>270 Win/243 Win Load Development Advice

[Natty270]

I am new to this forum and to hand loading. Before my Dad's best friend passed away, he gave me a RCBS press and his older Speer book and really encouraged me to get involved. I had already reloaded shotgun shells, but not Rifle. Since, Ol Jimmy passed and as a result I got his press set up and now i'm really enjoying the process of hand loading.

I started a year ago, did a lot of reading, and have developed a few loads for my 270 and 243. The loads are for hunting and 2019 results were positive.

I took the advice of folks on the forums and worked up multiple loads starting at Minimum in Jimmy's Hornady 5th edition and the old Speer Book.

The two 270 loads that worked the best out of my Abolt Medallion Browning 270 win were:

1. 58gr IMR4831 Hornady Cases CCI200 (above Max Load in Hornady V5, but Speer Book shows 58gr)-Hornady 130 Gr Interlock

2. 55.6gr H4831sc Hornady Cases CCI200-Hornady 130 Gr Interlock

Jimmy hand loaded for .243, so I picked up a Browning X-Bolt Hunter and worked up a couple loads for this rifle as well. Jimmy used RL-22 43.4/44.4

1. 40.9 IMR4831 Hornady Cases CCI200-Hornady 100 Gr Interlock
2. 42.5 H4350 Hornady Cases CCI200-Hornady 100 Gr Interlock (can't find H4350 right now)

I worked up some loads with RL-22 in the name of Jimmy as his notes were in his book, but have not shot them yet..43.4, and 44.4-Hornady 100 Grain Interlock.

My results at 100yards with the loads I listed were sub moa, but from what I read, I can even get more accurate by adjusting OAL.

I feel like i'm on the right track and have really enjoy this new world of reloading and developing accuracy I haven't realized before in my rifles.

Thanks for taking the time to read my first post, and for your responses.

Any added advise you can add is greatly appreciated.


Nate

[hooligan1]

If you can get accurate and consistent measurements from case head to ojive, that would be a start.
Some of the fellas here, like myaelf use Hornady's LNL comparators for that.
What you are actually measuring is bolt face to the lands on a closed bolt, other words BTO or base to ojive..
Coal is overall length which doesnt tell you where the ojive of the bullets sets off the lands.
With the Hornady tool, you use modified cases and can get accurate measurements from any bullet you want to load.
I tend to start with a. 010 jump, and try a median powder load, and shoot a 3-5 rnd group, if its not decent, try. 020 off, you may find moving the jump in larger increments will get there faster.
It depends on the barrel and what it wants, sometimes a long jump, sometimes it likes to be close, you have to test and find the sweetspot.

[hounddawg]

a video is worth 1000 words, spend a half hour so of your life watching and they will cover the subject pretty in depth

https://www.youtube.com/watch?v=RDoJWZXQMjg
https://www.youtube.com/watch?v=e7bo_QmyOJw
https://www.youtube.com/watch?v=EtLAmANcywI

[Natty270]

I realized that and edited the post. Thanks

[ReloadKy]

Welcome to the forum, it is a great place to learn and bounce ideas / possibilities off of others. I myself started reloading the same two calibers as you. Now I am addicted to the point where I am trying to add a 7th rifle to my safe so I can reload for it!! Have fun, be safe and enjoy the process!!

[Natty270]

Thanks for the quick responses. I really appreciate it.

I'm going to continue to hone my skills with your assistance.


Looking to try different bullets and see the results. 270 Nosler BT, Nosler Partition, SST are already worked up. 7mm Rem mag also has rounds ready for shooting.

Thanks again fellas

[Colorado Redneck]

Load data and manuals are a great thing. I would recommend getting a recent edition of a Hornady book. Since you are loading their bullets, that would furnish the data and the components used by the development staff at Hornady. The Nosler manual also provides a great description of the process determining the most accurate COAL. Components are a variable that can affect the performance of a load, and starting with the same brass, primer and bullets as described in a manual is a safe way to begin a load. For example, I found that Federal cases in 243 Win. yield high pressures than Winchester, and caused pressure signs like very flattened primers at lighter charges. An additional bonus is, you can get addicted to trying new powders, lighter or heavier bullets, different cartridges that leads to more guns that require additional dies and bullets and other powders....and on and on ya go.

[Unclenick]

I'll add my welcome to the forum.

One thing to be cautious about is that load data can become obsolete. Almost all primers have changed starting about 1989 through the following decade. Several popular powders, like Varget, had burn rate variation complaints in the '90s that was fixed in the early 2000s, but I wouldn't know what burn rate old data was actually developed with. IMR powders all began to be made by changed processes around 2010 and on, and while they seem to be pretty consistent with the older stuff, you just don't want to assume that, so new data is better.

Fortunately, today you are able to look up a lot of current load data online without buying books (they have other things worth reading, but just for data they are not necessary). Check the sticky on this forum for lists of online load data sources. Hodgdon and Alliant and Western Powders all have broad load data that has been pressure tested. The advantage to using powder makers as the data source is they know the powder they develop loads with properly represents their targeted specifications. The downside is you see limited bullet selections in it. Bullet makers also publish load data, but you never know if their lots of powder were on the slow or fast side of specifications, so you get more bullets, but less certain charge weight.

[T. O'Heir]

58 grains of IMR4831 is 2.2 over the current Hodgdon Max too. Variations in manuals can do that. Hodgdon used a 24" 1 in 10 barrel.
H4831sc uses the same data as regular H4831. Your 55.6 grains is slightly below Hodgdon's minimum. Variations in manuals can do that too.
42.5 of H4350 for a 100 grain .243 is 2.5 over Max. The H and IMR4350(been using that for eons with 90 and 105 grain bullets.) are very, very close(#117 and 115 respectively. The new IMR4451 is #116. And is supposedly more temperature stable.) in burn rates but are not the same.
The 40.9 of IMR4831 is a mid range load that's closer to Minimum than Mid.
"...by adjusting OAL..." That is true, but it's also a 100% trial and error thing(there is no math formula) that really isn't necessary. Especially since you're already under an inch.

[Natty270]

Thanks for the info T.

I don't have a chrono yet, and I obviously need one so I can measure the fps of my rounds.

I'm a bit concerned now about the safety of the 58 grain rounds. There were no signs of pressure issues from my limited knowledge.

I have seen multiple posts where fellas are loading that same bullet, and trust the old books. They discuss how attorneys have gotten more involved in the newer publications due to liability issues??

I also read about how the powder has changed over the years, and I get that aspect of it too.

I have quite a few rounds of the IMR 4831 loaded in the 58 grain load. Should I reconsider shooting these rounds out of my rifle? They are very accurate, but I don't have to shoot these rounds if they have the potential to do undo damage to my rifle. I have seen the term "barrel burner". I'm not sure if that would apply here or not? I do enjoy shooting, but these rounds are for hunting only.

Im going to get some new books. I'm using the Hornady 4th Edition (given to me) for the load data for my 270 and 243 with exception of the 58 grains of IMR 4831 in the .270, I got that data out of the Speer #10 Manual. The Speer book was my first reloading manual, given to my by my Dad's best friend. I read it from cover to cover.

I appreciate the members in this forum for their generosity and willingness to share their wealth of knowledge.

[Unclenick]

I have seen multiple posts where fellas are loading that same bullet, and trust the old books. They discuss how attorneys have gotten more involved in the newer publications due to liability issues??

The problem isn't attorneys, except to the extent they recommend not publishing loads the pressure has never been measured for. The old load data was often developed in a production firearm by the pressure sign method alone and never pressure tested. If your gun was more lightly constructed or your chamber had tighter tolerances or your bore was a little narrower than the manual author's particular test gun, or, especially, if you used brass that was a little softer than theirs, you could expect to experience higher pressures and or pressure signs when they didn't. Primer cups and case heads are not calibrated measuring instruments, so the pressure sign method was always very imprecise at best. About all you can say is that it can be generally valid in your gun with your components if you run enough samples, but is not necessarily so with any other gun or components.

Today, even though the SAAMI standard only requires peak pressure measurement, most outfits own computerized instruments that provide complete pressure curves and that has allowed them to spot anomalies and other funny business they don't want the general handloader exposed to. Indeed, the progress, because it has depended on computers, in part, has been rapid enough that using the old manuals is a little like relying on obsolete road maps for navigation. It'll be right in some places and wrong in others.

The main thing is to understand lawyers aren't dictating the changes; technology is.

[sako2]

Hodgdon's site list a max of 55.8 with imr4831. https://www.hodgdonreloading.com/data/rifle

[reynolds357]

Originally Posted by hooligan1

If you can get accurate and consistent measurements from case head to ojive, that would be a start.
Some of the fellas here, like myaelf use Hornady's LNL comparators for that.
What you are actually measuring is bolt face to the lands on a closed bolt, other words BTO or base to ojive..
Coal is overall length which doesnt tell you where the ojive of the bullets sets off the lands.
With the Hornady tool, you use modified cases and can get accurate measurements from any bullet you want to load.
I tend to start with a. 010 jump, and try a median powder load, and shoot a 3-5 rnd group, if its not decent, try. 020 off, you may find moving the jump in larger increments will get there faster.
It depends on the barrel and what it wants, sometimes a long jump, sometimes it likes to be close, you have to test and find the sweetspot.

I have a comparator. I also have a candle. I get much quicker results by smoking a bullet.

[hooligan1]

Reynolds357, you can do your method to find lands, but how does smoking a bullet help with precise bto measurements.
If you have the modified cases, and the comparator, there is no reason to smoke the bullet.

[mxsailor803]

Natty, I’ve been reloading both rounds for deer hunting since the early 90’s as a kid with my grandfather. I actually still use his same data til this day. Now I don’t try to push the daylights out of either cartridge. I use Sierra ProHunters exclusively and 4064. Are either the best? No but the powder specifically has a broad range of cartridges that it can be used in. As for charge weights, I personally don’t tell people the weights. Is it a secret? No. I don’t want someone to misunderstand what I told them and blowup their gun and get hurt. I can tell you that I’m pushing the .270 about 2900-3000fps and the .243 about 2800-2900fps. I’ve actually never varied my seating depths for finding the lands. I’m also not loading for one specific rifle as we have 7 different rifles chambered in the 2 cartridges and I am not going to spend the extra time when all the rifles will cloverleaf a 5 shot group at 100yds. Good luck in you new hobby and shoot straight

[Natty270]

Hey fellas thanks again for the responses. Understanding now that my data was outdated, I picked up the new Hornady Reloading manual, and a Hornady cam bullet puller and pulled and reworked the rounds that I had over max. I was able to take it easy on the bullets. I resized and worked up some new loads based on my existing data, and the Hornady 10th edition data. I wish I would have known this from the start, but I live and learn. I had some mid grade rounds in IMR 4831 for my .270 130 gr bullet, that i'm starting with and going up in .3 increments but staying under max. Same for the .243 in the 95/100 grain bullets. I'm also working up a couple in RL-19 in the 100 grain bullets. Lastly, I had great success with IMR4064 working up a Varmint load for my .243. I worked up a 58 grain VMax to shoot mickey mouse at 100, and a 75 grain Vmax to shoot under 1 moa. Both these rounds shot bulls and I did not have to adjust my scope. I was quite surprised. As for the RL-19, it also shot well out of the 243 with the 100 grain interlocks. I can see why by buddy had that recipe highlighted in his old book 43gr. No pressure signs.

Thanks again, and I really appreciate the responses.

gonna be 50 today in Wisconsin. I better get outside!

[sako2]

Natty if you can find some rl16 give it a try with those bullets.

[Natty270]

Thanks Fellas