reloading experts help me here

spinnerbob · 10-17-2005, 06:47 PM

My groups are hitting consistently 4 to 6 inches higher than the factory amo with which I had previously sighted in at 100 yd.

So tell me, does this indicate a higher velocity?

Also, some of the higher powder loads shoot a bit lower on the target. Now is it safe to assume that, despite increasing powder grain, the velosity is less? Would this be because there is an optimum ratio of powder to free air inside the case? I don't get why it's happening.

Any help appreciated.

traks44 · 10-17-2005, 06:49 PM

Alot of factors here. It would help to know what caliber and what bullets along with powder charge. The rifle model as well

spinnerbob · 10-17-2005, 06:51 PM

Quote:

Alot of factors here. It would help to know what caliber and what bullets along with powder charge. The rifle model as well

Savage 30 06

Barnes tsx bt, 180 gr.

IMR 4350 POWDER.

55 gr powder, high group.
55.5 gr powder little lower group.
56 gr powder, little lower.

dla · 10-17-2005, 07:04 PM

Your barrel is whipping. Great example of why people float their barrels.

You are correct about the relationship between velocity and point of impact. However, these half grain increments are going in the wrong direction. One thing you will discover is that there will be a "sweet spot" load where your rifle will shoot "one-hole" groups. But it will be very load sensitive.

traks44 · 10-17-2005, 07:05 PM

With no obvious pattern I am gonna say either barrel heat, or barrel fouling. I shoot my 7mm Remington with handloads and I clean my barrel every 5th shot at the range and you can tell a difference. If you are not waiting very long inbetween shots then heat could be a player as well. The load looks good, same powder I use. I would check scope bases and clean your gun very well and hit the range again. Some days are like that at the range, but I really dont believe the powder differnce can cause that much fluctuation.

I almost think something else might be really wrong to be off that much like you say at only 100 yards.

FireCat · 10-17-2005, 07:11 PM

Just my 2 pesos worth here, depending on factory maker factory ammo normallly shoots slower. Mainly because of all the older guns out there, also bolt action are stronger than lever and automatics,so when a manufacture builts a load they have to take all things in consideration. But if you tailor handload a round for your rifle, it should shoot faster and thus hit higher than normal factory loads, expecially in Magnums. Now with that being said 30-06 has been around a long long time and there are rifles out there that come chambered in every configuration you can think of, prewar europe made, spanish made some are soft ateel and some are ok. so I would imagine that the trusty ole 06, that the factory puts out, is loaded prety light compared what you could do to one. A good friend of mine loaded his pre 64 06 with 57.5 gr H-205 MV WAS APPROX 2850 WITH A 24IN BARREL. with a 180gr Nosler

spinnerbob · 10-17-2005, 07:14 PM

Quote:

With no obvious pattern I am gonna say either barrel heat, or barrel fouling. I shoot my 7mm Remington with handloads and I clean my barrel every 5th shot at the range and you can tell a difference. If you are not waiting very long inbetween shots then heat could be a player as well. The load looks good, same powder I use. I would check scope bases and clean your gun very well and hit the range again. Some days are like that at the range, but I really dont believe the powder differnce can cause that much fluctuation.

I almost think something else might be really wrong to be off that much like you say at only 100 yards.

interesting: I was cleaning every 5th shot, and waiting till the barrel was same temperature between groups. The barrel is free floated. Barring some other explanation, i'm going to suspect the powder variation. The same happpened with the 168 grain bullets. after a certain point, increased powder lowered the point of impact.

It was at the max load, or a grain below it that I had the highest point of impact. None of the groups were too bad, just wondering about velocity. very wierd.

Yeti · 10-17-2005, 07:44 PM

With all due respect to the other posters, where your bullets are hitting with the change in load is not an indication of velocity. It is an indication of when your bullet is leaving the barrel during the harmonic vibration cycle. You can not infer anything about velocity based apon what you are seeing. The POI difference between the factory load and hand load is more likely due to the different burn rates of the powders. The different burn rates set up different harmonic vibration cycles. This is what makes your bullet POI change.

Buy a cheap chrono (@ $85) and your loading will benefit greatly. There is no way to guess the velocity. I have tried and consistantly been proven wrong by my chrono.

Good luck,

Yeti

Maverick Maxcat · 10-17-2005, 08:19 PM

Another factor is recoil. The longer a bullet is in the barrel, the more the rifle will rise in recoil before the bullet exits, leading to "higher" groups with slower loads!

BrianMaguire · 10-18-2005, 08:12 AM

Are the groups fine? You should not care where they are hitting, you should care how the groups look, at least in my novice reloading experience. I speant the last 6 months loading 06 for two Rem 700's. 4350 is a good powder but I found the 180 grain bullets did not perform well. I found 165's and 150's did nuch better.

Are you cleaning for copper fouling? I have one gun that copper fouls pretty bad and it really effects the groups. It is not something you can clean out with a regular cleaning. I have read that you can fire lap a copper fouling gun to reduce this. There are some older threads on this issue.

Hunt'nFish · 10-18-2005, 09:39 AM

Spinnerbob,
Just because they impact higher doesn't mean higher velocity.
I've seen lower vel handloads shoot higher and yes I scratched my head as well. Recoil? I don't think so, the bullets are long gone before the rifle mass even begins to move.
Barrel vibrations? Yes, I think this has something to do with it. We know the barrel vibrates and that the vibrations change as a powder charge (velocity) is changed. I have load eval targets on a relatively thin 26" Browning Mod1876 .22-250 falling block that shows group movement as the powder w/ increased and it took on an hooked eliptical shape with groups moving down as velocity was increased.
I think theres a lot that goes on here. And screwy things happen, but the short of it is the vibration get bigger as velocity goes up.

I also thing that in really fast calibers the 1st & 2nd zeros can get mixed up. Typically in and .30-06 the 1st zero is ~25yds or so and the second zero 100yds, but as velocity increases the 2nd zero moves out and the 1st zero moves more toward 100yds were the 2nd zero was. Taking this to the extreme I can see where I fella can get them mixed up. That's why it really important to shoot at say 300yds to make sure the actual trajectory and the theoritical trajectory are matching up. The .30-378wby of my brothers was a prime example, we chased our tails a bit when we sighted it in in and it was way off the paper at 350 when it should have been dead on. Now when I rough zero at 100yrds I always make sure the bullet is ABOVE line of sight not dead on. If the bullet is above line of sight I know for a fact that the 1st zero is something closer.

I do not think this is your issue though. I think your just seeing the effects of barrel vibration and I wouldn't be concerned. Just because the groops move doesn't mean that accuracy will be better or worse. Most thin sporter weight barrels have at least two sets of sweet velocity points. It's just a matter of finding what they are.
If you take a handload and vary just the powder charge & nothing else and shoot groups of increasing powder charges, you'll see group size vary accordingly. Now take the group size data and graph it as a function of velocity. You see a sinesodial pattern that increases in apmlitude and velocity increases. The points where the group size is the smallest occur when the barrel was fully defelected up/down at the moment the bullet exited the muzzle. Why? Accuracy is at it's best when the barrel moves the least per time, ie. fully defected up or down. Accuracy is at it worst when the barrel at a zero crossing. We are seeing the the fundamentals of calculus at work here.
Do a powder eval in a floated sporter barrel and you'll see what I mean. Kinda cool stuff really. I never do a load eval w/o varing powder in 1/2 to 1gr increments.

I have some very interesting data & graphs for those who care. In general when I work up a handload, I pick my bullet, primer and powder based on manuals, burn rate info, and velocity goals. Then I pick a seating depth, typically .010"-.020" off the lands. Then I load groups of 3-5rds in 1gr increments from Min to max recommended powder charges and then I go shoot them. I start w/ the smallest powder charge and shoot for group, I inspect the cases for traditional pressure signs if I don't have it hooled up the Oehler PBL pressure equipment. I shoot each powder charge on a new target and record all load data on each target. Whe I see the primers start to crater and case heads swell .001", I stop. I then plot the data and let the rifle tell me what it wants. Keep in mind ambient air temp plays a role, so I like to do hunting load evals on 80-90F days to insure safety. Nothing worse than to develop a hot load on a 50F day and then use it in the 100F antelope flats and have case stick the bolt shut. VERY DANGEROUS AS WELL!!
Do all your load eval on hot days. This is another reason why I like big magnum calibers, you don't have to push the throttle on them. Just pick a sweet shooting powder charge even if it is simply moderate pressure wise. If you want to make a 300mag out of an .30-06.... go buy a .300mag.

Your humble ANAL gunsmith and reloader,
Hunt'nFish

-----------------------
Mike Knifong Gunsmithing
Beaverton, OR
ultramag338@yahoo.com

BrianMaguire · 10-18-2005, 11:07 AM

Quote:

Keep in mind ambient air temp plays a role, so I like to do hunting load evals on 80-90F days to insure safety. Nothing worse than to develop a hot load on a 50F day and then use it in the 100F antelope flats and have case stick the bolt shut. VERY DANGEROUS AS WELL!!
Do all your load eval on hot days.
Hunt'nFish

What is your take on the cartridge temperature? Say you have shot 3 rounds, chamber another and take too long to actually shoot it. The cartridge is now in a hot chamber and increasing in temp. I have noticed that it can make a big difference.

Hunt'nFish · 10-18-2005, 01:18 PM

Brian, good point!
Chamber temp can have a BIG impact on what the next bullet will do. Some powders like the newer Hodgon Extreme series are less sensitive to powder temp. I've been using Retumbo in bro's .30-378wby and it seems to be very forgiving. But even it shows some movement at it's 350yd zero after 3 quick ones. (that's how I really like to practice, it's closer to reality anyway.)

If when I'm doing a load eval I wait 2-3min between shots w/ bolt open to keep the barrel at a warm but not hot temp.
Hunt'nFish

Ifishsum · 10-18-2005, 01:26 PM

It does make a difference Brian. It's the powder temp that causes the difference in pressure - I've heard that many competition shooters keep their ammo in a cooler on hot days for more consistent results. Some powders are more sensitive than others - I use Hodgon Extreme powder for my hunting rifles because it's not supposed to be as affected by temp.

I actually have a winter load and a summer load for my .204!

spinnerbob · 10-18-2005, 02:34 PM

So I've heard a lot of "No's" on the velocity raising the point of impact, saying it's probably "barrel vibration." And yet, what are the odds that the variation is almost exclusively up and down, not left to right??? Most (almost all) of the shots were close to dead center in the left/right context. The higher powder charges just hit lower.

wouldn't vibration have an equal chance of moving it left or right?

Recoil sounds like a possible explanation, but I'm hearing some "No's" on that score as well.

This is odd.

Are there any ranges where you can pay a couple bucks to shoot past a chronograph? Near Eugene?

Ifishsum · 10-18-2005, 02:51 PM

If you've only tried one bullet and powder, I wouldn't consider it strange. A different bullet or powder would probably be different, and that could be up/down or left/right. When working up a load I don't use a chronograph - I don't even pay attention to where the bullet prints. I'm after the consistently best group. Once I settle on the load, I adjust the scope to correct POI. The idea is to find the sweet spot then duplicate it - once you've found it for that bullet/powder combination, it doesn't really matter where it is in relation to other loads IMO.

alaskan · 10-19-2005, 08:18 AM

Ifishsum, the chrono will help you find the loads that have the least variation in velocity, and that will be the most accurate. The chrono will tell you if you pulled a shot and amde a good load look bad or a bad load look good. I can't even imagine doing a load workup with out one anymore.

Ifishsum · 10-19-2005, 09:11 AM

I agree with what you're saying-it can be an excellent tool but many people focus too much on the actual velocity instead of the SD and end up loading for speed instead of accuracy. I've only been loading for 3 years and I didn't want to fall into that mindset so I've avoided one so far. I'll likely get one within the next year, mostly to analyze and tweak the loads I've already had good success with.

Pulled a shot? What's that?

alaskan · 10-19-2005, 12:32 PM

While I agree most people get hung up on speed, trying for the fastest bullet speed and falling in love with that load, consistent shot to shot velocity is what you are after, and the only way to see that is with a chrono. You will only have good accuracy if you have consistent velocity.

Hunt'nFish · 10-19-2005, 01:46 PM

Your 100% right, velocity is not everything....
but it is darned important to us hunters.
Normally a 1/4 or 1/2moa rifle kills just as dead as a 1moa,
but speed (ie. energy) is just as important.
Like I said, that's why I like magnums, you don't have to hotrod them to get your speed.

Low SD's are nice and a measure of good powder choice and handloading skills, but it does NOT mean it will shoot the better than a load with a higher SD. Like I said if you vary powder charge (even if they all have low SD's) accuracy will vary up and down as a function of barrel position/defection. In most hunting rifles a 30-40fps SD is nothing, and doesn't detract from accuracy one bit. Now in a HB benchrifle were goups are measured in .001 of inch, yes it does matter.

I still content he's just seeing barrel vibration affects.
Think about it. He's seeing how many inches of movement?...3" or so? Velocity, meaning drop, can not account for that mathmatically. However if you defect the barrel .010" to .020" of an inch, it can result in a lot at 100yrds. ie. .010"/24" = X"/100yrds... answer: .5"...WOW, that's not that much. Maybe there's more going on that I think.
There was a fella by the name of Mann that did a lot of work on bullets in flight around the first part of the 1900's and after I read his work, it became obvious that screwy things happen to bullets that very, very few people understand, and I gave up trying to. Proof is on the paper and we just react, and roll with it.

I will say this I have a fully bedded Rem700 w/ glass clear up the barrel channel and it doesn't vibrate very much at all. It shoots just about every load regardless of bullet weight & speed in to the small spot. However because it is a wood stock, I feel it "could" be suscepable to warpage w/ the seasons. It's sealed real well and doesn't seem to shift, but it's always been ing the back of my mind. I've chosen not to free float it because it's a .338 and I may shoot 200's in it one trip and 250's another and having it shoot to the same point is convienent.

Hunt'nFish

slowbuilder2005 · 10-19-2005, 06:50 PM

Quote:

[snip]Are you cleaning for copper fouling? I have one gun that copper fouls pretty bad and it really effects the groups. It is not something you can clean out with a regular cleaning. [snip]

The best way to avoid copper fouling is to stay ahead of the problem from the start. That said, give the rifling a good soak with Sweets 7.62, wet it again and let it soak again. Brush then run a swab through it. Repeat the whole process until no more blue shows up on the swab. When you are done, clean with normal solvent and lightly lube like always. THEN stay ahead of it and clean before shooting too many bullets through it. Many guns will break in and foul less over time too.

Good luck,
Brian

PS: And wear a gas mask ...ammonia fumes are nasty. I just open the garage and the back door to the garage so I can get cross ventilation and I stay upwind...