What a difference half a grain can make

Mutley

Well-Known Member
I decided to load some target rounds for the 6.5x47L as I am going to do some Club meets at the NRA this year. Still being fairly green as far as reloading goes and with the rather limp start initially with my Hunting loads still fresh in my mind, I decided to start right in the middle of the suggested Min and Max load for the Scenars.
This being 32gr, 32.2gr and 32.5gr of N140, CCI 450 Magnum Primers with a COL of 2.736"
Even though the wind was a bit fresh today, I am lucky to have a nice pit that I can test things in, it does not stop the wind but calms it a bit. I am amazed that as the load went up, the group tightened some much with just half a grains difference.
And yes, I know, 3 shots groups??? :D

Anyway the pic shows the results of my first three Scenar loads, job done I reckon. Just luck though, not claiming to be 'Super Reloader' all the same I am very chuffed indeed.

6547139gr.jpg

Not quite so dramatic a change on the 123gr Scenars, still a work in progress.

6547123gr.jpg
 
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That's very well done. When I'm fine tuning the powder in my loads, I frequently try 0.2 gr steps, sometimes testing a good result with the same powder weight again and +-0.2 gr.

Regards

JCS
 
One hole groups like that are not luck, to many things has to be right for this to happen, nice one :thumb:
 
Nice handy work fella. I'm still green on the reloading myself. I work up in .5gr if best group I is 35 I'll fine tune with 34.6, 34.8, 35 and 35.2 (checking pressure signs).
At the first stage of working up in .5's I've found a couple of times when the group has started to open up again one of the next two have closed right up (still below max etc) and that's the one I've fine tuned then. Had some reliable help mailed by Muir and Brock Norris (Trade) on here. All good fun eh
 
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Mmmm, I've been quite on the fence as to whether reloading is really worth the hassle. However, this just goes to show what a difference it can make. I realise 3/4 to 1-inch groups with Sako 90g Gamehead in my Sako A7 and have been quite satisfied with that. However, seeing you get the load just right for your rifle and key-holing three rounds, gives pause for a re-think. Thanks for sharing Mutley and the helpful target/load images, most illuminating :tiphat:
 
Putting in the practice and tweaking the variables is what its all about. Having reloaded for far too long now, I would be manipulating the seating depth next, this should in most cases shrink your best group if at all possible.

Keep up the good work it will pay off in the end. :D
 
Putting in the practice and tweaking the variables is what its all about. Having reloaded for far too long now, I would be manipulating the seating depth next, this should in most cases shrink your best group if at all possible.

Keep up the good work it will pay off in the end. :D

I think the seating depth will be good to explore on the 34.2gr 123gr's before upping charges, as I think I twitched on the lower shot of the three, that's seems the best group as the 34.5gr seem to be slightly larger.

Thanks for the comments guys, I have read plenty of stuff on reloading but in fairness most of the useful stuff has been from the SD.
 
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That's very well done. When I'm fine tuning the powder in my loads, I frequently try 0.2 gr steps, sometimes testing a good result with the same powder weight again and +-0.2 gr.

JCS
+1 that's also the way I do it and find it does have a material effect
 
I find reloading very relaxing and its a good feeling to shoot something with bullets you have reloaded like catching a salmon with a fly you have just tied...
 
Very good result with the 139gn scenar. It's the same when you find a really good hunting round, that groups well. It gives you a lot of confidence with those tricky shots and is one less thing to think about during bullet placement. I'd deffinately recomend reloading to anyone.
 
Not knocking your efforts, but one 3-round group doesn't prove anything. If your next ten 3-round groups are the same, then you can start to say "my rifles shoots to a half inch" or whatever. A half-inch rifle always shoot to a half inch. A rifle that occasionally shoots thre erounds into a half inch is not a half inch rifle, any more than a Ford Escort that once recorded 100mph (downhill with a tail wind) is a 100mph car.

I doubt that the 1.5% change in powder charge you mention is why you achieved that group, though it could be. Have you eliminated every other variabl? Are sure that the grip exerted by all the necks on all the bullets is exactly the same? Are all you cases concentric, are you measuring concentricity? Are all of the bullets seated to a uniform depth? (In my experience, bullet seating depth has much more effect than does small variations in powder charge.) How is the rifle supporte during firing, is it supported on sandbags fore and aft, or clamped down onto a bench? Was it shot indoors or out of doors? Unless you've eliminated all other variables, I shouldn't put much weight (no pun) in cause and effect from a minor change in powder charge.

When we tested Eley Tenex at the factory indoor range, a few years ago,the rifle was clamped down in a jig which itself was boltedto a steel cabinet weighing probably 200lbs. The rifle couldn't move when being loaded, fired, or unloaded. All that human body interference was eliminated. The air was as still as possible. For each batch of Tenex, we fired ten groups of ten rounds, 40 round per batch. The impact point for each shot was triangulated by three cameras at the target, to a precision of 0.1mm, displayed on a screen at the firing point, and recorded bythe computer. Sometimes we might get a group of, say, 8-9mm for the first 9 shots and then shot 10 would blow it to 13mm. The first five shots might have been a 3mm group but by shot 8 it had become a 9mm group for example. At the end of the session, the rangemaster was able to overlay all 100 shots for a given batch of Tenex. Only then could you begin to see the true potential for that batch. Some batches might show four or five really tight groups, say 10mm or less, but also two or three blown out to 18mm. Others were more consistent, one might produce eight x 10 round groups of 11-12mm and two at 14mm. Which is the better ammo? The one that is consistent at 11-12mm or the one that shot some really tight groups of 8mm (and then threw a few big groups)?

Just to re-iterate. I'm not criticising you Mutley, not in the least. I'm simply saying that you'll need to burn up some more ammo before you can be confident that you've got the right recipe. It certainly looks to be heading in the right direction. [Good taste in dogs, too.]

-JMS
 
+1 to JMS. Very good example with 10x, although the next problem would be that the rifle shoots differently when not clamped...
 
JMS, it all sounds a bit fancy to a relative newcomer to reloading. In no particular order, I just trim to size, FL resize, Chamfer/deburr, put a uniformer to the flash hole, clean primer pockets, use a TM and 505's for powder charge. I use a comparator for measurement. I'm afraid that's it.
As for Clamping and Indoors? I am an ordinary real world shooter/hunter (no offence intended to anyone) all my testing is prone, bipod and rear bag and outside, when our delightful weather allows it of course. I am only playing with the Target stuff to have some informal shooting on Club days at the NRA, I wont be doing anything serious, just seeing what the rifle can do, so its not the be all and end all, just posting my findings to date.
I fully take on board and understand what you say, looking forward to the next session and will take it from there. Oh and my Woofer (Mischa) is a real cracker, Cheers.
 
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