After seeing how well the MU plug worked in my H&R, I drilled out an old encore plug 1/32 deeper to accommodate an #60 o-ring. The exit hole was enlarged by .003 in.
Fired 20 100gr loads. Ignition was quick and consistent, even with rem ml primers, no blowby, firing pin bushing was squeaky clean. Ran a dry patch after 10 shots and got a small amount of fouling but it made next loading more difficult. O-rings stayed put and looked like new. Clean up was easy, without water.
The project was easy and cheap and effective. $1.97 for package of 10 o-rings at Lowes.
