New member.. Kimber 8400 300WSM accuracy??

[clawman]

CAUTION when considering Tubbs Final Finish!!
I just used their system on my Remington 257 Roberts. As far as the before/after on my pet loads is concerned, overall length 2.960 before and 3.038 after.
Yes, the cartridges need to be .078 longer to touch the lands now. Haven't worked on a new load yet but that is taking a LOT of metal out of the throat.

 

[Rifleman1st]

Try different bullet weights. One of my rifles shoots 150 grain bullets into 1 hole, yet the same rifle shoots 2" + groups with 165 grain bullets no matter what I do with the load combination.

 

[Ldigio21]

For anyone who is not familiar with Hill Country Rifle,I have had 3 accurizing jobs and one rebarrel. Overall I am very satisfied with the results. My Browning A bolt in micromedalian rebarreled with a Lilja 22 " barrel to a 7mm-08 Ackley improved is now a one holer even when fire forming brass!! It does not care what bullet type or weight is used. I have a Kimber Super America 7mm Remington mag accurized. It consistently shoots under an inch, but more importantly if I were to shot one shot per year at the same target it still groups under and inch. It is extremely stable over the long haul which I find incredible for a wood stocked rifle. I have not had to change the scope adjustment in over 5 years. Also had a Belgian Browning in 30-06 accurized. Same great results. When the 300WSM came out I bought a Browning A-bolt and sent the rifle to them. They built me a 7mm WSM before the caliber was even released. I had to invent my own load data. This gun consistently groups .5" to .75" with Swift A frame bullets which while, great terminal performers are not match grade bullets. I prefer them for hunting so I am willing to sacrifice a little on paper. There is no other company I would use at this point as they have performed so well. By the way, this is not a "paid political announcement" I just feel that they deserve the cudos based on the way they have performed for me over the years.

 

[WapitiBob]

HCR won't touch a Kimber now days.

 

[ERH]

First..Great Question!
The 300 WSM is a great cartridge. The 8400 is an excellent rifle. I own a Kimber 8400 Select Grade in .338 Win Mag. I love its looks. I have been able to get 1 inch groups with hand loaded 180g Nosler AccuBonds but larger bullets like the 200, 225 and 250g bullets do spread out to as far as 1.25 to 1.75 inches at 100 yards as bullet weight increases. The 250g AccuBond in .338 can kill almost equally as well, a Cape Buff as a 300g .375 H & H Magnum as the point blank energy is virtually identical at 4000 ft-lbs but can kill a Muley Buck with 180g heads at 500 yards shooting MOA 180g heads. The shooter has the most built in error at that range with adrenaline, poor rests, lack of practice at that range. How good are you? Scope? Magnification? Bench rest gear etc.
The 8400 rifle is lighter than most and the barrel is pencil thin so carrying less weight is a reason to buy if you are a mountain hunter or one who is carrying all day long.
I was, like you, initially disappointed for the dollar spent in getting worse than MOA for the heavier bullets. And not even sub MOA for any hand loaded bullet.

It is important to note that most new rifles will improve in accuracy over time and need more than 100 rounds shot to accurize a rifle. Cleaning and shooting after each session is essential. I would Google Breaking in a new rifle to see techniques you might use on your Kimber.

Dwight Van Brunt says that because the barrel is thinner you will have to let the barrel cool between shots and my barrel does heat up fast so he says first shots count more in accuracy.
No question my 8400 is very beautiful but it does not appear to perform at a sub moa level when repeat shots are taken with my caliber and limited experience with the 8400. Bull barrels on other rifle brands absorb heat and deliver more accuracy but are heavy as heck to tote in the high mountains. My sons Savage Model 10 in .308 Winchester, heavy as heck bull barrel with an accutrigger shoots 3/4 to 7/8 groups with 140g Sierra HP hand-loads but is not in the same league at all for delivered energy. Too heavy for deer hunting all day in the field.

That said, you can spend more money and get guaranteed sub-MOA on the same kind of 8400 weight gun and get really good performance as guaranteed sub-MOA three shot groups. I have found that the simms vibration laboratory barrel dampener does reduce group size by a sizable margin on my 8400 with 200g Nosler e-tips from 1.5 inches to 1 1/8 inches.

I will say this on rifle accuracy, when you find a rifle that shoots sub-MOA groups for most of the ammo you shoot, then treat it like gold. I have a Ruger M77 Hawkeye African in .375 Ruger that shoots 260 grain Nosler AccuBond bullets in 5/8 inch groups at full power loads at 100 yards. I have to load down for deer and accuracy changes little. I am afraid there is no equal to this rifle without giant dollars being spent.gun)

 

[azgutpile]

I have a Montana 8400 in 300 WSM. And here is what has worked for me.

The bedding on the rifle is crap, it is bedded, but they used a slave action instead of your actual action. When you look at it, you might see pieces of paint and bedding flaking off. Also, when you have the rifle rebedded, make sure that the magazine box isn't being compressed between the stock and the action.

Have the trigger weight adjusted down. I currently have mine adjusted to 13oz and i like it alot. I've tested it by banging the rifle around a lot and ive never had it go off accidentally. Either way, I still don't load a round in the chamber until I'm ready to shoot.

Make sure you torque the ation bolts down in the correct order. The front one first and then the back one. I torqued mine to 50 inch pounds.

At first I had the kimber/ Leupold based and leupold rings. I feel that I had to much movement with these so I Purchased a Ken Farrel aluminum rail and Warne low rings and it is now rock solid. Unfortunately, this leaves the scope a little high, so a good cheek weld can be tough. You might try an aftermarket cheek piece.

If you decide to reload, the 180 grains accubonds and the 168 grain Barnes tsx/ ttsx work great. Both bullets shot great with 62 grains of IMR 4350, Winchester brass and fed 215m primers ( 1/2" to 3/4" groups @ 100 yards). I've tried other bullets without much success and these bullets were recommended by a kimber tech.

The gun is very light and has a lot of vertical recoil, so if weight isn't an issue add a Harris bipod. This made the recoil more enjoyable. Also make that you hold the rifle the exact same way every time you shoot for groups. And since the barrel is so thin, wait ten minutes between shots this way your barrel has a chance to cool completly.

If your still not having succes try jb bore past. This was recommended by a tech at kimber and it worked well.

Please forget the typos, I used my iPhone for this post.

 

[ERH]

I would be interested in what a Gun Smith would say on the Bedding of the 8400 since Kimber touts a superior bedding. I shall investigate.

Bolt torque is important and the sequence is also important. I have a torque wrench that I bought for my Ruger M77 to ensure the main lug is factory spec.

Trigger pull for target can be as low as you have it but in the woods with cold fingers, 3 pounds allows enough feel and is widely supported by veteran hunters for a multitude of reasons. Most rifle triggers break above 5 pounds and are responsible for many inaccuracies as is flinching. I always wear a shoulder pad at the bench. I use a Lyman Electronic Trigger Pull gauge to check trigger weight. It is the best tool for this.

 

[Dalebow]

I have used HCR to accurize many rifles as well as bought rifles from them. They are top notch class acts.

As stated they will not touch the kimbers as they are inconsistent. Kimber makes a fine pistol but the long guns can be good and bad, depends on what you get.

far as 300 wsm my HILL CO rifles Harvester is a .45 gun all day long with factory 180gr loads, my McWhorter is a .15/.20 all day long with factory 165 and 180 grain loads. My savage 300wsm is half inch all day long with wincherser powermax 180 grain factory loads.............

with a Kimber you will be lucky to get a 3/4 group. it needs to be bedded, have the crown checked, have the trigger adjusted, but most of all you will have to handload to get that rifle to find a load it likes.

Good Luck because 300wsm is one fine caliber and you will love it!

 

[CogburnR]

I have a Kimber 8400. It shoots about an inch with most loads @100yards and delivers a number of different loads to pretty close to the same spot which is nice. Mine is a 270WSM and will shoot better with Retumbo than any other powder.The 8400 is meant to be a carry rifle and is built light with a small barrel as previously noted.

I have a Winchester M70 featherweight in 300wsm also, it shot about the same way until I had the action bedded. It now shoots sub MOA. As the barrel warmed the bullet impact would move up and to the right, it no longer does that but the groups grow with barrel temperature. The Win M70 and Kimber are quite similar.

One thing I would do is shoot some groups with a bipod at longer range like 3-400 yards while letting the barrel cool between shots and keeping the ammo at a stable temperature. You might be surprised at the results. Mine doesn't like being shot from a vise.

 

[D.ID]

My hunting partner has a beautiful kimber in 22-250 and an old beat to hell remington 788 in 22-250 with unknown barrel in the white, camo tape residue all down the barrel and dents and scratches all over the gun...........The 788 is a tac driver with most ammo and the kimber has tried everything under the sun and still only shoots a 1.5" average @100yrds. Sometimes they just don't run like they should even when you spend the coin on them. If your not emotionally attached to it trade it in before putting even more into it. Just my two cents, good luck.

 

[longrangehunter300wsm]

i have shot the kimbir 8400! and i am a 300 wsm nut! it should be shooting lots better then that! maybe have someone shoot it and see how they do! or start reloding!
it could also be a problem with the barrel from the factory! that happens sometimes!