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> Just got my Foster-Manson 30-06 AI rifle...
Just got my Foster-Manson 30-06 AI rifle...
@ 01:08 pm (GMT) |
Rob Bird...back from the gunsmith today! I went with a 26" barrel plus brake. It's a tall drink of water! For reference, here it is between a Swedish Mauser and a Kentucky rifle kit project (it's the black stocked one).
And between a Schmidt Rubin 1911 and a Weatherby Vanguard 257 Mag. 
The great news is that a 208 gr ELD-M seated to the lands is 3.402 inches and fits nicely in the magazine. 
Even that length seats the bullet down past the neck/shoulder junction. 
Can't wait to shoot it! Next step, fire-forming brass. |
Replies
@ 09:50 am (GMT) |
Nathan FosterRe: Just got my Foster-Manson 30-06 AI rifle...Well done Rob, good to see that this has all come together. That will be a very hard hitting, clean killing load. |
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@ 02:14 pm (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...Thanks! |
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@ 12:14 am (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...Just a bit of an update: subsequent range visits have been about the same, did some velocity testing with a Magnetospeed which is a bayonet style chrono that mounts on your barrel, for those unfamiliar. It gives me speeds about 25 fps slower than my Caldwell traditional chrono, but still just a shade below 2800 fps with the 208 grain ELD-M.The most significant development has been the absolute need to go beyond just neck sizing. After a couple of firings, it will crush fit to chamber and the bolt will stick even if I'm ejecting an unfired round. This makes for less than ideal performance with some pressure spikes. If I back it off to where a totally stripped bolt will close with just gravity, which is about 2 thou, it will fire and eject easily with no bolt sticking. I have not been able to find anyone that makes a 30-06AI shoulder bump die (though custom options are available), but Hornady do have a full length die for it. It works well as long as I anneal and then FULLY clean out the inside of the neck and use dry lube in order for my expander mandrel to bring it back up to correct neck size without problems. I'm also going to be going with a little more neck tension in an effort to improve extreme velocity spread. I've been running a mere 1-2 thou, which is what the Lee collet die gives me. |
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@ 04:26 am (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...Ok, lots has happened...good and bad. I started full-length sizing with a Hornady match die because it's the only one I can find in 30-06 Ackley. It does a good job, good neck concentricity (and I'm turning necks). I bump the shoulder back 2 thou from where the bolt body (sans spring) just won't quite close on its own. All was going well, but I didn't love my Sightron S-TAC, so I put on the "trusty" Burris and went at it. Never got good groups, and ended up figuring that it was doing poorly because it was at the absolute left end of its windage adjustment. So I put the Sightron back on, did a better job mounting this time and the eye relief is better. Groups tightened back up.SOOO, I thought why not take something pretty good (consistently .6 inches/1.5cm or under) and make it possibly better? So I did a seating depth experiment. Three shots each at 20, 23, 26, and 29 thou off of the lands. 20 grouped at .4 inches, 23 grouped at just over 1 inch, 26 grouped at .16 inches(!), and 29 had an unexplained missing shot. It wasn't on paper. But the other 2 were .4 inches. Didn't worry too much about the missing shot, though I could not explain it at all. The target backer is full of holes, so I didn't bother looking. Anyway, I figured I had a winner at 26 thousands off the lands. Loaded up 10 of them just like it and went back. Shots 1-3 were fine (not as good, but fine), then shot 4 was 1 inch to the right. Shots 5 and 6 were back in the group, though it was shaping up to be a .75" group. Then things went to hell and never came back. Out of 10 shots, 4 were absolutely out of the group, and not in their own group at all. Vertical and horizontal dispersion. All about 1 inch or slightly more from the main group (though all were to the right and downward). Afterward I thought maybe I was inadvertently allowing the barrel to contact the sandbag. So I made up 10 more and went back. I also took 5 new ones to fire form. Of those fire-formers, except for the first fouling shot, the next three grouped nicely, the last was a misfire (think I may have made the primer pocket too deep??). On to the main event, I could not get a group at all. Didn't even fire them all, I gave up. I'm hoping it's the scope, though having two scope failures, while not impossible, seems somewhat improbable. I checked my action screws after the last time and they were tight (over 50 inch pounds). The only thing with the rifle that I have noticed is that the last centimeter of the bore, right at the muzzle, is getting pitted. Could this be due to the muzzle brake? I will say that I noticed this while I was still getting good groups. Soooo, damn it. Elk trip is in mid October. I was planning on starting to do more long-range work now. Hope I get this figured out. |
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@ 06:23 am (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...Not that it matters terribly, but I told things slightly wrong. With the exception of shot 3, the first 7 shots were within .688 inches. Five of those were within .385. Shot 7 went well to the southeast. Here's where a possibly important detail enters the picture: after shot 7, I adjusted the scope a few clicks up and back down, then a few clicks to the left and back. After that, the last two shots shifted over an inch to the left from shot 7, and left of everything else and down. They were also not even close to grouping, with about .6" between them.
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@ 08:12 am (GMT) |
Nathan FosterRe: Just got my Foster-Manson 30-06 AI rifle...Hi Rob, this is one of those situations in which trying to solve a problem via the internet may simply lead to further confusion. I will try to help with some thoughts, but they may be of little value as I really need to have the rifle in front of me.The S-Tac is a budget type item, yet the build quality is good. I have used this on rifles up to .50 cal and have not had anything fall apart which has been beyond expectations. Tracking has been reliable. But as always, just because I have not experienced a failure, this does not mean that failure cannot occur. Mount stress can be a problem. Once in a while, a Tikka or Sako bay be set up incorrectly for base milling. Rings with ball jointed plastic inserts rings normally take care of misalignment but there are instances where the error is very high. This is a negative aspect of rifles with integral mounts. If not milled correctly, problems can be difficult to rectify. If the action can take a Weaver style mount (e.g. Burris base adaptor for Sako), one can then use canted rings, canting laterally rather than vertically. Regarding your description of a tight chamber, unable to handle neck sized ammo - An AI chamber should be checked (during reaming) with AI head spacing gauges. If a gunsmith tries to wing it, the chamber could end up too tight or loose. Having said this, some smiths (having obtained the correct gauges) try to cut a very tight chamber, thinking that this will improve accuracy and keep customers off their backs. Either way, a tight chamber can cause problems, also with variations in case temper. This could be a factor, though it does not explain the missing shot. I really don't know what to say about the muzzle and brake as I cannot physically study your rifle and may instead insult the smith via incorrect comments. If the threads are not cut square to the bore (not the outer), are poorly cut, or if the threads and bore of the brake are not true, these can ruin accuracy. Any uneven build of carbon may exacerbate the uneven gas flow. In order to make some determination, it is important to know how the barrel was chucked for thread cutting. But of course as soon as you start asking these questions, it can create tension with the smith. From time to time however, you may come across work that has been performed by an utter moron, to the point that one can physically see the wonky threads, making the problem nice and easy to determine. To be honest, on a barrel of this length and weight, you would be better off without the brake. The brake reduces some recoil at the shoulder, but may cause a nervous reaction due to noise or a blink reaction / habit after being hit in the eyes with gases or ground debris. The cost to benefit ratio does not add up. The missing shot is quite a concern. I don't want to take a stab at it because I could be way off base. Everyone is in such a rush at the moment, supply shortages etc, resulting in rushed work. There could for all I know, be some flaw in the barrel, a delamination, a bit of swath jammed between a groove and land. The next will require reading of my Reloading book, to put the info into context... Regarding the jump experiments. The jumps you mentioned are all very close to each other. The differences in tolerance from bullet to bullet offset the differences in jump, so the experiment is not useful. One thing I am often asked is - "I set up my dummy round at X length but when I seated my batch of ammo, they all came out at different OAL's. Should I therefore adjust the seating die for each projectile so that the batch is all the same?" The answer is no, because if you carry on this way, you will get nothing done. Place this in the overthinking / fiddling / micromanaging basket. Instead, work with meaningful changes. In other words, set the dummy up at X OAL, then make up three shots. Set the next batch 20 thou shorter, the next another 20 thou shorter. Just use the dummy and stick with it. A second problem occurs if the neck is very tight and after using the dummy (seating little bits at a time), the actual seating of ammo produces a little spring back, resulting in a slightly longer OAL. Steph is the master of this, due to the fact that she seats a little and rotates all loads so the seating of the ammo is the same as the seating of the dummy. Patience is what makes her ammo good, yet she never gets carried away micro managing. A single eye roll puts me in my place before taking my packed lunch and packed ammo to the range. If you are are not seating incrementally, then some spring back may occur, about .010 if the neck is really tight. Strategy is the key word here. You can for example, seat the dummy .010 lower than needed, then let the batch do whatever it likes. Or, you could set up (measure) a few dummy projectiles (after measuring in chamber). One dummy is used to set up the seating die, the next dummy is used to confirm. But after seating your first actual bullet for testing, don't keep on measuring everything that comes out of the press. Overthinking can really muck things up. Recently I was shooting a Bergara 2.0 .300 PRC rifle. The rifle barrel was too light / thin (thinner than a T3) for the cartridge. The bore (when bore sighting) was about 15 MOA out of alignment with the scope in order to get it printing on target. In other words, the barrel itself was so whippy, that it flexed about a quarter inch by the time the bullet left the bore. It took a long time to get the rifle printing along with some head scratching, checking the mounts etc. When I finally got it printing, I had grave concerns as to the quality of the bore, especially after a shot went missing. Fortunately, I have no attachment to the rifle, I simply wanted to study and learn. The absence of stress / expectations helped a great deal with problem solving. I found my missing bullet - went through the same hole as the first. After spending a period of time with the rifle, I concluded that while the barrel was of an immensely ill conceived design, the execution was excellent and capable of very good accuracy. Although I like the Bergara rifles in general, I would not recommend this particular rifle / cartridge to anyone as the recoil is simply too severe for accurate field work. I would however recommend this as a base platform / donor in a heart beat. In any case, the point I wish to make is that one can become very distracted by various factors. The 'aim at one target - hit another' created a thought path, causing me to wonder whether one of my bullets had even hit the target. Not sure if that helps any Rob. |
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@ 01:24 pm (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...First off, my experience as a mechanic has taught me a couple of things. First, to not disregard any possibility entirely. Second, if there's a new problem, review the last change(s) made. Regarding the first point, it is possible, even if not probable, that both scopes are having issues. Regarding the second point, this has been overall a well behaved rifle. Lots easier to deal with than my .257 Wby I was working up a load for last year. I've been overall pretty pleased with its performance. I've just been trying to whittle away at it, both to improve the load and also improve my reloading and shooting skills. I am guilty of overanalysis often times so your advice in that area is well placed. However, when I'm learning something, I like to learn it deeply so tooling around with parameters helps me get a greater sense of what I'm doing. So I have to try to balance the two things.So, my current resolution is to merely return to a seating depth that was giving consistent results, just not consistently under half inch, though damn close (average .550 on known loads). The first time it opened up was when I upped my neck tension by 1.5-2 thousandths. But the very next time I did my seating test and got groups of .425", 1", .16", and .462. But once I tried replicating the best one, that's when things went sour. So, I'll go back to 2 thousandsths neck tension and seating 50 thou off the lands and see where that gets me. Hopefully back on track, but I'm prepared for worse. Which leads me to your thoughts. Regarding integral mounts/misalignment, are their any outward signs on a scope tube that could indicate that this stress has been excessive? Tight chambers: I have an Ackley go gauge and it closes fine. Is it possible that there still be a tight chamber? I didn't really notice it until around the 4th reload (not counting fire forming). Do you absolutely never have to bump a shoulder back? I will try it without the muzzle brake. I've actually been curious as to how bad it will be. I've cleaned the brake once and carbon buildup is currently looking pretty minimal. Though I'm not sure how much it takes to influence things. And I'm assuming the squareness of the threads to the bore can't be checked without proper tools. Regarding my reaction to the brake, I'm basically 100% sure I'm not flinching. I double up on ear protection and the recoil is totally manageable so I feel no aversion to it. I have yet to get dust in the face... My small seating depth changes were due to my trying the advice of a well known reloader/F Class shooter on YouTube. I admit, it seems absolutely tiny. Though I momentarily became a believer when I had a large change from 20 to 23, but the fact that it then went back small at 26 didn't really add up. You are supposedly looking for nodes where you get a range where the groups tightens up followed by it opening back up. Mine didn't fit that description. I'm certainly not married to the process! Regarding seating methods, I do them in three stages, turning the case each time. Sounds like maybe Steph does them even more gradually? And what do you call tight when it comes to neck tension? I do appreciate the advice to not measure every one that comes off the press. I absolutely do that, so it's nice to hear that I shouldn't. One less thing to worry about. As always, thanks so much for your detailed response. |
@ 10:16 am (GMT) |
Magnus VassbotnRe: Just got my Foster-Manson 30-06 AI rifle...Hi Rob.Man, I've been there a few times. Don't envy you right now. It sounds like it might be a picky barrel, or a twitchy "sweetspot". Shooting pretty good for a while, then suddenly not so good, then suddenly good to half good. Know the feeling all to well. Unless your current plan of going back to the beginning works out, then maybe it could be worth while to try something radically different, just to probe a bit wider. As I recall, you are at a pretty high velocity. I think I would try to find a lower sweet spot (150-300 fps lower), just to see if I could get the rifle to behave in a consistant manner. If it then behaves properly over several 5-shot groups over several days, the rifle and scope is most likekely fine. It's "just" a load issue. As far as the Cortina method with jump (3 thou increments) goes, I think it is important to see it in the right context. Cortina and his likes are always trying to squeeze things down from a "mediocre" 0,5-0,3 moa to 0,1-0,3 or whatever they find satisfactory, for RANGE use. In those instances 3 thou increments and fine measuring equipment is all good, and one can live with a tiny sweetspot within those limitations. But for long range hunting use, we are looking for a load that shoots somewhere around 0,5 moa +/-, and does so even if the ammo is banged around a bit, taken in and out of the mag 10-20 times in rain, snow, dust and what not, before finally being fired at an animal that is usually not that far off anyway. I always try to find a load with an "accuracy window" of atleast +/- 10 thou, preferably more. I therefore use 0,5 or 1 mm (20-40 thou) incrementswhen searching. I might do some fine tuning there after, but generally If I cant't get the bullet to shoot to the desired accuracy within that lee way, I rather go for a bullet of less bc, if it's more accurate and otherwise terminally satisfying. Or I just accept a slightly shorter reach, for now. After all, if it shoots 1,2 moa consistantly, 350 yards is still ok. Or with such a good bc frangible bullet as the 208, a very low sweet spot might be worth going for, for now. Just my thoughts. Good luck! |
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@ 11:19 am (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...I really appreciate your input, Magnus. Wise words! |
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@ 12:08 pm (GMT) |
Rob BirdRe: Just got my Foster-Manson 30-06 AI rifle...Just to follow up, I went back to about 2 thousandths neck tension and am seating 55-60 thou off the lands and groups tightened back up. Got some time at a long distance range and absolutely pounded anything under 450 yards/400 meters and even hit 820 yards first try, and again on the follow up. Target was a 12x16 inch (30x42cm).Will be doing some dry firing and working on form at home for this last month, as well as one to two more times at the 100 yard range. Then out to Idaho for elk in mid October. Just need to find a bull to get my crosshairs on! Thanks to all who have followed and contributed. |
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