16ga.com ~ View topic

Member Joined: 31 Aug 2005 Posts: 1257 Location: Nebraska

Has anyone used Alliant 20/28 powder in their small gauges, or believe that it would be appropriate for our lighter 16 efforts?

I am loading it in the 28ga. and am very happy with it. Burns very clean and the powder drops are super consistant. It costs a little more per pound but you use a little less so overall costs are about the same.

I also think that 20/28 would make a very good 16ga powder, especially for 7/8 & 1 oz. loads. It's burn rate is similar to Unique but it is a denser powder. In my 28ga. I use a #14 bushing where #19 is needed for the same load with Unique.

I would like to load something up and sent it in to Tom Armbrust but I am not sure where to start. Anybody have any ideas?

Guest

SL I would start with a known 20 gauge load that is in the pressure and velocity range that you are shooting for using the brand/type hulls and primers that you intend to have tested then add 10% more powder to account for the increased hull capacity. Be sure you weigh the powder charges and shot charges individually then send them off to Tom for testing by UPS. WARNING Don't shoot these before you get the test results back from Tom.

Toms address is: Ballistic Research
1108 West May Ave.
McHenry, IL 60050-8918

Be sure you identify the hull/length, primer, powder/charge weight, shot weight and crimp.

Also include a phone number he can reach you.

Member Joined: 31 Aug 2005 Posts: 1257 Location: Nebraska

I see the 16ga as closer to a 20ga than a 12ga--we tend to use powders with 20ga applications more so than 12ga, except for some of these lighter charges of shot where some 12ga target-appropriate powders work well. I look at what we have in 16ga that closely approximates what is listed for 20ga, and go from there.

I'd think a loading that gets high/near max pressure for a 20ga and 7/8oz of shot in a given type of hull and type of wad would be a good starting point for a 16ga with 7/8oz and less shot. Presumtion would be that the larger hull/wad diameters would result in reduced pressures, maybe comparable to slightly higher velocity. If pressures drop too much, so be it at least we have a starting point.

It's probably been stated before regarding this process, but everyone should be aware that loads sent for testing must have their shot and powder charges individually scale-weighed, not thrown from the press' bushings. It's only a handful of shells, so it's not too much bother, but has to be done for accuracy's sake.

kgb

Guest

Tony that is a great tutorial, thanks.

Joined: 06 Mar 2008 Posts: 596 Location: 17603

Tony,
Thanks for the math, and the detail. I must confess I simplify it;
Up the the powder charge; velocity increases the same %
Pressure increase is TWICE that percentage.
Fast powders can hit a "spike" point where all bets are off,
so when I'm dreaming up loads I always use "slow for gauge/caliber" powders.
Can't recommend my approach, but it works for me.
With my case of DR16's and the free testing, I'm thinking of trying some
Clay Dot behind 3/4oz. Judging from some of the Red Dot data for the 16ga,
I'm guessing 18grs of Clay Dot in a Cheddite might be interesting.
Cheers,
R*2

Guest

Nice job, Tony. I have to admit I do not have a specific formula, but I pay close attention to the relationship between the hull capacity, powder burn rate, and powder charge weight. Like Russe11, I'd rather ere on the side of slightly slower powders, but not too slow burning. It's been interesting to look at the data so far. I think we as a group will get these loads dialed in nicely by the end of the summer. My bench is clear and ready. I have to load up a bunch of 3/4 oz skeet loads and then I'm going to start with the Federal hull, 7/8 oz w/International Clays and a Win primer. I'll dig out my chronograph and see what 16, 16.5, and 17 grains do for FPS and go from there. When and if I can get something in the 1200 fps range I'll send it for pressure testing.

Joined: 28 Mar 2008 Posts: 1460 Location: Eagle, Nebraska

wow. Interesting if not a little hard to swallow all in one post. I am going to print that so I can get it into my head. I am interested for several reasons,

trying to create a good 24ga load and data is hard to come by and I am looking at 20ga data, then back to 28ga data.(for same hull/wad/pwdr/primer etc) And I think I have some good places to start.

Your method may help in that regard, may help in finding a good short 10ga load too!

Member Joined: 31 Aug 2005 Posts: 1257 Location: Nebraska

It'll take me a little while to understand that all, Tony, but thanks for putting it down on "paper". The primers area another element with huge
impact on a load's performance and I've seen them not follow assumed
rules without being able to definitively blame the powder for the effect.

kgb

Joined: 08 Feb 2009 Posts: 1310 Location: Western WA

Joined: 08 Feb 2009 Posts: 1310 Location: Western WA