg FPS from a 3" EMP.

1454 Avg FPS from a S&W 5" 1911

1644 Avg FPS from a 16" AR

Shot so well I bought another 1K...

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^^+1^^

I've had very good results with Walkalong's Little Lasers in both my G19 and Sub2000 Gen2.

egd said:

BDS and Walkalong, do you find it "worth it" to buy the lighter bullets and load specifically for the PCC? Is there enough of a difference in accuracy over the loads you usually shoot in your pistols?

I shoot steel challenge, uspsa and some idpa.

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I think it depends on the distance to target.

Lighter 90-100 gr bullets traveling at 1450-1650 fps will drop less than 115/124 gr bullets traveling at 1250-1350 fps, especially out to 75-100 yards. With 115/124 gr loads at 100 yards, I have seen around 6" - 9" of vertical stringing while 100 gr loads around 5" of vertical stringing - http://www.thehighroad.org/showthread.php?p=10286159#post10286159

With 115 gr FMJ/HAP loads I am using as reference for Mythbusting plated bullet comparison thread, I got around 100 fps spread while 100 gr RMR Hardcore Match plated load with Promo produced down to 12 fps spread - http://www.thehighroad.org/showthread.php?p=10245856#post10245856

Another thing to consider when shooting at longer distance is the transonic effect on the bullet as bullet slows down from supersonic speed to subsonic speed around 1126 fps. At 100 yards, 9mm bullet will slow about 200 fps, so loads that chrono above 1350 fps should stay supersonic and produce smaller shot groups at longer distances, especially when factoring in reduced vertical stringing from bullet drop. If your load will likely go through transonic speeds before reaching the target, you can adjust the load to ensure it stays supersonic to target or subsonic at the muzzle.

For closer targets to 25 yards, I think the effects of bullet drop and transonic effect is small enough to not matter on the group size and for developing match loads, I would go with loads that are most accurate with your match pistol. If your targets are at longer distances, you may need to consider using a different load that will produce smallest group size.

Walkalong said:

RMR 90 Gr JHP 7.2 Grs 3N37 1.065 OAL 83 degrees

1644 Avg FPS from a 16" AR

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1644 fps? Yup, Walkalong's "little lasers" - I was happy with 100 gr RMR plated RN load accuracy around 1450 fps , now you are making me want to try even lighter jacketed bullet loads.

I have 95 gr Montana Gold JHP and RMR is selling 95 gr Armscor FMJ (seconds) for $65/1000 (with 5% THR discount) so may order them for testing - http://www.thehighroad.org/showthread.php?p=10359009#post10359009

I just shot my first uspsa match with the pcc today-very fun!

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Yes, fun indeed!

Dudedog just shot his first USPSA match and you may want to check out the match shooting tips we are "coaching" him with in the Competition category - http://www.thehighroad.org/showthread.php?t=809836