.38-55 Range Report

Big Al1

Went to the range yesterday and shot the 1893 Marlin. Tried two different loads, 6 grains of Trail Boss, (thanks Mike) and 21 grains of IMR 4198, both with 255 grain cast bullets, forearm rest, open sights and old eyes. The Trail Boss load was , as CPJ said, a real puddy tat. Almost no recoil, the muzzle report was more of a quiet pphhhtt, and you could hear the bullet cutting paper. The 4198, not real good, didn't group well, but a much higher velocity, 1300 vs. about 900 for the Trail Boss.
I also noticed the primers were backing out, it also did this when I test fired a primer only, no powder or bullet, just to make sure to gun would go bang! I'm just going to stick to the puddy tat loads, and enjoy the rifle for what it is, a 120 year old antique.


Four shot Trail Boss load, two in one hole. Lower bullet hole is from another rifle. Minute of gong at 100 yards.



.38-55 next to big brother .45-70



Backed out primer. Any ideas of what may be causing this??

CPJ! What is the reduced load you shoot in the .45-70?

tennmike

Glad that Trail Boss load worked for you. You can adjust the load up a bit for hunting. I use that 6 grain load for deer within 70 yards, and it's worked every time. Nice clean hole in, and nice clean slightly expanded hole out.

As to the backed out primers, sounds like you have an overly generous amount of head space. I'd get a GO and NO go gauge and check it.

Edit to add: None of the three rifles I have in .38-55 have experienced backed out primers with that Trail Boss load. Remington rolling block, Marlin made in 1990s with full octagon barrel, and that ugly little Frankenrifle on a 20 ga. shotgun frame.

Jay

knitepoet beat me to it. That is exactly why the primers are backed out. Bring the pressure up a bit so it can re-seat the primer after detonation.

I once nearly locked up a revolver trying to detonate primers rather than try to remove them with the decapping pin in a die, taking a chance of setting a primer off in the die. Once the primer backs out in a revolver, it drags as you try to rotate the cylinder.

Edit - Although after looking at published load data, 6 grains should be a good starting load charge. I don't see in the OP if it's just doing this with the TB loads or with both loads. If that's the case, Mike is probably spot on with the excessive headspace thought....

Ranch13

What diameter of bullet?

tennmike

.38-55 is a rimmed case. It headspaces off the rim of the cartridge. Only way a primer can back out is if there is a sizable gap between the breech and the case head. Once the cartridge case is seated in the chamber and the case rim is against the chamber shoulder, it can go nowhere but backwards.

There is some variation in rim thickness between the various manufacturers, but not that much.

Big Al1

I would concur with the headspace problem, it did it with both loads. The 4198 load is a lot peppier. Bullets are .379 Diameter.

Teach

Start sticking layers of masking tape onto the back of an unfired cartridge until the action gets difficult to close, then extract the case, peel the layers off, and measure the thickness of the tape. That should give you a ballpark guess about the amount of headspace you have. If you've got more than 2 or 3 layers, it's probably got too much headspace.
Jerry

Big Al1

Teach wrote: »

Start sticking layers of masking tape onto the back of an unfired cartridge until the action gets difficult to close, then extract the case, peel the layers off, and measure the thickness of the tape. That should give you a ballpark guess about the amount of headspace you have. If you've got more than 2 or 3 layers, it's probably got too much headspace.
Jerry

You were reading my mind, that's exactly what I was going to do.

NN

Very nice work

Big Chief

My 8X56R Steyr-Mannlicher can suffer from a different sort of case volume problem and you get "Smokey" cases. Too little powder for the case capacity. Reloading data is scarce and Lee just reprinted the data for an older cartridge (8X50 or 53R?).So it was trial and error working up to a safe load without the smokey cases.

In fact, years ago when I owned a S&W model 25 .45 Colt, all I had O/H were some 230 grain bullets made for a .45 ACP, so I loaded them up and there was way too much space left in the case. They also had smokey cases, come to thunk of it. Blowback where the charge doesn't have enough to expand the case completely in the chamber when fired so residue/blows back around the brass, so I've read and been told.

But how does that explain Bullseye powder where very little is used and it leaves a lot of room????? Maybe because it is "Fast"?????

Big Al1

I don't think it's an under pressure issue. There is no blow back. Pressure for both loads are about 21,000CUPs with 25,000 as max. I did the poor mans head space gauge, as Jerry suggested, and stopped adding tape after six layers at .025". I also noticed the rim is not counter bored into the chamber, it fits flush on the barrel and the breech bolt encloses the rim. Looks like I'll have to have the barrel set back or just get it relined.

Big Al1

It would have to be set back one full turn so the sights will index, then faced off to the proper headspace.