Lyman no 2 alloy
- Thread starter johnnyjr
- Start date
Winelover
North Central Arkansas
I beg to differ.
Just finished testing 308W cast loads with two different alloys/BHN's. Original accurate load was 26 grains of SR 4759. Had to back the load down by 6 grains, to get decent groups from the softer alloy. Same gun, same bullet, same lots of brass & powder.
Winelover
North Central Arkansas
All military, LC-07
RBHarter
West Central AR
Fit is king .
The more variables you remove at the bench the fewer you will have on the range.
I had what should have been 1 lot of LC 43 . After a lot of shooting with 2-3 of 5 kissing and the rest of 5 18" away I emptied 128 rounds with breathing, trigger , hold etc . I had 4 very clearly defined 2.5" groups and a few fliers . I discovered that the rifle put bullets in a different place for 2.2 gr of case weight and that I had cases that ran from 178-207 gr and varied about 10gr of water weight . When those variations were eliminated I had 5 touching in .980 outside groups .
Change one thing at a time .
I changed primers in an SKS and groups dropped from 8.5×11 at 50 to 3×5 at 100 .
If it chambers freely it's not too big .
I've had a 7.62 and 7.7 that needed .318 to fill the throat and .316 for the grooves . Also a 6.5 that needs .272 .
There are situations where filling the throat and swaging a bullet into the grooves won't work . A .301 would slip fit and chamber but the last 22" of barrel were .277×.284 .
With jacketed I have the example of jump to the lands doesn't matter , obviously it can but when you have an 06' that that groups the same with the bullet .08 in the neck as .350 , and will take a 4" OAL you get to use the argument. However I'm only now loading to test the theory in a 25-06' and 7×57 .
Alloy doesn't seem to be in the equation until you break 32kpsi . Obviously dead soft even PC with a check isn't going to be really happy in full boat 9 , 357 , and 40 but it works in 30/30 and 45-70 . Linotype will probably foul a 45acp , 38 , and 45-70 , so apply some sense to this .
Some bullet designs in some applications want/need/are best served by a huge kick in the base the next time they want a long flat push ......of course both happen in the same .007-9 seconds after the sear breaks so it's a perspective thing .
Have faith in the knowledge here .
My resume' includes learning to paper patch because gas checks were expensive and I only had to buy a sizer once .
15 yr and I still wander around in the weeds with some of these guys shaking their heads in both often disbelief and very rarely awe . My triumphs include matching jacketed speeds and groups in 222 ,30-30 ,32 Rem, 358 Win , 6.8 SPC ,7.62x39 , and 45-70 . Also every pistol from 380-45 Colts with cast , stops at 38 Short 357 mag and Ruger level Colts leaving little to nothing to collect if I wanted a 44 .
These guys and more like them got me here .
The more variables you remove at the bench the fewer you will have on the range.
I had what should have been 1 lot of LC 43 . After a lot of shooting with 2-3 of 5 kissing and the rest of 5 18" away I emptied 128 rounds with breathing, trigger , hold etc . I had 4 very clearly defined 2.5" groups and a few fliers . I discovered that the rifle put bullets in a different place for 2.2 gr of case weight and that I had cases that ran from 178-207 gr and varied about 10gr of water weight . When those variations were eliminated I had 5 touching in .980 outside groups .
Change one thing at a time .
I changed primers in an SKS and groups dropped from 8.5×11 at 50 to 3×5 at 100 .
If it chambers freely it's not too big .
I've had a 7.62 and 7.7 that needed .318 to fill the throat and .316 for the grooves . Also a 6.5 that needs .272 .
There are situations where filling the throat and swaging a bullet into the grooves won't work . A .301 would slip fit and chamber but the last 22" of barrel were .277×.284 .
With jacketed I have the example of jump to the lands doesn't matter , obviously it can but when you have an 06' that that groups the same with the bullet .08 in the neck as .350 , and will take a 4" OAL you get to use the argument. However I'm only now loading to test the theory in a 25-06' and 7×57 .
Alloy doesn't seem to be in the equation until you break 32kpsi . Obviously dead soft even PC with a check isn't going to be really happy in full boat 9 , 357 , and 40 but it works in 30/30 and 45-70 . Linotype will probably foul a 45acp , 38 , and 45-70 , so apply some sense to this .
Some bullet designs in some applications want/need/are best served by a huge kick in the base the next time they want a long flat push ......of course both happen in the same .007-9 seconds after the sear breaks so it's a perspective thing .
Have faith in the knowledge here .
My resume' includes learning to paper patch because gas checks were expensive and I only had to buy a sizer once .
15 yr and I still wander around in the weeds with some of these guys shaking their heads in both often disbelief and very rarely awe . My triumphs include matching jacketed speeds and groups in 222 ,30-30 ,32 Rem, 358 Win , 6.8 SPC ,7.62x39 , and 45-70 . Also every pistol from 380-45 Colts with cast , stops at 38 Short 357 mag and Ruger level Colts leaving little to nothing to collect if I wanted a 44 .
These guys and more like them got me here .
JonB
Halcyon member
For Rifle (and most pistol), I use matching headstamp...and prefer to have same lot if possible.
Mixed headstamps are probably ok for 50 yd rifle shooting, but you'll likely get the occasional unexplained flyer.
Signed,
The Guy who has an explanation for every flyer.
Bret4207
At the casting bench in the sky. RIP Bret.
You made my point. You changed the FIT to suit the Bhn. FIT IS KING, always. We can have the discussion on what makes up fit, and you will find Bhn down the list, but it's not the whole bag of donuts.
Winelover
North Central Arkansas
Went and weighed 25 of the LC-07 308W brass that I'm currently using. Average case weight (with primer installed) was 181.05 grains. Heaviest was 182.1 grains, lowest was 180.0 grains. Mere two grain difference. For all practical cases, same lot.............I'm not using a bench or even bags.
Bret4207
At the casting bench in the sky. RIP Bret.
Of course it is. Static fit and Dynamic fit. You altered the dynamic fit of the bullet by altering the powder charge. Theres a whole thread on "What is Fit" someplace if you want to go look at it. Trust me, you were playing with fit.