Put a bunch of rounds through the chrono today

[ColoradoShooter77]

This is in an AR-15, 16" barrel, 5.56 chamber

Load #1 : 24.8 grains IMR 8208, 55 grain FMJ, L-C case, CCI 400 primer, seated at 2.230". 3 shots were as follows 1) 2863 fps, 2) 2836 fps, and 3) 2761 fps. That extreme spread is a little high. Velocity is a little weak, 1/2 grain off the max. Maybe this powder isn't all its cracked up to be.

Load #2: 25 grains Accurate 2460, 55 grain FMJ, PMC case, Wolf WRM primer, seated at 2.230". 3 shots here as well....1) 2821 fps, 2) 2827 fps, and 3) 2803 fps. Much better extreme spread, but velocity is still weak. I'm going to bump this one up to 26 grains.....max is 26.7.

Load #3: Mini-14....24.8 grains IMR 8208, 55 grain Nosler B-Tip, L-C case, CCI 400 primer, seated at 2.250". 3 shots.....1) 2921 fps, 2) 2953 fps, and 3) 2963 fps. That's a pretty good extreme spread and it gained 100 fps in just 2.5" of extra barrel, the Mini is at 18.5".

Hi Point 40 carbine with 155 grain Berry's and 7.5 grain longshot, 1) 1382 fps, 2) 1359 fps, and 3) 1377 fps. This is with a minimum charge of Longshot, I could really push this thing hard with a good JHP bullet and 8.5 grains.

Ruger SR40-C with 8 grains CFE Pistol and a 135 grain Berrys, 1) 1148 fps, 2) 1137 fps, and 3) 1162 fps. Hodgdon claims 1300 fps with the minimum charge, its not even close.

Walther PPX 40 with 155 grain Berry's and 7.5 grains Longshot, 1) 1033 fps, 2) 1020 fps, and 3) 1004 fps. I don't care for the recoil impulse of this powder, its very sharp. I'm going to relegate this to 9mm and run Longshot in the 40.

Ruger SR9-C with 124 grain Berrys and 5.3 grains Unique, 1) 1110 fps, 2) 1077 fps, and 3) 1093 fps. This is a good load that duplicates factory ammo.

Colt 1911-22 with Federal 36 grain ammo, 1) 948 fps, 2) 995 fps and 3) 968 fps.

 

[kcofohio]

Ruger SR40-C with 8 grains CFE Pistol and a 135 grain Berrys, 1) 1148 fps, 2) 1137 fps, and 3) 1162 fps. Hodgdon claims 1300 fps with the minimum charge, its not even close.

That is curious, I have never seen where Berry's has made a 135 gr. 40 cal. bullet. 155 gr., yes.

 

[ColoradoShooter77]

My bad....the 135 grain is Ranier.

I also meant that I am going to relagate the CFE pistol to 9mm duty and run the Longshot in the 40. I don't like the recoil impulse of the CFE pistol in the 40, its very sharp. The Longshot is a "push".

 

[LiveLife]

Ruger SR40-C with 8 grains CFE Pistol and a 135 grain Berrys, 1) 1148 fps, 2) 1137 fps, and 3) 1162 fps. Hodgdon claims 1300 fps with the minimum charge, its not even close.

135 grain is Ranier

Load data Hodgdon published used Nosler jacketed hollow point and Rainier is plated bullet. I have found some rounded base of plated bullets to leak more high pressure gas around the bullet and reduce muzzle velocity. Also, if Rainier is FP/FN bullet, the JHP bullet will get seated deeper which will generate greater chamber pressure - http://www.hodgdonreloading.com/data/pistol

135 GR. NOS JHP CFE Pistol COL 1.125" Start 8.0 gr (1,303 fps) 29,500 PSI - Max 8.9 gr (1,392 fps) 33,800 PSI

Also velocities published was tested using a 4" barrel. Your barrel length/groove diameter/start of rifling/leade length may differ which may leak even more high pressure gas (in addition to using plated bullet) which would further reduce muzzle velocities.

 

[ColoradoShooter77]

That's true, I'm using a 3.5" barrel and I didn't realize that plated bullets were so much slower.

The .223 gets slaughtered in the 16" barrel, I'm losing a solid 300 fps versus a 24" barrel.

Just to get to 3000 fps on the 55 grain bullet, I'll have to run darn near max charges.

 

[Reefinmike]

Sure is fun to tinker with different loads once you have a chrony. I cant believe i went 4 years before spending $75 on one. Most data for my auto pistols was as i expected. It was neat to note that powder coated lead bullets go 80-100fps faster than a fmj with the same powder charge and seating depth. Some of my 357 mag loads really impressed me. 164gr powder coated lswc traveling 2000fps from a 16" barrel

 

[ColoradoShooter77]

I think its awesome that the 40 carbine is pretty much equal to what a 10mm pistol produces, speed wise.

I'm sure I could get the 155's over 1500 fps with a stout charge of Longshot and a good JHP.

 

[Bart B.]

You're not using the same barrel nor powder lot used to develop the load data. And you're not using the same thing to hold the rifle. It's normal to get lower muzzle velocities than published loads. Several people shooing the same rifle and ammo can easily have a 100 fps spread in average velocity. If you shoot your rifle in free recoil, muzzle velocity spread will be 1/4 to 1/3 of what it is hand holding the rifle.

There's nothing wrong with using near maximum charges. That's what gives highest velocities safely.

 

[GBExpat]

How well did each test load group?

I ask because I always capture accuracy data while checking velocity data.

One way to explain that is to say that I am being efficient ... but I think that it may be more accurate to say that I am a bit lazy.

FWIW, I will run up to a 10rd string (the max size for my Chrony) with each new test load. Essentially, as many rounds, up to 10, that the firearm can hold without a reload ... shooting over the Chrony at a target (separate, IDed target spot for each test string so that I may later analyze the grouping results).

EDIT:

BTW, when I first read your @SUBJ "Put a bunch of rounds through the chrono today" I thought that the Thread was going to be about someone else who shot the crap out of their Chrony.

 

[Dudedog]

Longshot isn't happy until you get to the higher end of it's range but boy does it work well once you get there.

Chronos are neat and now they are fairly inexpensive.
Glad you shot over the chrono not thru it. They lead charmed lives you know.

 

[ArchAngelCD]

Just a note and suggestion, 3 rounds is barely good enough for accuracy tests but not good enough for velocity and SD tests. I suggest you use at least 5 rounds for both velocity and accuracy tests for a more reliable results. Ten rounds for velocity, SD and other related numbers is best IMO.

Thanks for posting your results.

 

[Bart B.]

How credible is a number of shots to represent the real accuracy you can count on all the time? Statistically speaking, consider the following:

Single group size multiplied by maximum/minimum multiplier equals approximate size limits for 19 out of 20 groups fired. Here's the results for different numbers of shots per group:

Shots per group ________Max_________Min
3____________________2.45_________.40
5____________________1.53_________.67
10___________________1.27_________.81
20___________________1.12_________.89
30___________________1.09_________.92
50___________________1.06_________.95

The record single 5-shot 100 yard benchrest group is .0077" The benchrest record aggregate (average) of several 10-sot groups at 100 yards is about 32 times bigger. The largest single group in that agg record is about 40 times bigger.

Muzzle velocity averages and standard deviations have the same probabilities.

 

[ColoradoShooter77]

I'm going to do a new test this weekend, 5 rounds of each load in each caliber. I found some Hodgdon data on a .223 pistol with a 15 inch barrel, even a full load of H-4895 only produces 2880 fps with a 55 grain bullet. I'm running a 16 inch.

I might as well get used to crappy velocity in the short barrel, I'll be lucky to get it to 3000 fps.