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< 16ga. Ammunition & Reloading ~ rgl load velocity |
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Posted:
Thu Oct 01, 2009 3:17 pm
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Member
Joined: 02 Feb 2007
Posts: 371
Location: mpls mn
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I messed around with some loads using RGL hulls, federal primers and dr16 wads ¾ oz shot. Here’s what I came up with -btw I know nothing about reloading or pressure use data at your own risk
14 grains green dot
High velocity-1236 f.p.s.
Low velocity-1207 f.p.s.
Average out of 5 shots- 1221 f.p.s
Standard deviation -11 f.p.s
15 grains green dot
High velocity-1293 f.p.s.
Low velocity-1259 f.p.s.
Average out of 5 shots- 1272 f.p.s.
Standard deviation – 13 f.p.s.
16 grains green dot
High velocity-1336 f.p.s.
Low velocity-1319 f.p.s.
Average out of 5 shots- 1330 f.p.s.
Standard deviation – 7 f.p.s.
16 grains IMP PB
High velocity-1288 f.p.s.
Low velocity-1221 f.p.s.
Average out of 7 shots- 1247 f.p.s.
Standard deviation – 22 f.p.s.
I also tested 5 RGL factory loads, that averaged 1220 fps
Standard deviation of 7, which surprised me a little – I measured out all my powder and shot charges very carefully with my pact scale-even cut shot in half to get a perfect 328 grains of shot. How does a factory get such consistent loads? my next question has anybody else test these loads what did you come up with? |
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Posted:
Thu Oct 01, 2009 8:22 pm
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Joined: 06 Aug 2009
Posts: 960
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The factories match the powder to the payload. Green Dot and PB are on the slow side for the 3/4 oz loads, in a 2 3/4" 16 Gauge hull. Once you find the right powder, then you have to find a primer that matches up with the combination. Pressure is next, the pressure needs to be kept over 9000 PSI, it isn't a huge deal, and you can get lower pressure loads to be consistent, but pressure is your friend.(I know I will get comments.) The crimps need to be properly formed and at a uniform depth of 3/64" to 1/16". The big edge the factories have is all new components and components designed for that load. Mostly powders for every application under the sun.
As far as weighing powder and shot loads, while I won't come right out and say it is wasting time, I will say that your time could be better spent. A reloading machine should be able to throw +/- .2 grains on powder and +/-5 grains on shot. Those are extreme variation numbers, with most loads being at half that tolerance.
The other number that you need to look at is Extreme Variation when velocity testing. That number is almost more important than Standard Deviation. Extreme Variation on velocity should be kept to 35 FPS and under. For 3/4, 7/8 and 1 oz. loads in a 16 Gauge, that should be fairly easy, unless you use powders that are on the slow side, then it will get a bit more difficult. 7 FPS SD is also easy to achieve for those loads.
Below is an example of the kind of load that I have reloaded on a MEC 9000H 12 Gauge and the results. The test was done on February 7, 1997. The purpose was to find out just how good my target reloads were. The test loads were actually loaded on the progressive with no weighing of powder or shot beyond setting up the machine. The equipment was:
Oehler M- 35P with Skyscreen III, start screen at 2' from muzzle.
Piezotronics - Transducer, Amplifier and Digital Volt Meter
D & H 30" - 12 Gauge Test Barrel, with 2 3/4" Chamber, cylinder choke,
D & H Universal Receiver.
Temp 37 Degrees F - Bar. Press. 30.18 - RH 52%
Corrections were:
+4 FPS +180 PSI
Federal Gold Medal 12 Ga. 2 3/4" hull
CCI 209 Primer
18.5 Grains - IMR 700-X
Federal 12S3 Wad
1 1/8 oz. # 7 1/2 Lead Shot
Average of 5 loads
FPS PSI
1,226 9,600
1,221 9,500
1,232 10,000
1,222 10,000
1,227 9,700
Average FPS 1,225 SD 4 EV 11
Average PSI 9,760 SD 230 EV 500
There were 7 more loads as I was working in .5 grain powder increments. The worst was FPS SD 11 EV 28 the best was FPS SD 3 EV 8.
Just so you know my biases. I am not a low pressure fan. I like to use the fastest burning powder I can for an application. |
_________________ Mark |
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Posted:
Thu Oct 01, 2009 9:09 pm
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Member
Joined: 09 Dec 2005
Posts: 989
Location: Las Vegas
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Mark: I agree with everything you say. However, for us shooting older guns pressure becomes an issue so we have to walk a tightrope to some extent on that issue. I also use an Oehler 35 and agree it's tougher to get consistently low extreme variations with lower pressure loads.
Matt |
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Posted:
Thu Oct 01, 2009 9:19 pm
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Joined: 06 Aug 2009
Posts: 960
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Matt,
I know that my views aren't popular with folks that have Damacus barrels and some with Euro guns with different/ lower proof pressures than the standard SAAMI stuff.
In this case I was just trying to help a guy get some consistent loads, and I know if he goes the low pressure root he will get more bad than good.
I wish I had that Oehler Chronograph, heck I wish all that equipment was mine, but it belonged to the company I worked for. I have a ProChrono now. So far it has been consistent and reliable. But I could trust the Oehler, I can't even remember how many shots I put over it, thousands I am sure. They sure are nice stuff. |
_________________ Mark |
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Posted:
Fri Oct 02, 2009 6:04 am
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Member
Joined: 16 Jan 2006
Posts: 1008
Location: Sandy Lake, PA
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robp wrote: |
How does a factory get such consistent loads?
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The type of gunpowder reloaders get to buy is called 'cannister' grade smokeless powder. It is made consistent so each container (more or less) is identical to the next one you buy. Ammo manufacturers have no such constraints. They formulate their own powders to meet their needs; they could mix a fast burnrate powder with a certain percentage of slow powder, add a little deterrent coating...whatever it takes to meet their needs. We can't buy such powders. Well, not exactly true. Some internet sites such as patsreloading.com sell surplus OEM powders but you pretty much use them at your own risk. And there's no telling if the next 8# jug with the same number on it will be anything close to what you bought before.
Ammo manufacturers mix and match different batches of powder to achieve certain speed and uniformity standards. They have ballistic laboratories to test their finished products. But custom gun powder is only one way to achieve low standard deviations. Wad pressure and crimping are other ways. Remember, the manufacturers always use brand new components. Us handloaders rarely do. |
_________________ ------------
Davy 03C&R FFL |
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Posted:
Fri Oct 02, 2009 7:52 am
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Member
Joined: 02 Feb 2007
Posts: 371
Location: mpls mn
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I am shooting modern guns -pressure isn’t too much of an issue for me. Once I get a consistent load velocity wise I will send it off to be pressure tested. I betting I won't have a safety issue developing a 3/4 oz 16 gauge load with 1200 - 1300 fps. I am only measuring my test loads one at a time for the sake of consistency. I will set up a charge bar and be done with it once I find a load I like.
Any suggestions on powder and primer combinations? Is 700X fast enough or would red dot or tite wad be more appropriate in terms of using a powder with a faster burn rate?
How about primers. What's works -a cool primer matched with a fast powder of vice a versa? |
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Posted:
Fri Oct 02, 2009 8:29 am
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Joined: 06 Aug 2009
Posts: 960
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Robp
Mr. Hammack had a 3/4 oz , 16 Gauge load checked recently. He used Red Dot, it was very consistent, the best load I have ever seen. I am sure that 700-X would be fine also. I would start with Winchester 209 primers. Tite-Wad seems OK but, I think Red Dot or 700-X are better candidates.
A few suggestions, be sure that the crimps are firm and deep enough. Use only once fired hulls for testing. Don't get crazy with wad pressure. Use just enough to seat the wad on the powder 25 lbs. max. On a MEC reloader just enough that the wad pressure indicator bumps a bit on the full downstroke. If your crimps are good they will exert all the wad pressure needed for a consistent load. Consistency has a tendency to go south, if you start crushing wads. Let the gas pressure do the crushing. The less you manipulate and the less you add little fancy ideas to shotshell loads the better things will go.
My suggestions come from real experience. In other words I made a lot of mistakes, and screwed up enough to know what not to do.
I hope this helps. |
_________________ Mark |
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Posted:
Fri Oct 02, 2009 10:01 am
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Member
Joined: 02 Feb 2007
Posts: 371
Location: mpls mn
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Thanks for the tips I was pretty carefull in selecting the best crimps out of my green dot loads but I have to admit a couple of the PB loads were pretty sloppy I always use 1 once fired hull for testing. |
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