HS6 Powder TOO Slow For SNUBBY?

[HorizontalMike]

I have been working up a 125xtp load for my 642 2in. using HS6 powder. I have been using my 4in 686 as my load testing gun. I thought I was doing just fine, that is until I tried to chronograph this 125xtp 38+P load in my little 642 snubby.

I know/understand that nearly all reloading books use long barrels in order to maximize FPM. Personally, I do not know of any "Snubby Reloading Manuals" (please post me a link if such exists).

I have attached a screen shot of five strings I ran this morning using my 38 workup loads, both 38 and 38+P. The first four strings are of 38+P loads and the last two are my standard 38 load. Both are for 125xtp bullets.

I thought the results were a fluke, as I had had similar problems recording/chronographing 125xtp yesterday as well. Thought maybe I didn't get the chrono set up properly (too much sun, fluorescent lamps, etc) , so today I set up the chrono with the powered diffuser light, turned of my overhead Fl tubes, and made sure the chrono was further into the shop and away from the sun's glare.

I still got a big FAIL when trying to test these loads on my 2in snubby. When using my 4in 686 and my 2.62in 627PC, I got solid numbers.

Please take a look below, and share your thoughts...

 

[Nevada Ed]

First off, HS6 with a 125 xtp was accurate in my 686 6"........

6" barrel standard load at 1037fps.
2" M49 standard load came out at 867fps.

CFE at 862fps, w231 at 840, Unique at 870fps for standard loads.
With a full load 800-x, Red & Green Dot and Unique powders can reach 900fps in my snub nose.
However, even with this high fps, I do not use this weigh/style of
bullet for my SD use in the M49.
I did like the accuracy when one full grain less than my maximum loading.
Good shooting.

 

[Eddietruett]

Speer has some loading data on their website with .38 loads out of a 2” mod 15 and .357 out of a 2.5” mod 19 if I remember correctly

 

[rockquarry]

Have you experimented with the distance you have your screens set at? With a snub nose gun, that could make a difference.

Like Power Pistol, I've found HS-6 to be a great powder, capable of good accuracy and velocity, but within a pretty narrow spectrum in comparison with other powders as for versatility. Magnum primers are usually recommended with HS-6. I've compared standard and magnum and could see little if any difference in velocity or accuracy.

This is based on personal experience only; no links.

 

[joe44va]

Cool.
I guessing that a 2" barrel with light bullets doesn't allow enough time for full pressure to develop so all the powder doesn't ignite. Any powder left in the cases or elsewhere? In essence, the powder is too slow.

 

[muddocktor]

You are getting interference from unburned powder crossing the chrono. If you back off another yard or so it might clear up. I have had the same thing happen with me before; it gave way abnormally low numbers. Moving my chrono out another yard or so stopped the interference in my case.

 

[HKSmith]

I think Muddocktor is on the right track with his suggestion above. If some of the OP's loads were in the 200 ft/sec range they would have less recoil than a .22 LR round, which the OP didn't mention. Also, the Speer manual has data for 2 inch barrel .38 Special and +P loads, some of them using VV 3N37, which is a slower powder than HS6. Generally the fastest loads in snubbies are the same as the fastest loads in longer barreled guns (with lower velocity, of course).

 

[HorizontalMike]

You are getting interference from unburned powder crossing the chrono. If you back off another yard or so it might clear up. I have had the same thing happen with me before; it gave way abnormally low numbers. Moving my chrono out another yard or so stopped the interference in my case.

I actually did back off to about 3-1/2 to 4yd from the chrono, just to see if that was a/the problem. Not clear, but string #5 results may be indicative of such interference. Four of the ten shots were <200fps while the other six shots much higher, with Hi=907fps. Plus, the very first shot in string #2 registered at 978fps! So... maybe...

As far as un-burnt powder on the concrete floor, I didn't really see any, after sweeping and collecting in a dustpan. What I did find was plenty of very fine burnt greenish-black powder remnants. The sound of ALL rounds going off seemed to be the same to me (w/earmuffs).

Also, now thinking/wondering aloud, if a 2in 125xtp snubby MAX is something more like 7.0gr of HS6...? I think I'll work up some @7.0gr and actually test them in a 2in snubby. First though, I still have a box of these loads so I'll back off to at least +5yd from the chrono and see. Both my snubs are DA-only so I need to fire slowly and accurately...

Don't really need 38+P loads for my 4in 686, since I'm getting ~1400fps with my 8lb of N105 in .357 158xtp. What I do not know and would like to see, is penetration & expansion tests related to the 125xtp @1,000fps. Maybe that would be a "safer" SD load in a crowded mall (more expansion with less penetration)...?

 

[scooter123]

If you are using a Shooting Chrony chronograph the position of the bullet through the screens can also have a big effect on the results. Had to learn this lesson by basic experiments because it's NEVER mentioned in the manual but the bullet need to pass over the sensors at an elevation dead even with the brass rings that join the diffuser support rods. Any higher or lower and you'll see some really flaky results. Add in powder debris being picked up by the screens and the end result could be what you have observed.

 

[HorizontalMike]

...[snip]... Magnum primers are usually recommended with HS-6. I've compared standard and magnum and could see little if any difference in velocity or accuracy.

This is based on personal experience only; no links.

Yes, I am using CCI#550 Magnum primers... forgot to mention that...

 

[WR Moore]

OK, the standard distance for chronograph work is 15 feet, muzzle to center of the screens. Closer than that, you run the risk of the muzzle blast/particulates triggering the start of timing.

You're also having problems with your basic setup. Most instructions for skyscreens/optical sensors specify NOT to use fluorescent lights. The flickering of the lights can throw the sensors off. The best way to clock loads is in bright sunlight with the use of diffusers. It's also a good idea to check your setup with .22 lr. before testing. Velocities from a rifle should run 1100-1200 f/s.

Your velocities are similar to what I get with Power Pistol in the 4 inch barrel, but PP seems to have less variation than you display.

 

[ArchAngelCD]

My prime powder for building .38 Special +P ammo is HS-6 especially for the FBI Load. I have found using a magnum primer will air in a full burn of the powder but more over, they shrink the SD numbers to single digits.

*Warning* The charge below exceeds most current data available but was published in the past. If you choose to use it blame no one but yourself if something goes bad.

Here is one of my loads, the FBI Load:
Winchester .38 Special +P case
158gr Hornady LSWC/HP
CCI 550 Primer (Magnum primer on this load)
7.0gr HS-6
COL 1.475"
4" M686 ---- 2" M640
927.0 -- AV --- 888.9
955.1 --- H --- 897.1
905.4 --- L --- 876.6
49.7 ---- ES --- 20.5
20.7 ---- SD ---- 7.9
17.0 ---- AD ---- 5.9

 

[HorizontalMike]

My prime powder for building .38 Special +P ammo is HS-6 especially for the FBI Load. I have found using a magnum primer will air in a full burn of the powder but more over, they shrink the SD numbers to single digits.

*Warning* The charge below exceeds most current data available but was published in the past. If you choose to use it blame no one but yourself if something goes bad.

Here is one of my loads, the FBI Load:
Winchester .38 Special +P case
158gr Hornady LSWC/HP
CCI 550 Primer (Magnum primer on this load)
7.0gr HS-6
COL 1.475"
4" M686 ---- 2" M640
927.0 -- AV --- 888.9
955.1 --- H --- 897.1
905.4 --- L --- 876.6
49.7 ---- ES --- 20.5
20.7 ---- SD ---- 7.9
17.0 ---- AD ---- 5.9

Thanks for the info. I may have or NOT worked up a max load for my 38s 158xtp yet, but do have this thus far:
158gr Hornady XTP
CCI 550 Primer (Magnum primer on this load)
6.4gr HS-6 Above max in LEE, but inline with others
COL 1.475"
4" 686
796 -- AV
846 --- Hi
762 --- Lo
84 ---- ES
31 ---- SD
*Anyway, I have shot up all of that load and will need to add more rounds.

As stated in OP, I still need to get a good chrono on my 125xtp 38+P loads in my 2-inch snubbies. According to the LEE book, I could go as high as 7.8gr of HS6. I have only loaded 7.7gr so far. My 4-inch chronos look good, but not the 2-inch data.

As discussed above, there is a likelihood that my 2-inch shots are throwing out too much debris and resulting in null readings. Will try backing up to 5yd from the chrono, and making some other adjustments to see what I am truly getting.

After all that, I'll get to working up the 158xtp loads...

 

[Rule3]

There is nothing wrong with HS6 for snubby loads.


Speer Manual has "short barrel loads"


What brand of chronograph are you using??


10 to 15 feet is needed for distance.


The main issue I see is all the failures are due to KIMBER!



Yea old saying, the powders that do best in long barrels(velocity) also do so in short barrels. Which are slower powders. Unique can almost do it sometimes with some bullets and the Moon phase is correct.
No, I am not going to get in that old debate again.


My best guess is you have chrono issues


Don't know if you have checked out this thread?


Duplicating Buffalo Bore FBI Load

 

[fredj338]

IF you want max vel, slower powders always give you that, regardless of bbl. You will get more blast & flash & a faster powder might be within 20-30fps, but that is the fact jack.

 

[reddog81]

Nothing wrong with the gun. Nothing is wrong with the powder. The problem is the chronograph as others have suggested.

If you were getting velocities that low you'd have had stuck bullets in the barrel. Once you go under the 500 FPS range you start to run into problems.

 

[HorizontalMike]

Finally Got Actual Data

OK.......... I finally got some results that I can believe, not necessarily great results but OK.

Personally, IMO, it was the highly reflective overhead door (in background of image) that was throwing off the chrono. Sure, 15ft is better than the 5-10ft (recommended from the owner's manual), but truly think the former is more likely than the latter. After all, both the 686 and 627PC did well at the shorter gun/chrono distances, and WITHOUT any chrono cover/shield.

Bottom line is that I thought I would get better FPS results at 7.7gr of HS6 with the 2in. LEE goes to 7.8gr of HS6 and Hornady goes as high as 8.1grains. I probably will NOT go that high because with this light load I get a lot of powder residue/buildup. There has to be a cleaner alternative.

*Poor Kimber haters, just watch as others start to copy the ergonomic aspects of the K6S, much less the 6-round vs 5-round capacity in a small frame. IMO, this is a game changer.

 

[Rule3]

Well I see you have a good chrono but what is all the junk hanging on it?? The work buy registering the distance in lighting between the diffusors and the open space.



You shoot out of your garage??


Put it outside in the real Sunlight. Believe me it will work, I have one here in Florida.


The Kimber is a very nice gun, pricey but very nice trigger and build.

 

[HorizontalMike]

Well I see you have a good chrono but what is all the junk hanging on it?? ...
You shoot out of your garage??
Put it outside in the real Sunlight. Believe me it will work, I have one here in Florida.

The Kimber is a very nice gun, pricey but very nice trigger and build.

Because it works
Yes
No it doesn't
And yes it is a fine revolver

Thank you for your input...

 

[rg1]

I solved my snubby erratic velocities by switching to AA#2 powder with 110 and 125 gr Hornady XTP's. I was getting about 300 fps between high and low with slow for .38 powders. Not the chronograph in my tests. AA#2 using Accurate Arms data gives good velocity with 110-125 grain bullets.