.348 W + Trail Boss = No Joy!!!

[rbertalotto]

Ok,  I bought a Browning (Winchester) Model 71 this week. Sent away to Buffalo Arms for some brass which came in within two day! Great service here! Jamerson brass....

I found some Hornady 200g bullets at my local gun shop and a box of factory Winchester  348 ammunition.

Wanted to try "plinking" loads with the Hornady bullets so I used the TrailBoss powder formular...Fill the case to the base of the bullet, weigh this charge and start at 70%.

I loaded 5 rounds at 14.5G of TrailBoss, 5 at 16.5 and 5 at 18.5.....Off to the range.

Loaded the 14.5g load...pulled the trigger...couldn't open the action! Had to use a cleaning rod to bump the case out of the chamber before the lever would move and the case would extract. Primer was flattened like signs of high pressure......Strange....

I tried a factory load and the recoil was much greater, but the case extracted beautifully. Tried another factory load and the gun ran great. No issues!

Tried another 14.5g load. Same result. Very little recoil and a stuck case.

Thinking something was wrong with the brass, I measured every dimension and it was exactly to spec and identical to the Winchester factory brass.

Thinking that the 14.5 load was too low of power and doing something strange, I tried the 18.5g load. Same result, little recoil, locked up gun, flattened primer.

I returned home and pulled the remaining cartridges apart and reloaded them with a stout load of 4007SSC and 3031...Much higher pressure ratings than the TrillBoss loads....

Back to the range and these loads fired and ejected perfectly!  Smooth as silk....and very accurate I might add. Not a "plinking" round as the recoil was stout.

Strange that a light load would show signs of pressure and lock the action up tight, but a full house load worked great.

It couldn't be "predetonition"  as the case even with only 14.5 grains of powder was 75% full. TrailBoss is an extremely bulky powder.

Any ideas?

[pony express]

Sounds pretty odd. I never used TB in a .348, but I have used anywhere from 9-12 grains in various .30 to 8mm milsurp calibers with no such problems (Cast bullets only). Closest thing I came to a .348 was 8mm Kropatchek, which is a re-formed .348 case necked down a little, and the shoulder blown out some. I think I used from 11-12 gr in that.

[Charlie Bison]

Odd. I've been loading 348 w/16 grains of Trailboss and shooting it in my Browning 71 with zero issues. For me, it has been very accurate.

[Trailrider]

This does sound a bit odd... Did you notice any ignition delay or hangfire with the TB load? Did you try pulling the bullets from the factory loads, reloading with the 14.5 gr TB and re-seating the factory bullets?  Did you try backing off on the TB loads at least firing a single round? Trail Boss is certainly a bulk powder, but still rather fast-burning. It may be that the "formula" is just a bit off for this powder in such a large, bottlenecked case. 

[rbertalotto]

No ignition delay...no hangfire....

I didn't pull the bullets of the factory cases and experiment as you suggested. Good idea!

Lots of folks are reporting using TB in 375 H&H and other, much larger cartridges with excellent results. A few have reported using TB in the 348 with cast bullets....16g under a 250g  or 200g cast bullet.

Maybe it is the jacketed bullet that it didn't like?

[pony express]

Have you used that particular can of powder in anything else?

[rbertalotto]

Yes, this was an open bottle of TB that I use in 38-40 and 45Cowboy Special.....Have loaded a few thousand rounds from the same batch of powder that I bought at the same time (6 bottles) with the same batch numbers.