2nd Range Trip

[rugerbh103]

I hit the backyard today. I'm only setup for 50 yards at home. I stayed with the same load as last time, but added a Ox-Yoke Wad. The Wads really shrunk the group, but I'm still having an issue on the first shot. The top group is 3 shots, 5 1/2 inches below is the first. I've had shift before, but never this severe. I cleaned the bore with an alcohol patch followed by a dry patch before shooting. I'm hesitant to hunt a fouled bore with T7, but may have to.

Any guesses on velocity? I don't have access to a chrnograph. Knight MK-85 24 inch barrel, 70 grains T7 FFG, Ox-Yoke pre-lubed Wad, and a No Excuses 460 .503. I just got the brass range rod. The weight made a huge difference in loading and cleaning.

 

[snapbang]

Are you cleaning the bore between shots??? Windex, spit patch?

 

[deermanok]

I always pop a few caps before I load my rifles to add a little soot in the barrel. Even so, I still have one particular rifle that will throw the first shot off to the left or right a couple inches.
I never could figure out an answer.

 

[rugerbh103]

I did swab the bore with a spit moistened patch between shots.

Is the residue from the caps corrosive?

 

[MrTom]

No. Modern caps are no-corrosive. Or should be.

 

[rugerbh103]

OK, I'll have to try that. A couple inches wouldn't bother me, but this much concerns me. We have a new anterless firearms season in September. I'd like to use this rifle.

 

[HC]

Some shooters using conicals put a wrap of Teflon plumbers tape around the bullet for the first shot. It seems to help keep the first shot in the group. Good luck.

 

[sdporter]

The Teflon tape trick does help. At the suggestion of someone on the forum here, I’ve started making a sabot from the tape. Cut two pieces about two inches long or so, make a cross out of them, set the bullet in the middle and putt the ends up to cover the bullet. It does help me.

 

[rugerbh103]

I've never tried the teflon. I have some in my kit, I'll give it a try.

 

[52Bore]

Very nice.
I’d use 1250fps and a BC of 0.2
I’d repeat/verify that 1st shot another day. At 50, that seems way too low for just a clean bore.
Good luck

 

[rugerbh103]

Thanks for the info. I'll definitely try it again.

Just trying to get an idea on the energy and if it would work out at 100 yards.

 

[52Bore]

Just trying to get an idea on the energy and if it would work out at 100 yards.

You will blow holes thru deer with that load and distance. I’ve never recovered a heavy bullet and I’ve shot deer to 300.

 

[rugerbh103]

Thanks the heavy conicals are still new to me.

 

[user 25154]

May I inquire as to why u r using 70 grains 777? Is it a recoil thing? If so I understand. I had one of the first 54 cal. Mk85 that knight made. Made in his shead. Had craved stock. I know the 54 had a higher 120 volume charge. Think the .5o was like 110 maybe 100? Any how, I think your problem is obturation. And changing bore conditions. Hence fouled bore higher velocity. Upping your powder charge to atleast 85 grains by volume r 90 would be better. Should really help. I never had problems as long as I shot over 90 grains in mine. Gun drove nails at 50 yards with 120 grains by volume and 425 grain soft lead conical. 1 and 1/2 inches at 100 yards. Was best plunger gun of the 90's in my humble opinion for the money. Mine hated light charges of powder. If recoil is a problem might try lighter bullet. I killed alot of deer with tc 350 maxi ball had like 3 grease grooves. Come in yellow box. Also grease will shoot alittle faster. The lube really helps. Also use a Walter's veggie wad r something close. Far best performance. Not needed thou to just kill deer. U should get atleast 3 shots without cleaning. If u use grease Groove cast bullets. Atleast I did. I shot 5 shot groups. Shot 5 then clean. Hopefully this will help. Some like wool wads. My gun didn't any better with wool than it did without any wad.

 

[rugerbh103]

It is a recoil thing. Messed up my shoulder pretty good this year. Tore my labrum in 3 different spots and ripped several muscle in the same shoulder. 70 grains is about all I can handle right now.

 

[user 25154]

Yep. That will do it. Don't know if u can use them where u hunt,but if I remember right. Those rifles where made for sabots. Shoot lead real good also. Black harvester sabot and 250 r 300 grain Barnes all copper might be good. Less recoil. U may find gun doesn't do what it's doing now with a sabot. Also thors r good. Might try sizing pack. That no excuse bullet is great but your gonna get recoil. U might be able to shoot a 300 grainer at say 85 r 90 grains volume and not get alot of recoil. Think minimum suggested load for the 50 cal. Was 85 grains. I shoot 468 grain .45 cal. And a 300 grain bullet just kicks less. Those rifles had 1n 26 twist. I think?

 

[rugerbh103]

Got out today. All the load data is the same. Started trying the teflon tape. That is the low shot. As you can see, it didn't help in my rifle. If anything, the shot is farther out. I brought the rifle in and completely cleaned it. After letting it sit about an half hour, I decided to fire a squib load with BH209. That seemed to resolve the issue.

If it stops raining by Friday I am going to foul the barrel with a few caps and test a cold shot. I have my fingers crossed it will work as I am not excited about hunting on a fouled bore. Once I decide on a method, I'll sight in on the first shot. I have always done that just never had a rifle shoot so far apart between the 1st and 2nd shot.

One more question. I am noticing a lot more fouling in the breech area compared to shooting sabots. I understand it's the nature of a plunger gun, but the difference is noticeable. The heavy conicals are new to me, is this to be expected?

 

[HC]

Heavier bullet = more pressure = more blowback.

 

[rugerbh103]

Makes sense.

 

[Mar Nut]

rugerbh103, I have a BK92 Knight that I bought when they came out in 92. Same 24" Green Mountain barrel as the MK 85. I called Knight years ago and talked to a tech about using Blackhorn in it and he said it was built to handle Blackhorn but they were not allowed to advertise it because of the plunger system, but it would take a heavy load no problem. Well, I converted to the 209 system using the red plastic jacket and never looked back. I load it pretty heavy and shooting the Knight Red Hot 250 grain copper bullets, 3" high at 100 it only drops 5" out to 200. But with a light load of Blackhorn it will not work, like 3" groups best it will do. Use to use Triple seven and it would not shoot light loads. These guns shoot best with heavier loads I believe.