DIY- Ruger Trigger Blast Shield/Shim Spacer

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DIY- Ruger Trigger Blast Shield/Shim Spacer

Post by Bullseye » Wed Dec 31, 2008 1:44 pm

I saw that JJ FUNK had written this great informative posting on another forum. He graciously agreed for me to reprint it here for the GTOL membership's use. Thanks JJ! Bullseye

Blast Shield - revisited : Originally written and posted by JJ FUNK in June 2007.

Author's note - I did this on another board, and have been linking to it every time that someone asks about loose receiver to grip frame fit on an MK series pistol, so I thought that maybe I should stick it on this board too.

JJ



I first of all want to take the time to acknowledge the fact that I am not the originator of this very simple yet very effective item. I believe it was On-Target Guns, who used to make these out of shim stock. That being said, these have come up again, and after finding the information concerning the manufacture of a blast shield I immediately went home and tried my hand at it. That was some time ago, and I have been using one in my MKIII for about 6 months now. A few notes about that, The original design was centered around use in a MKII or MKI, and incorporated a "tail" that slid behind the trigger to give an almost complete seal. However, in a MKIII the spur on the back of the trigger makes this a difficult place to put anything, and when I did thread the "tail" into that slot it immediately rendered my pistol in-operable. Also, on one of my MKII's after I put in a trigger which had the pre-travel adjusted out of it, The tail was once again in the way. So the tail is absent from all blast shields which I use. Yes this allows a little more debris to "float" towards the trigger mechanism, but I still think that blocking some is better than none. When I made my first one, it didn't fit. The second one didn't either. So, be patient when making one for yourself. I use empty adult beverage containers, cut open and then washed out.

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After that, the original designer had you using a dremel and fairly precise measurements to make a blast shield. As he was using shim stock, that is understandable, but for a tin can, a pair of scissors, and a sharp knife (Exacto knife if you have one) works just fine.

First I cut a square that is about 1" by 1-3/4"

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Then I lay it into my MK frame and pen in the diminsions of the front receiver hook, notice that I am using the vertical leg for the width measurement, not the actual hook portion.

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Now using a sharp knife, or hobby knife, simply score-cut the square out.

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Now for a test fit, and remark and cut off the outer edges to your liking. You'll notice that I left the rear edge uncut.

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Now, you'll have to trim the rear of the shield to fit. I prefer a convex cut, just a fraction of an inch shy of the magazine.

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That's IT!

Afterwards, you'll notice a tighter fit between your frame and receiver, which for some older guns is a real benefit, and this is much easier to do right than vicing the frame. Whether or not is worth it, I'll leave that up to you guys. I won't shoot any of mine without one. The coverage is easy to see upon comparison, and especially after you have the receiver re-fit.

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The middle MK is the old Blast shield design, ater having the "tail" cut off. The red blocks are representative of where you should expect to find ash, gunpowder and other crap buildup.

Hope this help some of you guys that were having questions.

I know it's not a great photo, but here is accumulation after about 150 rounds of Walmart Federal bulk.

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JJ
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Post by Bullseye » Wed Dec 31, 2008 2:10 pm

Also to give due credit to the now defunct On-Target Guns, these are some of the original pictures of the trigger shield once offered by them for Ruger Mark II & 22/45 pistols.

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On-Target Guns ceased to sell these and other products in 2004. Bill, wherever you are, these were some great parts you designed.

R,
Bullseye
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