777 Load Question
 

I switched to 777 today and I am not gtting a good group. I am using a load of 100 grains with 209 winchester primers. I use the hornady XTP's 240 gr. At 100 yds, out of six shots, all were in the kill zone, but no relative groups. It seemed as if all shots were within 3 inches each way of the bulls. Basically, no better than a 6 inch group. I was using a rest and also dry patched between shots. After the fourth shot, I cleaned with solvent and shot two more times. Any suggestions would be helpful. I may try moving down to 90 grains. Would too heavy of a load cause what I have witnessed?

Gun: Thompson Center Black Diamond

Are they .430 XTP's? I had good accuracy with 80gr Triple 7 2f and a .430 XTP in a green CR sabot years ago in a CVA Magbolt 150. Try Sabotloaders technique of patching between shots for accuracy.

They are the 50/44 XTP's with the black CR and I am using FFF triple 7. Im thinking if I go down to 90 grains that should be about 1840 FPS. Back to the range tomorrow. Hopefully I will have better results. Im afraid to drop too much when it comes to grains because I dont want to lose range, but then again, if I cant get a group at 100 yds, long range wont matter anyways. I would love to be able to shoot at least 150 or 175. 200 would be great!!!

I think you have the wrong bullet for that type of range.

Black CR sabots are for .45 caliber bullets.

Good observation Omega 45, That not a valid sabot/bullet combination. Also, with my black diamond 80 to 85 grains worked best.

This 100yd group was shot Friday with 100gr volume of Triple 7 3f using 300grain Harvester PT's in a Harvester smooth sabot out of my Pro Hunter with Encore Bergara barrel. I believe 90 grains was a tighter group but I cannot find my notes from a few months ago. :confused0024:

Shot 1: 1736 fps
Shot 2: 1748 fps
Shot 3: 1769 fps

Sorry!!! I just checked and they are the .45/240 with the black CR. I am heading to the range now. Im going to start with a low grain load and move up from there. Hopefully I get a group and at least get a starting point. Thanks for the information. I will let you know how I do today.

Blast away. :fighting0007:

I am thinking 80-90 grains with that combo.

My first question would be - do you need the Crush Rib sabot? If the bore is not that tight and in a Black Diamond it should not be but that does not mean it isn't, I would really try a different sabot. Older Crush ribs can leak pressure around the outside unless they are crushed tight. I would bet you would have better accuracy with a standard black Harvester, either the sort black or the long black. The other option is the MMP HPH-24 which comes standard with TC bullets.

One other thing I think that Harvester has changed the design of the crush rib sabot to help it retain pressure by putting the ribs on in a diagonal patern vs the normal striaght up and down pattern. The diagonal pattern would help the sabot seat in the lands and grooves better IMO.

Do you have any smooth sabots.... if you do maybe remove your BP and push a couple down through and see what you think...

One other thing check your barrel to stock channel - is the barrel getting caught in the channel in anyway....

I shoot most often 110 grains in a simular gun but I do use a different and a bit longer bullet most often.

I shoot a Black Diamond XR. 100 grains of Triple Seven 2f is a good load. This is what I use and have good results.

Try swabbing the bore with Windex, not a dry patch. Lightly dampen the patch and work that barrel in short strokes. Triple Seven does leave a fouling. And a dry patch is only going to push it around. There is no need to use solvent to swab the bore on the range. After the damp patch, then run two dry patches.



This is my BD shooting 100 grains of T-7 and some 250 grain Shockwaves in the supplied sabots. This is 50 yards of course with a 4.5x32mm scope.



This is the BD shoot 120 grains of Pyrodex RS and 250 grain XTP's in black harvester crushed rib sabots. Again only 60 yards but I was working loads that week.

Swab well, let the barrel cool, and try changing to the green harvester crushed rib sabots. Also when I shoot .44 caliber stuff I like heavier bullets like the 300 grain. But you have a free floating barrel and one of the best shooting rifles made.

my Black diomond will shoot very tight groups with 80 gr 777 and 240xtp, usually bullets touching at 100yds.Up load to 100 gr and group opens to about 2inch at 100yds. Very consistent gun, not real picky on load or bullet.

Well, decreased my load to 90 grains of triple 7 with the 240 XTP's and my group actually got worse. Im going to go out and try 80 next and if that doesnt work, im going to try a new bullet (heavier and longer) while at the same time going back up to 100 grains. I guess it's a process of elimination now. Thank you for the feedback. I will keep you posted.

Try a different sabot.



My Black Diamond is the older model with the shorter barrel and the plastic stock. It is a good gun but mine had a problem. Sighted the gun in with the ramrod in place and it shot very well. With the ramrod removed the bullet went to a different poi. The barrel did not fit well in the stock.

TC floated the barrel by making the rear stock/barrel contact point lower than the front one. That caused the barrel to be jacked up when the rear screw was tightened. The rear contact point in the stock was built up with Acra-Glas jel and no more problem.

I also have the older model with the shorter barrell and plastic stock. I see that the barrell floats away from the stock, but I didnt think it mattered though since the scope is mounted to the barrell. Is there anything I can do to fix the probblem or the floating?

I will try a different sabot also.

The ramrod interferes with the free floated barrel: It is attached to the barrel by the thimbles but is held in the stock by plastic catches. My gun shot very well when the ramrod was not in place. It shot much less well with the ramrod in place.

my brother in law had the BD plastic stock and you could hold the stock and hold the barrel and move back and forth is there play when bolted up of so take it to gun smith and glass bed the gun and it shot much better after

i'm not sure what happened with those short barrel TC Black Diamond rifles. There were a lot of them for sale by discounters and others years after TC quit making them: Could be that they were factory seconds or something.

I've scoped and sighted in 6 or 8 of the short barreled Black Diamond guns and they are tack drivers. There was one besides my own that was problematic: It also had a plastic stock and it came from a discounter.

Im confused as to why the floating barrell would make the gun shoot off. I always thought the scope was lined up with the end of the barrell and therefore the stalk had nothing to do with it. Is there flex in the barrell when the gun goes off or something that I am missing?

its not the scope and barrel lined up its movement in the stock and barrel moves point of aim when you shot and makes your rounds go all over the place bedding the stock and barrel will stop this movement and I would bed full stock this has worked for me in all my ML its not a centerfire and yes you can have very little flex all gun do bedding full stock can help stop this did you see of you have movement betwene your stock and barrel plus when you put your ram rod in your gun put your fingers betwene your stock and barrel and then push your ram rod in and see of there is movement it will move the barrel up you do not what this