Hey folks I have a question for you, I've been working on a 6.5 x 55 project for awhile now and have got it shooting pretty well but I think I may get a little heavier barrel and I was told that I could get it chambered in the 6.5 x 55 AI! while most of the bullets I shoot are in the 100 - 120gr range I was wondering if the AI would be worth the extra trouble? any thoughts or experiences would be great. Later,

Kirk

NOt in my opinion....

I know someone who went that route and his ballistics are no better than the ballistics on my regular 6.5 x 55s....

It might give you a little more with 140 grain bullets, but the lighter bullets, the AIs are usually yielding LESS velocity.....

cheers
seafire

That's kinda what I've heard but hey I'm not afraid to ask! Thanks

Kirk

I've only been shooting a 6.5 Swede for a very short time, but it doesn't look to me like "improving" the case would help much, as the case body doesn't have a lot of taper to start with.

Going to an AI would give you around 4% capacity increase or about 2.32 grains. I'm sure many will quote some huge jumps from the factory ammo to AI. However factory standard for the 6.5x55 is in the 47,000 range while loaders will load to 63,000 plus for the AI. At same pressures on numerous AI style conversions I have done over the years tested with pressure barrels and stain guages. At the same pressure you get 1% velocity for 4% powder. So 1% of 2800+/- is 28fps. Not worth my time and $$ unless you just simply want a wild cat.

Load to the 63,000 range with new quality brass. If you are going to use long bullets most of the time. Set the chamber up to allow you to seat the bullet out as far as possible and maximize yur net case capacity.

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However factory standard for the 6.5x55 is in the 47,000 range while loaders will load to 63,000 plus for the AI. At same pressures on numerous AI style conversions I have done over the years tested with pressure barrels and stain guages. At the same pressure you get 1% velocity for 4% powder. So 1% of 2800+/- is 28fps. Not worth my time and $$ unless you just simply want a wild cat.

Bingo....excellent analysis....

Have you noticed the AI crowd has been somewhat quiet on the subject the last year or so......

I've got a 6.5 x 55 BJAI. It looks cool, and I can load it up, but I have to admit that the stock Swede is a great cartridge as is. If I had to do it over, I probably wouldn't.

The AI version on the 6,5x55 increases the volume with 13%, being one of the more sucsessfull AI's. But, for the bullets as light as the one you mention, it is hardly worth the trouble. 140grs+ and long barrrels, is were it really shines.

Good info folks and many thanks! the only AI I had any experience with was a 280AI, after a couple months of not being able to get it to shoot the barrel came off was set back and a wonderfully accurate rifle was born. I'm leaning toward a 26" barrel while a bit long to tote around in the woods it should really shine where I hunt in the sand hills and firebreaks. I've not started loading for it yet but I hear that factory ammo is pretty much the reason besides the metric designation it has not taken off very well here in the states but hey I'm not a magnum kinda guy so I hope it fits the bill. Later,

Kirk

Would this also apply to the Roberts then? It shoots light bullets. Same capacities, 56 vs 60 grain for the AI version.

Funny thing is I remember reading that a 60 grain case was the ideal capacity for the .264 bore. Are we saying the 56 gr case is faster? Or that the AIs velocity increase isn't worth the bother?

Is there something magic about the 56 gr case? If so the .260 AI should be perfect for a short action.

Sorry if I got too far off track but I'm still juggling the merits of all three cartridges and thier AI versions.

Since the cases are the same length, more or less, I like the 6.5-284 as a 6.5x55 alternative in lieu of the 6.5x55AI. Either way, if you're not planning on shooting long/heavy bullets, you could use a short action, rather than a long action. I currently have 3 rifles in 6.5-284 and, for whatever reason, the fastest barrel of the 3 is a 22" Winchester 70 featherweight that was rechambered from 6.5x55. I am shooting mostly 95 grain VMax, 120 grain BT, and 129 grain SST/SpirePoints.

Jeff

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The AI version on the 6,5x55 increases the volume with 13%

That I would need to see. I might have been a touch low and it might be 6% and 4 grs of powder but 13% would raise the capacity to around 65.5grs. Real close to 6.5-06 range.

I think it's real close to 6GR. increase in powder volume but don't quote me on that. I don't have the AI case dims in front of me. Later,

Kirk

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I think it's real close to 6GR

I have never built a 6.5X55AI But both my 257 Roberts and 7X57s added right at 4grs. I can add 6 by doing the AI and switching case brands. But, to me that don't count.

The 13% is quoted from someone else, do not remember who, but the Swede has more of a taper than the Roberts or the '57. I have read several plases that it is one of the more sucsessfull AI's.
I will try to look up some facts.

Sweede

Length @ Shoulder 1.71
Shoulder .435
Base .481

Bob

Length Shoulder 1.727
Shoulder .429
Base .473

The taper seems pretty close. I'm just puzzled that Mr. Ackley himself is reported to have said that the Sweede couldn't really be improved, but as stated the Bob can. Similar case capacity, similar improvement in capacity and the bore is only .07 different.

Is it possible that it was a true statement back then because of the limited variety of powders avalible and no longer true now?

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The taper seems pretty close.

I do find it interesting that the 6.5X55 numbers I show stop the shoulder at the usual .454 range. Instead of using the same case taper and blowing it out to .461. If you are going to the trouble every little bit helps.

My 6.5x55AI is running the 140gr a-max from a 26" 1:8 PacNor at a comfortable 3000fps +/- at the accuracy node. No pressure signs yet and good case life. I am partial to AI's as I have yet to have one NOT go well under 1/2moa at even 400yds and further, but mine are all match tubes so that needs to be considered.

the AI shoulder makes trimming less frequent and IMHO allows a better burn characteristic when experimenting with very slow powders and heavy pills. YMMV

I'll fill a lapua case both unformed and formed later if I get a chance and post what MY REAMER added to internal volume.

Do you reload your own cartridges? Do you shoot a lot? If you do, you may benefit from the AI treatment in that less case trimming will be required and neck turning can be put off a while longer. Most people just look at the AI treatment from the additional velocity perspective, which is probably the least useful way of looking at it. If you don't anticipate shooting that gun a lot, the treatment probably isn't worth the cost and trouble of doing it and having to fire form cases, which wears out barrels faster...Rusty.

This little project will probably go to the dog towns and will get shot often but not excessive! the 223 and 17 Rem do the bulk of the splatering but it is nice to have something for the dumb ones that think since they are out there a ways we can't get to them. I do punch paper often also and the steel plates and I think the 6.5 should be right at home out to the 1000 yard range but most of the shooting will be on the dogs out past where the 223 leaves off. I am figuring on a 1-9 twist barrel at 26" of length to get the full effect of the Swede with the lighter bullets (100 - 120gr.) I'm not a velocity nut but I DO hate brass preperation! Later,

Kirk

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My 6.5x55AI is running the 140gr a-max from a 26" 1:8 PacNor at a comfortable 3000fps

Let's see that is 100FPS higher than my Nosler book shows for the 6.5-06 even adjusted for 2" longer barrel. And higher than all but one of the 264wmag loads.

I've built numerous AI and pure wildcats like the Gibbs etc. Several with pressure equipment.
While I could achieve some of the super high velocities I've seen stated over the years never at pressures I would choose to shoot. But to each his own.

quote:

Originally posted by ramrod340:

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My 6.5x55AI is running the 140gr a-max from a 26" 1:8 PacNor at a comfortable 3000fps

Let's see that is 100FPS higher than my Nosler book shows for the 6.5-06 even adjusted for 2" longer barrel. And higher that all but one of the 264wmag loads.

I've built numerous AI and pure wildcats like the Gibbs etc. Several with pressure equipment.
While I could achieve some of the super high velocities I've seen stated over the years never at pressures I would choose to shoot. But to each his own.

Just think what one could do with a .264 Win Mag AI!!!!!!!!

I have the data in front of me from that manual, now go to page 182 and check the load data for the 6.5x55 swede in a 23" barrel with the 140gr pill and RL22 running 2740fps. Now add 3" and a match chamber with increased internal capacity (albeit very little) a 4 groove tube and you are at the 2980-2990 I am at under 85* +/- temps

and since I was already at the bench today, I ran the weight test.

fireformed lapua brass:
empty= 182.3gr empty
full to top of neck with water= 245.2gr
internal cap= 62.9gr water

non-formed brass from the same lot and sorted by 1% variance in weight:
empty= 183.0gr
full to top of neck with water= 240.7gr
internal cap= 57.7gr water

that is a 5.2gr increase in volume, now compare that to the 6.5-06, which I also have improved in a pacnor 1:8 26" and can tell you that the 6.5x55AI picks up a LOT more than the 6.5-06AI does when improved. The 06 doesn't get much at all.

This is the same lot of lapua brass, same lot of primer. The chamber is correct as the shoulder crush is very evident when chambering new brass of any make. The neck is also much tighter than factory but just barely above turning the brass.. YMMV

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I have the data in front of me from that manual, now go to page 182 and check the load data for the 6.5x55 swede in a 23" barrel with the 140gr pill and RL22 running 2740fps. Now add 3" and a match chamber with increased internal capacity (albeit very little) a 4 groove tube and you are at the 2980-2990 I am at under 85* +/- temps

ok...but what does your chronograph say?

Have you actually chronographed this load from your rifle?

quote:

that is a 5.2gr increase in volume

I don't have a 6.5 case much less a 6.5AI to check. I've done a number of 257 Roberts and 7x57. The normal increase is right at 4.2gr of water. Most 06 based AI increases I've had are around 4.9. I have no clue why the 6.5 would be different than the 7x57. Like I said I have not measured it.

Normally staying at the same pressure I can't use all the case capacity as powder increase. IE a 7% increase will not allow me to increase powder by 7%. It will be less. I cut 2" off my wifes 5X57 barrel and it lost 35fps.

For a quessimate take your 9% case increase and assume you can increase powder that much and stay at the same pressure. 4 to 1 gives you a 2.25% velocity increase. 2740x1.0225=2801 now add another let's say 50fps for 3" you get to 2851FPS. You say a larger chamber volume. I usually found that gives lower pressure and velocity.

Like I have said on other posts. I do not doubt the velocities many are getting from the AIs nor do I doubt yours if you have measured it. All I can say is I've done a lot of testing of 7x57 & 06/280 based AIs and full wildcats over the last 30+ years. Many using strain guages and pressure equipment. What I have found is at the same pressure you get approximatly 1% velocity for each 4% powder(not case capacity)increase. Velocity increases higher than that are normally from higher pressures. The AI case and normally tight rechambers hid the normal indicators. With most cases I didn't start seeing "normal" pressure signs until I was around 75,000. Then just a slight change in charge cause blown primers. Anyone is free to load to what ever pressure they feel safe. I simply choose not too.

quote:

Have you actually chronographed this load from your rifle?

The listed velocity is from the chronograph.

ramrod340, like I said also, I have the 6.5-06AI and the 280AI as well, and I can tell you that the 06 based cases don't seem to me (for what that's worth) to gain much, but these swedes (this being my only one however) picked up a lot. Now, that is to say my chamber is TIGHT, cut with a match reamer as were the sleeves in the dies. I also am only running a 4 groove tube which picks up a tad due to less jacket intrusion, albeit not an overly large figure.

so with that capacity gain, a tight chamber, and 4 groove super-match tube and RL22 I am getting just at the 3000fps mark and an accuracy node. The best accuracy node which I have settled on for target work (this was to possibly be my 600yd rifle, and it appears it will replace the 1000yd rig for this purpose) is around the 2890-2910ish fps mark where is eems to hold a weeee tad tighter on paper. The guys running this same chamber with 28-30" tubes are running the low nodes at 2950ish (basicaly the same as mine with more barrel length).

I also agree and have stated in many AI discussions in the past, that the AI WILL NOT show pressure signs like bolt lift and flat primers until the range you have experienced. My 6.5-06AI with an 8twist 26" PacNor and 140gr a-max pills ran all the way to 3208fps with not one single traditional sign, other than the pockets being ready for a shotgun primer That was my first experience with the hidden pressure signs that the AI is quite famous for in my safe. I have learned to stop wayyyy back from max, especially in tight chambers. Get this,....now you really won't beleive me,....the powder charge is only 47.1gr RL22 wayyyyyyy less than book max for even the standard swede of 50.?? grs on RL22 in the lilja test barrel they used in the nosler manual. Now also keep in mind my throat is a bit short so I can chase the lands and the bullet does take some of the powder capacity when seated to the base of the shoulder junction. I would etimate this load in my set-up at maybe 90%+ density.

if I get a chance this weekend (supposed to rain heavy) I would like to push this load out to maybe 600yds to start getting ready for some matches, and I will chrono the loads again but I don't see it changing much as the last time I got 5 readings within a 20fps ES, so I can't see the chrono having been affected by lighting angles or other issues that day.

this is just what my rifle/rifles have produced over my equipment. I can't say they will all do this, but mine does, for what it's worth.

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Get this,....now you really won't beleive me,....the powder charge is only

Didn't say I didn't believe. Just gave results of many years of fooling with AIs and wildcats. A shorter more tapered case will always give a higher % than a longer one. The starting point is lower. You blow one out and change the shoulder to the same point you will get roughly the same increase in vol. So from a percentage standpoint the smaller case will give a greater % increase and in theory a greater % velocity gain.

A fast lot of RL22 could account for your lower load volume.

I can't even begin to count the number of AIs and widlcats I've fooled with over the years. I still have more wildcats than factory. I took my own super improved 280 case from 243-416. I've still found the best thing they gave me was a great topic for around the campfire at hunting camp.

I read that another poster here has a 257 AI that equals .257 Weatherby velocities so it's not at all surprising one would find someone who's 6.5 X 55 equals .264 win mag velocities....the .257 roberts and 6.5 X 55 cases are so similar in profile.....

It's just too bad that neither Weatherby or Winchester knew this before they went and spent all that time and effort to bring their magnums to market.

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It's just too bad that neither Weatherby or Winchester knew this before they went and spent all that time and effort to bring their magnums to market.

But then they wouldn't have gotten all that bad press for burning out barrels with all that extra powder.

And here I just bought a set of 6.5x55 dies on the way home this afternoon! now I'm thinkin' I might need to look into this AI option a little harder, I just so happen to know a guy who has the reamer I found out last night so fella's you have more exp. with these rounds so what do ya think? go for it or just stay with the standard? My chambering is in your hands. Later,

Kirk

Ksmirk,..I won't go on record as "recommending" the AI over it's parent in most any case. I happen to enjoy wildcatting, so this is just an excersize in spending money, burning powder, and collecting data, for me. I find them suited for slow powders, which opens a small margin in the slower powders for some long heavy bullets and longer ranges. I find a imp rig to be mostly a waste for 300yds and under as the parent would easily have filled the bill with no extra work involved. The 40* shoulder has in my experience allowed use of some very slow powders with great efficiency. For example, the 6.5-06AI readily digests RL25 and H1000 with 140gr pills. I even had retumbo burn enough to get 2900+ fps with good accuracy and an acceptable powder residue amount. NOT that I am suggesting these, as stated, I like to wildcat.

ramrod340, wasn't be precocious, I was trying to be a bit humorous when stating that. I have trouble beleiving this charge is this stout myself. I was just suprised and thought I would pass that along. You can hear a small rattle of powder under the pill when shaking the round, but not much,..maybe another few grains or less left over. I say she maxes out with this bullet at maybe 51-52grs total, which as we both know WILL be a 70K+ load.

And I see we have both seen the same thing with the long cases,..they just don't get much other than case life and maybe a few steps slower powders for very heavy pills. But I still like that option.

Kirk, It is your rifle what would make you happy. Like I said I have more wildcats than factory. If you like the idea of a wildcat then go for it. With that said if it were mine. I would set the chamber up to allow me to set my planned bullet out as far as possible and still function correctly. This would give me the highest net capacity. Then load it to a nice easy 63,000 and be looking at 2775-2850 depending on barrel length and your barrel.

Yes the AI does reduce the trimming. But how many times would you need to trim anyway? Once twice? Fireforming take more time than trimming. I start out with 80-100 cases and rotate through them before loading one a second time. I let my cases grow until they need trimming and then trim them short. Can't remember needing to trim a case twice.

Question I have for you. If you stay standard will you wish you had gone AI? You can always go standard to AI later if you are not happy but not the other way.

Points well made on the pressure issue with AIs Ramrod. They do mask conventional high pressure indications in my experience as well, FWIW.

Well let's see, this rifle will probably see ranges in excess of 300, I love load development and tinkering, I'm in good with a gunsmith, I have a 6.5 x 55 barrel now. Hell why not! I might bother some of you fella's for some starting loads and one other question, as for fire forming can you just fire a standard 6.5 x 55 in the improved chamber? I would guess this to be correct and who would be the better choice to order dies from? I normally use RCBS but hey if I can find them more reasonable it would not hurt my feelings at all and has anyone had any luck with using the reamer to rework a standard set of dies? Later and thanks fella's.

Kirk

If the chamber id done correctly factory 6.5X55 should be a crush fit. When I form I use COW. But if using a bullet. Go cheap bullet and a heavy 6.5X55 load of a faster powder. I think the faster powder forms the shoulder better.

Midway list the dies.
http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=660975

As will as huntingtons.

Good luck

I agree with ramrod's load technique, that is how I do it,..heavy bullet into the lands, and a mid range load of fast powder= great shoulders and bodies every time.

have RL22 and 4831sc on hand.

If the chamber id done correctly factory 6.5X55 should be a crush fit.

By this I would guess that the bolt should be a bit hard to close? what part of the standard cartrige would interfer with the AI chamber? and one other thing, When I form I use COW.? when you say it I will probably know but terms may be different.

JustC, I've heard that RL19 and RL22 work pretty well with this round. Later,

Kirk

I'm sorry when I form I normally use cream of wheat and fast pistol powder and a little TP to hold it all in. When I use a bullet I buy the cheapest I can and then use a faster powder and a heavy parent load
.
It is the shoulder/neck hitting the new chamber. When I mean crush fit you should feel a little resistance as you close the bolt. Like a normal reload that needs th shoulder set back a touch.

Ok I see where your coming from now When I finally get around to the new barrel and goodies which is going to be a little while off I might bother you fella's again about some load help. Later,

Kirk