Powder Position Sensitivity

  • 644 Views
  • Last Post 18 March 2019
  • Topic Is Solved
Eutectic posted this 23 January 2019

In the last 15 years I have used more Red Dot in rifle cases than I have in shotgun shells. It had been my principal powder in light rifle and some pistol loads. I have tried other powders, however Red Dot was always a staple. Because of the popularity of Cowboy shooting, several new powders are available specifically for light loads in large cases. I decided to see if Red Dot was still a good choice.
I am looking at position sensitivity and decided to use a 30.06 and a light load. Powder charges were measured not weighed, so measurement precision is integrated. No one weighs plinking loads, do they? Accuracy was not evaluated, it is rifle and cartridge specific.
I assembled powders recommended by other shooters.

Red Dot, double base, high nitroglycerine, low density, extruded large circular flakes;
Vihtavuori N310, single base, moderate density, tiny extruded grains, measures precisely;
Tite Group, double base, high nitroglycerine, high density, flattened ball, measures precisely;
Trail Boss, single base, very low density, huge extruded flat perforated disks;
Winchester Super Target WST, double base, moderate density, flattened ball, measures precisely.

I wanted to test Vihtavuori N32C, made especially for Cowboy loads, but none was available locally and I did not want to pay HazMat fees to get it.

.
Ok, here are the results details follow:
Powder       Charge    Difference                 Standard Deviation
                                 Average Front/Rear
Red Dot       6.0 gr.       6 fps                                  17.7
VV N310       6.2 gr.       5 fps                                   8.7
Tite Group    5.8 gr.       6 fps                                   16.7
Trail Boss      7.3 gr.      15 fps                                  27.8
WST             6.3 gr.       8 fps                                    11.5

VV N310 wins, lowest spread and smallest standard deviation.
The results for N310, Red Dot, Tite Group and WST are very close. Considering the standard deviations, they might easily change places on a rerun, even in the same rifle.

Tite Group wins the cost contest, lowest charge weight. 

Trail Boss came in last, which was surprising, as 7.3 grains is almost half a case full.  Trail Boss is the only powder where a double charge or even a case full will not blow up a modern rifle or revolver. This is an important advantage where Cowboys are using progressive presses.
All the loads burned clean. 

The details:
Lyman 31141, cast in 2% tin 6% antimony, sized 0.310 beeswax / jojoba lube no gas check. Seated to crimp groove but not crimped.
Charges adjusted to average 1025 fps plus or minus 25 fps with powder at the rear of the case.
Powder charges thrown using a RCBS Uniflow measure into Winchester 30.06 brass, neck sized, with CCI large rifle primers.
Eddystone 1917 Enfield - Stock except for the Stock (a Bishop)
Rounds chambered, then rifle held vertical muzzle up or down and placed carefully on the bags.
Test rounds fired alternately, powder front of case, rear, front, rear ect.
10 rounds forward powder, 10 rounds powder rearward.
Velocity instrumental at 6 feet
Standard deviations calculated using the small sample correction.

Thoughts:
I expected double base powders to do better because of ease of ignition. I also thought the dense powders would be at a disadvantage. I was wrong on both counts.
The velocity and charge weights are under the recommended starting charges for some of the powders. However, the close results on four powders suggest I did not set up the conditions rigorous enough. Maybe I should have chosen a lower velocity.
It would be interesting to see testing done i a larger case like a 45-70.  
Steve

Attached Files

Order By: Standard | Newest | Votes
onondaga posted this 23 January 2019

Eutectic you said,

"The velocity and charge weights are under the recommended starting charges for some of the powders"

That opens a validity and safety question on your method. Disappointed depressed You over estimated the number of people that shoot or are interested in unsafe loads.

 

Gary

Attached Files

RicinYakima posted this 23 January 2019

Gary,

"That opens a validity and safety question on your method. Disappointed depressed"

Do you know how that is determined? Lyman says it is simply a 10% reduction of maximum load. No testing, no nothing. To the best of my knowledge, only Hercules actually tested for minimum loads and they published data up until the 1970's. Since then there is nothing because everybody knows reloaders want maximum velocity.

Today, you can calculate that by looking at Dick Lee's Reloading Manual #2 and calculating backwards from the maximum pressure level to get close.

Ric

Attached Files

onondaga posted this 23 January 2019

Ric,

I am familiar with TiteGroup and Trailboss and wouldn't shoot below their recommendations and certainly wouldn't do it with powders I'm not familiar with. Powder makers minimum loads are a safety margin and Eutectic said he loaded below minimum. Error toward better safety instead of toward disaster is an important guideline for posting articles on loading ammunition.

Gary

Attached Files

Dukem posted this 23 January 2019

They are "gallery" type loads for cryin' out loud. They aren't going to hurt a damn thing. Thank you Eutectic for taking the time and trouble to do this. Don't get beat down by the sky will fall comments. I found it interesting and useful.

Duke

Attached Files

  • Liked by
  • MarkinEllensburg
  • Tooweels
OU812 posted this 23 January 2019

Which powder burned cleaner. Is there a good method to determine?

Attached Files

max503 posted this 23 January 2019

I wish you would have included Unique.  Is it position sensitive?

Attached Files

Ed Harris posted this 23 January 2019

In my experience Unique was more position sensitive than Bullseye or TiteGroup shooting subsonic loads with 200-grain bullets in the .30-'06.  452AA and WST give results very similar to TiteGroup for the same charge weight, but they are less dense. In the RCBS Little Dandy measure measuring small charges you can go up one rotor size for the same charge weight as Bullseye.  The fast-burning spheroidal pistol powders burn cleaner than Unique or Bullseye.  452AA and WST very much so.  

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

Attached Files

  • Liked by
  • M3 Mitch
tlkeizer posted this 23 January 2019

Greetings,

From my limited experience, powder position of H414 can be critical in light charges.  I shot the first groundhog shoot with the 25-06 using H414 for one of my loads, and had to make sure I elevated the rifle and slowly lowered it for firing to insure good ignition.  I had 2 hang fires in my first three shots, then raised the rifle and had no more hang fires.  The loads were a grain above the minimum listed, and I used CCI 200 primers, don't know if magnum primers may have made a difference but am not willing to try as I have other loads that go "bang" when the trigger is pulled, not "pop, pause, bang".

TK

Attached Files

  • Liked by
  • M3 Mitch
Eutectic posted this 24 January 2019

TK,

Slow burning rate ball powders, that is anything slower burn rate than about Auto Comp are not suited to reduced loads. This is because they are heavily deterrent coated to slow the initial burn rate. There have been warnings about reducing WW296 and H110 loads for decades, but this applies to any slow ball powder which is not mentioned.

Very slow extruded powders have the same characteristics but it does not become a problem until much slower. This is why IMR 4895 can be used in charges down to one half maximum and give consistent results. You should be using a faster extruded powder in your 25.06 if you want moderate velocity loads. The LEE handbook gives good advice on reducing loads..

Steve

 

Attached Files

  • Liked by
  • M3 Mitch
Ed Harris posted this 24 January 2019

I've found that 4064, Varget and RL15 can be reduced similarly to 4895, without a filler IF you stay within 75% of a full charge.

If you use a loose Dacron filler tucked into the caseneck to take up the free airspace, and also use a "hot" primer like a WLR or Federal 210 you can go down to ~50%, about 25 grains in a .30-'06 or 20 grains in the Krag, .303 British or .308, or 15 grains in the .30-30.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

Attached Files

  • Liked by
  • M3 Mitch
Larry Gibson posted this 24 January 2019

The relatively large difference in the SDs between "powder forward" and "powder back" are very much an indication of different ignition and probably time/pressure curves.  Since Eutectic stated "Accuracy was not evaluated, it is rifle and cartridge specific." the most problematic issue with "powder positioning" was negated.  My own similar tests with basically the same burning rate powders in the 30-30, .308W and 30-06 demonstrated a large variance in the SD and the ES when the powders were positioned forward and back.  The greatest variance was, however, on target.  There were basically 2 groups vertical to each other with each load (100 yards).  The powder positioned back giving the highest velocity and thus the highest group.  The powder back also had the smallest SD/ES and gave the smallest groups.

As to the use of such loads with such powders in such cartridges as being "unsafe"......they are not unsafe at all.  The only potential problem is a bullet becoming stuck in the barrel with too low of a charge. 

   

Concealment is not cover.........

Attached Files

John Alexander posted this 24 January 2019

Good work Eutectic,

Always good to see actual experimental data on useful questions. 

John

Attached Files

Scearcy posted this 24 January 2019

I shoot better in a match if I assume my load is position sensitive. Could all be in my head I suppose  but it is an easy adjustment on the line.

Jim

Attached Files

Eutectic posted this 25 January 2019

OU812,

I did look to see if the loads burned clean.
Some powders left what could be termed "dust", none left any powder grains.
There was no visible difference in residue between forward and reverse position.
Trail Boss and WST were very clean burning.
Tite Group seemed to produce more smoke.

These observations are subjective, so I did not include them.

 

 

 

Attached Files

  • Liked by
  • M3 Mitch
R. Dupraz posted this 25 January 2019

Some clubs have a rule that prohibits raising the muzzle to position the powder at the rear of the case. So to simplify things and for consistency, before chambering, I just stand each case upright and then carefully, keeping it horizontal, shove it into the chamber and don't sweat it. No matter what powder I may be using or where I'm shooting. Eliminates one more variable or maybe two. 

Then work on the important stuff like my marksmanship and Bench technique. My cast rifles shoot well with this routine.

 

R. .  

Attached Files

  • Liked by
  • RicinYakima
  • M3 Mitch
Scearcy posted this 25 January 2019

I do precisely what R. Dupraz does. I dislike raising my muzzle above the horizon at the urban ranges we use.

Jim

Attached Files

  • Liked by
  • RicinYakima
  • M3 Mitch
BigMan54 posted this 25 January 2019

I switched to TiteGroup when it came out, because the Hodgdon Rep, told me that it WAS NOT position sensitive.  So all my Cowboy Action & plinking loads went from Bullseye/Unique to TiteGroup. Haven't had any problems. Although I still use 5.0grs of Clays under a 225/230 TC in the .45 Colt. If it ain't broke don't fix it.

Long time Caster/Reloader, Getting back into it after almost 10yrs. Life Member NRA 40+yrs, Life S.A.S.S. #375. Does this mean a description of me as a fumble-fingered knuckle-draggin' baboon. I also drool in my sleep. I firmly believe that true happiness is a warm gun. Did I mention how much I HATE auto-correct on this blasted tablet.

Attached Files

  • Liked by
  • M3 Mitch
John Alexander posted this 25 January 2019

I also do what RD does. Once you get into the habit you don't even know you are doing it and it eliminates that possible variable. It mostly  only works when shooting from the bench so for plinking or hunting is nice to have a powder that doesn't care.

John

Attached Files

  • Liked by
  • M3 Mitch
Eutectic posted this 15 March 2019

The recommended starting load for Trail Boss is 70% of a full case. I would expect the SD would be lower at this level, but the velocity and noise are going to be much higher. 

In my experience Unique did not perform well until loads were much heavier, supersonic and noisy in the 308 and 06. It also did not give accuracy as good as a heavier charge of a slow rifle powder at the same velocity.

I did not test Bullseye, I have used it, the charges are almost the same as Red Dot for the same velocity. Accuracy with Bullseye was very good, but Red Dot always seemed to give a slight accuracy edge for me.

Any of the fast powders tested will be worth experimenting with for accuracy in gallery loads. I now have a nice selection and plenty left so the temptation is great.

Steve

Attached Files

  • Liked by
  • M3 Mitch
Qc Pistolero posted this 17 March 2019

OU812,
Tite Group seemed to produce more smoke.

 

 I agree...and so does Power Pistol and Blue Dot.I hadn't noticed until I started shooting indoor.I now avoid using them indoor so as not to get angry looks by fellow shooters.

 

 

Attached Files

Eutectic posted this 18 March 2019

QC,

I have shot thousands of rounds in NRA 2700. Bullseye produces more smoke than VV 310 or WW 231. This is hard to quantify with cast loads since cast loads produce smoke from the lube.

My experiments with jacketed bullets show this conclusively. Hercules powders have polyester and rosin in the composition which may contribute to smoke and black residue on the firearm. However they frequently give smaller velocity spreads compared to other powders  I am not a powder chemist but Hercules is doing something right!

Steve

Attached Files

  • Liked by
  • M3 Mitch
Close