My Kimber Montana Tinkering

Joined
Oct 7, 2020
Messages
52
I've learned so much from reading this post. I always use a gunsmith but have a few Kimbers I may mess with now. Thanks!
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Some ramblings on future plans. If you happen to read it, feel free to shoot holes in the ideas.

Not made it out to the range yet, my second daughter was born on the 16th. I have been wanting to isolate the rifle more to remove myself from the accuracy equation as much as possible. However I don't own anything for shooting off a bench as I have yet to see a shooting bench I want to carry in the woods. I was thinking about a bipod, but not sure I would use it and as I removed the standard sling swivel threads from the stock attachment would be an issue as well. Spartan Precision Equipment has the best solution with their Gunsmith Adapter, but the bipods start at $145 (plus $36 for the adapter), not cheap for something I may not even like using.

My wife has a strong enough tripod for photography, so I was looking at ways to use that. I came across the PIG Saddle (1.4 lbs and $135) and HOG Saddle (15.8 oz and $309). Both are too heavy for me to want to carry them in the field, and are cost prohibitive for something that would see minimal use at the range (no point training with something I will not carry). As I have Arca Swiss plates laying around I could install two threaded sleeves in the stock. Two sleeves would be to prevent rotation. This could be used with a glassing tripod for a minimal weight penalty. However, I don't like the idea of a plate hanging off the rifle, primarily for aesthetic reasons and I have helped justify this with the probably bogus argument that it will add something to hang up on brush. Regardless, it would stand out from the rounded stock of the Kimber quite a bit.

What I ended up deciding on was the Spartan Precision Equipment Davros head (4.7 oz, $96.50) with a Gunsmith Adapter (9 g, $36). I can use the tripod I already have. This is only a slight weight penalty compared with the 3.0 oz Fusion 3.75 inch Arca Swiss plate I have on hand while being a much more elegant solution. The set up is also light enough I would be willing to carry it if already packing a tripod for glassing. Plus, if I want to add a bipod later it gives me the connection point and I really like the fact that the Spartan bipods are designed to be removed as I have never liked the idea of a bipod hanging off my rifle.

Now I just have to wait for the parts to arrive from across the pond.

I have been considering side mounted QD connection points for quite some time as I have never (starting at 13 when I got my first rifle with a sling) liked how traditional slings carry a rifle. This is due to the only way to quickly put the rifle in play is using an off side, muzzle down carry. I had considered the Safari Sling, but it always struck me as a kludgy solution, and it does not lend itself to being a shooting aid. Yet, I was not sure where to install QD sockets or if I would actually find it better than the traditional location, especially as I use the sling as a shooting aid. So I have not tried it so far. Looking at the Springfield Waypoint got me thinking about this again. Thanks to @Rockwell, @BCoker, and Todd Dow of Rifle-Craft and his free book Slings in the Wild, I know where I want the QD sockets located now.

I'm going to put a socket on the left side, just forward of the barrel taper and another one on the right side about 1/2 inch below the comb and forward of the recoil pad. I also ordered a RS-3 sling from Rifle-Craft as it appears well thought out and I felt like I should give Todd some business due to how helpful his free book was in this process.

So in traditional nerdy, gear head fashion I have thrown money at it. Hopefully with more accurate precision than my shooting. ;)

https://rifle-craft.com/

While I have only read two blog posts of his, I also have to thank Dave Chenault of Bedrock and Paradox for the idea of using QD sockets on a traditionally rifle, especially for non-traditional attachment locations.

Edited to reflect that the arca swiss plate is made by Fusion, not Black Rapid as I incorrectly stated. The plate is designed to work with a Black Rapid camera sling, hence my confusion.
 
Last edited:
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Well, I opened a can of worms. My barrel was floated enough that I could slide a piece of paper between it and the stock, but thinking about a tripod made me wonder how much pressure it would take to flex the stock and close the gap, turned out not much. So I started sanding thinking that I would just need to remove the paint from the channel. However, it ended up needing more removed than that and turned into a problem of I needed more space, but creating more space removed structure and introduced more flex. I'm at the point where it takes a good bit of pressure to create contact, however I think I'm going to have to add some weight and stiffen the forend. In hind sight, I probably should have left the thick bedding job in place and just drilled out a little of the pillar to get adequate thread engagement.

When I started. I had already sanded out the shank area some.
20201028_210159.jpg
Using the section of barrel I cut off as a sanding block.
20201028_210413.jpg
You can see how uneven the stock material is. Before painting I had tried to sand off all of Kimber's primer without sanding the substrate.
20201028_210531.jpg

This is the point where I stopped. Then yellowish portion is thin enough I could push my finger through it into the low density foam underneath.
20201028_233547.jpg

I could just put a thin coat of epoxy over it to seal, but the loss of structure has made the stock quite a bit more flexible side to side as well as up and down. There is enough gap that as long as I don't lean on the gun there would not be barrel contact even if resting the forend on something.

I think I'm going to pick up a 300 spin carbon arrow to stiffen the forend along with using about half inch thick cross supports of syntactic foam, spaced an inch or so appart, to hold the arrow shaft in place and provide support between the sides of the stock so it all functions as one unit. I think this will give close to the same strength as completely filling the forend with syntactic foam for a few ounces less weight.

Before I do this I need the Spartan Gunsmith adapter as I want to build it into the structure, rather than drilling into the structure to install it.
 
Last edited:

stmcelroy

FNG
Joined
Oct 27, 2020
Messages
2
Great work.

Hope you can get it to shoot smaller groups.

I'm going back and forth between a Kimber or a Barrett Fieldcraft, thus far the Fieldcraft is winning.
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Great work.

Hope you can get it to shoot smaller groups.

I'm going back and forth between a Kimber or a Barrett Fieldcraft, thus far the Fieldcraft is winning.

If you can find a Fieldcraft (Barrett has indefinitely paused production) I would grab it and not sit on the fence. I prefer the CRF action of the Kimber, but Barrett is a much better company.
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
The Spartan Precision package has crossed the pond, but will not be at my door until Thursday. I got the Rifle-Craft package today. I like the sling quite a bit. I'm holding off on installing the QD swivels until I'm ready to do everything so I can get it all done with one batch of epoxy.

Picked up some Beman 300 spine carbon arrows that where about half off today. At 9.5 grains/inch they are not the lightest, nor the heaviest.

Out of curiosity I did some math. At a diameter of 0.297 inches the carbon arrow has a density of 0.544 g/ml. The syntactic foam has a density of about 0.436 g/ml. So the foam is lighter than the hollow arrow. The foam is pretty solid and stiff too. I had been thinking the arrow shaft would be lighter, however now I'm thinking of the arrow shaft more like rebar in concrete than as a structural filler.

If anyone is nerdy enough to be curious as to how I arrived at the density for the foam.

West System 105 epoxy with 207 hardener has a cured density of 1.15 g/ml. The cheap microballoons I'm using have a density ranging from 0.1 g/ml to 0.6 g/m. Mix ratio is around 1 part epoxy to 3 parts microballoons. This gives a calculated range of 0.36 g/ml to 0.738 g/ml at an average of 0.55 g/ml.

I also have a chunk of cured syntactic foam that was left over. It is roughly cylindrical in shape. Floating it and measuring how much sticks out of the water gives an estimated density of 0.436 g/ml, which is within the calculated range. Of course the best way to calculate the density would be to measure liquid displacement to get volume and weigh it for mass. However, I have no containers with accurate enough measurements gradients to make this work, so I had to settle for estimations instead.
 
  • Like
Reactions: wyo
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Cut and sanded arrow shafts.
20201106_233849.jpg
The QD cup and Gunsmith adapter, checking clearance with arrow shafts.
20201106_231235.jpg20201106_235219.jpg

Done for the night. I took advantage of the cold weather and cracked the garage door to extend my pot life. Glad I did as it gave me time to pack around the arrow shafts with syntactic foam. I'm thinking I will fiberglass over the cut out to seal off the stock. I could not bring myself to pack the entire forend with syntactic foam.

When mixed thick like this, the syntactic foam does not stick well as epoxy does not coat the mating surface, the fix is to put a thin coat of epoxy on everything before applying the foam.
20201107_012755.jpg

You can see where my 3/4 inch bit walked drilling for the gunsmith adapter.
20201107_012831.jpg

Rear QD socket.
20201107_012520.jpg
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
I really like the shooting sling. The tripod is also nice, but I need to practice more with both and the Spartan head does not have the holding power to really lock the rifle down.

The lighter trigger pull is great.

10 rds
20201113_134930.jpg

10 rds
20201113_142821.jpg

20 rds (two 10 round groups stacked on top of each other).
20201113_152807.jpg
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Overall the forend work, QD sockets, and Spartan Gunsmith adapter added only 1 and 7/8th ounces.
20201115_054308.jpg

The bare weight is 6 pounds 11 and 1/4 ounces.
20201115_054543.jpg

120 rounds down range after firing pin spring change and no missfires.

I'm probably done tinkering with this one. I'm really happy with how it turned out.
 
Joined
Oct 6, 2014
Messages
1,383
Location
Wasilla, Alaska
You know I bet your groups really tightened up because you sanded out the channel. I would bet that you were getting contact with the stock before. I know my Adirondack was. Groups were 2-3 MOA. Afterwards groups were 1/2 MOA.
 

Huntsalot

FNG
Joined
Mar 4, 2017
Messages
65
120 rounds down range after firing pin spring change and no missfires.

I'm probably done tinkering with this one. I'm really happy with how it turned out.

Great thread, with lots of good info. Any updates on the misfires?
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Great thread, with lots of good info. Any updates on the misfires?

No real updates. Between life, cold weather, and trouble finding ammo I have not put many more rounds through it. No issues with the few that have gone down range and yesterday I took a 230-250 pound black bear with it at 25 meters.

I did find some target ammo, so once I make it to the rang I will update.
 
Joined
Oct 6, 2014
Messages
1,383
Location
Wasilla, Alaska
No real updates. Between life, cold weather, and trouble finding ammo I have not put many more rounds through it. No issues with the few that have gone down range and yesterday I took a 230-250 pound black bear with it at 25 meters.

I did find some target ammo, so once I make it to the rang I will update.
Were you on 1x with NX8 and both eyes open when you shot that bear? Close range is going to be awesome with this little scope.
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
Were you on 1x with NX8 and both eyes open when you shot that bear? Close range is going to be awesome with this little scope.

That scope is indead awesome for close range. I approached on 1x with illumination on. I ended up laying down and waiting for a good presentation, and when I did that I moved it to 2x. Still shot with both eyes open.

In hindsight, I should have suppressed the desire to fiddle and just kept it on 1x. The finishing shot was on 1x from about 10 feet. The bear ran 10-15 feet after the first shot and piled up in the brush grunting.
 
OP
Marbles

Marbles

WKR
Classified Approved
Joined
May 16, 2020
Messages
3,711
Location
AK
IMG_0190.jpg
It was late in the day and I almost did not get a picture as I had left my camera on the boat. Of course, my buddies 13 year old son had his phone on him. Next time I will look around and make sure a tarp is not in the background.
 

Jbehredt

WKR
Joined
Mar 4, 2017
Messages
1,710
Location
Colorado
View attachment 290420
It was late in the day and I almost did not get a picture as I had left my camera on the boat. Of course, my buddies 13 year old son had his phone on him. Next time I will look around and make sure a tarp is not in the background.

My wife could make that disappear with photoshop in ten minutes. Maybe you know somebody with similar skills.
 
Top