On my 197 Ranch rifle there slack on the end the op-rod travel it accommodates a 1/16 in buffer with room to spare. It does not interfere with the bolt at all.
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Installed the 1911 buffer on rear over the guide rod/spring rod as shown. Does it make sense to put one on the front over the gas busing too or will the gun not cycle. miy mini only has 60 rounds through it and is a 581 series with newer tapered barrel. Or is the rear one enough?

I just use a rear one. I tried one up front but they don't last very long from all the heat and gas, and I don't believe there is much benefit to having one there.

Why pay $10-15 for a single Mini-14 buffer when you can get 6-8 1911 bufers for $10-12, plus they work better and you can use them on your 1911.

I got TEN 1911 buffers for $5.99 plus shipping-$11.99 total vs. one for $14.95 (buffer technologies) plus shipping that you need to sand to get to fit. Just installed rear one and not installing on one gas port. The ones I got are just under 1/8" thick. Put stock one in, as is, and sanded one down to 1/16th inch to replace if stock item thickness causes any cycling problems. Will know more tomorrow after range trip.

Waiting on my harris HBRM 6-9" adjustable leg bipod and stud swivel backing plate harris #2 adapter. Got the #14 adapter but don't want to install on gas block for many issues; 1st- bulky, 2nd- read acuracy issues 3rd- just one more thing to worry about loosending up. Like the fac that once installed, can easily remove bipod and use my sling with the QD swivels and it also works with bipod on.

Also ordered the wheeler engineering scope mounting kit to lap the ruger rings for a perfect fit for my leupold VX-2 3-9x/40mm scope. Prefit the scope and it os perfect with the rings that came with the mini- enough clearance for the front lens to clear by 1/8"-1/4".

Next mod is adding a mo-reaper sight/muzzle break combo if it will fit the mini 581 series. If not, the scope it is and oem sights. With the new tapered barrel, not sure if it even worth adding the barrel stabilizing strut as I've read it tha accuracy improvement is minimal.

I used a piece of old mudflap on the back and it works great.

The front buffer was a bad idea. It held my oprod slightly out of battery, and my accuracy went to hell with a quickness. I removed it at the range and everything returned to normal.

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A gun is like a parachute: If you need one and don't have one, you won't be needing one again.

I used to use a toilet buffer but switched to 1911 after I picked up some for free.

From what you guys are saying on the newer minis the op-rod does not touch the gas block when the bolt is closed. If this is the case you don't need a front buffer. I have an older 197 series Mini the bolt does hit the gas block. Back in about 2008 we were making buffers out of all kinds of things and some guys were using 1911 buffers. The 1911 buffers were a little thick when used as front buffers so some guys thinned them up a little. If you install a front buffer check it. With action out of the stock pull back on the op-rod a little you should be able to move the op-rod a little before the bolt starts to move if not your buffer is too thick.
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Actually, the op rod contacting the gas block or not has been highly variable along the entire Mini production, some guns the op rod does not contact, most it does. The newer Minis have a step on the face of the op rod I believe was designed to contact the gas block. That seems strange to me, since I read an article by a professional shooter who worked for Ruger, testing rifles and making recommendations on how to improve accuracy. He said that consistently the most accurate Minis he tested, were ones that the op rod did not contact the gas block.
Observations on the Ruger Mini-14

Ah you must be talking about Ed Harris i will ask him about this these days he hangs out on a cast bullet forum. He is a go to guy on reloading and he did a lot testing on Minis when he worked for ruger. He is also the guy that designed the 7.62x39 bullet molds for Lee.
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My 581 was throwing brass about 15 feet at 120*. So I cut a piece of vacuum
belt and punched a hole in it, installed it on the back of the rod/spring.

WOW! Now it throws the brass at 90* and the farthest away was 45 feet! Consistently 30+ feet! There was also some dings in the brass! The buffer hole is big enough for
the spring to go over it. Is the buffer supposed to stack the spring some? IOW smaller
than the spring, but over the op rod?

Hmm. I wonder if the bounce of the rubber is causing the op tod to travel forward sooner therefor hitting the brass like a bat to a ball. Try leather. It softens the blow as apposed to bouncing the energy back.

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"The very atmosphere of firearms anywhere and everywhere restrains evil interference - they deserve a place of honor with all that's good." -George Washington

Ok, I'll try leather after i try making a smaller hole in the buffer. Sounds like
what might happen. Thanks!