.348 Winchester + TrailBoss = 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?

[Tatume]

If you would like some reduced loads try H4895:

https://www.hodgdon.com/PDF/Hodgdon%20H4895%20reduced%20rifle%20load.pdf

This is also the powder I'm using with bullets cast from the RCBS 348-200-FN mold. Recoil is pleasant, and accuracy is outstanding in my CPA Stevens 44-1/2.

Take care, Tom

[rbertalotto]

Thanks Tom,

As soon as my Accurate mold comes in, I'll try that.

[missionary5155]

Greetings
I would be calling the manufacturer of Trailboss before firing this powder or any other without some information to go by. You are dealing with a bottle neck case. Bottle neck brass tends to change burn characteristics of powder.
There is a lot of reliable printed info on the 348. I would tend to do some study before assuming Trail boss can be randomly loaded the way everyone thinks and states it can.
Mike in Peru

[NSB]

Trailboss can generate some pretty high pressures. Do some more reading on it. It isn't specifically a low pressure powder.....really. I have a half pound of it left from my dealings with it and it'll sit there forever before I use it again.

[Geezer in NH]

Sorry but you reloaded them. Not anyone else's problem , legally IMHO.

Stuck case and then added more powder?????????????????????

[Artful]

http://www.imrpowder.com/PDF/Trail-Boss-data.pdf

Hmmm, for 308 winchester 56 gr H20 volume they show
150 grain with starting 10.0 grains trailboss 1176 fps 25,800 psi
150 grain with max load 14.0 grains trailboss 1417 fps 27.100 psi

For 30-06 Winchester 69 gr H20 Volume they show
150 grain with starting 13.3 grains trailboss 1061 fps 14,700 psi
150 grain with max load 19.0 grains trailboss 1477 fps 26,400 psi

for 300 win mag 89 gr H20 Volume they show
150 grain with starting 18.0 grains trailboss 1302 fps 18,400 psi
150 grain with max load 25.5 grains trailboss 1687 fps 28,600 psi

So on your 348 Winchester which should have
about 75 gr H20 case volume
you used a 200 grain J-word (a heavier bullet)
and started with 14.5 grains of trailboss which showed pressure signs immediately.

I'd call Hodgden which imports trailboss and ask them about it.
Does anyone have quickload on their computer to run a rough guess.

[DAVIDMAGNUM]

I think the answer is very simple.
There are no loads for the 348 Winchester with Trailboss on the Hodgdon Reloading Center.

[wrench man]

I've never used it in a bottle neck case?, but it's great in straight walled cases!, wish I could find some more!

[dubber123]

The 70% of a charge that comes to the base of the bullet formula applies ONLY to straight walled cases from my understanding. You were likely quite high into the excessive pressure range in your bottlenecked case. Glad you and the gun are ok.

[jcren]

I suspect primer push out is the problem. You are reseating the primer when driving it out. Basically, the load doesn't generate enough thrust to hold the case head against the breech/bolt surface and the primer pushes itself back. I have had this happen several times with super reduced revolver loads and with a .243 break action. Enlarging the flash hole (Mark the brass for light loads only) to bleed primer pressure or increasing the load should fix the problem. By the way, bottle-neck cases also tend to get shorter aftre several firings with reduced loads for the same reason.

[rbertalotto]

I suspect primer push out is the problem. You are reseating the primer when driving it out. Basically, the load doesn't generate enough thrust to hold the case head against the breech/bolt surface and the primer pushes itself back.

I agree...This is not a "High Pressure" issue. Similar to what happens when you fire an empty case with just a primer.....And I was using federal primers which are very soft.
I measured case rim diameter compared to the factory ammo and it is identical. No pressure sign. 14.5 grains of TB in that size case simply can't create a high pressure scenario. I'll confirm this with IMR tomorrow. This ain't my first rodeo. 40 years of reloading and designing three cartridges of my own design suggests that jcern is on to something here.

BTW...IMR suggests TB is a great powder for bottle neck cartridges. This document says even if a load isn't listed, just use the 70% formula in ANY rifle cartridge

http://www.imrpowder.com/PDF/Trail-Boss-data.pdf

[chuckbuster]

I thought TB was recommended for use ONLY with CAST BOOLITS?

[theleo]

TB is meant as a powder for reduced loads that you can't double charge. It actually generates quite a bit of pressure and if you compress it your very likely to blow up what ever you are shooting, Hence their warning not to. I'd go back to the drawing board and start it 3-4 grains lighter. I was looking at using that powder for reloading a 45-90 but the loads for TB at 800-900 FPS were generating as much pressure as the 1800 FPS loads according to Lyman. TB=reduced recoil but full case not reduced recoil and reduced pressure.

[quilbilly]

I have found that TB must be looked at volumetrically with bottleneck cases. I don't even bother to weigh charges and just make a brass dipper to fill the case. Any loads below 75% or above 95% load density causes strange things to happen including huge pressure spikes. My 30/30 absolutely loves TB with a load density of 90% and the Lyman 130 gr plain base boolit for an MV of 1250 fps. My 338 WM had no pressure problems at a similar 90% load density and the 220 gr Lee boolit but the muzzle velocity (1650 fps) simply wasn't enough to stabilize the boolit. You didn't say where the powder was in the case in relation to the bottom of the bullet so I can't help but wonder about the load density.

[enfield]

the Lyman book has loads for 2400, 4227, 4198 and 3031 I would try something known, (and safe ) then see if there is extraction issues.

[tdoyka]

I thought TB was recommended for use ONLY with CAST BOOLITS?

cast boolits and jacketed. i've used in 444 marlin and 200gr hornady xtp's, 30-06 and 308 and 30-30 and 270 and 6.5 creedmoor and....using quite a few jacketed bullets.
now i use only cast for my 444, 45-70 and 30-40 krag.

[rbertalotto]

As the original post states, I tried 3031 and 4007SSC with zero issues.

[jcren]

Any further developments rbert? I use tb in a 30-06 and am curious what you figure out.