Since I've had such terrible luck getting my .338 MAI to shoot even modest groups, and since Ol' John's same rifle shot well, and since I'm beginnig to clutch at straws, I decided to step back a bit and consider other initial constraints from those I have been working under.
 
Just a brief recap of where things are to date:
 
Ol' John (AKA LLANO JOHN) built two .338 MAI rifles - one for himself, and one for me.
 
His has an Adams & Bennet 26" barrel, mine a Lothar Walther 24" barrel.
 
They were chambered with the 200-grain Combined Technology Ballistic SilverTip bullet in mind as the primary projectile.
 
I took his rifle in hand, installed a pressure sensor, and started working up loads. His rifle shot well from the start, and I was able to come up with some loads that shot no worse than MOA.
 
When I got my rifle I commenced to work up loads, starting with the loads I had developed for John's rifle. As the chambers were cut with the same reamer, by the same person, I assumed this starting point was reasonable. I also wanted to try 180-grain Accubonds.
 
I had trouble right from the start, but it was 'scope (actually base) trouble. I fixed that. The next range session, the 'scope I was using shot apart. The next range session was inconclusive - too many "things" going on. The next "range session" was at Recoil Junky's in prep for the elk hunt. That was only a couple of shots just to make sure it was "on the paper" after transport. THEN it was a powder issue (at least that's what I think the problem was) and blowing primers (during the hunt) with loads that had been fine in John's rifle and mine. After completely re-doing loads, AND replacing that 'scope, the best I have been able to shoot is 5 MOAs. The current 'scope is a 50-year-old, fixed-power 4X Leitz, with a German-style reticle - two horizontal posts and one vertical, that do not meet in the center. I don't particularly care for this kind of sight picture, but I thought the 'scope was a good one. I'm now having my doubts.
 
As I discussed this matter with Nels and others (here http://thehunterslife.com/forums/showthread.php?p=66165#post66165 ), I was focused on the 180 and 200 grain bullets. In that discussion, I noted that the bullets that shot best for me in my .338 Win Mag were the Nosler 210-grain Partition, and the Hornady 225 SP - both flat-based bullets. All my rifles shoot flat-based bullet better than boat-tails - no exceptions. (A couple of rifles wil shoot boat-tails almost as good as FBs, but certainly not better.) However, I wasn't particulary interested in even trying the Nosler and Hornady, because given their weight and the smaller case capacity of the x57 case, I didn't think I could wring enough velocity out of them to satisfy my terminal performance benchmarks. Those benchmarks being: Muzzle energy of 3500 ft-lbs or less; carry 2000 ft-lbs out to 300 yds; and be less than 9" low at 300 yds when sighted in for a 6" target.
 
Because I am at the point of clutching at straws, I decided to have a look at what QuickLoad predicts for the Hornady 225 SP. Well, well, well. Keeping the pressures to very reasonable levels, I should be able to get the 225 to deliver 2100 ft-lbs out ot 300 yds and only be 7.5" low. Muzzle energy is a tolerable 3400 ft-lbs, and predicted chamber pressure is 53,789 PSI. If the QL predictions turn out to be close, I'll have "room to move" both directions to find the precision sweet-spot.
 
So...
 
At this point, I am going to buy a new 'scope specifically for this rifle, and
load up a variety charges for the .225 Hornady bullet. I'm considering fire-lapping the barrel, but I will wait 'til after I scrub the barrel with Wipeout, AND the next range session with the new 'scope and loads.
 
By the way... the load I mentioned above for the 225 yields an estimated muzzle velocity of 2608 f/s. I can drop that back to 2555 f/s at a chamber pressure of only 50,200 PSI, and still have 2000 ft-lbs at 300 yds, a ME of 3261 ft-lbs, and a drop at 300 of 8.4".
 
If my problem getting the MAI to 'shoot' is bullet-related, maybe this will be the solution.
 
Paul

It seems like even the worst modern bullets would group better than 5" @ 100yds out of a good rifle. I'm betting on the scope & mounts or something else like bedding, crown, or an action oddity.
 
Has the rifle ever shot good groups since it was built?

Just keep tinkering....you will figure it out. I have had very good success with the Tubb's fire lapping system...I've averaged around 40% better groups across the board. Regards, Rick.

Well, I just ordered a new 'scope (from Midway:undecided: ). (Paul_H, that store you mentioned doesn't sell anything but Tasco and Burris.) It might arrive by Saturday. I'll get some Wipeout tomorrow, and I'll load up the 225s this evening. If the 'scope, Wipeout, and new loads don't result in a significant group-size reduction, I'll be getting a Tubbs fire-forming kit. Prolly will anyway. It just occurred to me that I do not have a .338 bullet mold, meaning that I won't be able to cast lead bullets to use in the fire-lapping. Hmm.
 
As far as the fire-lapping goes, I wuz thinkin' that I would use my standard fire-forming charge of 15 grains of bullseye, pushing a cast bullet out at about 1000 f/s. However, it occurs to me that "fast" might be "good" for fire-lapping. From those that have done it, what's the skinny on "fast" vs "slow"?
 
Paul

Quote from: gitano;66190Well, I just ordered a new 'scope (from Midway:undecided: ). (Paul_H, that store you mentioned doesn't sell anything but Tasco and Burris.) It might arrive by Saturday. I'll get some Wipeout tomorrow, and I'll load up the 225s this evening. If the 'scope, Wipeout, and new loads don't result in a significant group-size reduction, I'll be getting a Tubbs fire-forming kit. Prolly will anyway. It just occurred to me that I do not have a .338 bullet mold, meaning that I won't be able to cast lead bullets to use in the fire-lapping. Hmm.
 
As far as the fire-lapping goes, I wuz thinkin' that I would use my standard fire-forming charge of 15 grains of bullseye, pushing a cast bullet out at about 1000 f/s. However, it occurs to me that "fast" might be "good" for fire-lapping. From those that have done it, what's the skinny on "fast" vs "slow"?
 
Paul

Hello Paul. The bullets are already treated....there are 5 grits from course to very very fine.....for 28 bucks, you get 10 bullets of each grit. The techie told me to just shoot a normal load. It takes 50 rounds for the full treatment. So, neither fast or slow.....just a normal load. Regards, Rick.

Certainly an interesting mystery.  Both MAI barrels 10 twist?  Nothing odd with the LW barrel muzzle or land/groove dimensions?

After cleaning with Wipeout, pushing a oiled lead slug from the breech to the muzzle may tell you if any dimensional restrictions exist.  Then slug just the muzzle end and see if it is bigger than the one you pushed through.

Elaborate on the "powder problem".  If the same chamber reamer was used by the same person on both barrels, it sounds like using the same cartridge/load between the two rifles resulted in vastly different pressures? There may be something there.

Anything odd with the cartridge brass, like thick or uneven neck thickness?  I've had 8mm brass that has given me fits with variable neck thickness and inconsistent neck tension.  Because BT have less bearing surface than FBs my guess is the BTs excerbate the effects of unsymmetrical neck "release" of the bullet and enter the rifling less than square and true.

Lastly, my experience is limited to fire-lapping with soft lead, and that practice is slow as possible.  3 to 5 grains of red dot, enough to fill the grooves and cut the high spots, but not "lead" the barrel from hot gases or excessive velocity. Plus if you get one stuck, you can easily push it out. Not so with a jacketed bullet.

Don't forget the Wipeout!

Nels

Rick - I knew about the kits, but I also knew you can buy the various grits separately and 'roll yur own'. Plus, does Tubbs make a kit as large as .338?
 
Nels -

QuoteBoth MAI barrels 10 twist? Nothing odd with the LW barrel muzzle or land/groove dimensions?

To tell you the truth, I can't remember, and I haven't slugged the bore or measured the twist rate. I would be more than a little upset if either characteristic was out of "spec", but you raise a good point. I should check those things out.[/SIZE]
 
The "powder problem" was another 'mystery' that I am almost certain was due to differences in lots of I3031 powder. I used some 25+ year-old powder for load development with John's gun and preliminary work with mine. When I got ready to go to Colorado for the elk hunt, I bought a new cannister. I used up the old cannister to load the first 5 or 6 round of ammo going hunting and loaded the rest of the huntng loads using the new powder. When we shot the rifle at RJ's, we used the cartridges charged with the old powder. Upon extracting the case after taking a parting shot at the south end of a north-bound elk, HB noticed that the primer simply fell out of the case. When I fired tested a shot, the same thing happened. Since all the old powder was gone, there was no way to test the two side-by-side, but I simply cannot figure out another reasonable explanation.
 
The brass has been reloaded multiple times, and is in fact the same brass I used to develop loads for John's rifle. I trim necks to uniform thickness before the first loading, and do not mess with them after that. I don't think that's the problem.
 
I think what I'll do WRT fire-lapping is follow the instructions if I get a kit. If i decide to 'roll my own', I'll probably keep it slow as you described. I'm thinking I might run a slug through the bore before I start; half way through the process; and again at the end to see if I can feel a change.
 
I will not forget the Wipeout!
 
Thanks,
Paul

Paul, I have done several barrels, I just used 600 grit abrasive for rock tumbling and Clover fine valve lapping compound, put some on a steel plate, put a bullet on the plate and put another piece of steel on top, than rolled the bullet around for a while.
I used 4gr of Universal, just enough to get the bullet out of the barrel.
I shot about 15 to get the worst barrel shiny, some only needed 8-10.
I use only as many as are needed to get the results I want.
I have a bottle of LBT abrasive someone gave me and some dry 600 grit, I will send you some today.

Just a quick update:
 
After staring at the thing for a while I decided that I would simply tear everything down, and start over completely as if I had just received a new rifle. I'm glad I did as there were some eye-openers.
 
First, the simple stuff. The twist is 1:10 and the bore slugs at .330" and .338". I don't feel any particularly "easy" or "rough" spots as I move the slug fore and aft. (On a side note I'll pass on a little trick I just learned that is good for "feeling" the bore - make the slug out of aluminum foil. It's trivial to do, and you can get a good feel because the aluminum tends to grab.) Casting the chamber revealed a couple "things". First, Ol' John did an excellent job cutting the chamber. The finish is almost mirror smooth, but still has enough texture to grab the case. However, the leade and throat are very short. I've only got about 0.200" of leade - the area between the mouth of the chamber and where the lands start. ALL of my cartridges were being pushed into the lands to one degree or another.
 
I received the new 4-12x40 Simmons Masters Series 'scope and am satisfied with it so far. We'll see how it works "in real life". I also picked up (for a song) a 2.5-10x50 AO Simmons with BDC turrets from EBay. It too appears to be working as built. The 50mm objective is "a bit much" for my tastes, and fiddling with the BDC turrets in the field is a great way to lose a critter. Nonetheless, I'm bound and determined to get the rifle figured out. If the 50mm 'scope with all its gadgets helps get things on track at the range, then so be it.
 
Finally, I re-took precision chamber measurements, precision fired brass measurements, AND the bullets' actual measurements, (all of them from the Barnes 160 X to the Hornady 225 SP), re-entered them into QuickLoad, and started over completely with load workup. Having to seat the bullets considerably deeper has a very real effect on charge calculations. Honestly, I think that was a significant part of my problem. Based on the QL calculations and Optimal Barrel Timing theory, the 180 Accubond (Yay! ) and 225 Hornady are the two best bullets, (defined by delivering the most energy at the greatest range), for this rifle's chamber dimensions and barrel length. I've mounted the new 'scope, loaded some of each bullet (180 and 225), and it's back to the range I go.
 
I'll let ya know how it goes.
 
Oh yeah... I didn't forget the Wipeout. :)
 
Paul

Paul,

Hang in thar, bud!!!  VV150 powder is not doing the trick for you?  Strange............:undecided: .  Ordered a new computer the other day......maybe I will get to visit more than once a week. Duhhhhhh!:Banghead:

See you'uns soon.

Ol' John

Hey John, good to hear from ya buddy! Gimme a call when you get a chance please.
 
As for the MAI, I've been to the range with the 225s. (Actually two weeks ago, but THL was down for me for 13 days.)
 
It was a 'good' day as range-days have been going for me lately. I took only the MAI with the 225 Hornadys and the Fifty with both 400 and 500 Northwest Custom Projectiles loaded to "proper" muzzle velocity/muzzle energy. I was using XMR 2495 in the Fifty and I3031 in the MAI. In the MAI I loaded for a "hot" Optimal Barrel Timing charge of 47.79 grains, then backed off in 1% increments down to 46.37 grains (-3%). The Fifty got a similar type of loading (starting velocity, then back off in 1% increments to -3%) for each bullet weight. In the Fifty, I started with the MV/MEs I wanted, (instead of the top OBT), then loaded down from there.
 
Both rifles had new sights. The Fifty got the new higher front post, and the MAI got the new Simmons 4-12x40 Masters Series. (The Simmons was purchased on Ol' John's recommendation... another bit of good advice from Ol' John.) I'm very, very pleased with the Simmons.
 
After bore sighting, I started the MAI out at the lowest charge. The groups were still poor, starting with vertical spreads approaching 3". However, the horizontal component (usually the element mostly attributable to the shooter), was 2.1" in the first; 1.1 in the second; and 0.4" in the third. However, when I shot the last group, the whole-group-size shrunk down to 0.6". (All these groups are 3-shot groups.) :) It appears that the MAI "likes" it hot. This is the same thing I observed in John's MAI. Namely, the best groups were from the hottest loads. While the 47.79-grain load is 'tolerable', I really don't like being that near the upper edge of pressure. I'm going to load some close to 47 grains and see if I can still get good groups.
 
There are a couple of other elements to consider here as well. One is that I haven't shot the 180 Accubonds with the new loads yet, and secondly, I haven't tried VV N-150 that I used when developing John's loads. The reason I haven't used N-150 is that according to QuickLoad, it gives considerably lower muzzle velocities with higher pressures. Put another way, I3031 gives the highest velocity for the lowest pressure. Still, I'm going to try both N-150 AND 4064. 4064, because it's been a consistent performer in medium-capacity cartridges for a long time.
 
So... I've finally found a charge that gives the precision I know this rifle is capable of. Of course, having a 'scope that finally actually works helps too.
 
The group sizes were:
 
46.37 grains of I3031 - Horizontal(X) = 2.1", Vertical(Y) = 2.6" - 2493 f/s
46.84 grains of I3031 - X = 1.1", Y = 3.2" - 2513 f/s
47.33 grains of I3031 - X = 0.4", Y = 3" - 2534 f/s
47.79 grains of I3031 - X = 0.4, Y = 0.6" - 2554 f/s
 
I think the large vertical component might be due to variations in chamber pressure because the loads are "down" too far for consistent ignition. Muzzle velocities of the lower charges had higher standard deviations (almost 20 f/s), than the OBT charge (12 f/s). I was using 'standard' primers, and I might try magnums to see what happens at lower charges. By the same token, I would have expected the 225s, being kinda heavy for the case capacity, to facilitate good ignition. So... Being "too far down" may not be the cause of the vertical spread. Which by the way, wasn't "stringing".
 
As for the Fifty, I am extremely pleased with it. I was concerned that the high front post wasn't going to get me down enough at 100 yds. Not only did it get me down enough, it was right on. I'm about 5.5" high with the 500, and 4" high with the 400. Both with the top loads, giving MVs of 1717 f/s for the 500, and 1921 f/s for the 400. According to calculations, that should give me a 32" drop at 300 with the 500, (meaning I wouldn't have to aim "off hair" on a bison), and the 400 will be fine for everything else (moose, elk, coastal brown bear) out to 200. Actually, I feel confident enough with the Fifty to shoot at elk or moose at 300. I haven't had a chance to try the Fifty at 300 yet, but I'm pretty sure I can keep all shots in 12" at 300 yds. That'll do for buffalo and Texas exotics , if I ever get drawn.................
 
Paul

Quote from: gitano;66682As for the MAI, I've been to the range with the 225s. (Actually two weeks ago, but THL was down for me for 13 days..... AND 4064. 4064, because it's been a consistent performer in medium-capacity cartridges for a long time.
 
Paul

I am confident you will figure this out and 4064 may very well be the ticket. THL was down for 13 days for me too, however, there was a good reason........hunting!!! Regards, Rick.

Quotehunting!!!

So.... What's "the rest of the story"?
 
Paul[/SIZE]

Paul, here's some testiment to Wipe Out and firelapping. Remeber the 300RUM? Well here's some before and after pictures. The first is a very sad group. Granted I've fired amaller groups but not very consistantly.



After firelapping and Wipe Out. The top group on the second shot my cell phone went off in my shirt pocket. Yes dear, I will water the horses before I go too work.  The second group is after I shut my phone off and went to see if the horses actually needed water.



It would appear that the groups will at least be more consistant and with some load tweeking and practice, I should be able to get them smaller. Hopefully before the barrel gets burned out.

And yes, I did water the horses.

RJ

:laugh: :laugh: :laugh:
 
I got a belly-laff outta that one RJ.
 
Since I was able to tighten the groups by 1) being more diligent, and 2) working up loads a bit, I had put the need for lapping aside for the moment. However, these pictures are testimony to the effects of thorough cleaning and lapping.
 
I got some lapping compound, and I think I'll fire-lap the barrel after the next range session with some different powders and the 180-grain bullets. The only wrinkle at the moment is lead bullets in .338 for the lapping. I suppose a 20-dollar bill to Lee isn't too much to spend under the circumstances.
 
I've got the .375 and the .358 barrels for the Steyr project, and both being A&B bbls, I think I might start out by lapping them. Although, from all I've heard, A&B barrels shoot fine right from the start. We'll see.
 
Thanks for the laugh and the info,
Paul