Thursday, October 9, 2008

Improved powder selection

I was doing some target shooting with the 58 caliber round ball load that I developed. I could not reproduce hitting a target at 100 yards like I was able to do a previous week. (See the first posting.) Thinking about it I started to get concerned about the amount of "blow outs" the bottom skirt on the wad was experiencing. About half of the wads that I picked up off the ground had a split in the side of the skirt. One wad had the bottom skirt totally flipped up all the way around. I started figuring this would cause irregular velocity performance. It doesn't exactly explain why I didn't hit the target. There was also more wind that day but the round ball should not have been blown off that much.

Anyway I decided that for the slug load that the Nitro 100 powder may be too fast and that I would be better off with a slower powder. So picking from what I had on hand I tried Clays and Universal.

13.4 grains of Universal gave a speed of 1039 FPS but the inside of the barrel was very very littered with unburnt powder. This load was not going to generate enough pressure to burn that powder. So I did not pursue Universal.

Clays gave good clean burning results.
10 gr = 983 FPS
11 gr = 1120 FPS
11.4 gr = 1157 FPS
12 gr = 1196 FPS
13 gr = 1252 FPS

I ended up settling for the time being on using 11 grains which was basically a 1.6cc scoop. From a test firing I recovered 4 wads. Two had pin holes in the skirt and two were ok. So this was better but still a little suspect.

My next test would be to use 700X. However, I was trying to get ready for a youth deer hunt at Fort Knox last weekend that at the time would be in a couple days.

The irony is that, after having gone, I have decided that early October Youth deer hunts are a waste and you get realllly chigger bit! It was too warm and hardly anyone saw a deer. During the regular gun season, off post, he can use a good .223 round that is good for deer size medium game. So I may not end up ever using the 20 ga slug load I developed. We'll see. I have a couple more children that are still too young to hunt that in future years may want to try something on post during the regular quota hunts

So this next Saturday morning we will go squirrel hunting. We are a lot more likely to get a squirrel. I am still unsure of what to do about a shot hunting load though. I think that I may add some more lead shot to the hollow butt of the gun to reduce the recoil of firing standard 20 ga hunting loads. Also he'll wear a shoulder pad.

Monday, September 1, 2008

Low Recoil 20 ga shotgun

Background History
For around 15 years I have been hunting on post at Fort Knox in their annual deer quota hunts where they do not allow modern rifles for deer hunting. They limit the hunters to shotgun slugs or muzzle loaders. This year I wanted to sign my 11 year old son up for the youth hunt weekend there but would need to come up with a round he could fire that met the requirements. A couple seasons ago I had gotten a single shot H&R youth handi-rifle for him to use in a .223 rifle caliber. I realize it is a marginal deer caliber but he would not shoot the .243 a second time after trying it for one shot. That had been my first choice. We have not yet been able to shoot a deer with the .223 but he has enjoyed shooting it at the range.

Low Recoil 20 ga Shot load
Earlier this spring I took advantage of the barrel swap ability of an H&R single shot and got the receiver fitted for both a 20 ga smooth and rifled slug barrel. One shot of a standard 7/8oz at 1300 fps load was enough for both of us. He got knocked back a step and I observed that it kicked harder than my 12 ga shotgun because the gun was much lighter. My overall feeling after the fact was that I would have been better off with a 28 gauge for shooting shot. However, having bought it I wanted to try and make the 20 ga work. Also the 28 gauge barrel was only available as a fixed choke. So I started researching low recoil 20 ga shot loads. I bought all sorts of shotgun loading manuals and was disappointed that they had nothing on low recoil loads. What I finally came up with on the internet was an Alliant cowboy action load for ¾ oz at ~1000 fps. It used 9.5 grains of Nitro-100 powder. So I invested in a Lee Load-all and the necessary components. I took my son back to the range to try it out and he said it was better but still kicked too much. So I then finally ended up adding about a pound and a half of lead shot to the hollow stock of the gun to make it 6 ½ pounds and buying him a shoulder pad at Wal-Mart. Finally he was ok shooting the 20 gauge. The first shooting goal with the load that I had was for him to qualify for the Boy Scout shotgun merit badge by hitting at least 12 out of 25 on two different rounds. After several weekends working on it he did it. At that point he was tired of shooting and I am hoping that giving him a break will renew his interest in shooting skeet or trap with me this fall. I think that I like shooting more than he does.

Low Recoil 20 ga Slug load
So having gone through that whole exercise on a 20 ga shot load I turned to the 20 ga slug load. I looked at the commercially available loads for a low recoil one. The best one seemed to be the Low Recoil Federal True-Ball. However it had a little more recoil than what I was looking for from doing the math to compare it to the shot load. So then I started seeing what I could put together myself. There are Lyman slugs available but I was hesitant to go through the hassle of molding them even though I already mold my own Lee slugs. (Since then I found I can buy the Lyman 20 ga slug for 30 cents each from Gardner at http://gardnerscache.com/12_gauge_sabot_slugs.html). While researching slugs on the internet I ran across comments about .575 round ball loads in the Lyman 3rd edition Shotshell Handbook. So I bought a copy on Amazon.com. Then to avoid the trouble of having to mold the balls I decided to try using a .570” ball that was available for muzzle loaders on http://www.midwayusa.com/ . When including the wad pedals it still gave me about .012” of squeeze down in my rifled barrel which seemed likely to be enough. Unfortunately the recipe gave a resulting speed of 1500 fps using Blue Dot magnum powder. The recipe worked well at 1500 fps however it kicked really hard and so I started slowing it down. I tried it at 1300 fps and it was better but still too hard. So the next step was to go down to 1100 fps which I had suspected would be what the speed needed to be. My problem was that as I slowed down the load by reducing the powder amount the Blue Dot stopped burning well and was leaving a lot of unburnt powder in the barrel. My fear was that I was going to end up with an unpredictable load that in cold weather might perform very differently. As I was pondering this I realized that the powder solution for the shot load would likely work for the slug. I was dropping the ball in the same plastic wad and the weight was only 1/8oz less plus the desired speed was about the same. I tried 9.5 grains of Nitro 100 and a WAA20 wad in a Winchester hull. That gave 1066 fps. (By the way I measure the speeds with a Crony. http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=688064&t=11082005 ) A Remington hull left the powder a little loose with the same load and gave 1040 fps. So my final load was my next test which was to try 10.0 grains in a Remington hull. By pushing the ball in the wad down to the correct position for a folded crimp the powder was tight and I could not hear any shaking. The resulting speed was 1087 fps at about 10 feet from the muzzle which I decided was close enough to my goal of a 1100 fps muzzle speed. The powder burns well in this load with a typical small amount of residue.

Yes I am aware that this is an extremely marginal deer load. At 100 yards the speed should be 865 fps giving 464 ft lbs. I have seen 900 ft lbs given as a minimum recommended figure for deer. However, Kentucky allows handgun elk hunting with a 100 yard bullet energy of 550 ft lb so this load may not be unethical for deer. See http://fw.ky.gov/deerguide08elk.asp Also the sectional density of this round ball is about half of the recommended value. A .223 is a much better youth load giving better down range performance and less recoil. My .223 firing a Federal P223Q with a Nosler Partition bullet will give you 998 ft lbs at 100 yards and they are listed by Federal for Medium game like deer. I am going to pick up a box of those for the regular season and practice with cheap FMJ rounds. However modern rifles cannot be used on base. (Ironically I noticed that in the September 2008 American Hunter magazine from the NRA they had an article indicating that one study done by Mountain Top Technologies Inc. showed that shotguns were potentially more dangerous than rifles when you included ricochet travel distances.) So this round ball load can kill a deer but bullet placement is important (as normal) and the deer will likely run some distance.

At the range this slug load had a 100 yard spread of 8” from an 8 shot group. See the target image at the end of the post.

20 ga Round Ball Slug Recipe (~1100 fps muzzle speed)
· .570 lead ball (279 grains or about 5/8 oz.)
· 28 ga, ½” fiber wad to go in the plastic wad under the ball (9.3 grains was the weight)
· WAA20 plastic wad (30.4 grains was the weight)
· 10.0 grains of Alliant Nitro 100, this was the typical amount measured by a Lee dipper but I also adjusted it with a Lee powder scale each time to ensure consistency.
· Winchester 209 primer.
· 20 ga Remington STS Hull
This load is a tight fit in the hull and I found that it worked best to user the wad rammer to push the ball and wad down to the best position that gave a good crimp and then repeat that ram position each time. I ended up using a tape measure to check the handle distance from the floor to ensure that I got it right each time. The wad with ball is too tight to just drop by itself down onto the powder and has to be pushed down. I suspect that I could also get Hodgdon Tightwad powder to work but have not experimented with it. One reason that I wanted to use the Remington hull for this was that it made the hull different from my shot load where I was using a Winchester hull. However, they are still easy to mix up since both hulls are yellow so I mark the slug shells with a permanent marker.

20 ga Shot Load Recipe
· 3/4oz shot (I had to measure this with a Lee dipper as the Lee Load-All did not have bushings small enough to do this shot load or the powder load which was annoying.)
· 9.5 to 10 grains of Alliant Nitro 100 using a Lee dipper. The data says 9.5 grains will produce a velocity of 1037 fps.
· WAA20 plastic wad
· Winchester AA hull
· Winchester 209 primer.
· Normally the shot is a little loose so I have been using a 28 ga 1/8” felt wad under the shot or a Poly-wad spread-r on top of the shot to finish filling up the space. The Polywad does a very nice job of evenly spreading the shot for close shots.

Polywad results
A couple extra comments may be appreciated by folks interested in the spreader. See the following web site for the sales pitch http://www.polywad-shotgun-shells.com/spred-r-spreaders/. I did some testing and got the following results at an approximate distance of 10 yards using the same 20 ga barrel and an improved cylinder choke.
· 7”-9” spread with no spreader and magnum shot. The pattern was not a nice circle. (Possibly the uneven pattern was due to firing less than the standard 7/8 oz load for this gauge.)
· 11” spread using the Polywad spreader as the only change. (22-57% more)
· 12” spread using the Polywad spreader and chilled shot. (33-71% more) Overall the Polywad produced a more even distribution of pellets and a nicer round cloud than what should be the standard load out of my barrel.
I have also made a 12 ga spreader load that I have in mind to use on a couple close incoming skeet shots like the station 7 high house and station 8 for both shots. The 10 yard test results were similar to what I got with a 20 gauge. Shots were fired from a 30” barrel with a skeet choke.
· 9-11” and 10-11” spreads with a regular load. Once again there was some irregular shape to the pattern. (Possibly the uneven pattern was due to firing 7/8 oz instead of the standard 1 1/8 oz load for this gauge.)
· 9-12” and 12-13” spreads with an overshot card.
· 13” spreads with a Polywad spread-r. The pattern was more even and measured the same diameter at 90 degree angles. Overall this wad repeatedly produced a larger and more consistently round pattern.