Where to go after my first step of load development?

[Doc7]

I shot my first handloads today...it was very fun and I am glad I have delved into this. For 7mm-08, the cost savings are significant unlike loading for my 9mm pistol or my 223 rifle. Savings on the order of almost a dollar per round for my typical hunting ammo are available for the 7-08.

I started with a good factory load, Federal blue box which is a Hotcor bullet. They call it a 150 but the only .284 Hotcor is 145grn so that is what I bought. I also have Nosler Ballistic tips to move on to next as a deer round, but the Speer bullet itself is already a good deer bullet and much cheaper to be an everyday practice round.

I loaded all rounds to COAL of 2.730" which is what all load sources for this bullet call for (Speer site and Hodgdon load data site), using 9 1/2 primer.
Edited to add: New Starline Brass, which was FL Sized, trimmed to 2.025", chamfered, deburred, Primer pocket uniformed, flash hole uniformed. Lyman Ram Primer seated all primers to 0.004".

All groups were 3 shots for initial data purposes.

I started with a factory load warmup off of sandbags prone and shot a 1.035" group (range is 92 yards). Then I proceeded to my handloads with IMR-4895 and I shot my 3 "Sighter" rounds (utilizing the OCW website as a source of how to start off selecting charge increments) which were 38.5 grn, 39.4 grn and 40.2 grn. These went into a 1.118" group so I was definitely feeling good now.

After that it fell apart with the IMR-4895. 41.1 grn = 1.346", 41.4 grn = 1.994", 41.8 grn = 1.616" and 42.1 grn = 1.930". I didn't even shoot my max load. I shot another factory load just to check myself if I was doing very poorly and it was 1.3" which is typical of me shooting this load.

I went onto my Varget loads and this was very promising but now I don't know what to do next.

Warmup rounds of 37.6, 38.4 and 39.3 grn Varget were not any special group like they were with the IMR-4895. But then 40.1 grn 3 shot group was .793" and then 40.4 grn = .662" - with two in a hole barely larger than bullet diameter. Then it widened again with 40.8 grn = 2.30"! I didn't call any fliers. I did put a 4th round into this group and any 3 shots would have been 1.6" so even if there was weird thing happening with one round the group still would have been much larger than the previous charge weight. Then 41.1 grn = 0.936" and 41.5 grn = 1.70"!

To summarize, with Varget and my 145 grain Speer hotcors in my Tikka T3:
40.1 grains .793"
40.4 grains .662"
40.8 grains 2.30"
41.1 grains 0.936" (this was 4 shot group as well)
41.5 grains 1.70".

I took 9 minutes between groups and the rifle barrel was cold to the touch prior to each group.

I don't know what to do now...as I understand it, variations in ambient conditions, powder consistency, etc can cause a load to act like a load an increment above or below it. All of my loads are immediately adjacent to a much worse load. Seems like even if I find a good one, it will not work when it is in the 20s or in the 80s.

I think i am giving up on IMR-4895 altogether at least with 145 Hotcors at 2.730" COAL. I will give it a go with the Nosler Ballistic Tips Nosler/Hodgdon website loads as well so it may prove to be a winner there.


Wife and I are giving up social media including message boards until Easter after tonight, so I will drop by later but after that if you notice I don't reply, you can safely assume I am following safe handloading practices and just taking a break from the internet for a few weeks.

 

[Doc7]

Here is a photo of my Varget Target.

 

[Doc7]

View attachment 829623 Here is a photo of my Varget Target.

 

[Stevenvalleyky]

Doc7 THR isnt social media, thats what Facebook, Instagram, Pinterest, and Twitter are to me. Website forums I don't consider social media.. just keeping you a technicalities to be able to check back in here before Easter.
Now for the important part, have you looked at maximum cartridge overall length? There are several ways you can measure this including the Hornady tool, the dowel rod method and my favorite, doing this.(see pic)
A full length size a case, and then I take a Dremel with a cutting wheel and cut a slice down the neck. This allows a bullet to still be held firmly in place but can be pulled out by hand generally. I deliberately leave the bullet almost so far out that it's going to fall out of the neck. On a bolt action, I will just put the cartridge in single feeding thru the ejection port and cycle the bolt closed. Then when I open the bolt, I will stick my finger on the case while it's being ejected so it doesn't fly out and move. The bullet will push up against the lands and then slide back into the case until the bolt is fully closed. If you are careful the bullet will stay in place and then you can measure that to find the distance to the lands. Some bullets like the be jammed into the lands, some like a small jump and a few even like a big jump or are tolerant of a big jump. Some bullets shoot good either way in certain rifles. Every rifle is different, even rifles made by the same company in the same caliber and model can be different. Having a dummy bullet that will stay in the case fairly tight yet be able to move in and out fairly easy will let you measure the distance to the lands for that particular bullet as well as the maximum length you can use in a magazine. What you hope for is that the maximum length for the magazine is longer then the distance to the lands that way you are not limited by the magazine. With a single shot, obviously you can load as long as the case still has good neck tension on the bullet.
You have to be careful with making them too short as the pressure can be greatly increased which can also happen when you jam bullets into the rifling but thats for another discussion. I noticed you stated a coal of 2.730". My Lee manual lists a minimum overall length of 2.800" for just about all 7mm-08 loads.v, Most but not all bullets will shoot more accurately with a smaller jump. I would start with a .010-.025" jump assuming it will fit in your magazine and do the testing again or at least retest the promising loads. Ive generally had good success with Hornady SSTs and Nosler ballistic tips in 3 different calibers at .010-.015"jump and I don't generally have to move from there as I usually find an accurate load with every powder I try. Some are better than others and it's always a good idea to have more than one accurate load worked up for a particular bullet just in case we have shortages again or you are just unable to find a certain powder.

 

[Doc7]

Thanks, I will do some testing in that.

I agree about 2.800” COAL being typical , but the 145 HotCor has a 2.730 in both the Hodgdon site and the Speer site loads.

I am sure I will find magazine length is the limiting factor with the Tikka T3.

 

[Fine Figure of a Man]

Seems like even if I find a good one, it will not work when it is in the 20s or in the 80s.

Varget seems to be working well for you and it is very temp stable.
For your COL check out this link; http://bulletin.accurateshooter.com/2009/03/berger-tips-for-loading-vld-bullets/
I used to think longer was always better, often it is not.

 

[brasscollector]

That shot low-left on the 40.8gr Varget load looks like an anomaly to me, flier or not. Personally I would continue up the ladder if there is room. If not I'm going with that 40.4gr load and doing an OAL test.

 

[Doc7]

Regarding going up the ladder - I had no pressure signs but these were the max loads for this bullet when checking multiple sources.

I love this site - have been a member since before I owned my first firearm - and look forward to growing more. However as a neophyte loader , I am taking a steady dose of caution with regards to COAL and Max Loads. Lyman 49 is very insistent to not exceed Max loads (and I am comparing book where available, but more typically it seems the Bullet manufacture and powder manufacture and compare those together as Lyman only lists one bullet for each weight). Additionally, Lyman 49 does not have a chapter or any information whatsoever on varying COAL from what they list for a particular bullet, so I applied that advice to other load sources as well. I do indeed look forward to learning more about varying COAL.

I do believe I will load up more of some of these loads with the 145 Speers, and then get working on the same IMR 4895 and Varget / 120 Nosler ballistic tip loads next.

 

[Bfh_auto]

I would try seating 40.4 out a little bit and see if it tightens up.
Also bracket it on either side to see if it's a decent sized node.
I'm not a huge fan of the 4895s. I know some people get them to work, but I have always found something better.

 

[z7]

Doc7

Don’t be afraid to load long, here is my method for rifle (bolt)

Find the max oal where the bullet just touches the lands or maybe a .005” jam into the Lands or maximum magazine length, whatever is shorter and load to the longest length you can without jamming the bullets too bad (I am ok with .005”)

Then do a normal ocw work up with a chronograph

Once I see a series of tight groups (like you got) break that down and test a few 5 shot spreads of that range (40.0, 40.2, 40.4, 40.6) with a chrono to try and understand when you are out of your node

Once I figure out the “middle” of the node I will do a Seating depth test and I will seat the bullet deeper into the case, further from the lands, assuming I am not crunching powder, pressure should not drastically increase with a small (.005”) reduction in coal, it should decrease with more jump

If the known middle of the node gets tighter groups at a particular oal, and I am ambitious, keep the oal and try +\-.2grains on either side of the preferred oal and middle of the node
If at any time you are happy with what you have, and the gun will function and feed in s way that makes you happy, stop doing load development and start shooting stuff

Last time i realized I wasn’t a good enough shooter to make this work and settled for a .5 Moa load with sd under 10fps

 

[Doc7]

Thanks guys.

I just loaded up 10 each of 40.2 and 40.4. I am sure I’ll have lots to report when I’m back online after Easter. I plan to load up Nosler Ballistic Tips 120s in the next couple of weeks as well. My plan and hope is to have the HotCors as a good practice load and the 120 NBTs as a preferred deer and antelope round, although I am sure both rounds will suffice for my needs (particularly in East Coast woods whitetail country).