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retumbo and the 300RUM, a little help please
JustC
Member Posts: 16,056 ✭✭✭
nononsense or anyone with experience with this powder, I could use some help.
I switched from the 200gr Matchking and 88gr of H1000 (max in my chamber) and went up to the 216gr clinch rivers with retumbo. My 10twist 30" tube has shown me mediocre accuracy at best. I got some .6-.7 at 100yds friday afternoon[:(] and then today pushed it out to 200yds. I got up to 91grs without finding anything that was acceptable, so now I have to skip tomorrows 600yd match[:(!][:(!][V]
anyway here are the questions
1. is it temp sensitive
2. does it need to be near max loads (book lists 95gr as max and I am 4 grs shy due to my chamber being rather tight, but no pressure yet)
the specifics
1. brass has 7x on it, almost done for
2. fed 215M primers
3. 216gr clinch rivers seated .005" into lands
4. cases have .002" NK tension
5. body die set to just pull the shoulder foreward .002"
6. Retumbo powder running from 3040-3150fps ish from 87-91gr charges
why chase the game when the bullet can get em from here?....
Got Balistics?
I switched from the 200gr Matchking and 88gr of H1000 (max in my chamber) and went up to the 216gr clinch rivers with retumbo. My 10twist 30" tube has shown me mediocre accuracy at best. I got some .6-.7 at 100yds friday afternoon[:(] and then today pushed it out to 200yds. I got up to 91grs without finding anything that was acceptable, so now I have to skip tomorrows 600yd match[:(!][:(!][V]
anyway here are the questions
1. is it temp sensitive
2. does it need to be near max loads (book lists 95gr as max and I am 4 grs shy due to my chamber being rather tight, but no pressure yet)
the specifics
1. brass has 7x on it, almost done for
2. fed 215M primers
3. 216gr clinch rivers seated .005" into lands
4. cases have .002" NK tension
5. body die set to just pull the shoulder foreward .002"
6. Retumbo powder running from 3040-3150fps ish from 87-91gr charges
why chase the game when the bullet can get em from here?....
Got Balistics?
Comments
Don't you have another rifle set up for 600 yd. matches? How about the 6.5 x 55 AI? Heck, I'd take a good solid .308 Win. if I had ammunition loaded with something along the lines of the 168 gr. AMAX or even the 175 MK. I hate to hear that you have to miss the match.
I have backed away from the Retumbo for the most part as I can't seem to get the results that some of the others write about. It's not that I get bad results, they're just inconsistant over a long series of shots. I don't think that it burns as clean a some of the other slow powders and I'll gladly take a slight loss in velocity for a cleaner barrel over the length of a long match or shooting session.
1. is it temp sensitive Not that I've experienced
2. does it need to be near max loads (book lists 95gr as max and I am 4 grs shy due to my chamber being rather tight, but no pressure yet) Yes, it seemed to need to be near the top end before I got any performance
the specifics
1. brass has 7x on it, almost done for I'd start with new brass especially if you haven't annealed
2. fed 215M primers I like the 215M but it seems that CCI has some good points
3. 216gr clinch rivers seated .005" into lands
4. cases have .002" NK tension
5. body die set to just pull the shoulder foreward .002"
6. Retumbo powder running from 3040-3150fps ish from 87-91gr charges
(3, 4, 5, 6)
As you know, I haven't shot any of the Clinch River's so I can't speak to that as a problem. I'm getting good results from the 210 Berger VLD's though and I'm running at about the same velocity range as you, right around 3050 - 3100 FPS. with the same length barrel.
Is your barrel a Krieger? Or who made it for you? Have you run a borescope down its throat recently or looked at the area just behind the crown about an inch in? I don't think that it makes a huge difference anymore but sometimes it seems to be like primers and I have to change out the barrel for another design. Mine all currently have 1:11 twist for competition and I've got everything from 1:15 on up to 1:8 if I need it. The Schneider and L-W polygonal barrels are showing some promise.
If you're pulling the shoulder forward then you're getting about 0.002" crush when you close the bolt?
Maybe you need a bit more neck tension. I had that problem a couple of times and believe it or not, it can make a significant difference especially if you haven't annealed.
That's all I can think of right now but that leaves the 'hunt and peck' process which can take a bit of time and barrel life. Maybe try to anneal 10 cases and see what happens. Then increase the neck tension by 0.001".
Best.
How about RL25? any other consistent powders? how has that worked for you with the 210's? These clinch rivers are VERY close when set side by side. Have you seated them in deep or let them have a small jump for best results?
This tube is a cryoed, PacNor select match from 1.250-.995" at the muzzle (before the vais break of course). 1:10 5 groove.
The problem with the 6.5x55AI is that although the load ladder was very convincing with the 140gr a-max pills, I have not run it a second time to verify the first trip as the summer heat set in and I did not feel that 95*+ was a good temp to run in if for no other reason than barrel cooling time. Do you usually take your first ladder and have consistent luck with the accuracy load or do you verify it a second time? That may just be part of my * approach[B)] Not to mention I have been wanting to see if I could get this rifle a bit more consistent and see if the 210-220gr pills would take out a bit of the vertical dispersion. The SMK's without trimming the meplats are some-what variable in dimension. Maybe the 220gr SMK??
I suspect maybe a tad of carbon fouling somewhere??? The tube only has 321rnds since new, so I am doubting firecracking or major erosion at this point. I let it soak in wipe-out overnight last night and have it soaking again right now. Maybe a good scrubbing with the nylon brush and some shooters choice is in order here.
and I AM getting the .002" crush for a good compressed fit while just barely resizing the expansion ring so I can get them to come out of the Wilson seater die (same reamer). 2 firings and they have to be resized at the base to come out.
Thanks so far.
why chase the game when the bullet can get em from here?....
Got Balistics?
If you haven't tried annealing yet, you could be in for a treat. There's lots of instructions about the different procedures that you can use and 6mmBR has an article about a particular piece of equipment specifically for annealing. A dim room helps to see the color change and if you want some assurance the first few times, you can buy a product named TempiLaq which changes color with temperature changes.
http://www.tempil.com/productdisplay.asp
http://www.brownells.com/aspx/NS/Store/ProductDetail.aspx?p=13124
Some people prefer a lead pot for a more even and controlled anneal on the neck and shoulder area.
Re-25 is what I've been using for quite some time, probably five years or a little more. But I've also had good performance from V V N-170 and Ramshot Magnum. The H-1000 should be nearly perfect according to what a couple of others have to say. The first three burn fairly clean but the H-1000 can be pretty dirty. That's when you can increase the neck tension a touch and get a little better burn, that's if the necks aren't too work hardened.
"I suspect maybe a tad of carbon fouling somewhere???"
That would be my thought. Probably just in front of the throat. Nothing that a good and careful scrubbing can't fix. I doubt the fire cracking but I would find someone with a borescope just to be sure what the barrel looks like from one end to the other.
Two observations and please don't take offense, it's only my opinion:
Pac-Nor tubes that I've tested for hardness have been just a little softer than I like. It's not bad because the guys that make button barrels need the steel a little more soft but it doesn't help with wear. Cut rifle barrels are harder than the button barrel. Cryoed barrels machine differently than non-cryoed barrels do. The steel feels sort of rubbery when you cut it. John Krieger has reduced his process from two cryo trips to one.
I seat the 210 Bergers into the lands otherwise they won't shoot worth a hoot, at least in my barrels. I also trim the meplats for consistancy. All of the bullets that I've looked at need the meplats trimmed due the process of getting the jackets pointed up. I just got a new batch of 220 gr. Sierras so I haven't had a chance to work with them at all.
Ladder testing, to my way of thinking, is done once then I do some significant refining. I'd take that 6.5 and go shoot tomorrow.
I hope some of this makes sense...
Best.
I may try annealing with these old cases as a test, if i mess up, they are bound for the trash anyway. I don't think that by neck sizing and barely body sizing that a case-head seperation should be an issue, but pockets will no doubt be toast in 1 more firing, if they even hold one this time around.
What range of RL25 showed harmonics for you?
Thanks, this rifle has driven me nuts for 2 straight days now. It is usually nothing but operator error, and now the operator can't get it to do a darn thing[B)] I may be abandoning retumbo soon unless I go to a 240gr SMK.
Let me know how the ladder goes with the 220smk, I have a box here I can try.
why chase the game when the bullet can get em from here?....
Got Balistics?
NO carbon fouling? Hmmmm... I would have banked on that one. Oh well, that's one thing down and some more tests to run.
Those older cases are ideal for testing the annealing process, as you say, there's nothing to lose and maybe something to gain. I'm not trying to tell you what to do but I would test anneal 10 cases and keep 10 cases as is to use as a control. Don't do anything different to all 20 cases except for the anneal on 10 cases. Load the same, size the same, prime the same, etc. If I had unlimited time, I would try an additional 0.001" of neck tension on 1/2 of the annealed cases. The problem that could come up would be an increase in pressure but that would combat fouling if you were seeing that in the barrel. It can have an affect on accuracy.
Your system for sizing is exactly what I do for accuracy cases and there shouldn't be any problem with separation at all.
I'm seating 0.010" into the lands. VLD's, at least the ones that I shoot, are NOT more lenient, ever. They seem to require more fussing than the flat base bullets do. That's another whole conversation... I haven't been able to prove, that further (deeper) into the lands makes an improvement in accuracy in my rifles. My opinion is that the folks that claim to seat deeper like 0.020" - 0.030" into the lands are really seating the bullet somewhat deeper into the case, increasing pressure. It's hard to prove one way or the other but if that works for them, so much the better.
Accuracy nodes in my one rifle appear at roughly 3050 FPS which is where I try to work and there is another one up at ~3250 FPS. but that's too hard on the entire system. Case life is 2 or 3 firings and it can't be doing the rifle any good. There is another one that is lower than the 3050 FPS. but I like the way that everything works at the 3050 FPS. All three powders work well at this level also. The VihtaVuori 100 series powders don't get the velocities of the Reloader series but they perform great. I had to cut back on using the V V 500 series powders due to an increase in erosion over the standard powders. I do use them in my hunting rifles, though.
Unfortunately, I won't get to the 220 MK's until probably February or March. I have a really pressing business project that needs to get done this winter, no matter what. This is even putting my winter Match schedule on hold for this next year. No choices, oh well.
Best.
ADDED:
I just found this and thought that I should pass it on. It a new powder for large capacity cases and the 50 BMG. Supposed to be out early 2006:
http://loaddata.com/articles/PDF/New Powder From Hodgdon.pdf
so far I have allowed it to soak in the original formula hoppes all day today and have run maybe 60 strokes with the nylon brush. I am getting some dark grey continually on the patches and I feel like it is smoothing up some, but couldn't that be the brush wearing down a bit?? or don't the nylon bristles wear fast like the bronze????? if so, I would say there may have been some carbon buildup. How much of that grey is normal? I havn't run into a problem like this even in factory barrels before. Must be the retumbo because 250rnds of H1000 never acted like this.
What have you found fastest for carbon removal? the wipe-out is wonderful on copper, but I just "feel" that it isn't doing a 100% job on the carbon. There is always blue at the front of the patch and some carbon at the rear,..that has bugged me since day one. (could be in my head[:p]) What do you think of Montana Extreme 50BMG, I havn't tried that yet but Bill Shehane and Rich DiSimone seem to love it, both of whom took time to talk at length with me when they had never even met me.[8D]
Oh yeah,..I think I am going to look for a small motor and build an annealing box like Rich built in that article. What do you think of that idea??
why chase the game when the bullet can get em from here?....
Got Balistics?
Try some GM "Top End Cleaner" from your local Chevy dealer, on that carbon. I haven't used it myself, but I've heard others highly recogmend it.
Some guys like a mag full of lead, I still prefer one round to the head.
How is the stock project going?
why chase the game when the bullet can get em from here?....
Got Balistics?
Sorry, I've been working all weekend and I didn't see this 'til now.
This is what I've been using (below), the MPro7 is easier on me chemically but I do carry a can of TEC for some occasions. Then I follow with the 50BMG for the copper. I do use the nylon brush but sparingly. If I use Wipe-Out, my cleaning routine is down from 2 hours to about 15 or 20 minutes per barrel depending on the load and number of shots. I can get a rotation of 4 barrels going simultaneously and have them finished in no time.
From 6mmBR:
"Here is what we recommend for an "average" factory barrel. After 25 rounds, or when accuracy degrades noticeably, spray some MPro7 or GM Top Engine Cleaner (TEC) down the bore from the muzzle. (Insert bore guide in breech first. Keep your MPro7 or TEC in a small plastic pump bottle for muzzle application). Let that sit a bit, then follow with a patched soaked with the same cleaner. Repeat. Then, apply the same MPro7 or TEC generously to a bore brush, and run the brush through the bore 3-4 times, breech to muzzle. Allow some dwell time between strokes. Always use a wet brush. GM TEC cleans a little faster but it has some dangerous solvents, so handle with care. MPro-7 is non-toxic, non-flammable, non-corrosive, and biodegradeable. It comes in liquid or gel, and is also sold as "Hoppes Elite" cleaner."
The nylon brushes do wear out but they don't color any of the patches, that has to be from fouling. The tough fouling is usually right up in the throat area and for a few inches, probably the worst place for it to occur, because it can be damaged so easily by aggressive cleaning. Try the TEC, let it sit for a few minutes and brush a few times.
My guess is that Retumbo uses a fairly potent deterrent(s) to get the burn rate down and it's also creating the tougher fouling. That's just supposition but it makes sense according to my experience.
If you can't find a reasonably priced motor, try the second hand store and get an older record player and take it apart. I've even used the turn table (platter) if they are aluminum which the older ones can be. I think that you'll be impressed with annealing.
Best.
I have it cut to length now, and a pad installed. Will be able to work on the final butt shaping now.
I may have to add more rosewood in the pistol grip area (not enough material in the claro blank) but that won't be bad as it'll balance out the rosewood front rails.
Some guys like a mag full of lead, I still prefer one round to the head.
nononsense, when you say sparingly with the nylon brushes, is there a reason for that? I have been under the impression they won't scratch the surface, hence my switch from bronze to nylon. Is it the carbon itself you worry about? How many strokes in a removal session? I try not to use them at all in match tubes, but this problem is perplexing. It seems that powders like RL22 and 4831sc and the like clean up easy (unless I need to investigate other bores as well)[:0]
I just ran another patch and after another 4hrs or so, it is getting much better. Maybe some TEC and one more scrubbing will do the trick.
almost forgot, where are you getting the 50BMG, I can't seem to locate it.
Thanks
why chase the game when the bullet can get em from here?....
Got Balistics?
Here is a link to the Montana X-treme website for web orders:
http://www.montanaxtreme.com/find_a_retailer.php
It's a list of retailers that carry the Montana products. I got mine as a sample for testing.
The carbon will scratch and score the bore, the nylon brush itself will not as you say. Here is the brushing explanation from one of the manufacturers:
"Here's the brushing method: Pass the brush all the way out the tube, and unscrew it before the next pass. Brush breech to muzzle only. Do NOT draw the brush back down the bore. (A reverse pass, even with a "clean" brush, just drags fouling residues back into your rod guide, where they can be picked up and passed back into the barrel on the next forward pass.) Clean the brush and wipe off the shaft of the cleaning rod before each pass. After 3-4 brush strokes, run a damp patch through the bore again once or twice. Then run a tight-fitting dry patch to remove the carbon cleaner."
I don't know what your shooting schedule is but I think if you call Chris at Pac-Nor to explain the problem, he might want to see the barrel. Just a thought.
Best.
One thing I forgot to mention, maybe this will make some sense to you. I fired the first string, round robin style. 1 shot of each of the charges at each of 6 x-rings for 1 hole per target. Now it has been 60* that day and at 4:30 is starting to cool down quick. I wait for say 15min and the temp is maybe 10* cooler +/- and I fire the second string round robin. EVERY impact is low and left across the board. They then stay that way except for a few flyers which still never make it up to the original impact for the first string. They are also spreading out to the .6-.8moa from the ~.3moa of the previous weekend (although those were I beleive in the 87 and 87.4gr range and the ladder this weekend is run from 87.8 - 90.0 and 91.0gr)
I could see the groups growing due to the harmonic being inconsistent, but that drop to low and left had me puzzled. I am guessing must be powder fouling? Keep in mind the temp drop could have been a almost 20* during these 30rnds in 6 shot strings.
why chase the game when the bullet can get em from here?....
Got Balistics?
You are always shooting those big RUMs, don't they knock a filling loose once in a while?
why chase the game when the bullet can get em from here?....
Got Balistics?
The velocities on your first 3 shots is simply perfect, what were the results of the other shots in the same string? I'm not sure about the temperature sensitivity problem if there is one. I'm not aware of any and I haven't experienced any. But that doesn't mean that in your circumstances that it didn't occur. That's a pretty extreme change for a short period of time. I would think that the warmth of the barrel and chamber would have a balancing effect on the temps. I have had that POI change when I work up my loads here in the heat then go out of state to colder climates but I always take enough ammunition for testing before a hunt. I've shot the freezer/hot day tests with lots of ammunition combinations but I didn't do any with Retumbo.
At that time of the day, I would be more suspicious of the changing angle of light without having tested the temperture problem. Then factor in the potential of fouling and it appears that this powder is not working, no matter what you find as the absolute culprit.
The funny thing is that this rifle is tested and proven with other bullets and powder. Yet when you switch to CR bullets and the Retumbo, things start changing and showing aberrations on the targets. I find it hard to believe that it's a problem with the CR bullets and I am more willing to say that the powder has a problem in this system. Change the cases out to new ones or do the anneal test and then look into the neck tension after first making sure that the barrel is clean. Then let's knock it around some more. Nice rifle by the way.
Best.
I have now gotten clean patches after last night running the nylon brush and removing at the muzzle like you suggested with some shooters choice (5 days of constant soak with patches and brush intermitently aplied) I beleive the grey must have been some carbon fouling, or at least I would like to think so as that would be an answer or sorts.
The chrono started to error because of light angles that afternoon for the 4th and 5th shot, but I think the #4 round was a tad higher in MV due to a warmer chamber. Still, single digit SD either way.[;)] I just wonder about inefficient burn that low in the powder charge. I talked to some other users who, with 210gr bergers needed around 93gr's to really clean up the soot on the necks. The barrel was a shilen in 30" 1:10, so I am beting his throat length and chamber dia should be closer to mine than to saami, so he may have provided me some good intel. I would like to build the anneal machine and run the 10 to 10 like you suggested with this newly cleaned barrel. It still feels like glass from the leade to the muzzle, so I know she is in good shape for maybe another 700rnds (fingers crossed). If she cleans up with a 12 o'clock lighting angle and the carbon gone, then we know that was it. maybe I can get a few hours for saturday to try it.
I have 20 cases from factory ammo that have been fired 2x, think they are fresh enough to run another ladder without annealing?
One more question I have been meaning to ask,..I have a box of bullets I traded for a while back, but they are unmarked. these are 30cal, 215gr with some sort of "bronze/browninsh" see-through coating. Is that Danzac? and who makes the custom 215gr match 30cals? I think the guy told me they were JLK's, but I am wondering. If they work, where can I find more of those? It looks like I may just run back to the 210 berger because you can get them on a consistent basis.
Thanks
why chase the game when the bullet can get em from here?....
Got Balistics?
During a dawn to dusk test with a north facing target we could get 1 ring left and 1 ring right, center (x) target hold at 1,000 yards. We were running a whole series of tests and this set up let us do the lighting shift along with a dozen others. This late in the year, the differences could significant relative to distance without correction.
A week of cleaning would have really irritated me!
Make sure that the factory 20 cases are consistant to one another and that they are reasonably or relatively close to the batch that you have been shooting.
Increasing the powder charge and/or increasing the neck tension does increase the pressure and therefore the efficiency of burn in the cases and barrel. That's a good thing as long as you stay within the limits of the system and a point that I've been trying to make with lots of shooters with regard to reloading. I'm not slighting you at all, just reinforcing the idea.
I don't have any 215 gr. Match bullets on my list nor have I found any to shoot. It could be that Jimmy made a test batch for someone and you got a box. It's hard to say... but Jimmy's out of the business and my impression was every box that was on market got bought up in about 15 minutes after he announced his retirement. Maybe Bob Cauteruccio?
Danzac is Tungsten DiSulfide and silver-grey in color when applied to bullets. If there appears to be a clear coating on your bullets, it's possible that it's Fastex but that usually dries clear without being able to see it at least on the test bullets that I played with a while back.
Best.
I see sierra made it to 95gr's with the 220gr matchking. I know they have a harder jacket, so I am hopeful that the bergers or CR's will let me get to 93grs and hopefully find a harmonic.
why chase the game when the bullet can get em from here?....
Got Balistics?