NEW LOAD WORK UP ADVICE

[mike243]

I was having a root around in my not very tidy reloading cupboard and found a box of 165gn Nosler Partitions, I loaded 5 with the same data and seating die setting that I use for my current .308 load 165gn Speer SBT's, which do shoot fantastically well with clover leaf groups, but I am looking to change the bullets in both my C/F rifle loads to Partitions, I'm just back from my range, pic attached

My question to the more experienced reloaders than me on here is, which way from here, tinker with seating depths or powder charge initially to try and reduce the groups size, I would be happy with sub 1"

Thanks in advance Mike

 

[jcampbellsmith]

I tune powder first at present in 0.2 grain increments. I rarely measure or tinker with seating depth.
Regards
JCS

 

[mike243]

I tune powder first at present in 0.2 grain increments. I rarely measure or tinker with seating depth.
Regards
JCS

Thankyou JCS for that piece of advice, I am hoping to work up the load with as few shots a possible especially with the current shortages of everything, I have plenty of powder and primers, I happened onto a couple of bottles of varget a year or so ago and have most of a 1000 brick of Federeal GMM primers but bullets seem thin on the ground and without them the whole job is buggered, I'm hoping I can get to where I am happy within 30ish rounds, by only shooting 3 shot batches, not the best but when needs must and all that, once I have worked the load up if I shoot a dozen rounds a year my deep freezers will be over flowing

 

[disco_ike]

What seating depth did you use? Did you use factory coal or a X-thou off measured for the previous bullets?

From my understanding (and from using Yew Trees) the copper likes a bit more of a jump than a lead.

But I would work up the powder first then if you get it tight on powder then play with depth. Powder seems to have the largest impact from my experience.

 

[Lancaster]

New component, new work up.
I'm not sure about this bullet in this calibre, but I would have started with a bit lower charge, worked up past the current load and gone a bit higher, COAL may be the same but the amount of bullet shank in the neck almost certainly isn't, so barrel harmonics will change.

 

[25 Sharps]

Start out again, work up in increments of powder weight. Then if you feel it necessary play with seating depth.

I’ve never really bothered with the latter but the last couple of .223 loads have benefited from it. the last .308 load was 3 bullets touching set at the length for my old rifle so I’ll leave it at that.

 

[mike243]

Start out again, work up in increments of powder weight. Then if you feel it necessary play with seating depth.

I’ve never really bothered with the latter but the last couple of .223 loads have benefited from it. the last .308 load was 3 bullets touching set at the length for my old rifle so I’ll leave it at that

I've started at max load which is where my old load ran best, so the only way is down, I don't mind that, I'm not looking for a laser beam, just reasonable accurate

 

[25 Sharps]

Drop back 5% and work up in increments, if it shows promise and you want to tighten load up some in 10 thou increments forward and backwards.

On my 6.5x55 yew tree load 1/2 grain of powder down went for around an inch to a little fingernail sized clover leaf, around 8 mm edge to edge

 

[Lancaster]

Start out again, work up in increments of powder weight. Then if you feel it necessary play with seating depth.

I’ve never really bothered with the latter but the last couple of .223 loads have benefited from it. the last .308 load was 3 bullets touching set at the length for my old rifle so I’ll leave it at that.

Maybe you should play with length a bit more, copied from my load spreadsheet showing a load I made up for a friends .243.

Norma Case	Ramshot Hunter	Charge	Nos 95gr BT 1.125" bullet	Fed Primer	Length With .20 Col	COAL				Group " @ 100yds
		44.2			2.565	2.895				2.4
		44.2			2.54	2.87				1.35
		44.2			2.515	2.845				0.469
		44.2			2.49	2.82				0.96
		44.2			2.465	2.795				3.52
		44.2			2.44	2.77				1.13

 

[25 Sharps]

Possibly and probably will in future but I seem to get lucky and pretty much always something that groups around 1/2 moa or better during initial testing, which is plenty good enough for me.

Now, if I don’t I start playing with length.

 

[Lancaster]

Possibly and probably will in future but I seem to get lucky and pretty much always something that groups around 1/2 moa or better during initial testing, which is plenty good enough for me.

Now, if I don’t I start playing with length.

The load above was worked up for a BRNO .243 of an indeterminate age that he paid £100 for, changing length made a lot of difference for an apparently bggrd old rifle

 

[25 Sharps]

The load above was worked up for a BRNO .243 of an indeterminate age that he paid £100 for, changing length made a lot of difference for an apparently bggrd old rifle

It is amazing that a few thou can take it from 3.5” to 0.5”!

 

[Lancaster]

It is amazing that a few thou can take it from 3.5” to 0.5”!

It is, and to be honest it was one of the more extreme examples from my spread sheets, but, as you know, It's all about harmonics and, probably, how far the throat had moved over a few decades.
When I work up rounds case length is +/- 0.001", bump length to shoulder is 0.002/3" from a fired case, charge weight is +/- 0.1gr, so 25 thou is a pretty big distance

 

[25 Sharps]

It is, and to be honest it was one of the more extreme examples from my spread sheets, but, as you know, It's all about harmonics and, probably, how far the throat had moved over a few decades.
When I work up rounds case length is +/- 0.001", bump length to shoulder is 0.002/3" from a fired case, charge weight is +/- 0.1gr, so 25 thou is a pretty big distance

Yeah, throat wear on an old .243 is likely to be pronounced!

 

[mike243]

I had a bit of time at my reloading bench this morning and then back to the range with 4x3 shot batches each with 0.2gn less powder, I shot the groups at 50yds today, it is much easier to keep the reticle on the centre of the target, I am going to try the 45.0 and the 45.2 loads again, the first is 1/2" and the 45.2 to see if I pulled the lower shot where the first 2 almost went through the same hole