Hunting Washington Forum

Equipment & Gear => Guns and Ammo => Topic started by: 7mmfan on February 14, 2020, 02:36:24 PM

Title: Finding good "node"
Post by: 7mmfan on February 14, 2020, 02:36:24 PM
As I continue my quest to develop a load for my 7mm-08 that even vaguely resembles the accuracy I get in my 7 mag, I've come across this term several times. Many use it like a common term we should all just know. In my research, I've developed a rudimentary understanding of it, the idea of timing the exit of your bullet with harmonics that reach the end of your barrel at, or at nearly, the same time allowing the least amount of deviation of the bullet leaving the barrel, allowing for the best accuracy.

There appear to be methods of determining this without gross amounts of shooting and testing. Does anyone have any experience with this?
Title: Re: Finding good "node"
Post by: Alan K on February 14, 2020, 03:22:51 PM
QuickLoad seems to get me in the ballpark when first starting development, then I fine tune from there.
Title: Re: Finding good "node"
Post by: 7mmfan on February 14, 2020, 03:27:19 PM
Quickload is a program that you need to purchase correct?
Title: Re: Finding good "node"
Post by: Magnum_Willys on February 14, 2020, 03:29:52 PM
https://www.6mmbr.com/laddertest.html (https://www.6mmbr.com/laddertest.html)

Good review of shooting a ladder, and Optimum barrel time.

https://www.6mmbr.com/Quickload.html (https://www.6mmbr.com/Quickload.html)
Quickload tips
Title: Re: Finding good "node"
Post by: Magnum_Willys on February 14, 2020, 03:35:29 PM
Quickload is a program that you need to purchase correct?

Yes, but it won't tell you much until you accurately measure your fired case volume ( weight the water it holds) and accurately measure your average velocity from a couple fired rounds.  Then with this data and measurements of your cartridge and bullet you can start getting educated what-ifs as you change powder.  To develop an accurate load with it you must subscribe to the optimum barrel time theory that suggests your node is reached at a specific time the bullet is in the barrel based on barrel length.  Quickload gives you that time - adjust your load so the two times meet and viola ! Instant accuracy.   If only it worked so easy - but sometimes it does.   Usually if you are new to it you get a good load dialed in after a few hundred rounds because you get to be a better shooter by then - was it you or the load?   
Title: Re: Finding good "node"
Post by: 7mmfan on February 14, 2020, 03:45:43 PM
Well i'm to the point that most of the time I'm convinced it's the load or the rifle because I can shoot exceptionally accurate groups in other rifles. This one rifle has me trying to think of ways to streamline my process for developing a load for it because thus far, I've had no luck.
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 04:03:18 PM
If it just wonít shoot try some other components, bullets or powder.
Title: Re: Finding good "node"
Post by: 7mmfan on February 14, 2020, 05:24:50 PM
I've tried all kinds of components, thats the problem. Different bullet/powder combos, different primers, seating depths, etc... best I've gotten is 1.5" group. I'll admit though, I've bounced around a bit while trying those different things and I'm trying to streamline my system to make it easier to track and find good combos. What I read was guys using these OCW and OBT methods for finding node and load options. I just struggle with paying for the system. Probably worth it for my time in the long run though.
Title: Re: Finding good "node"
Post by: Karl Blanchard on February 14, 2020, 05:36:28 PM
It's really hard to give advice on hand loading because without seeing your process it's really hard to say one way or the other. One thing I will say is it's really hard to get sub moa accuracy out of a 1.5 minute rifle. Point being, all guns aren't accurate. Rifles are a dime a dozen. If it isn't up to standards sell it and get a different one. If you have shot that much and it's still not giving you positive feedback with changes then off that sucker.

As someone who has been guilty of this in the past, do not jump around! Its impossible to collect data when you aren't making calculated changes and adjustments :twocents:
Title: Re: Finding good "node"
Post by: buckfvr on February 14, 2020, 05:36:42 PM
what rifle is it ?
Title: Re: Finding good "node"
Post by: 7mmfan on February 14, 2020, 05:45:12 PM
It's really hard to give advice on hand loading because without seeing your process it's really hard to say one way or the other. One thing I will say is it's really hard to get sub moa accuracy out of a 1.5 minute rifle. Point being, all guns aren't accurate. Rifles are a dime a dozen. If it isn't up to standards sell it and get a different one. If you have shot that much and it's still not giving you positive feedback with changes then off that sucker.

As someone who has been guilty of this in the past, do not jump around! Its impossible to collect data when you aren't making calculated changes and adjustments :twocents:

I'm not quite ready to give up on it yet, but I am trying to create a system so I stop jumping. I have other members involved holding me accountable.

It is a Remington Model 700 Mountain Rifle, 7mm-08. Not a cheap rifle.
Title: Re: Finding good "node"
Post by: buckfvr on February 14, 2020, 05:50:47 PM
So I am inclined to believe that normally, you would have better results from this rifle model, but since it seems to be a problem, I am throwing in with Karl and suggesting you off that sucker........ I dont think its you or what youre doing.
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 05:51:24 PM
I hear of people shooting a ladder and watching for velocity flat spots or different powder charges that group together well. I donít think Iíve ever seen it. I will shoot a ladder over a chrono to find pressure and look for a good velocity range. Once I know that Iíll work with seating depth for accuracy.

This group was 10 rounds over a chrono, all of them different powder charges ranging from 2750 to 2950 FPS. Maybe if I shot much further I would notice shots grouping together but I donít have a range where I can set paper past 200 yards. Also this rifle shoots everything (except nosler rdf) very well so I basically just worked for velocity.
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 05:55:03 PM
Iíll also agree with Karl and buckfvr. Some guns just donít shoot like others. You can try things like bedding, or triggers etc to help it but thatís potentially pouring money into something that just isnít going to work. Offloading it and getting something different may not be a bad option, or having it rebarrelled, or the option is always there to just get it shooting as well as you can and quit shooting groups with it. 1.5 moa would serve well as a hunting rifle for moderate ranges.

Does anyone know if there is any factory 7-08 ammo that just shoots well in lots of rifles? It might pay to try something like that to see what the gun is capable of?
Title: Re: Finding good "node"
Post by: Karl Blanchard on February 14, 2020, 06:04:13 PM
I hear of people shooting a ladder and watching for velocity flat spots or different powder charges that group together well. I donít think Iíve ever seen it. I will shoot a ladder over a chrono to find pressure and look for a good velocity range. Once I know that Iíll work with seating depth for accuracy.

This group was 10 rounds over a chrono, all of them different powder charges ranging from 2750 to 2950 FPS. Maybe if I shot much further I would notice shots grouping together but I donít have a range where I can set paper past 200 yards. Also this rifle shoots everything (except nosler rdf) very well so I basically just worked for velocity.
spot on. I run up to pressure, look for a flat spot then tune seating depth. If you have a full grain spot where you are only 15-20fps in difference your load is gonna be a bit more forgiving. If your rifles accuracy isn't getting better or reacting to changes with different adjustments it very well could be a rifle issue. Especially since it's a rem 700.

This was a 15 shot ladder test with a 300 win and n570. Not a ton of data so I started low. Not much to gain there besides chrono data which I feel is most important. One thing it does tell me is seating depth should be left alone.
Title: Re: Finding good "node"
Post by: Karl Blanchard on February 14, 2020, 06:05:38 PM
This is a RUM ladder test from last weekend. Distinct POI shift once it jumped over 3,000fps but that was about the only noticeable reaction
Title: Re: Finding good "node"
Post by: 7mmfan on February 14, 2020, 07:58:30 PM
I did the same last weekend and ended up getting the 7 mag 100% dialed. Of 6 loads they started wide, tightened up to this and then began opening up again. I reloaded some more fine tunes loads on either side of the good group to make sure it's got some stability around it.

Just trying to get to this with the other one. I'll keep at it.
Title: Re: Finding good "node"
Post by: Magnum_Willys on February 14, 2020, 08:21:53 PM
I donít shoot under 300 yards.  A good load at 100 just doesnít tell me much other than the rifle has potential.   Positive compensation (good) looks worse at 100 yards and the long heavies may not be stabilized.
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 08:35:22 PM
I donít shoot under 300 yards.  A good load at 100 just doesnít tell me much other than the rifle has potential.   Positive compensation (good) looks worse at 100 yards and the long heavies may not be stabilized.
If the bullets arenít stabile at 100 yards they wonít be stabile any further.
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 08:39:31 PM
Iíve a 6.5, shoots better at 200 than 100....
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 08:42:45 PM
It is impossible for a group of bullets to consistently converge as distance increases.
Title: Re: Finding good "node"
Post by: h20hunter on February 14, 2020, 08:43:02 PM
So maybe group the heavy rounds for that gun at 220? Fyi, that's the max we can run em at my range.
Title: Re: Finding good "node"
Post by: Jonathan_S on February 14, 2020, 08:46:02 PM
Iíve a 6.5, shoots better at 200 than 100....

Sound to me like that 6.5 has a shooter that is better at 200  :tup:
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 09:02:54 PM
Impossible huh, better at 200 than 100???  Copy that
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 09:04:16 PM
Impossible huh, better at 200 than 100???  Copy that
Thereís this little thing called physics...

Can you explain how your gun shoots better at 200 than 100 all the time?
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 09:07:25 PM
Numerous guys, and smiths have experienced the same thing. I wonít argue with you, as it appears with the whitetail conversation, is what you wanna do...
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 09:09:49 PM
Numerous guys, and smiths have experienced the same thing. I wonít argue with you, as it appears with the whitetail conversation, is what you wanna do...
Just a simple question... no arguing.
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 09:16:43 PM
Dunno what to tell ya , I've a Pac Nor barreled 6.5 that shoots 140 vlds at 11\4" , 1 1\2" at 100, and 3\4" at 200. What ya shaggy  doo?? Will scooby call bs? Why would I lie?
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 09:26:35 PM
Iím not calling you a liar. If in fact that is the case it is caused by something with the shooter or optic. Bullets donít have a brain to know where to go back to to be on target after firing. Once that bullet leaves the barrel it is set in that direction, save for external forces (wind, gravity, etc).  it canít miraculously move toward the bullseye unless the wind happens to push it there or gravity takes it there.
 
I can say that sometimes I shoot better groups on a lower magnification setting than I do at higher magnification. Itís not that the gun shoots better at lower magnification, but more likely that I just aim better at lower magnification.
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 09:35:20 PM
Gotcha guess I'm Being rude, so says dale, I won't respond or have a constructive conversation.
Title: Re: Finding good "node"
Post by: Magnum_Willys on February 14, 2020, 09:37:40 PM
I can shoot 1Ē groups at 100 yards and 1.5Ē at 300.    Few people see smaller actual groups at distance but its common to see smaller moa at 300 vs 100 with long bullets that do take a bit to stabilize.  You wont see this with standard bullets just the 300 grainers or maybe long 230ís. 
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 09:40:48 PM
I can shoot 1Ē groups at 100 yards and 1.5Ē at 300.    Few people see smaller actual groups at distance but its common to see smaller moa at 300 vs 100 with long bullets that do take a bit to stabilize.  You wont see this with standard bullets just the 300 grainers or maybe long 230ís.

Oh you've done it now!!! Haven't you heard of physics????????  Yes, you are correct, thank you
Title: Re: Finding good "node"
Post by: Jonathan_S on February 14, 2020, 09:46:19 PM
How do bullets hone in to center after they stabilize downrange?
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 09:48:41 PM
I can shoot 1Ē groups at 100 yards and 1.5Ē at 300.    Few people see smaller actual groups at distance but its common to see smaller moa at 300 vs 100 with long bullets that do take a bit to stabilize.  You wont see this with standard bullets just the 300 grainers or maybe long 230ís.
The ďI can shootĒ is the important part there. It is not that the gun is more accurate at longer distance it is that you, the shooter are doing something different. Maybe you concentrate better at longer distance? Or parallax is less? Something like that. If you could set up a target at 100 and shoot through that target to one at 300 I can assure you that the group printed on the 300 yard paper will not be a smaller angular dispersion than that of the 100 yard target. There is just no way that a bullet knows where it needs to ďsettleĒ in to. Once that bullet leaves the muzzle it is set in that direction until an outside force affects it.
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 09:59:33 PM
What's the answer then? Faster twist?
Title: Re: Finding good "node"
Post by: Magnum_Willys on February 14, 2020, 10:01:56 PM
It may be positive compensation, stabilization, parallax or just a finer crosshairs at distance but regardless I find load development at 300 yards to be more applicable to long distance load development than shooting at 100 yards.    Iíve had loads that one-hole at 100 that were much worse at 1000 than loads that were not as good at 100.   
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 10:04:59 PM
Truth willys...
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 14, 2020, 10:08:48 PM
I wonít disagree that testing loads at a greater distance is better. Iíve seen some very small 100 yard groups that wouldnít shoot for crap at further distances. Take the group i posted earlier in this thread for example. Almost 200 FPS velocity spread still grouped sub moa at 100.
I just donít buy that a further target can consistently have a smaller angular group for the same shots fired.
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 10:10:33 PM
Triple digit spread??? Wow
Title: Re: Finding good "node"
Post by: Cheif on February 14, 2020, 10:11:46 PM
200 fps at that??? Good god!!! What powder???
Title: Re: Finding good "node"
Post by: BULLBLASTER on February 15, 2020, 06:28:42 AM
200 fps at that??? Good god!!! What powder???
It was a ladder working up from fireforming to full load in an Ackley improved chambering. Using h4895 the last time I chronod my finished load I had an es of 12 over w
10 rounds
Title: Re: Finding good "node"
Post by: jasnt on February 15, 2020, 08:18:55 AM
Iíve heard many different people talk about better grouping at 2-300 that one hundred. Brian litz talks about this in his book. Yaw typically from bullets not be spun fast enough at the muzzle but rpm speed degrades slower than velocity.  Never seen it my self as I always go with ďtoo fast of twistĒ.

When I start load development I start with seating depth and a low charge.  Load in increments from mag length or .015Ē off in .030Ē steps
Choose the best one and shoot over the chrono and find the velocity flat spots.  Fine tune seating depth in .005Ē increments if Iím not happy already.   

Maybe Iíve been lucky but Iíve never not found a 1/2 moa load in any rifle Iíve loaded for except for the rifles that I had burned out the barrel. 

Some folks have warned me going too fast twist can blow up bullets but I have yet to see it my self.  Recently I worked up a load in my 7 twist 243 and 62gr Berger target bullets at 3960.   They shoot great even at 735 yards.   Also played with a few 58gr vmax at over 4K and they hit the 400 no problem.   

Jme
Title: Re: Finding good "node"
Post by: wooltie on June 05, 2020, 01:22:42 PM
I had a m70, stock barrel that wouldn't group less than 1.5"  Even sent the gun to winnie to have the barrel evaluated.  They evaluated and lapped the barrel, sent it back to me.  No change in performance.

I swapped the barrel for a benchmark.

Kept everything the same - rifle stock, bullets, powder, shooting rests -- and the gun shoots moa or better now.

FYI I use Jason's method to find a load.  Works great.