- Joined
- Dec 15, 2019
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Long time lurker, finally joined. I have been shooting muzzleloaders for 40+ years and have just encountered an issue I have never had before.
It is an issue with an original Knight MK-85 I purchased back in 1992. It is a 50 cal SS with laminated Forest green camo stock. I have shot black powder in it for testing, but went to Pyrodex RS as its standard load. Since the day I first shot it I have used the now discontinued Sure Fire breech plug. Recently however I noticed that the brass sealing seat had some pitting in 2 very small spots and was allowing leakage. Knowing that these plugs can and do wear out, I installed the original breech plug as I no longer have any new Sure Fire plugs.
Due to the fact that Pyrodex has the dreaded sulphur odor my wife dislikes, I thought I would finally try some Triple 7. Two reasons, one for no odor, and the other to regain velocity I lost with the change in breech plugs.
I bought Triple 7 3Fg as it lists the higher velocity. I also bought some CCI #11 magnum caps as there were no standard caps available. I shoot 240 XTP bullets in either Knight HP sabots or the now discontinued Hornady green sabots I used to buy in bulk. With 100 gr of Pyrodex RS by volume using #11 CCI caps this load normally shoots 1/2" to 3/4" groups at 100 yds. Velocity chronographed was 1933 av with ES of 27.
Using 100 gr of T7 3Fg and the CCI #11 magnum caps the recoil was brutal, and groups were closer to 3" at 100 yds. Guessing that I was pushing it, I backed off the charge to 80 gr by volume and groups tightened up to about 1 1/2" on average. I cleaned between shots with a wet patch and then dry patch to ensure I was down to the breech plug for each shot. I didn't have the time, nor conditions to chronograph this day.
I shot 12 shots total this day and noticed that the impact was higher at both 50 y and 100 y than the Pyrodex RS loads with the standard breech plug by about 2 1/2" at 100 y. I can live with that as I can adjust the scope for POI.
Now for the issue.
Upon returning home I started the disassembly to clean the rifle. The breech plug was near seized! I had to clamp it in a vise securely and work the breech plug slowly back and forth to remove it. It was the most difficult removal I ever encountered with this rifle. Clean up after that was easier than Pyrodex and my wife enjoyed the lack of odor.
A day or 2 later I again went to shoot the T7 80gr 3Fg load. CCI #11 mag caps, 240 gr XTP and Knight HP sabot. This day I shot 14 shots to try and verify POI and group size. Again cleaned between shots with wet and dry patch to breech plug. As I had run out of Knight HP sabots, I had bought a prepackaged Hornady XTP 240 gr setup with the low drag sabots. The loads with the HP sabots averaged 1 3/4" at 100 y while the prepackaged shot 3/8" groups! I got to thinking maybe my HP sabots were "dried out" as they were 20 some years old. (However with Pyrodex they still grouped inside 1" at 100 y a few days previous.) As time ran out I returned home and again had the difficult breech plug removal.
Two questions: Is it normal to have difficult breech plug removal with T7 in Knight rifles?
Can sabots deteriorate over time, have less lubricating properties?
I did order and received 2 new packages of Knight HP sabots and a box of Hornady 240 XTP bullets for next trip.
Also, as I have interest in Blackhorn 209 powder, and 209 primer ignition I ordered a CVA Optima (and BH breech plug) to give that a try. I would have converted the Knight to 209, but Knight did not recommend plunger fire with Blackhorn 209, and the FPJ conversion for the MK-85 was not what I was looking for. The MK-85 has served me well these past 27 years taking numerous deer, the last a nice 8 pt this season. I was considering going smokeless at this point, but for my needs the cost is prohibitive.
Hopefully I won't have difficult breech plug removal with the CVA and T7.
I know it's a long post, thanks for reading and any info is appreciated.
It is an issue with an original Knight MK-85 I purchased back in 1992. It is a 50 cal SS with laminated Forest green camo stock. I have shot black powder in it for testing, but went to Pyrodex RS as its standard load. Since the day I first shot it I have used the now discontinued Sure Fire breech plug. Recently however I noticed that the brass sealing seat had some pitting in 2 very small spots and was allowing leakage. Knowing that these plugs can and do wear out, I installed the original breech plug as I no longer have any new Sure Fire plugs.
Due to the fact that Pyrodex has the dreaded sulphur odor my wife dislikes, I thought I would finally try some Triple 7. Two reasons, one for no odor, and the other to regain velocity I lost with the change in breech plugs.
I bought Triple 7 3Fg as it lists the higher velocity. I also bought some CCI #11 magnum caps as there were no standard caps available. I shoot 240 XTP bullets in either Knight HP sabots or the now discontinued Hornady green sabots I used to buy in bulk. With 100 gr of Pyrodex RS by volume using #11 CCI caps this load normally shoots 1/2" to 3/4" groups at 100 yds. Velocity chronographed was 1933 av with ES of 27.
Using 100 gr of T7 3Fg and the CCI #11 magnum caps the recoil was brutal, and groups were closer to 3" at 100 yds. Guessing that I was pushing it, I backed off the charge to 80 gr by volume and groups tightened up to about 1 1/2" on average. I cleaned between shots with a wet patch and then dry patch to ensure I was down to the breech plug for each shot. I didn't have the time, nor conditions to chronograph this day.
I shot 12 shots total this day and noticed that the impact was higher at both 50 y and 100 y than the Pyrodex RS loads with the standard breech plug by about 2 1/2" at 100 y. I can live with that as I can adjust the scope for POI.
Now for the issue.
Upon returning home I started the disassembly to clean the rifle. The breech plug was near seized! I had to clamp it in a vise securely and work the breech plug slowly back and forth to remove it. It was the most difficult removal I ever encountered with this rifle. Clean up after that was easier than Pyrodex and my wife enjoyed the lack of odor.
A day or 2 later I again went to shoot the T7 80gr 3Fg load. CCI #11 mag caps, 240 gr XTP and Knight HP sabot. This day I shot 14 shots to try and verify POI and group size. Again cleaned between shots with wet and dry patch to breech plug. As I had run out of Knight HP sabots, I had bought a prepackaged Hornady XTP 240 gr setup with the low drag sabots. The loads with the HP sabots averaged 1 3/4" at 100 y while the prepackaged shot 3/8" groups! I got to thinking maybe my HP sabots were "dried out" as they were 20 some years old. (However with Pyrodex they still grouped inside 1" at 100 y a few days previous.) As time ran out I returned home and again had the difficult breech plug removal.
Two questions: Is it normal to have difficult breech plug removal with T7 in Knight rifles?
Can sabots deteriorate over time, have less lubricating properties?
I did order and received 2 new packages of Knight HP sabots and a box of Hornady 240 XTP bullets for next trip.
Also, as I have interest in Blackhorn 209 powder, and 209 primer ignition I ordered a CVA Optima (and BH breech plug) to give that a try. I would have converted the Knight to 209, but Knight did not recommend plunger fire with Blackhorn 209, and the FPJ conversion for the MK-85 was not what I was looking for. The MK-85 has served me well these past 27 years taking numerous deer, the last a nice 8 pt this season. I was considering going smokeless at this point, but for my needs the cost is prohibitive.
Hopefully I won't have difficult breech plug removal with the CVA and T7.
I know it's a long post, thanks for reading and any info is appreciated.
