Acceptable variation in handloads?

[GOODWIN]

What would be an acceptable range for variation in fps between shots? Shooting .243 85 gr Sierra GK HP over 43gr IMR 4350.

Just trying to weed out some inconsistencies in my reloading. Thanks

 

[DaveB]

Well that is kind of a tricky question because a COLD barrel may have a slower FPS than a HOT barrel. And a bullet seated deeper into the case may have a different FPS than one nearly touching the lands.

Keep your variables under control: is it 43.3 grains or 39.5 or 43? You use the same primer? Barrel is clean but has at least one round since being cleaned? You seating the exact same bullet to the exact same depth?

If so, look for FPS to vary no more than roughly 40 FPS. Lots of people are under 20 FPS variance and I see some with sub 10 FPS variance, which speaks volumes to their loading acumen.

 

[GOODWIN]

Yes I'm controlling every variable I can ie charge, seating, depth, etc...at least the best I can do with what I got.

Seemed like last time I chronoed I was getting anywhere from 10- 60fps variation between rounds. Thanks for the info. I know I've got room for improvement. This round is consistently sub moa out to 200, just think I can do better.

 

[GOODWIN]

Right now steps I know I want to improve on are charge weight and quality of brass. Currently using digital hornady powder dispenser which I'm not too fond of. Id like to check it against another digital scale. I've also never bought any "top quality" brass. Usually just prepped fired cases from other factory loads. Just recently got some new Winchester brass and after inspecting, measuring, and weighing it I'm rather disappointed in the quality. Guess I just need to quit being cheap and buy some better brass.

 

[DaveB]

You will see a LOT of Lapua, Norma, and Nosler brass being used along with Pay once Cry once and similar sayings.

Reason is the brass is piece to piece more uniform in quality.

More importantly, the better quality brass goes further between trimmings and subsequently lasts a lot longer.

Just for the record, you are building a controlled explosion and you really don't want to be saving a few pennies a BANG.

 

[Jcalder]

I've used the same bullet and powder in my 243. My numbers were really good by my standards. My spread was 30 or under


Big or small, kill em all

 

[7mminatree]

10-60 fps isn't bad, neck tension is a big factor as well as a uniform charge.But holy crap we can pick at it all day. Like what kinda barrel you shooting, are cases fresh or several loadings, and have they been annealed. What kind of run out are you getting on the bullets. I guess I could keep splitting hairs. When you get down to less than 2 fps. variance let us know. I've never made it to perfection yet.

 

[Jcalder]

I've used the same bullet and powder in my 243. My numbers were really good by my standards. My spread was 30 or under


Big or small, kill em all

I told you incorrectly. I used imr 4064 with those. Using imr 4350 with 100gr loads


Big or small, kill em all

 

[GOODWIN]

You will see a LOT of Lapua, Norma, and Nosler brass being used along with Pay once Cry once and similar sayings.

Reason is the brass is piece to piece more uniform in quality.

More importantly, the better quality brass goes further between trimmings and subsequently lasts a lot longer.

Just for the record, you are building a controlled explosion and you really don't want to be saving a few pennies a BANG.

Good point.

On a side note. Anyone know someone say within 100 miles of Chattanooga that could turn a bolt face?

 

[mr.big]

switch primers and see if it gets better or worse,try all different kinds,,always clean primer pockets and seat primers with as close to same pressure as possible,,

 

[GOODWIN]

switch primers and see if it gets better or worse,try all different kinds,,always clean primer pockets and seat primers with as close to same pressure as possible,,

Yes something else I'm not as OCD about as I should be. I did switch primers with this last bunch so will see. Using a RCBS hand primer and it is tough to get the same pressure each time. Maybe I need to pay a bit more attention to that as well. :bash: :bash: :bash: ahhh, too many variables!!

 

[DaveB]

Yeah a lot of variables. What I do is eliminate a variable so lets do what Mr. Big suggests. You have a powder charge, bullet weight, and length. Clean the primer pocket and make sure it is flat by using this tool or one like it:
http://www.midsouthshooterssupply.com/i ... mer-Large-

Now, when you prime you can use your hand operated one (I have used the old round Lee for over 25 years) or you can go with this one. Some friends I trust swear this is the best there is and is on my Christmas List:
http://www.midsouthshooterssupply.com/i ... ming-Tool-

Now load up a small group changing the primer from say a CCI200 to a CCI BR2 or from a winchester LR to a Fed 210 or 210M.

Carefully shoot this small group. What you are looking for is a drop in your FPS spread which should correlate exactly to smaller groups. Next do the same thing with another different primer.

 

[mr.big]

magnetospeed really reads well and never shows an error code,,reads in any light also



these are from high end hand lapped barrels with real tight precision chambers,,factory bbls may not be as good and the chrono you use may not read as good as the magnetospeed

338 LM 300 gr Scenar Retumbo load


6BRDX 105 Scenar Varget load



6BRDX 68 Berger flat base H4895 load



6BRDX 105VLD H4350 load



I didnt photo but the 105 vld RL15 load I been shooting is at 2920 with SD 8

 

[DaveB]

Top notch loading Mr. B.

 

[GOODWIN]

Great info guys. Thanks.

 

[MUP]

You will see a LOT of Lapua, Norma, and Nosler brass being used along with Pay once Cry once and similar sayings.

Reason is the brass is piece to piece more uniform in quality.

More importantly, the better quality brass goes further between trimmings and subsequently lasts a lot longer.

Just for the record, you are building a controlled explosion and you really don't want to be saving a few pennies a BANG.

Good point.

On a side note. Anyone know someone say within 100 miles of Chattanooga that could turn a bolt face?

PM Sent