Page 1 of 2

AAC 125 OTM Recipes

Posted: Tue Oct 18, 2011 3:34 pm
by Dr.Phil
Now that the new AAC 125 grain OTM bullets manufactured by Sierra are available, lets share some loads...

My initial test regiment will be using:
- R&P 300 BLK Primed Brass
- LC converted brass primed with Federal 205M
- H110 Powder
- N110 Powder

125 AAC OTM (Sierra)
R&P Primed 300 BLK Brass
Case Length 1.368" (+/- .020")
OAL 2.23"
Starting Loads: 17.0 grains

Target velocity :2,000 fps from my 10" Noveske Barrel
(Reported velocity from a 12.5" test barrel & Rem factory ammo was 2,130 fps)
I will later do a ladder test to determine the optimum charge weight but will start with the Remington velocity since they have had such good results.

I ordered my bullets today and hopefully will be able to test them this weekend.

Re: AAC 125 OTM Recipes

Posted: Thu Oct 20, 2011 11:53 pm
by lmb7784
Tagged for interest

Re: AAC 125 OTM Recipes

Posted: Wed Oct 26, 2011 2:34 pm
by PaleHorse
TAG!

Re: AAC 125 OTM Recipes

Posted: Fri Oct 28, 2011 9:12 pm
by hugegator
In for the results. I'd like to see a gel test on these, too.

Re: AAC 125 OTM Recipes

Posted: Wed Nov 02, 2011 3:43 pm
by Dr.Phil
Finally got a chance to try these puppies out.

Just preliminary test results, but I am very impressed with the feeding of this new bullet.
(I would recommend using a VLD chamfer tool on your brass to keep from shaving copper off the jackets of these flat based bullets.)
I did not have a chance to do any testing with H110 yet, just N110.
Last night I made up a full test battery of both H110 & N110.

Barrel: 10" Noveske with TBAC 30P-1 mounted
Temperature: 62F
Elevation: 12' above sea level

Initial results with N110:
17.0 grains of N110
Average velocity: 2040 fps
Image

18.0 grains of N110
Average velocity: 2230 fps
Image
NOTE: This load exhibited pressure signs.
(Even when using R&P 300 BLK Brass, Blown Primers and ejector marks on case head were present.)

Next test will be an accuracy comparison between:
17.0 grains of N110 using R&P 300 BLK Brass
17.0 grains of N110 with converted PMC .223 Brass and 205M primer
18.0 grains of H110 with converted PMC .223 Brass and 205M primer
19.0 grains of H110 using R&P 300 BLK Brass

After that test, I will do a full Round Robin Ladder test to determine Optimum Charge Weight.

My prediction is that the N110 will yield the best results.
It may be a bit more expensive, but it is the cleanest burning powder that I have ever used...

Re: AAC 125 OTM Recipes

Posted: Thu Nov 03, 2011 3:04 pm
by misterchaos
I just purchased some of these bullets from Midway. Is 2.23" OAL what Remington uses for their factory load?

Re: AAC 125 OTM Recipes

Posted: Thu Nov 10, 2011 8:50 pm
by HotLead
Dr.Phil wrote:Finally got a chance to try these puppies out.

After that test, I will do a full Round Robin Ladder test to determine Optimum Charge Weight.

Dr. Phil,

Can you explain in detail how you do the Round Robin Ladder test? This is the second mention I have heard in a week about this test and I would like to learn more.
Thanks.

Re: AAC 125 OTM Recipes

Posted: Fri Nov 11, 2011 9:19 am
by Dr.Phil
I would be happy to.
The round robin Ladder test allows you to find a load that is optimal for your weapon.
This test is the quickest way to find your accuracy node and also negates as much error as possible.
Since I do a lot of long range competition, finding your node and loading to it can have a significant impact on your performance.

Jason Baney's article is the best I've seen explain it.
http://www.6mmbr.com/laddertest.html
If you follow Jason's process, you will have found a load that will be very accurate for your rifle and be tolerant to differences in load and environmental conditions.
(It is actually much easier to do the test than is sounds...)

Re: AAC 125 OTM Recipes

Posted: Sat Jun 02, 2012 10:10 am
by mjb2
So, any followup on the N110 loads? I can just barely stuff 17.0 grains under the 125 Sierra...loaded to 2.250" OAL.

Re: AAC 125 OTM Recipes

Posted: Mon Jun 04, 2012 8:54 am
by wildfowler
I've got a question about that round robin.

If you wanted to test subsonic loads for the optimum powder charge, do you still need to shoot them at 300 yards or greater? This is very interesting to me. Thanks for bringing this up.