I have had a Kimber Mountain Ascent in 280 AI for a couple of weeks now and wanted to share the results so far.

I own several lightweight rifles, including 2 Kimber Montanas, Titanium Browning A-Bolt, 2 Tikka Superlights, Browning X-bolt, and a Forbes Rifle. I was reluctant to buy a Kimber for a long time based upon the accuracy concerns, but that seems to be less of a concern as of late. I eventually bought a Kimber and it has turned out to be my favorite rifle. It is the Kimber Montana in 308, which is also the lightest, but I have always wanted a little more downrange energy. I have been looking at the 280 Ackley Improved in a Montana but when the Mountain Ascent came out, I had to have one. I found one on GB and began to trick it out. I put a Leupold 3-9x33 Ultralight scope and lapped the Talley extra low mounts. I removed the muzzle brake in an attempt to reduce further hearing damage�..ugh, the provided thread protector works well. I also reduced the trigger to 1.5 pounds. The Kimber triggers are easy to adjust and very crisp.

After I removed the muzzle brake and installed the scope, the rifle weighs 5# 15 oz. I like to backpack hunt and have strived to reduce all weight�. including my own weight, haha. Consequently, hunting has been much more enjoyable. While this rifle is very light, I have been wondering if I should of bought an Ascent in 308 instead; maybe that will be on my Christmas list next year. At 5# 15oz, the Mountain Ascent 280 AI compares well to my other guns. The Kimber Montana in 308 with a Leupold 3x9-33, Talley extra lows, and a replacement aluminum trigger guard, weighs 5# 11 oz. The extra 4 ounces of the Ascent 280 AI puts a long-action rifle in my hand in a caliber well suited to longer ranges.

The description on the rifle says the barrel is stainless with some coating on it, Kimcoat I believe. It looks like naked stainless steel to me. The fluting on the bolt is nice. I am not sure the fluting on the barrel reduces much weight. I think it is more aesthetics than function. I love the straight stock of the Kimber Montana and the Mountain Ascent has the same design, which reduces felt recoil. The factory Nosler 140 grains at 3150 fps are a formidable load, but the recoil is mild to very mild.






I cleaned the rifle between shots for the first ten shots and then after each group during the first session. As expected, since I was cleaning between shots and groups, the groups were not great. I was shooting factory loaded Nosler Accubonds in 140 grain. The results of the three-shot groups follow:

12-8-12
1.7� Nosler Accubond 140 factory � clean between shots
1.9� Nosler Accubond 140 factory � clean between shots
1.9� Nosler Accubond 140 factory � clean between shots
1.8� Nosler Accubond 140 factory � clean between groups
2.0� Nosler Accubond 140 factory � clean between groups
1.8� Nosler Accubond 140 factory � clean between groups

I took the gun hunting on 12-15-12. It is a great carry gun. I shot a couple of management does at 300 yards. The shot placement was not great but I didn�t have the best rest, it was windy, I was shooting over broom weeds, and hey West Texas whitetails are a small target. Even with less-than-ideal shot placement, the bullets hammered the deer. The gun was a dream to carry but I wish the hits had been more confidence inspiring. I should also practice those types of shots more.

I next loaded a few hand loads with Berger 140 grain VLD Hunting bullets. I tried to seat them near the lands but they would not work in the action. The longer seating would fit the magazine but they could not be ejected, and with a blind box magazine, that is problematic. Therefore, I seated them only as deep as required to allow them to function in the action with a CAOL 3.31". The wind was blowing about 15mph during testing, but here are the results of the three-shot groups:

0.7� 59gr H4831
1.1� 60gr H4831
1.3� 61gr H4831
1.2� 62gr H4831







I also loaded a few Ballistic Tips in 140 grain. Again, I could not get these seated near the lands so I seated them just enough to allow the rounds to function in the action. The bullets were seated with a CAOL of 3.29". For reference factory 140 Accubonds have a CAOL 3.28". A summary of the three-shot groups follows:

1.3� 60gr H4831
0.9� 61gr H4831
1.2� 62gr H4831



[img:center]http://i1167.photobucket.com/albums/q630/MarkBurkett/280Target4_zps50ba8c8a.jpg[/img]

I waited for the gun to cool between groups. The gun has very acceptable hunting accuracy and I believe the groups would have shrunk without the 15mph wind. I will keep tweaking the loads. I have another round of Bergers loaded with deeper bullet seating and I have also loaded some 162 Amax bullets.

I love the weight of the gun. The stock color is growing on me �.. slowly, but it fits me very well. When I pull it to my cheek I am looking down the scope. It surprises me that many factory stock are still designed for sights even though very few rifles like this have sights anymore. This stock is designed for a scope. The fit and finish is good. My gun feeds well. I love the trigger and like the stainless barrel. When I get the right loads, this will be a great backpack rifle. I don�t know if I could do much better.

Nice.......just be careful where you lay it down or you may be going home without your new rifle.

I'm glad they decided to leave the battleship grey coating off. Nice looking rig!

I'll be interested to see how it shoots the 162gr Amax, I'd also be interested in how it shoots the 168gr Berger VLD Hunting bullet.

Great write up. Thanks!

Mine also likes Re 22 and the 140 grain TTSX. My cold weather load is H4831. Same POI and close in velocity.

Nice review bud! What did the Forbes end up weighing all up?

Thx for the review, I've been around the same rig and it seems nice.

Be interesting to do some bedding work on that rig. And, it'll be interesting to see how it's shooting when you get around 150 rounds or so.

Thx for the review

Dober

(smart move keeping the brake off and by the way how'd the Browning Ti shoot?)

Side note, after it gets broke in and bedded and you're in sink with it I'm for betting you find a load that will perk along in the .75-.8" range.

Dober

It sounds like I am going to have to try Reloader 22 for this cartridge. I would appreciate any load data you have for this setup. I know all rifles are different but it might give me a good starting point.

Thanks for the comments. I have learned a lot on here. Hopefully, the information posted helps others.

I put a Leupold Ultralight 3x9-33 scope on the Forbes [24b 270] and it weighs 6# 5 ounces. It has a thicker barrel but a lightweight stock, thus front heavy. It is a nice feeling rifle with the extra weight out front. I accidentally banged the scope against the deer blind a couple of weeks ago. It chipped paint and dented the front of the scope housing. I checked the zero with a 3-shot group. The POI was still on and it printed a 0.5" group. It's a nice rifle and the Talley lightweight mounts passed the test..... again.

Dober

The Browning Titanium A-bolt shoots good. It is a 300 WSM and it only weighs 6# 10oz with a Leupold 3.5x10-40 and Talley lightweight mounts. I may be a wimp, but it kicks hard. Therefore, I have not shot anything heavier than 150 gr bullets. I haven't had a chance to work up hand loads yet but with factory Federal 150 Ballistic Tips, it is under 1 MOA consistently. I like the gun, but it will make you flinch.

Thanks for taking the time to fill us in! I'm waffling between the two, waiting for the SS Forbs to come out.

My 280 AI loves 64g of RL 22 and 140 TTSX's @3150.

Darktimber: Nice writeup and report...thanks.That out fit has a lot of appeal....a long action,lightweight with that sort of performance is nothing to sneer at...Mmmm I ain't getting any younger.....

Had you chronogrpahed the loads or did I miss that?Whats your thoughts on the recoil? I sold a Kimber Montana in 7mmWSM because I thought it was a rude, hard snapping little bugger.Is this Ascent manageable?

Thanks. I did not get to chronograph the loads. The fps references were printed on Nosler's box so I am not sure of the actual speed. Regarding recoil, I think I am pretty sensitive to recoil. It is not the pain but more the fear of developing a flinch. I was concerned the 280 AI would buck pretty hard with this light of a rifle, but it has been pleasant so far. I am sure it will be more noticeable with a heavier bullet, which I plan to test, but so far it has been pleasant, even at the range.

Thanks for taking the time to fill us in on this one

Thanks for the 411 and pictures. Nice looking gun.

Very nice write up and report, I'm not crazy about the brake and glad to hear its easily removable. Though I love the 280 and the 280ai would do just as well, I'd be excited if they released it in 7mm-08.

Nice write up. Thanks for that!

I'd be interested in how much recoil the brake would minimize -and-
whether or not the POI would change. Could run it "brake on" to practice and "off" to hunt.

That should be a great all-around rig for just about anything in N.A.... or even Texas!

Mind sharing your loads for RL-22 and H4831?

Took my Mtn Ascent in 280 Ackley out today. Only shot it a few times because it was 14 degrees. With Nosler 140 gr. Accubond factory loads recoil was like my 243 Guide Gun but I had the weedburner on the end of the 280. Cleaned after every shot so really can't tell about the accuracy so far but they are all in the same neighorhood. It's a very nice feeling and shooting rifle. I put a Swaro Z3 3-9x36 w. a 4A reticle on it. Pretty sure I could go hunting with it right now. I have a Montana 300 WSM and a Classic 270 WSM I have had since the 8400s first came out. The 270 short mag being one of my favorite rifles. I've never had any accuracy problems with either of them. The 280 AI may be my new favorite Kimber.

Since the last post, I took some advice and glass bedded the rifle. I am not sure if this made any difference, since I have not tried to duplicate some of the previous load results, but I feel better knowing that there is a good fit between stock and receiver. I only glass bedded the lug, one inch of the chamber, and the rear tang. I considered full-length bedding it, likes the Forbes rifles, but that can be done later if needed.

After bedding, I tested some 162 Amax and 168 Berger VLD Hunting bullets. While the sample size is small, and I should have taken some intermediate steps, it appears the gun likes the 168 Berger VLDs better than anything I have tried so far. The limited results of the 3-shot 100yd groups follow:

Hornady 162 gr Amax Bullets
1.3� 162 Amax 55gr H4831
1.5� 162 Amax 56gr H4831
1.5� 162 Amax 57gr H4831 (Hodgdon Max 56.4)







Berger 168 gr VLD Hunting Bullets
1.1� 168 Berger 57gr H4831
1.1� 168 Berger 57gr H4831
1.0� 168 Berger 57.7gr H4831 (Hodgdon Max)
2.2� 168 Berger 57.7gr H4831 (Hodgdon Max) flier






The Berger 57 grain loads felt fine and I saw no abnormal pressure signs. The two groups looked good and overlay each other. The 57.7 loads seemed hot, especially the one shot that was flier in the second group, located to the right. On that shot, the bolt lift was a little stiffer than others.

Based on Hodgdon website, the 57.7 loads push the bullet at 2779 fps. Given the BC of this bullet of 0.617, that puts approximately 1670 ft-lbs of energy downrange at 500 yards. That is pretty substantial for a non-magnum cartridge. The recoil was more noticeable today pushing the larger bullets. It was not painful but noticeable.

I plan to continue tweaking the 168 Bergers until I find a sweet spot, but in the meantime, this is functional elk and deer medicine.

How far are you 280 owners shooting?

Just 100 so far. Our range has up to 450 when I get dialed in next time in a day or two.

Try RL-19 and the 150 TTSX. I have the Montana version. You can see a couple of the groups from one of my earlier posts. Way better than what you're getting now, I think. You haven't found your optimum combo yet.

Some disagree, but I had to work on my form a bit to get top accuracy from my Montana. At first, I felt like it was exposing all my bad habits at the bench. Lightening the trigger also helped.

The trigger on my Montana is 1lb 3oz, and it feels none too light when I'm shooting from the sandbags or bipod...

No kidding . Mine feels like it's moving the rifle on the bags at 1.5 lbs

Great report. Looks like a test rifle to carry in the mountains.

I haven't tried TTSXs yet. I have tried them in factory loads with okay results. They get great reviews and have a good following. I will look for the earlier post. It makes sense that they would be more accurate. The less-dense copper will produce a longer bullet given the same bullet weight. The longer bullet should be more stable.

I agree with you on getting these lightweight rifles to shoot accurately. A light trigger becomes very important and how the rifle is held seems to make a big difference. It is all a trade off. I used to carry a 10.5 pound Sendero up the mountain, but I also remember heading back to camp early due to fatigue.

I tried a few Barnes 168 LRX bullets today with the Ascent okay results. The wind was blowing about 8 mph so it wasn't perfect conditions. The 3-shot groups are shown below:

1.4" LRX 168 57.0gr h4831
1.6" LRX 168 57.0gr h4831
1.1" LRX 168 58.0gr h4831

These were pretty hot. I didn't shoot the 59 grain group I had loaded. The primers were pretty flat at 58 grains. This is a small sample size. I will try them again later with lighter loads.

While there I shot some 168 grain Berger VLD Hunting bullets. Previously 57 grains of H4831 seemed to be sweet spot and that was the case today. The 3-shot 100yd groups are shown below:

1.2" Berg 168 56gr h4831
1.1" Berg 168 56gr h4831
1.1" Berg 168 56.5gr h4831
0.9" Berg 168 56.5gr h4831
0.6" Berg 168 57 gr h4831
0.9" Berg 168 57 gr h4831
2.3" Berg 168 57.7gr h4831

The photos are below:






The groups opened up at 57.7grains this time and previously. I am pretty pleased with these groups. I think I am reaching a point of diminishing returns.

I also noticed that the groups tended to open up if I didn't "hold" the rifle. It seemed that if I let it recoil freely, the shots moved or opened up on some of the hotter loads.

Nice report. Dialing in a rifle and doing load development is time consuming, and good documentation is often overlooked. .

Nice shooting! That is a light rifle so getting bug hole sized groups is tough, but you are getting some awesome accuracy out of the rifle and you'll still be able to move your arms at the end of the day!

One of these is on the shelf at my LGS

yep, looks like 57gr is your huckleberry

Darktimber, I thank you for taking the time to post your results. I have the same rifle and will soon start working up loads for it. I have a few questions,, Have you tried shooting it with the brake? I have read that the brakes on light rifles really improve accuracy. Also, have you tried ReLoader 17?

Thanks Sir

I shot back to back groups with my Montana (338 Fed) using the same ammo, and free recoil resulted in ~3" groups, holding basically like shooting offhand, but with the bags to steady things, resulted in .75". Free recoil and Montanas do not go together. In my opinion... Now my .308 with a 26" heavy barrel is a different story.

My Montana 338 Fed produced similar results until I pulled the front sandbag way back toward the trigger guard and got 1" with Fed ammo.

Yep. Bag under the magazine, hold it just like you would in the field if kneeling or offhand and it shoots like a champ.

The groups opened up at 57.7grains this time and previously. I am pretty pleased with these groups. I think I am reaching a point of diminishing returns.

I also noticed that the groups tended to open up if I didn't "hold" the rifle. It seemed that if I let it recoil freely, the shots moved or opened up on some of the hotter loads.

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This is what I have found with both of my kimbers. When I grip them the loads are very consistent. When I just sit behind the rifle and pull the trigger groups open up with some really odd fliers.

Thanks for the comments. I have not shot the gun with the brake so I don't have anything to add there. Recoil has not been much of an issue to me and I am usually pretty sensitive to it. I have a 300 WSM that is uncomfortable on the bench but this gun with 168 gr bullets seems mild to me. You know it goes off but it is not uncomfortable. I would like to know if the POI changes but haven't tried it yet.

It is very light and a dream to carry. I hunted with it a few times and noticed that you have to pay a little more attention to your technique. Being fast on the trigger is a bigger issue than with a heavier gun.

I haven't tried RL 17 yet.

I hope to get those Barnes 168 LRXs to shoot. I shot a few with okay results. It is an awesome looking bullet with good downrange energy. I started off a little hot I think and with very few loads. If you find a recipe yours likes please share it.

Nosler is releasing a new long range Accubond this spring and they have 3 offerings for the .284 size, a 150, 168 and 175 grain bullets and the BC looks very impressive. I hope to work up some loads using R17 and the 168 LR Accubond for mine. I'm using R17 in several calibers and the velocity and accuracy are really good.

http://noslerreloading.com/phpBB2/viewtopic.php?f=4&t=21141

I have made one more tweak to the rifle. I never liked the muzzle crown with the thread protector, so I re-cut it. It is hard to see what it looked like before from the attached picture. The top picture is how it came from the factory after removing the muzzle brake and installing the thread protector. The bottom shows the crown re-cut at 11 degrees with the thread protector. The thread protector participated in the cut also. It has blue thread lock, so it should not move.






I went to the range to test it out, but to my disappointment, the pet loads of 57 grains of H4831 Berger VLD Hunting 168 gr were not shooting well. The groups were in the 1.5" to 1.8" range. When I worked up the loads, the temperature was 40 degrees, now it is 85 degrees. Also, this load seemed to open up at 57.7 grains. Therefore, I suspected I could be having temperature stability effects. I backed off the load to 56 grains, went to the range again and the first two groups were 0.4" as shown below. The next two groups with 56.5 grains were acceptable, but a little more open at 0.7" and 0.9".








I think I will stick with the 56grain loads and NEVER tweak the gun again.

This thing is light, and a little tough to hold steady, but it is a shooter.

Would be great to know what speed your loads are doing.

Congrats on a nice rifle and thanks for sharing your work with us.

Very nice. Seems like it is humming along nicely.

Now you're cooking with Crisco. Looking good and you can't argue with that accuracy from an ultralight factory rig.

It is a lot easier on the bench than out in the field. I am very pleased with this one. The accuracy is very good for these lightweight guns. I once thought I needed a bull barrel to have an accurate gun, and they are a little more forgiving, but not fun to carry. Once you hone your shooting skills, a lightweight gun is just as effective and a whole lot more fun to carry around, which is what you do most of the time anyway.

Great info and thanks for going through the effort of sharing. Looks like a fine rig you have!