Is it my load or barrel?

[bteate]

Ok, here we go, I've worked on a load for my .338WM and have decided to go with 73gr of RL-19 because it just shoots better than anything I've tried. I started with 71gr and worked up to 73.5 at .010 off lands with the best group at 73gr (1.26", not exactly what I was looking for never the less). Then I started playing with seating depth, 73gr charge, CCI primer, Nosler brass went to .015" off- horrible,.020" off- barely under an inch, and .025" off- bad.
How can .010" and .020" off lands be decent while the .015" off was horrible? Harmonics is a bear, I guess.

The thing that really gets me, the first two shots of each group (.010 and.020" off lands) are always slightly right and the third is always about .8" to 1.3" high, but usually in line with first two. Is there anything different I can try or just load up some and don't worry about it?

I just like to have the best that the rifle is capable of. Who knows, it might just not be a tack driver, but it should do better (don't we all feel that way?).Then there's always a possibility of it being me.

Any suggestions? Here's a picture: it's supposed to be 73gr instead of 63

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[SJB358]

Although not a tiny group, it is still pretty respectable for any good bolt gun. I load pretty much everything at 3.34 and vary up and down from there a little. Seems like you are doing pretty good. That is about the same speed I was getting out of the Accubonds using 73gr's in my M70. Scotty

 

[DrMike]

Is it "always" two and then one? Is the order consistent? In other words, I'm asking about the random nature of the observation. Make certain to give lots of time between shots. I can see how the barrel doesn't heat as much between the 1st and the 2nd shot, but with the passage of hot gases through the barrel from the first two shots it needs time to cool before the 3rd shot. For meaningful data, you need to start from the same point each time to establish a baseline (establishing the norm). I use a clean barrel for starting to ensure that I can compare apples to apples. This may not make much difference in the field, but it does make a difference in measuring your groups. Blessed is the individual who has a rifle that is unaffected by the starting point, but that is not most of us.

 

[bteate]

DrMike, I try to give it at least 5 or 6 minutes minimum between shots. Do I need to give it a little longer? I just kind of started noticing the pattern and tried to remember the big groups and they were about the same. All of the groups (4) since I noticed it were the same. I'll let it cool a bit and try. I've even thought about leaving my target up overnight and start with a cold bore each morning, but I think I'm too impatient.

 

[DrMike]

Six minutes should be more than enough time. Giving that sort of time between shots would indicate that you are giving more than enough time. If the pattern is reproducible, it indicates a consistent problem rather than a random event, and that is intriguing. You can't really say the pattern is random without a sizable sample, but if it is consistent your data would certainly suggest something happening with progressive shots, and I would think that would indicate either the barrel is heating and walking or in some manner the action is moving in some consistently fashion. My instinct says that you have a decent load that is giving you MOA accuracy. Playing with seating depth and/or charge may tighten the groups, and can do so dramatically on occasion.

 

[hardpan]

Hi There.
I think that it depends on how warm the rifle gets and the outside temperature in calculating how long to let the rifle cool between shots. For my best groups on my belted mags, I let the rifle cool as long as it takes to get back to the temp it was before I started. Sometimes, it can be 30 minutes... On Sat, it was around 95 outside, and it took forever to cool the barrel. When it is in the 40s, a few minutes does the trick,
Hardpan

 

[1Shot]

I would say that it is barrel temp that is causing your problems. If from the starting of shooting it will consecutively put two in about the same hole and then the third will move up it is barrel temp. If you let it cool back to the temp before you fired your first shot and it shoots back with the first two shots it is definitely barrel temp.

For a hunting rifle if it shoots where I want it on the first shot I would not worry about it. If you do your part and put that first bullet where it is supposed to go you don't need another one. :grin:

For a big old 338 3/4" groups look pretty good to me. :shock:

 

[bteate]

update from this morning,
started with a clean bore, shot one fouler then proceeded to shoot a three shot group. The pattern of starting to the right then going left and up is still there. Between the first, second, and third shot was about 3-5 minutes. I decided to give it a lot of cool down time on the fourth (about 12-13 min.) and it was back to the right. I guess that the barrel just likes to walk around a bit. This is going to be a hunting rifle, so as long as my first and second are close when fired back to back it'll do I guess. I haven't tried that but I will when set the zero. Would fore-end pressure help this or would it make it worse?
Here's a pic from this morning:

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[Elkman]

I like most want all of my rifles to shot little itty groups the size of a dime at 100 yards. Most of my will some will not. As components,powder and my age change I sometimes find that I can not recreate those little itty groups any more. A minute of deer is about the size of a dinner plate with a little extra around the edges. A minute of elk and or moose is a "lot" larger. You have a load that shoots 3/4 inch groups, that is much more than is needed for hunting and probably a lot smaller than one can shoot in the field in various field positions. I would load .20 off and enjoy the ride. Thats my 02 :grin:

 

[caribouhunter]

when i had the barrel channel opened on my model 700 i started having this same problem. so i build up a new pressure point using aluminium tape layers and it solved the problem. might not in your case but it's very easy to try.

 

[DrMike]

Brandon,

What I see in this latest post is a rifle that shoots MOA, which is not a bad thing! The group is random, though falling within a defined group size. Elkman makes a good point that despite our desire to have dime size groups, dinner plate size groups are more than adequate for most game. Almost all my rifles will produce little bitty groups, but my hunting loads are selected on the basis of energy delivered consistently, bullet integrity and game I'm hunting. In other words, there are hunting loads that shoot MOA, and they work very well indeed on game. MOA is more than adequate on deer out to 600+ yards.

 

[bteate]

I tried the pressure point idea with business cards just to put a little pressure on the end.
results......

first two- side by side
third- 2" low instead of high

I might be on to something if I can just get the height right, whigh might be harder than expected.

caribouhunter, I'll have to look back at your post to maybe figure it out.

 

[CAhunter]

What brand of rifle is this? Maybe it could be helped my a simple bedding job? Also sometimes a rifle will actually get more accurate the further from the lands. Have you tried seating this load @.050 off or even .075 off the lands?

 

[bteate]

It is a Sako AV Fiberclass. I believe that its a McMillan stock that has aluminum pillars. Someone has done a skim bed on the action. I might have it figured out, but I'll know for sure in the morning. I could try seating deeper, but the pressure point deal made my problem reverse, too much, but never the less it dropped instead of climbed. If I reduce pressure by half, it should be right on.

 

[Guest]

I want to jump in here with my two cents on this subject.
I know with my 300 Ultra Mag being Overbore as it is and burning 96 grains of powder it really heats up the barrel, especially so since relocating from Colorado to the Heat in the South here in Tennessee. Shooting in the South is difficult dealing with the Heat on the range. The barrel takes forever to cool off. Typically I can group 2-shots normally cutting holes but not the 3rd as the barrel is to hot and blows open the grouping. As stated earlier it may take 30-45 minutes or so to return to a cold barrel. Hope this helps.

 

[caribouhunter]

i made my pressure by folding a small square of aluminum tape to get close to the barrel, then added layers taping the square on the stock and putting the stock back with a dollar bill in between the stock and pressure point. when i had to pull hard enough to get the bill out, i went shooting and the same pressure point is still there it just shoot good enough. but i wonder if i could tweak out more accuracy out of it by trying to fine tune it in this manner?

 

[bteate]

what I'm trying now is a 1/2"x1/2" piece of double sided foam tape, with the backing still on, between the stock and barrel at the tip. I'll shoot it in the morning and see if thats right or needs more or less. Then I can epoxy a bed close to the tip for the pressure point.

Thanks for everyones input.

 

[caribouhunter]

isn't foam to soft? i'd be afraid that it would not give consistent result, the foam will flatten over time. but it's just a tought i didn't try it.

 

[Antelope_Sniper]

I'd say one of two things is causing this.
A barrel that is not free floated, or a barrel that was not properly stress relieved.

 

[bteate]

well, after looking over every possible scenario, I started messing with the stock and didn't like some of the contact points around the action. After cleaning some paint from around certain areas when I put the stock back on, I had some serious pressure on the fore-end. To make a long story short, I'm sitting here looking at my very first bedding job. I don't think I'll sleep a wink tonight worrying about if I can get the barrel out and did I get enough glass in. Next time I"m getting the gel.

Oh yeah, foam is too soft, it didn't shoot worth crap this morning.

The good thing about bedding it is that I don't have to constantly think about what I could do different to make it shoot better, or should I say consistantly. At least for 4 or 5 days, anyway.