S&W 500 v. Trail Boss powder
Just an FYI and an important note or two about Trail Boss powder.
First, I did a BUNCH of research on the Trail Boss powder because I'd heard nasty rumors about not being able to use it with jacketed bullets and occurrences of violent pressure spikes (spikes, not just high pressure.) I spoke with Smith & Wesson, the maker of the electroplated lead bullets that I am using (LeadSafe bullets from Rainier Bullets), to the tech support people a IMR about the powder, and private email with people who'd experimented with the powder. I feel entirely confident in making the following conclusions:
- When loaded properly, Trail Boss does not cause violent pressure spikes ...whether with jacketed, electroplated lead, or lead bullets.
- According to IMR, Trail Boss powder may result in inconsistent groups when shooting jacketed bullets but should work just fine with electroplated lead and lead bullets. IMR did not explain why jacketed bullets may have inconsistent groups but said that their testing showed this. Probably something to do with inconsistent burn rates at higher pressures.
- Loading Trail Boss powder properly is a) maximum load is a full case no matter what, b) the powder should never be compressed ...it must be sitting loose in the case.
- Crushing or compressing Trail Boss powder breaks the little Cherrios disks of powder and as a result, the exterior burn-controlling coating on the powder is violated. If you do this, then yes, you can expect inconsistent burn rates and sometimes high pressure spikes. It's important to use loading practices that do not fracture the gun powder granules.
With that info under my belt, I loaded up 50 rounds of 500 S&W. I used Federal 210M primers, new Starline brass, my 335gr Rainier Ballistics LeadSafe electroplated bullets and seated the bullets to a COL of 2.038". With these bullets loaded to that COL, I could only fit in 12.6 gr of Trail Boss without risk of crushing the powder ...which means the 18.0 gr loading listed in the 2007 Hodgdon Annual Manual article on Trail Boss for the 500 S&W is a BAD LOAD and WILL compress the powder. I'm going to write to Hodgdon about this since it may result in dangerous loads for someone.
I still have not crony'd anything, but the 12.6 gr loads should be producing somewhere around 1000 to 1150 fps. In shooting them, the recoil seems about right for a load like that. Accuracy from these rounds was excellent. My best group had all 5 holes cutting each other and that was from 25 feet, 2-hand modified Weaver grip, double action, standing. My other groups were a little larger, especially after I was getting tired, but this group shows the potential of the gun with this load in it. Oh, I really like how the S&W double action trigger pull works on this gun. Switching to double action after shooting single action did not degrade my accuracy (this is only my second time out with this new gun)