Gentlemen:

I just purchased a new Kimber 84M rifle. This is Kimber's new medium length action with mauser extraction. It is a very nice action. Quite petite---the receiver OD is only 1.10". My rifle is the varmint model. It took me about 5 minutes to get the rifle in the barrel vise and spin the varmint barrel off [I can ruin a perfectly good rifle faster than anyone I know].

My sole purpose in buying this rifle is to rechamber it with a 20" tube into a light, short mule deer rifle [yes, I know, light rifles are bad, impossible to shoot accurately off-hand, etc.] and then drop it into a light, fiberglass stock.

I am in a quandry over which caliber I should chamber the rifle in. I simply cannot make up my mind. Any suggestions? I am leaning towards 7mm-08, possibly improved. GS bullets makes a 130 grainer with a BC of about .550. It should go 3000 fps in a 20 inch tube with a '08 size powder charge behind it. Duane Spooner's .257 DGR is very appealing. I love the quarter bore, but I don't think the .257 DGR will make 3000 fps with a 115 grain bullet and a 20 inch tube and I am just not satisfied with only a 100 grain bullet.

What other options? The .257 Ackley is a great cartridge, but with only a 20 inch tube am I wasting alot of powder? I think I am treading a fine line here between too much cartridge and too short a barrel and yet I really would like to make 3000 fps and throw at least 115 grains down range. The 7mm-08 strikes me as a good compromise. Should I bother to go with the improved version or with such a short tube [20 inches] am I simply wasting time and money?

Any input is appreciated/ What about the .250 Ackley Improved?

Thanks,

Jordan

25-284............

Big Stick:

I had not even thought of that Wildcat. I am aware of it, but had forgotten about it. You must have one to recommend it. What bullet weight do you use for deer? Everything I have read suggests that 100 grainers [Nosler, Barnes, etc] work well on deer in the quarter-bore. I would really like to load and use only one bullet but seem to have it in my head that 100 grains is just not enough lead---especially at the lower velocities I will probably attain. Any idea what how fast the .25-284 will motivate a 115 grain pill out of a 20 inch tube?

Thanks,

Jordan

Jordan,

I only have two of them.

I have personally never entertained the idea of shooting anything heavier than 100's and shoot 75's much of the time(X's for Game,V-Max for play).

My 23" barrel will make 3750fps,with the 75's and bust 3400fps,with the 100's. The 24" tube,will gain but a smidge on those speeds. Both are twisted 1-10".

I've never launched anything over 100grs of weight,in either,so can't comment upon those expectation levels.

I have four 7-08's and dearly love that chambering,but tote the 25-284's more these days. It is one hell of a great round and simply sizzles.

She's a 25-06 +P in a short action,very hard not to like that............

You will acheive a better expansion ratio and thus greater efficiency in the short barrel with larger bores. I would suggest either the .284 or .30/284 for what you suggest.

Fireplug

This may be a stupid question but when I was thinking about buying one and rebarreling to 358 win or 35-284 iwas told I would have to stick to the 358 because the bolt and reciever diameters were not large enough to take anything bigger than a regular ('06)case diameter that the action was origionaly designed for the 223 at the largest. So my question would be is the action large enough for the 25-284? I hope so as I would still like a 35-284 or maybe a 338-284 or heck maybe...

I would be very leery of going with anything other than a standard �06 diameter case size. Okay folks, correct me if I�m wrong, but the .284 case has the standard .473� head size with a fat body, right? So to get reliable feeding you would probably have have to mess with the feed rails. And if you alter the feed rails you have ruined that action forever more if you should ever decide to go to another caliber or try to sell it.

Also, heed Fireplug�s advice about expansion ratios and short barrels. You will get lots of muzzle blast and disappointing velocities. I think your original idea of a 7mm-08 is just spot on perfect for a light deer rifle, an improved version is okay too. I would also strongly recommend going with another inch or better two in the barrel.

A quality 22� barrel in a #1 contour properly bedded will keep everything lightweight but still accurate, and your 3000 fps goal with 130 grainers should be obtainable while still maintaining a safety margin.

Go with your first instincts, they seem pretty good to me. Just my dos centavos.

Forgot to add � I have a left hand short action Model 700 in .308 � a caliber that just does not appeal to me (okay, so sue me, if it�s .30 caliber I�d rather it be an �06 . However, sitting in a Brown Precision stock it weighs about 6 � pounds even with the factory 22� barrel.

That rifle has been calling to me for several years to replace that .308 barrel with a 22� Pac-Nor that duplicates the factory contour, chambered in 7mm-08. While I�ve never worked with it, that little 7 just appeals to me tremendously. Possibly because I grew up reading Jack O�Connor�s exhultations of the 7X57 and the 7mm-08 is just a �modernized� 7mm Mauser, a fine pedigree if there ever was one.

I recall that Elennor O'Connor shot the 7X57. I think Jack shot the bigger cartridges.

This new project sounds nice but such a expansion ratio, as mentioned, will not make a lot of energy at long range. Such are the trade off's.

I would always go with a standard cartridge.

Palladium:

Now that you mention it, I was told by the entity which makes the barrels on these rifles for Kimber [and the person shall remain anonymous] that even going to a 7mm-08 Improved would give dangerously high pressures given the diameter of the barrel cylinder in the area surrounding the case. The barrel dia just in front of the muzzle is 1.050. The person I spoke to said that if I was going to wildcat to 7mm-08 Imp., he strongly recommended a cylinder dia., of at least 1.075,
though the barrels he makes for Kimber have a cylinder dia. of 1.050. All of this causes me to think that the .284 might be too much case for this little action.

Jordan

I would think that 1.050" diameter barrel would be fine "pressure-wise" for the 7-08, if the action is "big enough". T/C Encores are often chambered for (full power) belted magnum cases, and the barrel is 1.000" diameter at the breach. Big difference in action design, though - the barrel diameter is not threaded at the chamber area, so maybe that has an influence on size/strength. Do you know what the thread size is? That may be the "theoretical" diameter should be used for pressure/case diameter limit?

My vote is for the 7-08 if you determine that it is "safe".

Just my opinion,

Bill

Bill:

Thanks for the input. I will mic the barrel shank when I get home from work today and determine the thread size as well [may have to call Kimber on that one] to ascertain a nominal diameter on the stub which screws into the receiver. I note that somewhere in the there advertizing material [if memory serves] that Kimber touts the fact that they use special steel for this action which facilitates the petite size of the action yet with adequate strength. Is this a legitimate claim? In other words, is there potentially a significant difference in the strength of the various steels which might be employed out of which to machine the action such that if Kimber has selected such a steel that the action strength would be significantly enhanced compared to other steels which might be used?

Thanks for any input.

Jordan

Jordan,

Looks like they are using 4140 alloy carbon steel ( http://www.kimberamerica.com/model84m.htm ), commonly used in receivers and barrels. Properly heat-treated, it's hard to beat.

Given the receiver diameter (1.10"), I would guess the threads to be from 3/4" to maybe 15/16" nominal diameter (my guess would be 7/8"), and wouldn't personally think that increasing the barrel diameter would increase strength or effect safe chambering. The minor diameter of the threads will be the "limitation", in my opinion ("longitudinal" stress limiting, not the "hoop"/circumferential stress).

I wouldn't think that the few thousandths removed from the ID of the chamber where the threads "end" (the "weak" point) would significantly affect safety, but also wouldn't (personally) take the chance. I'd stick with a factory 84M chambering (7-08) and not look back (better safe than sorry).

Hope this helps, Bill

Bill:

Thanks for the information: the shank mikes out at .792 [dial caliper measuring from the valley of the threads]. I am probably accurate to within a few hundredths.

Kimber has confirmed to me that indeed the petite size of the action contemplates the use of select steel, properly heat treated, which they have done. They have also advised me against 7mm-08 Improved on the ground that it compromises the safety margin too much. What did I expect them to say in this litigious age?! Actually, I suspect there is plenty of safety margin. What I am beginning to think however, is that the Improved version is not going to provide a worthwhile performance gain in a 20 inch tube and using light to medium weight bullets [120-130 grain]. I just question whether under the circumstances improving the 7mm-08 is worth the effort. Beginning to look more and more all the time like 7mm-08 is my caliber of choice.

Thanks all for your input.

Jordan

Jordan,

I agree with you, I'm not sure that the improved chamber would provide a significant advantage in this "short-barrel" scenario. Plus, if you don't use an improved chamber, feeding should be more reliable.

If it started as a 22-250, what about the 250-3000 Savage? If an X-08, don't forget about the 260Rem.

Take your time deciding and have fun!,

Bill

Jordan,

You mention restocking, I'm wondering who's stock you intend to use? I have purchased an 84m in 243 for my daughter. I have looked into restocking with a fiberglass. But I know of no one that is producing a stock for this action. I spoke with several makers, and it looks like a challenge to bed and fit for the action size, and make it look correct.

I hope in the future we see something of quaility produced to suit.

Many Thanks

HBH

HBH:

Don't laugh too hard! I am going to make my own stock from carbon-fiber/graphite. I have done alot of fiberglass work over the years [strictly as a hobby] and am presently building my own single-seat airplane too boot. I have made a wood plug to the proper specs and will build a two part stock mold from the plug. It has very nice lines---slender forearm and a small palm swell. The skin of the stock will be one layer of dupont carbon fiber/graphite with one layer of Kevlar 249 on the inside. It will be head curred to 225 degrees and vacuum bagged. It will be alot of work, but I believe I can develop a real nice stock for the 84M weighing about 12 oz with recoil pad and it will be very, very stiff.

Regards,

Jordan

.260 Rem!

Doc Lou:

If you have experience with the .260 Rem please share it. I had thought about that cartridge, being as it splits the difference between the quarter bore and 7mm, but I've read some things that cause me to wonder whether I can shoot a 120 grain bullet to 3000 fps in a 20" tube. That is my goal. If you have hands on experience with the .260 Rem, please share it.

Jordan

Jordan,

I will be the last to laugh at your stockmaking project. I too am building a composite experimental airplane, and think some technology transfer could improve composite stocks. Your Kimber in 7mm-08 with your own stock should be a great little rifle. Keep us posted.

Off topic: What airplane are you building? I am building a KR-2S.

Fireplug

Fireplug:

It is a little Quickie 1 [Q1]---a two wing craft [with a front canard] designed by Burt Rutan in the late 70s, early 80s. I found the partially completed kit in Sacramento, CA about a eight months ago. I am widening the fuselage four inches to accomodate my shoulder width and also extending the length four inches to accommodate a little more fuel. I plan on powering it with a Hirth 65 hp 2-stroke engine.

As originally configured and designed, these planes were powered by a 18 to 22 horsepower Onan opposed twin four-cycle generator engine and would cruise at about 120 mph with that motor. With the Hirth and the right prop, I am hoping for 160 kts cruise. Some owners have put Rotax 440s and 582s in the Q1s as well. The major downside of the two-stroke in this plane is that the craft is only designed to carry 'bout eight gallons of fuel. That is only about two hours worth with a 50-60 horsepower two-stroke. I think I can squeeze 12 gallons or more into this craft with a little creative reengineering. Hirth is apparently coming out with a high torque low-rpm two stroke in the 65 horsepower range with fuel injection. Rumor has it that it will get 'bout 3 gals per hour at cruise rpm, which is about equivalent to the best four-strokes in that power category. If I were a rich man, I would love to put an HKS 700 into it or a Hexadyne P-60 but they are way more than I can afford.

The KR-2S is a nice plane. I really like the looks of the craft. Would not mind having one at all. What will you power it with? My apologies to all for talking airplanes on a gun web site!

Regards,

Jordan

Jordan, I really like both rounds. However, I have always been a big fan of the 6.5 bullets because of their high BC. I have only used it on black tail and mule deer weighing up to 250 lbs at ranges of 20 - 150 yds. All shots (8) were instantaneous kills - I used 120 Ballistic tips everytime. I have not killed anything with my
7mm-08, but I have been with friends who have using 140 gr ballistic tips, and it works just as well.

I get about 3100 fps from a 24" barrel, thus You should get about 2900 out of a 20" barrel using 120 gr bullets - about the same as the 7mm-08 with 130gr. The improved version would also get you where you want to go a little easier, if your inclined.

You can't go wrong with either, however, IMHO the 260 is a little more versatile. It handles the smaller 85-100 grain bullets, which are for use on p-dogs, coyotes and the like, and 120-160 for the bigger stuff. As far as the 7mm-08, I don't like it for varmints, and if I am hunting something bigger than mule deer, e.g., elk, moose, etc., I am going to choose something bigger yet.

[ 06-13-2002, 01:26: Message edited by: DOCTOR LOU ]

260 Remington, try it ... you will like it!

Wyojoe, I am also a huge fan of the Swede, but it won't fit in a M-84 action. That's why the .260 Rem is so great - same ballistics in a shorter package!

[ 06-13-2002, 18:05: Message edited by: DOCTOR LOU ]

Jordan,

I replied about my plane via private message, in fairness to those here not interested in airplanes.

Bact to the rifle: Did you choose a cartridge yet?

Fireplug

My choice would be the .250Sav easily & if you don't believe me read what K Waters says about it in Pet Loads V#1

I can't suppress it any longer. Why did you buy the varmit model and not the lovely little 7mm08 or 260 Kimber already sells? Not that I have anything against changing a perfectly fine rifle. I have plans for a 84 in 7mm08 in the near future. I like the 284 but I hear the magazine is on the tight side, even for the 308 family. Just reread your first post and noticed that you like the GS 130 .284, they are 1.307" long, so seating to shoulder on 7-08 gives oal of 3.058". The 120 is 1.185" for a oal of 2.936". Just numbers, but if you are looking to optimize by going wildcat...

[ 06-14-2002, 23:11: Message edited by: djpepper ]

Pepper:

I purchased the Varmint only because it was the only rifle I could get!! My dealer got two of them in and tells me Kimber tells him not to expect anything more for quite awhile---not even a sporter. I have had a sporter on order now for about eight months. Given that I am rebarreling and building a new stock to boot, the only thing I really needed was the action. Thanks for running the numbers on bullet lengths---something I have yet to do. If Kimber made one mistake on this rifle it is not designing for a cartridge OAL of 3.0" IMHO.

Regards,

Jordan

Jordan,
I suspected that was the reason! I guess I thought only Canadians were having supply problems. As you may have noticed I said "plans", (I think the near future was a bit optimistic). Does seem like the rifle makers like to short-change us on short-action magazine length.

If I just wanted a nice light kicking rifle then I also would go with the 250 Sav. it just kills out of porportion to its balistics...A mild and gentle round that has proven itself in the field for eons and much better than the 6mm regardless of the stats, IMHO....

Otherwise I would go with the .308 Win., it is so mondane and common, but it just kills game with aplomb and leaves bloody good blood trails...I have found 30 caliber and up leaves much better blood trails than lesser calibers...

Hi Jordan:

Here's some hard data for you. I have a rem 700 Ti in 7-08 with the bbl. cut and recrowned @ 20" The 130 Speer w/44.0 of RL 15 = 2825 fps. ((DISCLAIMER: MY GUN, MY LOAD, DON'T ASSUME ANYTHING)) This is as hot as I want to load it. You might be able to beat the velocity (a little) with a 120 btip from Nosler or a 120 Barnes X bullet.

Advice follows.....Don't get hung up on the "the number" In the real world, it don't matter a-tall.

I recently rebarreled a rifle to 25-06 and chose a 22" tube. I thought to myself "boy 3300 fps. with a 100 gr. oughta be a wicked combo load" Alas, the gun "only" gets to about 3225 with the 100's and at first I was dissapointed. But after shooting it for a couple of years, and banging some running jackrabbits and a few of our Ca. deer....It (IS) a wicked combo load.

That 20" 7-08 will do ya just fine. (or .260 for that matter). Just lower your velocity expectations a bit, and those bambis will fall just as dead.

JimF

Hello Jordan,

Haven't had a lot of time to work up loads, but here is the only one that I've chronographed so far (Oehler 35P, screens 15' in front of muzzle, NOT corrected, so actual MV probably + 10-15 fps):

15" 260 Rem factory T/C Encore barrel. 39.8 grains of Benchmark (Hodgdon says 40.0 max), Fed 210 primers, 120 gr NBT, Rem brass. Average 2643 fps, s.d. 19 fps. Charges dropped from measure, not trickle charges. This stuff burns cleaner than any other powder that I've seen, absolutely no visible residue left in the barrel. I do consider this a MAX load, primers were pretty flattened.

You might be able to get real close to 3000 fps w/120s in 20" tube.

Bill

Jordan, Ray A. gave you my answer!

I love carbines and have had a scad of them. The 308 works better in a 20" or less barrel than any other round I've worked with. I also had a short-barreled 250 Savage (18.5") that was great... it would work "better" (more efficiently) in a 20" tube than any other of the "dual-purpose" rounds mentioned above. It's also one of those mythic "inherantly accurate" cartridges. A
supervisor at HS Precision once told me the 250 Savage is one of the easiest cartridges to get spectacular accuracy for. If I were getting a 22" (+) barrel, I'd go with a 260 or 257 Roberts.

BTW, since you're into home-built aircraft, ever heard of the Pietenpol "Air-Camper?"

Best Regards,

Brad

Brad:

May I ask what kind of velocity you obtained from that little .250 Savage and an 18.5" tube with 100 grain bullets? Thanks to all who have responded to my inquiry with information and experience. The expertise which is available on this board is tremendous.

Regards,

Jordan

Jordan; My 18" 250 SAV generated 2800-2850 with a 100gr bullet- shoot the same load in my 25" 250 Sav and it is 200fps faster.`I am going tro barrel a 21" 257DGR as an experiment, will let you know the velocity.
www.duanesguns.com

Used to have a 22-250 Ackley improved and for the hell of it I necked some cases up to 6.5 and seated some 140 grain bullets to 2.8". They look great.....the short case allows you to seat the bullets well out of the case and it has the look of efficient. Would be a great wild-cat with more charisma than the 260 Rem and more bullet weight than the 250AI.

Jordan, I think Duane answered your question better than I can. I had my 250 Savage a long time ago... before I had a chronograph. I figured the 100's went at 2,850 and the 117's at 2,700. Regardless, it killed deer very well, none ever requiring more than one shot. I have chronographed a lot of 308's with 18.5", 19", 20", 22" and 24" barrels. IMO, the 308 is perfectly suited to 19" - 20" barrels. With my last 19" bbl'd M70 in 308 Win, I got 2,750 fps with 165's and RL15. The Federal 180/Partition "High Energy" load went right at 2,700 fps. and was extremely accurate, all of which makes one question the value of handloading for this round if it's to be used on elk! My next 308 will wear a 20" tube. I doubt there's a finer, handier, general-purpose rig available than a light bolt action with a 20" bbl. in 308 Winchester. Accuracy with this round has always been top-notch in my experience.

Brad

go for the 7-08 imp. a 26" shilen or douglas air guage barrel in a light contour should still keep weight down. as for a bullet, try the 140 grn. xlc by barnes. I seat mine .030 off and put 45.5 grns of hogden varget under them. They chrono 3185fps average with no more than 5 or 6 fps difference in speed per load. As for accuracy, mine shoots less than 1/2 moa.