fastest way to develop a load

[dmax1800]

I've spent a lot of time, powder and bullets developing a load for a Win M70 300 Win mag and now I find myself spending a lot in developing a load for a Win M70 270 Win. I've tried ladder tests, but they were inconclusive because I apparently was at a bad seating depth. I've tried OCW testing, but the results were often not repeatable. I've tried incremental powder charge testing with 3 shot groups with different powders, different bullets and different seating depths. But again results were not repeatable. I shot over 600 rounds thru the 300 WM before I finally found a good load (5/8" groups at 100 yards). I've shot over 500 rounds so far with the 270 and still haven't found a good load; 3/4" or better.

Is there a better way to develop a load???

 

[Mikecr]

While fireforming brass, run Berger's seating depth test.
Once brass is fully fireformed(with zero FL sizing), size the brass as you intend, and shoot a ~300yd ladder with seating that seems best from earlier testing.
This should get you from coarse to fine tuning across the board.

 

[wbm]

I've shot over 500 rounds so far with the 270 and still haven't found a good load; 3/4" or better

Sounds like you have pretty much covered the types of load development tools that are the most popular. What rifle are you shooting in the 270?

My experience has been that a 270 that will not shoot a 130gr bullet good with Reloader 22 it isn't likely to shoot anything really well. It's like they were made for each other. There are exceptions of course and it is certain some wadi will come along and say it ain't so but it is so the majority of the time. After 500 rounds I think it is time to rethink that barrel. However if you still want to give it a go I would pick one 130 bullet and one powder RL-22 and work with it.

 

[shawnb]

I had the same problem, or so i thought. I gave up testing at 100 yards and stretched it out to 300+. That proved to show more than the 100 groups.

 

[dmax1800]

What rifle are you shooting in the 270?

The 270 is a Winchester model 70 featherweight with a wood stock and pencil barrel. I've had the bolt lugs lapped, recrowned, barrel hand lapped, trigger blue printed and set to 2 1/2 pounds. It still has the factory bedding for the stock (almost non existant) and recoil lug. I'm going to try some thin cardboard between the barrel and the forearm to apply a slight amount of up pressure on the barrel to see if that will calm down the "whippyness" of the barrel.

 

[wbm]

Some Winchester and Remington sporter barrels do like a bit of forward pressure. I had a sporterized Springfield 1903A4 with a Fajen walnut stock that was doing like your Winchester. I bedded the action and tried lots of load combos. Finally I used a piece of rubber from an old inner tube on the forend and it shot a LOT better. What the heck it's worth a go....you can always remove the shim.

 

[dmax1800]

While fireforming brass, run Berger's seating depth test.

2 problems: 1) I'm not using Berger bullets. 2) Because of the ejector blade, I'm limited to OAL of about 3.330 which is about 122 thou off the lands if I want the second round to chamber. The Berger seating depth test goes out to 130 thou off the lands. Again its trial and error finding a seating depth past 122 thou that works well.

Thanks for the suggestion anyway.

 

[BountyHunter]

First off, IMO thinking a factory featherweight barrel with questionable bedding is going to give 3/4" or better "consistently" is a stretch by a longshot!

You have fallen into the trap of fabled internet super accuracy for a factory gun and "all I have to do is keep testing loads" to find the super group.

The barrel is whippy because it is a mass produced factory pencil thin barrel that was never made to shoot 5/8" groups and that is not going to change with forend pressure either.

You have a consistent 1"- 1/1/2" gun and my bet is you have done that repeatedly with multiple loads. We are talking about a lightweight big game hunting rifle, not a heavy barreled varmint rifle.

Just how far do you plan on shooting that the 1 1/4" groups that you probably found dozens of times will not work?

To put this in perspective, you might have even a 1 1/2" group gun that you are not going to shoot over 500 yards absolute maximum with that rifle at a deer with an 18" chest. So you have a 7 1/2" vs a 4 1/2" group on an 18" target and that will not work?

You have shot out half the barrel on each gun at a cost of over $500 (materials cost) between the two and what is the return?

Most factory rounds and rifles pretty much allow you to do a little research on powders and bullets and narrow it down to 2-3 or less on each that will work and give you acceptable accuracy levels for a "factory gun" and light barrel.

First have realistic expectations. Many of the 1/4" internet groups you hear about are one out of 10 groups and not repeatable time after time. Custom guns and barrels different story.

However, if you want to continue testing.

Shoot two rounds at various combos over a chrono to see if they will group and in the desired MV range will do for starters. Minimum of 200 yds and 300 is better.

It is a little known secret that if two shots do not group, shooting three more will not tighten the group up! Do not waste time, powder and bullets.

Take a reasonably working combo and run the seating depth checks (start at max COAL for the magazine) to find the best depth with that bullet and then go back and tweak the powder charge to an acceptable realistic accuracy level at the desired MV based on what the nodes are for that powder and MV as shown by the targets and chrono data.

If you did not use a chrono on the ladder and OCW, and shooting at more than 100 you are just was wasting $ and time. A chrono gives you as much information or more and even Newberry (OCW founder) has come to realize that since he started when he said a chrono was not necessary.

You have so many issues here and the first thing that should have been done has not been (ie fix the bedding). Poor bedding and you will never get consistent groups.

I can go on and on to issues with cleaning, proper torque on actions screws, improper bedding pushing on barrel and action etc.

 

[wbm]

What Bounty Hunter said. He is telling you right!

 

[royinidaho]

Yes, bountyhunter's post was a bit lengthy but you got a good truthful full meal deal.

Going through that many shots is about 425 too many for either rifle.

I've seen the Win featherweight in '06 shoot sub 1/2 MOA on a regular basis with 168s and 180s. But that's the only one.

122 thou jump!! You may wish to build a bridge in there.

I'd consider shooting single shot.

Another option would be to skim bed the action, both ends, and the barrel to about 3 1/2" ahead of the recoil lug. If that turns out to be going in the right direction but not yet good enough glass to the end of the fore end.

If the first portion of the barrel being bedded doesn't move things in the right direction I'd give up. Really.

 

[trucraft]

First off, IMO thinking a factory featherweight barrel with questionable bedding is going to give 3/4" or better "consistently" is a stretch by a longshot!

You have fallen into the trap of fabled internet super accuracy for a factory gun and "all I have to do is keep testing loads" to find the super group.

The barrel is whippy because it is a mass produced factory pencil thin barrel that was never made to shoot 5/8" groups and that is not going to change with forend pressure either.

You have a consistent 1"- 1/1/2" gun and my bet is you have done that repeatedly with multiple loads. We are talking about a lightweight big game hunting rifle, not a heavy barreled varmint rifle.

Just how far do you plan on shooting that the 1 1/4" groups that you probably found dozens of times will not work?

To put this in perspective, you might have even a 1 1/2" group gun that you are not going to shoot over 500 yards absolute maximum with that rifle at a deer with an 18" chest. So you have a 7 1/2" vs a 4 1/2" group on an 18" target and that will not work?

You have shot out half the barrel on each gun at a cost of over $500 (materials cost) between the two and what is the return?

Most factory rounds and rifles pretty much allow you to do a little research on powders and bullets and narrow it down to 2-3 or less on each that will work and give you acceptable accuracy levels for a "factory gun" and light barrel.

First have realistic expectations. Many of the 1/4" internet groups you hear about are one out of 10 groups and not repeatable time after time. Custom guns and barrels different story.

However, if you want to continue testing.

Shoot two rounds at various combos over a chrono to see if they will group and in the desired MV range will do for starters. Minimum of 200 yds and 300 is better.

It is a little known secret that if two shots do not group, shooting three more will not tighten the group up! Do not waste time, powder and bullets.

Take a reasonably working combo and run the seating depth checks (start at max COAL for the magazine) to find the best depth with that bullet and then go back and tweak the powder charge to an acceptable realistic accuracy level at the desired MV based on what the nodes are for that powder and MV as shown by the targets and chrono data.

If you did not use a chrono on the ladder and OCW, and shooting at more than 100 you are just was wasting $ and time. A chrono gives you as much information or more and even Newberry (OCW founder) has come to realize that since he started when he said a chrono was not necessary.

You have so many issues here and the first thing that should have been done has not been (ie fix the bedding). Poor bedding and you will never get consistent groups.

I can go on and on to issues with cleaning, proper torque on actions screws, improper bedding pushing on barrel and action etc.

What he said.lightbulb

 

[Gary Kaney]

I have the same issue with a Sako 75 in 260 Rem. The bedding is ok, but mag. length is .150 off the lands. It just won't shot consistant. Going to bore scope it this weekend. .150 seems a bit far to me. Just bought it and the guy said he only put 250 rds. through it.

 

[Greyfox]

I also agree with bounty hunters post. I owned a Model 70 Featherweight in 270 and have a few friends that own the same rifle. While I'm sure there are claims of rifles that shoot bug holes, it's basically a carry rifle that shoots .75-1.0MOA. It will generally do it do the first three shots from a cold bore that has been fouled. it tends to shoot better with forward tip pressure on the thin barrel, but the factory stock's forearm design where tip pressure is applied as well as the bedding needs to be checked. The forearm has a smallish pressure point that can cause variable pressure and effect accuracy and zero. I removed it with sandpaper and replaced it with an epoxy pad that was applied once I determined the required thickness using shims. Mine definitely shot better and maintained it's zero with pressure on the tip. The factory injection epoxy used in the lug recess and rear tang is generally ok but should be checked for good contact. Hand loading is no mystery with this rifle. Standard style hunting bullets like the Nosler Accubond/Partition in the 130-150 gr range using published powder charges of IMR4350 or H4831 should get you the accuracy/velocity potential of this rifle. Mine served me well for years with kills from 50 yards to 400 yards. Then I got bit with long range with long range shooting.....................

 

[dmax1800]

First off, IMO thinking a factory featherweight barrel with questionable bedding is going to give 3/4" or better "consistently" is a stretch by a longshot!

You have fallen into the trap of fabled internet super accuracy for a factory gun and "all I have to do is keep testing loads" to find the super group.

I very carefully read and "listened" to what you said and I'm going to take your advice to heart. I am going to relax my accuracy expectation on my 270 and call it good for 1 1/4" to 1 1/2" consistently, which I think it will do. The funny thing about my 270 is that when the barrel is warm (at least 3 shots), it will shoot 3/4" or less. With a warm barrel, I hit a 5"x7" steel gong at 450 yards 90% of the time.

Thank you very much for candid view. I'm new to shooting and reloading. I did get caught up in the accuracy bug. I started by wanting my elk rifle (300 win mag) to be a 3/4" rifle so that it would shoot a 4" to 5" group at 400 yards so that I would have a little wiggle room on an elk. And I have finally done that, but it took A LOT of rounds and a lot of learning to get there.

I'm going to retest 2 of my most accurate powder/bullet combinations and test if some up pressure on the barrel will help with consistency. I'm also going to look into having the action bedded.

I'll post my results as soon as I get them.

BountyHunter, thank you again for setting me straight.