Sub Sonic Ammo Conversation

[pennys dad]

I am looking for thoughts and feedback on this.
I have been testing out different ammunition for the past few range trips. I am using a CMMG 22lr dedicated 20" government model upper. Testing distance is 100 yards and i am firing 10 rounds per string. I am sticking to 40 grn bullets.
What I am doing is seeking the most accurate ammo to price ratio.
I tested:
Federal Champion Target, 40 grn, 1240 fps, $5 for 50
CCI Mini-Mag, 40 grn, 1235 fps, $6.50 for 50
CCI AR Tactical Rimfire Ammunition, 40 grn, 1200 fps, $25 for 375
CCI Velocitor Ammunition, 40 grn, 1435 fps, $8 per 50
Federal AutoMatch Target, 40 grn, 1200 fps, $17 per 325
Federal Premium Gold Medal Target, 40 grn, 1080 fps, $7 per 50
Remington Thunderbolt, 40 grn, 1255 fps, $4 per 50
Winchester Super-X High Velocity, 40 grn, 1255 fps, $4 per 50
Eley Target, 40 grn, 1085 fps, $10 per 50
CCI Green Tag Competition, 40 grn, 1070 fps, $17 per 100

Best results so far have come from :
Federal Premium Gold Medal Target, 40 grn, 1080 fps, $7 per 50
Eley Target, 40 grn, 1085 fps, $10 per 50
CCI Green Tag Competition, 40 grn, 1070 fps, $17 per 100

I figure the sub-1100 fps rounds are doing best because the reduced recoil allows a very repeatable return to shooting position.

Now here is my question: Isn't subsonic about 1080 fps at 5000 ft?

[vintagearms]

I would also look at SSK subsonic although its not cheap.

[Intimid8tor]

Speed of sound is 1126 ft/s in dry air and 20 degrees Celsius. This value changes for humidity, temp and altitude. At 5K feet the speed of sound is 1080-1100 fps.

Not sure what you are asking. The 3 that are doing best are also some of the more expensive rounds which would make sense. Bulk ammo has a lot of variability in the rim thickness which impacts the consistency of the bullet.

[pennys dad]

HAhahahaha
WOw, ok I have head and chest cold so my thought process dropped off.

If Speed of Sound is 1080 to 1100 at 5k, and CCI sub-sonic "Silent CCI" travels at 1050 fps then it should work well out of my rifle and I can go ear plug less :-)

Right?

I pose the thought because I was going to order CCI Green Tag but noticed the Sub sonic was running at 1050 and it made me wonder.

[G-forceJunkie]

Bang for the buck, give Wolf Match Target a try. All "match" ammo is going to be subsonic.

[Quinc]

You haven't tried Lapua .22LR yet?!

It's only 27$ per 50 too!

http://www.grafs.com/retail/catalog/product/productId/9442

[Intimid8tor]

HAhahahaha
WOw, ok I have head and chest cold so my thought process dropped off.

If Speed of Sound is 1080 to 1100 at 5k, and CCI sub-sonic "Silent CCI" travels at 1050 fps then it should work well out of my rifle and I can go ear plug less :-)

Right?

I pose the thought because I was going to order CCI Green Tag but noticed the Sub sonic was running at 1050 and it made me wonder.

I would imagine it would work fine out of your rifle. Whether or not it is hearing safe depends on the db level at 1 meter.

A P22 with standard ammo has a db measurement of just under 161db

Hearing safe is low 130's I think.

[pennys dad]

good info, I appreciate the comments

Keep ear plug in!

[Izzy43]

I don't think this has been mentioned here so one of the issues with High Velocity ammo occurs when it transitions from super sonic to sub sonic (reverse of breaking the sound barrier). This causes a pressure wave at the tip of the bullet and causes it to wobble hence causes accuracy issues. This occurs at approximately 45-50yds depending on the enviroment. Sub-sonic ammo does not go thru this transition and will therefore always be more accurate than HV ammo.

One will not find any match target shooters using HV ammo, its all sub-sonic. The more you spend the more accurate it tends to be. My go to ammo is Wolf MT or SK Std + (actually the same ammo made by Lapua) and cost is $4.50-5.00/50. I have tried more expensive ammo but my skill level does not warrant the extra cost.

I purchase the ammo from J&G sales in Prescott, AZ. Cost is $4.65/50 if you purchase 10 or more 50 round boxes. When adding in shipping the sweet spot for cost is to purchase 30 or more boxes.

While not as accurate as the Wolf/SK you may find CCI Std Vel or Eley Sport locally at around $3.50/50.

[Intimid8tor]

I don't think this has been mentioned here so one of the issues with High Velocity ammo occurs when it transitions from super sonic to sub sonic (reverse of breaking the sound barrier). This causes a pressure wave at the tip of the bullet and causes it to wobble hence causes accuracy issues. This occurs at approximately 45-50yds depending on the enviroment. Sub-sonic ammo does not go thru this transition and will therefore always be more accurate than HV ammo.

One will not find any match target shooters using HV ammo, its all sub-sonic. The more you spend the more accurate it tends to be. My go to ammo is Wolf MT or SK Std + (actually the same ammo made by Lapua) and cost is $4.50-5.00/50. I have tried more expensive ammo but my skill level does not warrant the extra cost.

I purchase the ammo from J&G sales in Prescott, AZ. Cost is $4.65/50 if you purchase 10 or more 50 round boxes. When adding in shipping the sweet spot for cost is to purchase 30 or more boxes.

While not as accurate as the Wolf/SK you may find CCI Std Vel or Eley Sport locally at around $3.50/50.

That is good information on the instability when the round slows down. I was unaware of that. Thanks for sharing that info.

[pennys dad]

Excellent info Izzy43, Thank You

I am going to restart the test and keep all ammo under 1080 fps, 40 grn and under $6 per 50 at 100 yards.
Hmm I wonder if I can spin up a group ammo buy :-)

[pennys dad]

I am also doing similar test with my GSG 22lr which I am finding works best with 1200 fps and above.

[Izzy43]

Excellent info Izzy43, Thank You

I am going to restart the test and keep all ammo under 1080 fps, 40 grn and under $6 per 50 at 100 yards.
Hmm I wonder if I can spin up a group ammo buy :-)

Wish I had known earlier I just got 5000 rounds of SK Std + from J&G Sales. Maybe some others would be interested. J&G has about the best price and shipping only takes 3 days to SoCal.

Sending you a PM.