Mk85 is brutal on caps

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Muddly
Mk85 is brutal on caps

Post by Muddly » August 11th, 2014, 6:57 pm

My new MK85 blows caps to pieces and what few caps survive jam in the striker recess. I don't shoot heavy charges (70 to 90gr of Swiss) and I also get indications of striker bounce. I'm wondering if a stronger mainspring would help. This rifle was on the dealer's rack for at least 20 years and the spring might have taken a set and become weakened. I'm using the original Knight red hot nipple , which has 50 shots through it. Thoughts appreciated

GMB54-120
Posts:203
Joined:April 19th, 2012, 12:02 pm

Re: Mk85 is brutal on caps

Post by GMB54-120 » August 12th, 2014, 4:57 pm

Does the face of the hammer have a cone shape or just a small dimple? The surface that strikes the cap.
Green Mountain 54-120 Brush Gun
Elite 45 blued
Original DISC 45 SS
LRH 52cal

Muddly

Re: Mk85 is brutal on caps

Post by Muddly » August 12th, 2014, 10:20 pm

Flat faced. I thought my Black Diamond was hard on caps...Had an American Knight that used the FPJ's and every shot I felt like my forehead got sandblasted. Converted that one to caps and never had a problem. Got to figure it out

GMB54-120
Posts:203
Joined:April 19th, 2012, 12:02 pm

Re: Mk85 is brutal on caps

Post by GMB54-120 » August 13th, 2014, 7:30 am

Wild guess, the flash hole in the nipple is eroded or too large.

The reason i asked is because ive seen the cone shaped surface do that to caps.
Green Mountain 54-120 Brush Gun
Elite 45 blued
Original DISC 45 SS
LRH 52cal

Muddly

Re: Mk85 is brutal on caps

Post by Muddly » August 13th, 2014, 3:01 pm

Could be a nipple bored too large. This one has 50 shots on it( all mine). I'd love to shoot Ampco's in this one but they're too large for the factory tool. This on has the slotted breechplug. Guess I ought to get a hex plug. Then I can shoot musket caps too.

MuzzleMike
Posts:14
Joined:January 28th, 2017, 10:04 am

Re: Mk85 is brutal on caps

Post by MuzzleMike » February 17th, 2017, 2:22 pm

isn't the primer strike pressure adjustable ?

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