16ga.com ~ View topic - Pressure Trace II 16 ga benchmarking and calibration

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

Pressure Trace II testing is proceeding again after restoring the firmware in the module which somehow became corrupted. Some useful pressure data was collected for 7/8 oz loads with Clay Dot powder which showed comfortable headroom with 1225 fps loads compared to factory loads. 1290 fps loads also looked in line with factory loads but might be a little hot for skeet.

My Pressure Trace II testing uses factory loads as benchmarks. I am seeking lab tested pressure values for factory loads, especially Fed 1 oz Game Loads. If anyone has submitted factory loads to Tom A or Precision I would greatly appreciate a peek at the data.

My ultimate goal is to maintain a supply of lab tested factory loads from a known lot number for system calibration, but at this point any factory load lab data would be welcome.

TIA
B.

Joined: 04 Mar 2019 Posts: 1844 Location: Central ND

IMHO, you would be much better off buying 2 or more flats of new ammo with the same lot number and send 10 loads (5 loads is only an idea of what you have) to either Tom Armbrust or Precision. Lots vary and they don't always have the same powder in them, as they rarely use canister powders.

Or you can always buy primers, powder and wads all with the same lot number, to make your own reference loads and send 10 off to be tested.

You are better off sending in loads that you are 100% sure of their source, than to rely on what may or may not have been done by others. After all, you are trying to get accurate results so that you don't have to keep sending in loads for verification, correct?

I did this years ago, so I would know that my chronograph numbers are correct. I loaded my own loads and tested them.

Whatever you decide, keep a record of each time you shoot the reference. Over time the reference loads may change, it can take a few years for this to happen, but it might. Sometimes they get hotter and sometimes they drop off a bit. Just know it happens.

SAAMI addresses this possibility in their standards regarding reference loads.

If you are skeptical of what I have offered, you may want to speak with Tom Armbrust directly for his thoughts.

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

Mark, yes that is my intent, and we have a few flats at the club that would serve that purpose. I have already set aside a couple boxes for that. Having a few initial data points might help me get in the ballpark before I go all in with a formal calibration. I seem to recall that Tom cuts back on testing during winter months.

Thanks
B.

Joined: 04 Mar 2019 Posts: 1844 Location: Central ND

Yes he does. Until the end of March I believe.