cowboy action loads

Just wanted to see if anyone had any good advice for cowboy action loads. I'm using trailboss under MBC 125 TCFP in .38. Also wondered about COL? I've been seeing guys doing things i'm not sure of,like seating the bullet in a .38 to just under .357 COL. The bullets were seated a good bit below the crimp groove. I've never seen that one before and am not sure what the reasoning behind it was.

Maximum col would be the round fitting into the cylinder, minimum col is usually to the crimp cannelure.

To get a Trailboss starting load for your MBC bullet place the bullet along side of a case with the crimp cannelure at the case mouth, make a mark on the case where the base of the bullet would be, fill the case with Trailboss,dump that on your scale, record the weight in grains,take 70% of that weight and use that for the starting load. Alliant data states DO NOT COMPRESS Trailboss powder. You can work up to the maximum load, to get the needed velocity.

38 S&W Specal ,Trailboss and 125 gr lead bullet loads start at 3.0 grs.@753 fps, and tops out at 5.3grs @ 952 fps with a minium col of 1.445"

Most cast bullet manufactuers place the crimp cannelure on their bullets so as not to give excessive pressure with any known safe load data.

Just wanted to see if anyone had any good advice for cowboy action loads. I'm using trailboss under MBC 125 TCFP in .38. Also wondered about COL? I've been seeing guys doing things i'm not sure of,like seating the bullet in a .38 to just under .357 COL. The bullets were seated a good bit below the crimp groove. I've never seen that one before and am not sure what the reasoning behind it was.
my guess would be they're shooting .38's in a .357 cylinder and are seating the bullet out to mimic the shorter jump of a .357 bullet into shoulder step of the cylinder and/or the forcing cone..

I doubt it helps.

I've been seeing guys doing things i'm not sure of,like seating the bullet in a .38 to just under .357 COL. The bullets were seated a good bit below the crimp groove. I've never seen that one before and am not sure what the reasoning behind it was.

Howdy

It has nothing to do with minimum jump in the cylinder. In CAS our targets are close enough that that does not matter.

It is probably because they are shooting the same loads in a lever rifle. Lever guns can be very overall length sensitive. Depending on the specific rifle model, cartridges may not feed properly and may jam if they are too short. This can be particularly true with a rifle chambered for 357 Mag when shooting it with 38 Sp ammo. There is even one bullet made specifically for use in 38 Sp that is long enough that when it is properly seated and crimped, the resulting cartridge will have the same OAL as a 357 Mag. The Winchester 1892 and its clones and the Marlin 1894 can be picky about overall length. Same with the toggle link rifles like the Henry, Winchester 1866, and Winchester 1873.

Standard procedure in CAS, if one is shooting the same cartridge in both rifle and pistols, is to tailor the length for good feeding in the rifle. Revolvers don't care how long the cartridge is as long as the bullet does not stick out of the front of the cylinder. That way one round can be used in both rifle and pistol, without needing separate ammo for each.

Keeps things simple.

Howdy

It has nothing to do with minimum jump in the cylinder. In CAS our targets are close enough that that does not matter.

It is probably because they are shooting the same loads in a lever rifle. Lever guns can be very overall length sensitive. Depending on the specific rifle model, cartridges may not feed properly and may jam if they are too short. This can be particularly true with a rifle chambered for 357 Mag when shooting it with 38 Sp ammo. There is even one bullet made specifically for use in 38 Sp that is long enough that when it is properly seated and crimped, the resulting cartridge will have the same OAL as a 357 Mag. The Winchester 1892 and its clones and the Marlin 1894 can be picky about overall length. Same with the toggle link rifles like the Henry, Winchester 1866, and Winchester 1873.

Standard procedure in CAS, if one is shooting the same cartridge in both rifle and pistols, is to tailor the length for good feeding in the rifle. Revolvers don't care how long the cartridge is as long as the bullet does not stick out of the front of the cylinder. That way one round can be used in both rifle and pistol, without needing separate ammo for each.

Keeps things simple.
I wouldn't nessessarily think that would be that much of a big deal, but it would be akin to firing .22 Shorts in a 10-22.

Yeah, I can see where you'd have feeding problems.

Makes sense.

Howdy Again

CAS is a timed competition. It is a very big deal if your rifle jams because your rounds are too short.

Howdy

It has nothing to do with minimum jump in the cylinder. In CAS our targets are close enough that that does not matter.

It is probably because they are shooting the same loads in a lever rifle. Lever guns can be very overall length sensitive. Depending on the specific rifle model, cartridges may not feed properly and may jam if they are too short. This can be particularly true with a rifle chambered for 357 Mag when shooting it with 38 Sp ammo. There is even one bullet made specifically for use in 38 Sp that is long enough that when it is properly seated and crimped, the resulting cartridge will have the same OAL as a 357 Mag. The Winchester 1892 and its clones and the Marlin 1894 can be picky about overall length. Same with the toggle link rifles like the Henry, Winchester 1866, and Winchester 1873.

Standard procedure in CAS, if one is shooting the same cartridge in both rifle and pistols, is to tailor the length for good feeding in the rifle. Revolvers don't care how long the cartridge is as long as the bullet does not stick out of the front of the cylinder. That way one round can be used in both rifle and pistol, without needing separate ammo for each.

Keeps things simple.
Exactly...

I own and shoot a Marlin 1894C in .357 Magnum and when firing .38 Specials they feed fine when cycled slowly but when you cycle the lever quickly they will jam unless you build the .38's long enough to mimic the length of .357 Magnum loads.

Good explanation Driftwood Johnson, thanks...

Driftwood Johnson nailed it. For the Marlins, which my wife and I shoot in CAS, the magic OAL is 1.480". Anything shorter is going to hang up and cause delays, frustration and muttered expletives when trying to shoot fast. With a cast bullet, you can crimp anywhere you need to for a lever action rifle, providing the crimp doesn't end up in the lube groove. You're trying to prevent the bullet from collapsing into the case in the tube magazine with the crimp. If that happens, your stage is over, as the rounds won't feed from the magazine and you have to take the rifle apart to get them out.

Hope this helps.

Fred

I've also heard some talk about downloading the .357 case down to .38 specs to help feeding in the marlins and to help reduce the powder burn rings in .357 chambered revolvers. My only thoughts on this is i can obtain .38 brass a good bit cheaper and my Taylors&CO. "73" has'nt had any problems cycling at speed with .38s at 1.445. Anyone got any other info on this? I'm pretty new CAS, but have loaded for 3-4 years now and always stay with the printed load data. Since starting CAS i've seen alot of new tricks i'm uncertain of.

Some people do use .357 cases, but like you noted, .38 brass is more plentiful and a whole lot cheaper. I've got about 10,000 rounds of .38 brass right now, with about 3/4 of it loaded. The cost of that much .357 brass staggers the mind, since it's roughly double the price for once fired.

With your '73, you can probably use .357 brass, but with the Marlins you can't get 10 rounds of full length .357 ammunition in the magazine, which most stages require. You'll see lots of "tricks" in any shooting sport, and some will be new to you, especially being a relatively new reloader. Do your research before trying some of them.

There are lots of published loads for TrailBoss powder, so there's no need to experiment with it. Just go to Hodgdon's website and look under Cowboy Loads.

Hope this helps.

Fred

Howdy

Uberti redesigned the carrier on their toggle link rifles, the Henry, 1866, and 1873 a number of years ago. On these rifles there is no cartridge stop on the carrier. The round on the carrier functions as the cartridge stop, preventing the next round in the magazine from 'squirting' out of the magazine and onto carrier. The round on the carrier must be long enough to prevent too much of the next round from protruding out of the magazine, or the carrier will strike the offending round as it attempts to rise, jamming the gun. Just like with the originals, there is a bevel built into the carrier that shoves this next round back into the magazine as the carrier reaches it, so the carrier can rise.

Originally, the carrier on these rifles would jam if much more than the rim of the next cartridge was poking out of the magazine. Too much sticking out put the offending round beyond the reach of the bevel on the carrier, so it would jam as it met the round. This made these rifles quite OAL sensative. But a few years ago Uberti redesigned the carrier, extending the bevel further, so it could pick up rounds that were extending further onto the carrier. This change made these rifles much less OAL sensative. That's why today a '66 or '73 chambered for 45 Colt or 357 Mag can digest shorter ammo like 45 Schofield or 38 Special without jamming. I have an older '73 chambered for 44-40 and it is very OAL sensative.

With your '73, you can probably use .357 brass, but with the Marlins you can't get 10 rounds of full length .357 ammunition in the magazine, which most stages require. You'll see lots of "tricks" in any shooting sport, and some will be new to you, especially being a relatively new reloader. Do your research before trying some of them.

This is only true of the very short barreled Marlins with 18 1/2" barrels. There is no problem getting 10 full length 357 Mag rounds in the magazine of a Marlin (or a Winchester) with a 20" or a 24" barrel. I have a Marlin Model 1894CS with an 18 1/2" barrel and right out of the box it would accept ten rounds of 38 Special but only nine rounds of 357 Mag. Shortening the follower a little bit and cutting a couple of coils off the magazine spring allows it to hold ten 357 Mag rounds in the magazine now.

Regarding carbon rings in chamber with 38s and CAS: I shoot lots and lots of cowboy matches. I pick lots of brass and man the unloading table as much as anybody. By far the two most common calibers in CAS are 38 Special and 45 Colt, in that order. I occasionally see 357s, but not very often. Clearly, with all the 38s being shot in CAS match revolvers, nobody is very concerned about carbon rings in the chambers.