Need help choosing which load from these groups.(load devlopment) UPDATED ! new groups

[locotrician]

As the title states need help picking these groups apart. These are the first shots after break in. Specs are: stiller action,brux 27.5 in barrel, mcmillan a3 stock ,stiller 20 moa base , nightforce nsx5.5-22x56 in farrell rings reamer print shows .317 neck .188 freebore.fount reamer print. Cartridge is 7 saum shooting 162 amax. Groups shot at 102 [email protected]s

 

[locotrician]

More pics.

 

[wvlapua]

Curious..what are your reamer specs and what brass was used? I shoot a 28" 7saum but only load 180 hybrids with very good results from both H-1000 and Retumbo.

Left target is Retumbo..H-1000 on the right. All shots were from neck turned virgin remmy brass.

 

[locotrician]

I dont remeber the reamer specs off hand , its around here some where . The brass is remington . It is throated for the 180 vld but i have a bunch of amax bullets and they are way cheaper. Your groups are great id love to get this rifle where yours is.

 

[ShtrRdy]

It looks like it might be pulling together at 61 gr of H4831sc. Can you increase the charge from this point and see what happens?

 

[locotrician]

Yes i should be able to increase the charge weight as i saw no signs of pressure with the 4831, at 65 of magpro i have light ejector marks.

 

[wvlapua]

Couldn't find your specs. I asked b/c you may not be running enough bullet release, and neck turning may be required with remmy brass. Mine was chambered with a ptg .317 no turn match .188 freebore reamer. If I were to run nosler brass I wouldn't have to turn necks, but with remmy I do. Measuring the neck of a fired case will give you some idea.

 

[locotrician]

Good point . Ill measure it now , fired neck measures .3145

 

[Darkside-Six]

I'll be honest, none of them groups look real promising. if you've seen no signes of pressure then work up a few more loads in .5gr increments and see how it turns out.

 

[wvlapua]

Sounds like you may have a tight chamber. Measure a loaded round..you want around .003 bullet release unless you are shooting br with a clean/dry chamber all the time. Make sure you get all the cleaning solvents and oils out of your chamber before firing also.

Nosler brass with 180hybrids measure .315 loaded. Remmys are all over the place (do to uneven necks) but average .316. I turn them down to .314 to get .003 release in my chamber (.317).

 

[locotrician]

I believe you found my issue as i only measure a half thousandth difference loaded vs fired. I thought when i ordered the reamer i specified enough for a no turn chamber , guess i was wrong and i guess i need to find where i put the reamer and reamer print. Thank you very much for your help , i know better than to not check but i was so eager to get shooting i just didnt do it.

 

[locotrician]

Darkside-thanks for the reply and i totally agree , to me all these groups look equally bad and im used to only looking at group size , i have heard that at 100 you should only look at verticle and not worry about horizontal at 100. I dont know if that is true though.

 

[wvlapua]

I know what you mean..I did the same thing. Had ejector marks long before I should have, but only on some of the cases. And some would chamber a bit stiffer, then when i'd eject the unfired case you could see where it was contacting the chamber walls on the neck. Almost positive my fired brass measured the same before turning. Just get the 21st century neck turning lathe and an tube micrometer and you'll be set.

 

[locotrician]

I have the k and m neck turning set up, still in the box , guess its time to open it and read the instructions. Any particular brand/vendor for the micrometer? Thanks again for your help.

 

[wvlapua]

http://www.21stcenturyshooting.com/site/mobile?url=http://www.21stcenturyshooting.com/Tube_Mics.php

That's the one I use, and its tubing mic not anvil. Shop around, you can find it cheaper.

 

[wvlapua]

Not really familiar with the k&m turner..but if you can get different angled cutters, a 30° cutter is what you need.

 

[locotrician]

Here is a link to the turner i have. K&M Shooting - Micro-Adjustable Neck Turner Complete with Carbide Cutting Pilot, Carbide Cutter, and Shell Holder

 

[wvlapua]

Here is a link to the turner i have. K&M Shooting - Micro-Adjustable Neck Turner Complete with Carbide Cutting Pilot, Carbide Cutter, and Shell Holder

That will work. They just use a standard angle, probably 20°. But it is rather shallow and will be fine with your 30° shoulder. Just make sure you cut into the shoulder approx 1/32" or so to hopefully eliminate the dreaded donut. If you do get donuts after several firings, your k&m tool will except a reamer to cut it out. You'll want to size the brass with a non bushing die, trim to uniform length, run them through an expander mandrel, neck turn, size the case with appropriate bullet tension, then normal procedure from there.

 

[locotrician]

Ok i think i got it , thank you .

 

[hlee]

I'll be honest, none of them groups look real promising. if you've seen no signes of pressure then work up a few more loads in .5gr increments and see how it turns out.

Add to that the groups are wandering all of the place. Compare the op's groups to those posted by wvlapua. Notice that all of the groups are right in the lower left corner of the target. I don't see a lot of promise here.

 

[locotrician]

Remember there are 2 different powders involved in these groups. I believe that explains some of the wandering.

 

[locotrician]

Found my reamer print , .317 neck .

 

[Wildboarem]

Seems to be some inconsistencies in the load charges. You jump 1 gr for each load then .5 for the last load. Should be .5 apart go the whole test. I would load around 59.5-60 and work up over 61, +.5gr until you reach pressure. Might find another node, maybe around 61.8.

Sent from my KFTT using Tapatalk 2

 

[locotrician]

Only did that because it was the last bit i had left in the lot number for those powders. I used to do .5 grain increments to start but usually am able to find my load going 1 grain apart and with the unavibility of 7saum brass im trying to get there on as few firings as possible. I am gonna turn necks and if the weather holds ill be posting more groups this weekend starting at 60 and going up till i hit pressure with 4831. Thanks for all the responses gentleman.

 

[wvlapua]

Found my reamer print , .317 neck .

Definitely need to neck turn remmy brass. Nosler will be ok unturned, but still only gives .002 release. I hate that ptg calls that a no-turn match reamer.

 

[locotrician]

Me too but i know better than to not check , how many firings you getting out of the nosler brass?

 

[wvlapua]

Me too but i know better than to not check , how many firings you getting out of the nosler brass?

I use remmy brass..on the 3rd firing now. My gunsmith sent a dummy round with the rifle using nosler brass and a 180 hybrid. That is how i got the measurement.

 

[locotrician]

Turned my necks , and tried again , my magnetospeed v3 showed up today so i got to try that out as well . All shots from bipod with rear bag prone at 100 yards.

 

[DarnYankeeUSMC]

I would load a bunch at the 60.1. See if they maintain a low ES. Maybe some at the 60.5 and see what happens with a dirty barrel. I try to do load development with a fouled bore and 5 shot groups. Then load 20 in the groups I like the best and shoot them at separate dots. It seems to take some pressure off of keeping a group going. You can download some dot targets from SH. The site info thread in one of the stickys

 

[Darkside-Six]

I would load a bunch at the 60.1. See if they maintain a low ES. Maybe some at the 60.5 and see what happens with a dirty barrel. I try to do load development with a fouled bore and 5 shot groups. Then load 20 in the groups I like the best and shoot them at separate dots. It seems to take some pressure off of keeping a group going. You can download some dot targets from SH. The site info thread in one of the stickys

I'm going to agree with that. your 60.3 ma not be the tightest group but it's the closest to the point of aim. load up enough for a few groups and fire them at separate targets.

 

[locotrician]

Point of aim isnt at all the concern here. Group size and extrene spread are the focus. Good idea yankee i think ill try a dot drill and see where that leaves me . Thanks to all.