I have been told many times that some rifle barrels will not shoot close groups with, say, 180 grain bullets but will do so with 165 grain bullets.

Is there any basis to this claim and what causes this to happen?

They seem to and (I think) it has something to do with the barrel vibrations (accuracy nodes).

They will also show a preference for one brand and type of bullet over another. ie: one rifle will shoot Sierra BT bullets like a house afire, and another will shoot Core lokt flat based the best.

To paraphase the Hornady book: Each rifle is unique unto itself and generalities should be made with circumspection.

my ruger M-77 in .260 does not like 140s at all.. 129s do ok.. it really likes 120s

quote:

Do rifles really "like" some bullet weight and not others?

I'm not at all sure this is true. I'd rather say that some rifles don't shoot well with some specific bullets but that it may shoot very well with another bullet of the same weight.

Example: I have a Rem 721 in .300 H&H that shoots fine groups with 125 Gr BTs and also with 200 Gr A-Frames, but lesser groups with bullets between this range. I'm convinced that it's because I've limited myself to the bullets I've tried and not that the rifle won't shoot 150s, 165s and 180s.

After finding excellent groups with the 200s, it became totally unnecessary to shoot lesser weights.

quote:

Originally posted by Oxon:
I have been told many times that some rifle barrels will not shoot close groups with, say, 180 grain bullets but will do so with 165 grain bullets.

Is there any basis to this claim and what causes this to happen?

In my experience it does happen.

I don't think anyone has a universally valid lock on why it happens. If they did, they could likely sell the info for a lot of money.

Sometimes it may include the twist of the rifling, or shape and length of the throat. Other times perhaps the "tightness" of the barrel may be the culprit. Surely it is sometimes related to harmonics, as mentioned above, which may or may not include something to do with the bedding.

And, sometimes it may defy all logic.

But I have owned rifles like that, and still have a couple of them.

One is a Steyr SSG "Match" (not the "Marksman", but the even heavier barreled "Match" model).

The only thing I have EVER found which will shoot acceptably well in it is a case completely full of 4350, and the 190-gr. Hornady rebated boat-tail match bullet which is no longer available.

have tried at least 75 different loads and bullets in it. ALL the rest shoot 3" groups or so. With that bullet and charge, it will shoot 1/2" groups. Go figger.

yep.. there are some rifles that do that .. and if they don't shoot, they go down the road, for me.

anything that ONLY shoots 1 or 2 loads, and is hyper finicky, then I don't need it...

quote:

anything that ONLY shoots 1 or 2 loads, and is hyper finicky, then I don't need it...

only a couple exceptions..... my chapuis DR, and a 1938 m70 win in .22 hornet....

quote:

Originally posted by Oxon:
I have been told many times that some rifle barrels will not shoot close groups with, say, 180 grain bullets but will do so with 165 grain bullets.

Is there any basis to this claim and what causes this to happen?

Uhh, affirmative !!! I'm assuming you gave the 180 and 165 gr example because that's what came to mind, and the possible examples are way too numerous to mention.

This is interesting, first off because I have become so used to accepting it as a basic truth, that I've taken it for granted, frankly so much that I just didn't think to question it anymore.

Honestly, some of the things about barrels and what they liked that I thought were true, I've re-thought lately. The more I shoot and test different rifles and barrels, factory and custom, the more I learn something new. Two months ago, for example, I would have argued that a fast twist 7mm barrel could never shoot a 140gr bullet as accurately as it could a 160gr bullet, but my 7x57 just proved me wrong about that.

I could write a really long winded version on this, but I'll try to keep it short. First off, let's leave out 22 or 223 cal stuff, because those bullets are so twist dependent, it seems more so than other bullets. To keep the example short, about twist, you would not expect a 220 gr 30 cal bullet to do well in say a 12" twist rate, but most likely it would do well in a 10" twist. That's an example of twist. As far as I know all modern rifle bullets are twist dependent, and perform well within a certain range of twist. I always wanted to try a 30 cal 12" twist with 165 gr bullets, and I got a chance last January, and they shot so accurately that I can't see any possible room for improvment, so I'll probably not try any other weight in that particular rifle.

I have a CZ 550 in 7x57, which I'm pretty sure has a fast twist, and I'm real sure has a long throat. I was certain it would like 175gr bullets, but I have been dissappointed with them, using different powders, and seating depth. So, I tried 162gr, 160gr, 154gr, 150gr bullets, with the same results - about 1&1/2" groups is the best I can do. So, today I tried 140 gr bullets - bingo - under 1" groups. Go figure.

I have a 280 with a 10" twist which shoots exactly predictable - it doesn't like anything heavier than 145gr bullets, and shoots sub MOA with 140grs.

All the 9.3mm rifles I've tested shot 250 gr bullets just as accurately as 286 gr bullets, but different impact point. That could be coincidence about the 9.3 likeing different bullet weights, but that's been my experience.

It's been my experience that very few rifles shoot equally well with much different bullet weights. Almost all I've messed with have a bullet weight sweet spot. Some will come close with varying bullet weights, and of course there are way too many variables to mention or consider. I've got a 338WM with a 12" twist Lilja barrel that shoots 200gr and 225gr so equally accurate that I can't tell the difference in accuracy, but it opens up ever so little with 250gr bullets - given of course that my tests were limited to a few bullets of different brands. Those 9.3s and the one 338 are unusual IMO.

However, most of the time it's fairly predictable what bullet weight a given barrel will most likely shoot well. Simple examples are 30cal - 12" twist & 165gr bullet, 7mm - 9" twist & 160gr bullet. Most likely those combos will succeed. Find the right powder and charge weight is often about all there is to it. Of course there's lots of variables even in those two narrow examples, such as boat tail, flat base, all copper, not to mention that those twists will probably work well and maybe even better with bullet weights significantly lighter or heavier than those mentioned.

I've had some very annoying rifles that will shoot factory loads, sometimes more than one brand and weight, so well that I have a heck of a time working up handloads just to equal, forget exceed, the accuracy I can get with that rifle from factory loads. I have yet to figure that one out.

So, to answer your question as precisely as I can, yes I think most rifles have a sweet spot as to bullet weight preferences. Find it and be happy. A few rifles will shoot bullets of different weights (not greatly) so equally well that I can't tell the difference, although hitting the target in different places, which generally forces me to choose one, and sight in for that one. Some rifles are very predictable as to what they want to be fed, and others offer surprises. Some rifles are very - very easy to find a load that it likes, and some offer a challange, and some just don't make it.

So, that's why I quit asking this question a long time ago, and presumed the answer is a solid yes. Every rifle is somewhat of a mystery until tested at the range, and it's difficult to actually test a wide variety in a given rifle. Rifles are a lot like women, you really don't know what's there until you become well acquainted, and even then there's a lot of mystery, and a lot that you know but don't understand. Usually, I consider it fortunate to find just one load combo that gives acceptable accuracy. If I happen to have a rifle capable of it, and find more than one acceptable load, I simply consider that a bonus rather than expecting it. I've also learned to never expect a rifle to like some predetermined load, because that seldom happens. It can happen, but not often enough to be counted on.

I'm certainly open to other's opinion and experience, and learning something new.

KB

In my experience I have found this to be somewhat true. I have a Ruger 257 Roberts that I had rechambered to 257AI. It shoots some lighter (100gr)bullets adequately but not spectacturly. It puts 120 gr Corelocks in one ragged hole. On the on the hand I have a Sako Finnbear 30/06 that does not differentiate between anything from 150 to 220gr, it averages a little more than .5 for 5 shot groups.

Yes. Absolutely true. I have seen it far too many times in my personal experience to doubt it. Not only do some barrels show a preference to certain weight bullets, but some barrels will be far pickier than others. Also same goes for brands of bullets. Sometimes it's extreme, and sometimes it's just a slight change.

It happens, just part of the fun of handloading. Each rifle is it's own individual, and what works well in one rifle, or barrel, may not work at all in another. That's the way it goes.

I lean towards the concept of it being true. My Kimber Montana, .270 WSM won't consistantly shoot any 150 gr. bullet I've tried with any powder/charge combination I can come up with. It's been to Hill Country (no luck there) and even to a well known smith and a replacement Lilja barrel. Basically the same results. It does seem to shoot 130 gr. bullets much more consistantly - read Partitions & NorthForks.
By the same token, my rebarreled Ruger .257 AI with a Kreiger barrel has put 75 gr. V-max bullets into very close to 3/8" but what little experimentation I've done, I can't get similar groups with 85 gr. Noslers. Must confess that I haven't played with it in a number of years tho. Just my experiences.
Bear in Fairbanks

IME, it's the rare rifle that will shoot every bullet well. I have two, my 260ai & my 404jeffery. Still, they show preferences for bullet wts & manuf. My 338-06 is probably the most finicky. It will shoot any 250gr into nice small groups, most 200-210gr, but will not shoot any 225gr bullet welll, unless I slow it down to 250gr speeds, wierd, but that is how rifle bbls are.

quote:

Originally posted by Oxon:
I have been told many times that some rifle barrels will not shoot close groups with, say, 180 grain bullets but will do so with 165 grain bullets.

Is there any basis to this claim and what causes this to happen?

Without question, this is true. I have rifles from .17 caliber up to 7mm and each one has a preferred diet. Now with some the difference may be less than others but nevertheless it exists.

Oxon ----- Bullets will determine how your barrel reacts to it. Heavier bullets are longer than lighter bullets, that makes a difference. Bullets of different manufacturers are not always the same diameter, that makes a difference. A batch of bullets made on different days may be different by a very small amount, depending of how the equipment is set, that makes a difference. Your powder, primers, case, all can make a difference. Your barrel harmonics are all affected by these things. Hopefully you will shoot that rifle enough for the barrel to tell you what it likes. The answer to your question is, yes, different size bullets can affect your accuracy. Good shooting.

Sometimes it is not the weight, but design. I find my .223 1:9 CZ loves flat base bullets, so do my 8x57 and 7mm Rem mag.
While my 6.5x55 likes boat tail in 140 and flat base in lighter bullets.
My Howa .308 shoots everything well while my .308 BLR only shoots flat based 150 and 165 well. It is all about the design and weight.

My friend has a Browning A Bolt 7 mm WSM which shoots 1.5" to 2" groups with 160 gr Accubonds at 100 meters. He tried everything with the rifle, loads, seating depth etc. Then one day while they were shooting 200 and 300 meter tests with other rifles he decided to try the 7mm WSM. Bingo, it shot 2" to 3" groups at 200 & 300 meters! Sounds crazy but it is true. He has been hunting & shooting for 35+ years and is very experienced. The load flattens 600lbs Sambar stags.

My 458 WM shoots about 1 MOA with good 450 or 500 grain bullets, the groups open up to 2+ MOA with lighter bullets. Some 350 grainers shoot shotgun patterns. Believe the Win Mag throat is to blame.

A old rule of thunb is the longer the bullet per diameter the faster the rifleing it takes to stablize the bullet. In the .224 bore rifles it takes 1 in 7 inch rifleing for the 70 grain bullet while the 1 in 14 inch rifleing will handle the 50 -55 grain bullets. There are always exceptions to any rule of thumb. My best groups from a 30 caliber barrel with 1 in 10 inch rifleing has ben with a 165 grain bullet.

In my experince it is true that there is at least a preference for a bullet weight in most rifles but I'm not as knowledgeable as some of the folks here.

I do have an old ruger 30-06 that shoots almost anything, factory and handloads reasonably well and pretty close to same POI at 100 yards. But it has never produced that Wow 1/2" group with anything I've tried.

quote:

Originally posted by Oxon:
I have been told many times that some rifle barrels will not shoot close groups with, say, 180 grain bullets but will do so with 165 grain bullets.

Is there any basis to this claim and what causes this to happen?

Yes, it happens. but it is the individual rifle not necessarily the caliber. Why? Gremlins, dude.

quote:

Yes, it happens. but it is the individual rifle not necessarily the caliber. Why? Gremlins, dude.

Correct. And, therein lies the sillyness of asking people for "pet loads" as a shortcut to accuracy.

Thank you for all those replies - I'm new to reloading and this is all interesting info.

Go to Eagel Ballistic Research. Com and you will find a "law of physics" explanation that all reloaders should practice.
I had to learn the hard way.

My Savage 110 in .308 loves 150-155 grain bullets. Groups open up when I try 165 grains, and tighten in again at 180 gr.

You do not want to know the amount and money, time, and general insanity it took me to accept that. No matter what the brand, it seems that was the sweet spots.

My other rifles have some prefered bullets, but none as as picky as my .308. I have often wondered if barrel length didn't have an effect.

Generally there is one fact about twist, and that is "If it keyhole it is to slow" in al other situations twist matters less than ½ moa.
You can test all different setup, and only come to the conclution, "if the rifle is sound, it is basically about minor diferences in shape of bullet, consisten burnrate and ignition"

Had a rifle for test in an German magazine this month. They tested a cal 6.5x55 barrel with 11 different loads of factoryammo, wheighing from 123grains up to 156geains. They all put 5 rd groupe within 1 1/4" at 100yds
4 best loads within 0,4" there was both 123grains and 156grains under 0.4"

The basic need for predictable accuracy, is Straightness and Symetri

I have one rifle that is a one trick pony. It's a Ruger M77 tang safety RSI in .308 Win. The only bullet it will shoot well is the 165 gr. Speer Hot-Core. (Up yours Speer for discontinuing that bullet.)
That rifle is one of my all time favorites but it won't shoot anything else wort a damn. I got it cheap because the prevous owner said it was very inaccurate. He wasn't lying. The best 150 gr. bullets ever did as about 4" and 180's were more like 5 and 6" groups depending on whose bullet I tried. A friend suggested the 165 gr. Speer and with a stiff load of W-760, I got 2550 FPS from the 18.5" barrel and 1.5" groups. Not the greatest but acceptable as I really did like the way the rifle fit and handled for me. I've since done a slight bit of tikering, mainly elieveing the muzzle cap so that it no longer touches the barrel and groups have dropped to 1.25" on the average. One of these days I'll have to try 150 and 180 gr. bullets again just to see if they shoot better now.
FWIW, my better half tried to appropriate that rifle so I had to go hunt one down for her. Not wanting to hassle with load work up like I did on the first gun, I tried the "good" load in the new gun. It worked just fine, especilly after I relieved the muzzle cap. groups are about the same as the first gun.
Then, one day a guy at the range was shooting another one and cussing up a blue streak. His was also a .308 and I negotiated a third cheap buy. My pet load worked in that one as well and relieving the muzzle cap once more tightened things up.
I guess the point was there were three rifles, all in .308 Win. that would only shoot one specific load. Every thing else, so far has been shotgun patterns and not groups.
Now if I could only fid one of those rifles in 7x57 that the seller didn't think it was worth as much as the Hope Diamond.
Paul B.

I've been at this game for long enought to KNOW and have PROVEN to my satisfaction there is a relationship between bullets, twist, velocity and "ACCURACY"...IF accuracy is what you mean by "LIKE".

If you doubt this just play with a barrel dampening,("tuning") device or go to bobbing off the barrel a 1/2" at a time.

OR...a much simpler way...just change the load parameters...more or less powder(changes velocity, ipso facto the barrel vibration and node release point)...different primer...different bullet(different weight AND bearing surface).

Why do you think "working up a load" works so well.

Many if not most of the times people get locked into a specific bullet for a specific reason...what they hunt or the rifle they use or one/several of the millions of reasons men fight over something for some miniscule reason.

If you have a specific bullet you want to use just work on the load...seating point in relation to the lands...or the load components(one change at a time) and you will come up with a load for a bullet the rifle "likes" even though it "didn't like" that bullet with a previous load.

EXAMPLE: I have tried this test on several calibers over the years and is one of my normal load workup steps...you/anyone can do the same thing easy enough.

I work up a load that shoots very well...THEN...I change ONLY THE PRIMER...all the rest of the parameters remain the same...same bullet, powder, case and seating depth...shoot two or three - three shot groups per primer change and record the velocitis AND the group size.

I guarantee if the original load is anywhere close to 1/2" the change in primer can and WIIL produce a change in velocity AND a change in group size.

The quality of the barrel will impact this test but for the most part a "normal" factory barrel can have a large change, I've seen groups change from <0.250" to 1 1/2"...a hi-dollar benchrest/target rifle will show much less variation BUT there will be a difference in group size AND velocity...which means the bullet is exiting the barrel at a different point in the node vibration(different velocity)...the more vibration the more variation in the group size.

The average hunter doesn't give squat doddly to go through such a process...

Therefore the Like/Don't Like "stuff" has gotten mega media coverage...and under those circumstances...YES...some rifles LIKE some bullet and DON'T like other bullets...and the apples and kumquat arguments continue.

Don't believe me...one of the better writers for Shooting times did a very well written article on just this phenomenon several years ago...look it up.

Luck

quote:

Originally posted by Jim C. <><:

quote:

Yes, it happens. but it is the individual rifle not necessarily the caliber. Why? Gremlins, dude.

Correct. And, therein lies the sillyness of asking people for "pet loads" as a shortcut to accuracy.

Two very insightful posts that I completely agree with.

It can not be explained with Physics, Twist Rates, Metalurgy, or Deminsional Differences - though all effect the end result.

If you take a sequence of rifles, made on the same production line, on the same day, with the same barrel length and contour, chambered for the exact same Cartridge - some will shoot "some" specific Bullets better than the other rifles. And the vast majority will be at different Average Velocities.

Just the way it works.

My pre War Mod 70 .270 shoots IMR 4831 and 130gr bullets into 1 hole, all day long. My travel Pre 64 .270 shoots H4831 140gr bullets into one hole. Both are set up the same: trigger pull, LOP, etc. Swap out these "proven" loads and they open up.

Both have 24" Krieger barrels, difference is the contour.

I have a remington 700 mountain rifle(270 Win)that hates 130 gr bullets,but loves 140-150s.

This is definately true. And I suppose it's like the posters have already said, twist, harmonics, throat designs and freebore etc.

I will add that some bullet ogive designs and certain throat designs are tough to get working together and the very high BC designs are renowned for being tougher than more "regular" ogive profiles.

The things is that with ogive differences and length differences between different bullets of the same weight and what you can sometimes achieve changing the "jump" to the lands I think many folks give up too soon. Others try forever to make a lemon a shooter. There is a balance in there somewhere.

Why are some folks trying to reinvent the wheel????

I have been shooting various medium bore rifles since the late 1960's, and to the best of my knowledge, all rifles can be and are finicky in regards to the type bullet they shoot best.

What has got wrong with everyone???

Can't people have different experiences?

Most rifles are finicky to one extent or another. I've got one .30-06 and one .416 Rem. Mag. that just seem to put everything into the dame hole, but I consider myself truly blessed with those rifles.

In my experience, the .300 magnums are the most finicky. I had one that I was about ready to strip the scope and throw into the trash, until I found a load it "liked" and the groups more than halved in size. My experience is that the .300's like 180 graim bullets and don't like light bullets. But that's just my experience with a limited sample of rifles.

Have a Ruger tang safety that I had rebarreled to 7x57. Think the barrel twist is 1 in 10". Discovered Hornady 139 gr SSTs shot pretty darn good in it. Then I tried 154 gr SSTs. Best I can do with them is a little less than a 1 1/2" 100 yd 4 shot group. Expect a 3/4" or less group with the 139 gr SSTs.

It's not so much the bullet weight as the exit times for particular bullets in particular rifles.

for a very interesting paper that gives some theoretical backing to the idea of pet loads, see
http://www.the-long-family.com...%20barrel%20time.htm

I know this doesn't make for a lengthy thread with a lot of brainiac posits but I've got a 30-06 that shoots common old core lokt bullets far better than the other slicker, shiny ones. I've two 22-250's, identical in make, model, twist, trigger pull, etc, one prefers the 52gr Sierra bullet; the other one shoots the 53gr sierra best. In fact, most of my rifles show a preference for one bullet over another.
Why? Beats the shit out of me, I just go with the flow and feed them what they like. That way I get to do a lot more shooting and a lot less fretting.

Typically it's a twist issue, although not always. The longer the projectile the faster you have to spin it to keep it stable in flight. A lot of manufacturers tend to use twist rates that are a bit of a compromise. This allows the user to utilize a range of bullet weights BUT, like all compromises, some will probably work better than others. Back when I shot a fair bit of black powder a 1:48 twist was often advocated as a useful way to shoot both round ball or conical projectiles. And while you could shoot both, accuracy was usually fairly average let's say.

this is a fact, but in many cases you can overcome it by careful handloading, proper bedding, and trying different bullet brands.

You, in effect, are setting up different barrel viberations..Many times it will work, but in some cases it just won't..At best it takes a lot of time and patience.

The problem is every barrel is an inity unto itself as someone once said and thats also a fact.

In my case, if I run into the problem, i'll tinker with it a bit and if that doesn't show signs of improvement then I just get another barrel..

I don't know why some rifles wouldn't prefer one bullet weight over another. I have several rifles that prefer a certain brand of the same weight over others. Also have a couple of rifles that won't allow bullets of same weight but different make to impact at same place.