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Author Topic: Velocity difference in different grades of powder and in different barrel length  (Read 1767 times)

Offline GaryC

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I was able to do some chronographing last week during spring break.  I was interested in seeing the differences in velocity switching between 3F and 4F Goex and in the same powder but changing barrel length.

I used a 61 Navy with a 5.5 inch barrel and a 51 Navy with a 7.5 inch barrel and the 130 grain Lee conical pan lubed with a lube made from beeswax, soy wax, olive oil and pure lanolin.  Barrels were brushed with brass brush between strings loaded off the gun. 

Basically you gain about 100+ FPS using 4F over 3F.  Using 3F I gained about 70 FPS with 2 inches more barrel and had about a 100 FPS gain using 4F going from the short to the longer barrel.   The chronograph was 12 feet from the muzzle. 

This was just testing velocity, not looking at accuracy at all.  As an aside I had been using 17 grains 4F with the conical as the usual charge in the 5.5 inch, getting about 790 FPS from 24 shots over the chronograph (on a different day) with a standard deviation of about 41 FPS.  I tried 6 shots of that load off a rest at 50 YDs which hit into 8 inches but was 17 (!) inches above POA.  I think that is way high even the way these are sighted.  I will be making a new front sight after I try a few more loads with RB as well as conicals.

I have found that 4F in the navy and in the 31 Colt pocket revolvers burns cleaner and gives better velocity.  All the loads were poured using a volume measure, not weighed.  Given the same volume, you will get a bit more powder by weight going to the smaller granulation and as long as the charge burns efficiently you should get acceptable velocities IMO.  Others may disagree.

Regards
Gary

Pietta 1861 Navy 5 inch   
20 gr Goex 3F 130 Conical    
762.2   730.9 Vavg
735.9   
692           154.3 Ft-lbs
762.6   33.0   SDs
701.9            


20 gr 4F GOEX      
859.5   838.1 Vavg
781.4   
805.6   202.8 Ft-lbs
804.5   63.5   SDs
939.4      

Pietta 1851 Navy 7.5 inch
20 gr Goex 3F 130 Conical       
831.3   805.5 Vavg
833.6   
819.9   187.4 Ft-lbs
800.8   37.8 SDs
742.1      

20 gr 4F GOEX      
879.6   943.5 Vavg
931.4   
976.2   257.0 Ft-lbs
990.8   43.5  SDs
939.4      

         

Offline Hawg

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Sounds reasonable but why no 2F loads? I use 2F more than anything.

Offline GaryC

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Hawg, I have been using 35 grains 2F Goex with a 454 RB in the dragoon with good accuracy but I have not chronographed any of the loads yet.  That is a mild load in the dragoon.   No reason not to use 2F the navy but I expect you would get less velocity for a given volume. If I want max velocity in the 36 navy I will use 4F.  For plinking or targets I use whatever gives me the best groups.

I have shot some corned powder I made that screened about 2F in the navys.  In the 5.5 inch 20 grains volume averaged 624 FPS and 25 grains averaged 727 FPS.  With the 7.5 inch barrel 20 grains averaged 710 FPS and 25 grains averaged 828 FPS.  I'm not sure this would compare directly to Goex 2F. Basically my home made needs 5 grains volume more to get about the same velocity as Goex 3F.  But I was happy with it.  It is very consistent in the longer barrel. 








Offline ssb73q

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Hi GaryC, thanks for posting that useful chronograph data, I always like looking at chronograph data.

Regards,
Richard
There’s nothing better in the morning than the smell of bacon and black powder smoke!

Offline GaryC

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Hopefully somebody will find it useful.

Offline Hawg

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I'm sure velocity is lower with 2F but it's not enough to tell without a chrono. I was just curious.

Offline GaryC

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Next trip to the range I will give it a try and post it.  Not sure when that will be though.  Busy time at work.

Offline Captainkirk

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Gary, I would be concerned about pressure spikes using more than 30 grains of 4F. Seems to me my old Lyman Black Powder Handbook had something to say about that. I'll have to see if I can find it and refresh my memory...
"You gonna pull those pistols, or whistle Dixie?"

Offline G Dog

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I always like looking at chronograph data.

Regards,
Richard

Me too.  That's good data.  Can't get too much crono data.  Thanks, Gary.

Having no regular pan to prime, I don't use 4f.  I mostly use Pyro P or Swiss fffg (when it's available).   Experimentation is good, great even, but be careful. 
Schlong NIKE, bigly...

Offline GaryC

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Captain, I was using 4F in a 36 caliber, not in the 44. 20 grains was about the max I can seat a conical of 4F.  I used 35 grain of 2F in the Dragoon but I have not chrono'ed it.  I have an old Lyman BPH that has pressure data for 4F in the 36 IIRC, which was safe.  It is so old it has data for DuPont and Curtis and Harvey (I think).  When dad passed away I got his BP gear, among which was a can of Hodgdon 3F which I believe was made by Curtis & Harvey.  It was about half full and I shot it off without chrono. It was in a red metal can, which I saved.  I'll post a picture of it when I have time.  Probably from the early 60's.  IIRC the price was under $2.

Offline Captainkirk

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Captain, I was using 4F in a 36 caliber, not in the 44. 20 grains was about the max I can seat a conical of 4F.
If you stick under 20 you should probably be OK then. I have thought about using 4F in my Baby Dragoon...I might give it a try as it only holds about 10gr 3F
"You gonna pull those pistols, or whistle Dixie?"

Offline GaryC

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I use it in my Uberti Wells Fargo.  9 grains Goex4F under a conical or RB cast from an EMF replica mold I got on ebay is the starting load because that is what the measure that came with the small flask I got for the revolver throws.  I tried one cylinder of 13 grains of the same powder under a RB. It was too hot a load.  Caused hammer blow back and the bolt unlocked according to my notes as did 10 grains.  9 grains new Goex 4F was fine but the pistol still sucks caps no matter what.   

The GOI was also from dad's hoard.   Still have a can of DuPont 2F.  Red and white metal can labelled DU PONT in an oval in red letters and "SUPERFINE BLACK RIFLE POWDER" in black letters on the front and FFG appears to be stamped in ink.  The lot number is next to the lid on top and is not completely legible but the second line looks like 02-67.   The powder he had from the 60s still shot just fine.

I was mistaken about the price in the Hodgdon can of 3F.  It is $3.50.  It does not say who made it but it does say made in scotland.  Its a red metal can with red/white paper labels pasted on.

Growing up with my dad I got to shoot and handle and learn about a number of percussion and early cartridge rifles and pistols he collected.  I took such thinks for granted then but I really appreciate it now.

Regards
GEC

Offline GaryC

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Correction. The  13 grains was GOI.  I think that was a later name for Gearhart -Owen powder. 

Captain, I have a copy of the 1975 edition lyman black powder handbook.  It has pressure and velocity data for various loads of curtis and harvey and ang gearhart owen 3f and 4f powders that i used as a guide.   I can find nothing about presure spikes in the 4f loads but they might have that in a later handbook and i will take your advice and not use 4f in the 44 or heavy 36 loads.  Their pressure measurements were made with revolvers with one chamber modified to use a lead crusher and pressure data was lup.  17 gr 4f has been my normal load with lee 130 gr conical for a long time with no problems.

Wish i had chronographed the hodgdon to compare with the c&h data but ive used it up.

Offline GaryC

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Hear ya go Hawg.

DuPont 2F, Lee 130 grain conical/
20 grains volume in the Pietta Navy averaged 743 FPS.  (for two shots as I only had 2 lee conicals left.)

Same powder and load with conicals cast from a brass replica mould that average 142 grains the average velocity was 595 FPS, SD 15 for six shots in an Uberti London Navy which the conicals fit better due to their being larger in diameter that the lee.

20 grains of GOEX 3F with that bullet averaged 780 FPS, SD 25 for six shots.

3F got significantly faster speed over the same charge measured by volume if 2F. however I do not know if it the older DuPont 2F compares directly to GOEX 2F though I think they would be roughly comparable.

Accuracy from the 142 grain conical was only fair compared to what I get with the Lee conical or round balls.

Remington 10 caps, Chrony set up 13 feet from the bench. 

The DuPont 2F was from the late 1960's I believe, red/white metal can with black FFG stamped on.   I have read that DuPont sold their black powder facilities and tech to Gearhart Owen (GOI) in 1972 which later led to GOEX so I suspect they would be similar in performance.

Performance differences between 2F and 3F are about what you would expect.

Regards
GEC