H&R .223; low pressure test

[Jim]

I've always been fascinated with super subsonic loads. So, I ran a test today with my H&R .223 rifle.

I loaded nine rounds of 55 gr. FMJs over Bullseye in decreasing loads. The highest load was 5.0 grains of Bullseye and each load was decreased by .5 grains. The lowest load was 1.0 grains.

I knew, sooner or later, I would stick a bullet, but I was prepared for that. I started at the 5.0 load and worked down. Believe it or not, the 1.5 gr. load actually pooted the bullet out of the barrel. The bullet over the 1.0 gr. load stuck. I got it out with no problem.

There's no way I can quantify the muzzle report except to give you my interpretation of the volume on a 1 to 10 scale. I shot this test with out plugs or muffs because I wanted to hear the report as it actually sounded.

Assigning a level of 10 to the 5 gr. load, the 4.5 and the 4.0 seemed to be right at 10. I couldn't tell any difference. All shots below that were audibly quieter. I would say the 3.5 was about 7 or 8. The 3.0 was about 5 or 6. The 2.5 was about 4 or so. The 2.0 was about 3. The 1.5 was barely audible and the 1.0 stuck in the barrel.

The next phase of this experiment is to start working back up, looking for the sweet spot. I intend to start at 3.0 and go up in .2 gr. increments. The ultimate goal is to see how little powder is required to get the bullets to group at 50 feet. Once I determine that, I'll switch powders and start all over again.

The powders I'm looking at are all relatively fast powders. Unique, Red Dot, 2400 & WC820. It will take me a while to get all this done, but at least I got it started. I'll report as I progress through each powder.

[williamwaco]

Is a 3 or 4 quiet enough to shoot in my back yard?



.

[Jim]

I would say so. Of course, that depends on who your neighbors are and how close they are.

[izzyjoe]

i wonder how those would work in an AR, may not cycle the action but i could work it manually.

[Jim]

There's no way there's enough gas produced from this to cycle an AR.

[felix]

Jim, those are my results exactly in just about every rifle and pistol I have. I used a swimming pool as the target, with my sons retrieving the boolits. The boolits at 2.5 BE hit the bottom slightly via 12 feet of water. Impact was not solid enough to mark the boolit except gradually on the noses. Boolit weights were 50 through 300. Guns were 22 thru 45. Purpose was to get barrel measurements. 2.0 grain loads were not sufficient to clear all the barrels. Used a wad of toilet paper as the powder wad. ... felix

[Jim]

Felix, thank you for the verification and vote of confidence. When I start testing with Unique and Red Dot, I'm going to use a tuft of dacron as a locator.

[Larry Gibson]

Problem with reduced loads like that in the AR is as soon as the bullet passes the gas port a large amount of gas is vented into the gas tube. The reduction of psi can cause the bullet to stick in the barrel very easily.....been there and done that........I learned the hard way not to go below 5.5 gr Bullseye with 55 gr FMJs.

I developed what I called my "Panama load" (after years of reading Whelen's tales of reduced loads for hunting the Pamama jungles with his '03) for use with an M16A1 while I was in Panama and Central America. I'd pull the M193 bullet with a blasting cap crimperand dump the powder. A 45 ACP bullet was pulled and the powder from that put in the 5.56 case. The M193 bullet was pushed in the case backwards and the case mouth crimped (again with the blasting cap crimpers) in the canelure groove. Accuracy was quite good to 50 yards (a very long shot in the Panama jungles) and velocity was 1500 - 1550 fps. That Panama load was a single shot affair but that was ok for hunting and it was quite deadly on the small game there.........

Cast bullets, especially softer cast ones, can be driven much slower out of AR 223s and bolt/SS rifles w/o sticking a bullet though.

Larry Gibson

[Jim]

I just walked back in from firing nine pressure test rounds.

55 gr. NATO ball (FMJBT w/ cannelure).

2.0 to 6.0 grs. of Unique in .5 gr. increments.

1 gr. (weight checked) of 1" thick dacron tamped down over powder as locator.

Lake City Brass

CCI small rifle primers

I started at the 6.0 gr. charge and went down. The 6.0 charge flattened the primer just enough to get a print.

The bullet over the 2.0 charge stuck in the barrel about 9 or 10 inches in from the breech. Again, got it out without any problems.

[Hamish]

[QUOTE=williamwaco;1860995]Is a 3 or 4 quiet enough to shoot in my back yard?/QUOTE]

I don't know, what time does the BBQ/Testing Session start???

[izzyjoe]

thanks Larry, i did'nt think of that. i'm not going below 4gr. so that should work fine.

[Jim]

I fired the test loads I made up the other day.

FIRST TARGET

.223 H&R FITTED WITH 3X9 SCOPE SET TO 6X
UNIQUE LOCATED UNDER 1 GR. OF DACRON
55 GR. NATO FMJs
100 FT.
CHARGES ARE MARKED ON TARGETS

3.1 looks promising. I don't think the one flier was me, but could have been. 4.0 looks promising as well.



SECOND TARGET

SAME CRITERIA AS ABOVE EXCEPT:
BULLSEYE WITH NO LOCATOR

3.3 isn't bad except for the flier. 3.9 looks promising.

[GT27]

Looks to me like 4 grains of Unique is your "huckleberry" Jim,IMHO of course!GT27

[izzyjoe]

look's like 4gr. is what i'll try, i'll let you know how it work's in the AR. what was the distance you where shooting at Jim?

[Jim]

Izzy, thanks for bringin' that up. 100 ft. I forgot to include that in the test criteria.

[tacklebury]

I use 4.2 gr. Unique to replicate a .22 lr load. 1150 fps and groups well with a Winchester 40 gr. HP designed for Hornet. At 4.1 gr. and below, velocities across the chrony varied almost 60 fps on a 5 shot test. 4.2 was the first consistent load level that held less than 10 fps on a 5 shot string.