I am putting together a suppressed TC contender in 44 magnum. The twist is 1-20. I tested the carbine with 310 grain bullets cast from a Lee mold with gas checks. I used a Lee factory sizer die to apply a heavy crimp. 8.2 grains of NM04 (like Bullseye) gave 1050 fps with a stdev of only 7fps.

At first things looked good. I went through about 50 rounds testing various loads and sighting in. As I expended more ammo I noticed that my groups were degrading. At the end of the day I was shooting 6 inch groups at 100 yards and greater than 2 feet at 200 yards.

When I got home I noticed that I had a good deal of lead built up on the first few inches of the barrel. This was surprising as I used subsonic hard cast bullet with gas checks and I do not get this leading when using the same bullet at 1200 fps in my Blackhawk revolver. I need to find a solution to the poor accuracy and the lead buildup. Is it possible that a lighter crimp can help? Maybe I am damaging the bullet with heavy crimp?

I do not think the twist rate is too slow, but I will try a lighter (shorter) bullet to see it if helps. Any suggestions? Thanks.

Ranb

check the throat dia. size to that dia. and push them faster that will help! Clint

I am keeping it subsonic for use with the silencer.

Ranb

What Lube?
What alloy?
What are sizing the bullets at?

Larry Gibson

Larry asked the right questions. The bore should be slugged too. Need to know the size.
Hard cast or a gas check will not help if the boolit is too small in diameter. Many store bought boolits are under size and a lot of molds drop under size.
The factory crimp die is harsh and will size the boolit coming out of the case. You do not need much of a crimp at all, in fact the single shot doesn't even need a crimp.
All you need is decent case tension with a boolit hard enough to resist sizing when seating.
More boolit damage is done at the loading bench then when shooting.
Lube choice is important too.
If you are sizing the boolits, try shooting them without sizing. Put a soft lube in the grooves by hand if you have to.
If you are using LLA, get or make a better lube.
Make the boolits harder by water dropping or heat treating them. But they still must be the right size for the bore, at least .001" to .002" over.
A single shot or rifle can shoot pretty soft boolits but not if you try and stuff them into tight brass or crimp.

I am using wheel weights and dropping them into water from the mold. I use Lee's liquid alox applied with my finger after sizing. I have .429 and .430 sizers but have only used the .430 sizer so far

I will try unsized bullets with little or no crimp. I can also make a longer and wider expander to ensure the bullet is not damaged when seated. Thanks.

Ranb

quote:

Originally posted by ranb40:
I am using wheel weights and dropping them into water from the mold. I use Lee's liquid alox applied with my finger after sizing. I have .429 and .430 sizers but have only used the .430 sizer so far

I will try unsized bullets with little or no crimp. I can also make a longer and wider expander to ensure the bullet is not damaged when seated. Thanks.

Ranb

Try lubing the bullets before sizing and make sure there is enough lube, not too much but enough.

Larry Gibson

I made a longer and wider expander to keep from damaging the bullet during seating and loaded with no crimp. There was a bit less lead deposited in the bore, but the accuracy was still poor.

I will clean out the bore again and try it with 240-300 grain jacketed bullets subsonic. If this works, then I will keep trying the tips here. Thanks for the help.

Ranb

ranb40

Question regarding the poor accuracy; My factory TC barrel has a 22" twist, is yours a custom barrel or did TC change the twist?

If it is a 22" twist then stability may be the accuracy issue with the 310 gr bullets. I'm just thinking that as I've not shot any 300+ gr bullets out of mine.

Larry Gibson

Don't water quench... You are making the bullets too hard. At the velocities you are talking about, pressures aren't high enough to obturate the bullet correctly. If the bullet is sized to fit the bore, that is great, but if it is too small and it doesn't fit the bore correctly, you will flame cut past the check and still get the leading.

Try shooting some air cooled bullets, unsized, at the velocities you are working with, and see what that does for you.

Most commercial alloy (and commercially cast bullets) are too hard. Period. Softer is better, up to a point, and you are not at that point; your chamber pressures are too low...

1-20 twist is the only one I have seen in a contender 44 mag barrel. I bought this barrel from Ed Contender's thinking it was a 1-20 twist. It is engraved as a TC custom shop barrel. I pushed a cleaning rod with a tight patch through the bore and it turned a bit under 270 degrees, so it might be a 1-22 twist.

I will try some air coolled unsized bullets without gas checks this weekend. I will load them so they nearly touch the lands if possible.

Ranb

Be aware that a boolit must spin up in the twist different for each boolit length. A heavy boolit must be driven faster.
The 310 gr Lee needs a load like 21.5 gr of 296 to be accurate.
You are NOT going to get anything out of it with a powder like Bullseye.
You are also developing max pressure RIGHT NOW and forcing the boolit into the rifling before it can take the spin and that skid will open gas channels to cause leading.
Dump the magnum primer too.
Slow the pressure curve with slower powder. Do not download H110 or 296, go by starting loads, never less.
LLA works best if sprayed under the fenders of your car. Since boolits don't rust, why use a rust preventative?
So many do not realize that the faster you punch a boolit with faster and faster powders, the harder the boolit needs to be. Don't fall for the "obturation" junk, make the boolit the right size to start with.
You can not obturate a boolit! Obturate means "to seal" so you can EXPAND a boolit so that it will OBTURATE but that is where you throw accuracy out the window. Fit the boolit first.
A 1 in 20" twist is as slow as you want to go in a .44. If you have a 1 in 22" then the heavy boolit needs to be shot FASTER for accuracy. That means a slow powder to push the boolit for the length of the barrel, not a flash in the pan. Dump that powder!

exactly what bfr said.

I tried air cooled bullets, but same result. Lots of lead in the bore and poor accuracy.

I measured the length of the chamber. It is .215" longer than the case length. Is this usual? I was not able to seat even the 300 grain bullets out to the rifling. This seems to make for a long jump to the rifling from the case. This chamber seems to be better suited for the 445 super magnum than the 44.

I will try the slower powders. I want to find a good subsonic load. If I can not get good subsonic accuracy, then I will probably sell the barrel. I understand the need for faster twists when using longer or slower bullets. I have considerable experience in loading subsonic ammo, this is the first one to cause leading problems for me. I have found that NM04 works well for 45 auto and 9mm subsonic, but I guess this is not true for the 44 mag.

Thanks for all the suggestions so far.

Ranb

the contenders do have longer throats.
you can seat things out some further,and increase the case capacity.
i'd try that and a different lube before i gave up.

Excellent progress made today. It seems the key is the slower powder as suggested. I had one of those "Duh!" moments when I was looking in the barrel and realized that all of the lead buildup was in the first four inches of the barrel. It seems the faster burning powder is making the bullet run through the barrel and fail to start spinning along the rifling until it travels down the barrel a bit.

I started off the day with NM04 and 240 grain jacketed hollow points, the only ones available in the area right now. Two to four inch groups while shooting over the chrony with a stdev of 10 fps.

Limited testing over the chrony gave me a 1-1/4" group with the Lee water dropped 310 grain with gas checks loaded over 15 grains of WC820 giving 1150 fps. Looks rather promising so far. Very little lead left in the barrel, maybe a better lube will eliminate it all together.

I guess need a better bullet lube, one that I can apply without heating. Any recommendations?

I wrote to TC about the barrel. If they say the chamber is within specification, then I might try cut down 444 marlin brass to make for a better fit. The 444 has different dimensions other than length, so it might not work. Thanks for the help everyone. The more I learn, the more I know I don’t know.

Ranb

my contenter barrel will not shoot the 315 gr lee bullet and low vel. matter of fact the were key holeing at about 900fps. to long not fast enough twrist and not enough vel. I went with a250 gr hard cast nice little groups.

Well, cutting down 444 marlin brass to make a longer 44 magnum case does not work without inside case turning.

Ranb

This is only a suggestion that you may want to try.

Take the "can" off first if you have one already.

Cast up 25 or so really soft 44 bullets(bigger lube groove is better).
IF you have a 200+ grain bullet fill the lube groove with Turtle Wax rubbing compound in place of normal bullet lube.

IF 3 grains of BE will get the bullet out of the barrel, shoot 25 or so.
Go up to 4 grains if you have too, but slowest bullet that will exit the barrel is best.

After a thorough cleaning then go back to your normal loads.

If you don't want to do that then size your bullets a few thou bigger.

This is fire lapping?

Ranb

Yes.

Hence the low velocity and very mild abrasive

Do not worry about boolit jump to the rifling.
My most accurate revolver is the BFR 45-70, it will do an inch or under at 100 yards if I do my part. The boolit is so far down in the cylinder you need a flashlight to see it!
Then the gap and forcing cone to cross before the rifling.
Hard boolits solve any problems and the gun does not lead at all.
Felix is the best lube I ever used and if you go to Castpics, under research, you will find how to make it. You only need a few things, most of which can be bought at Wally World.
Beeswax, Lanolin, castor oil, baby oil and a bar of Ivory soap.
You can buy a pound of lanolin on the net. From Nature With Love or Majestic Mountain Sage. I think the last pound I bought was $8.
LBT soft is a super good lube too.
Try to stay away from Alox, the stuff burns in the bore and leaves ash behind.
If anyone needs it, ask and I will post instructions and my recipe.
The stuff can actually cut groups in half.