155 scenar factory loading

[dRb]

 

 

Are you neck or full-length sizing? Circular marks on the case-head are often caused by the ejector button as you chamber a round and extract the case as a result of the case being a slight longitudinal crush fit in the chamber. This forces the case-head tight onto the bolt-face and ejector. This is a common feature on neck-sized brass as the shoulder moves forward a little on each firing. Likewise, setting the COAL so that the bullet is well into the rifling which produces the same effect on chambering the round.

 

I rarely see circular marks around the case-head face caused by excessive pressure. What IS such a sign is the casehead showing even the slightest raised extrusion at a single point where it's been distorted by excessive pressure swaging it into the ejector cavity, or any other such feature on the bolt-face. At this point, you usually but not invariably get noticeable resistance on raising the bolt handle due to additional effort needed in primary extraction and the bolt-face cutting the little extruded section as it's forced over it.

 

How often have you fired the cases and are primers still a good fit? Any case that shows true pressure signs externally usually sees the case-head and with it the primer pocket expand in two, at most three firings so it has to be scrapped. A not uncommon life for Lapua standard (large primer) .308 Win brass with true 'warm to hot' loads is five to six firings at which point the primer fit is noticeably looser even though it's still just tight enough to avoid gas leakage. These loads wouldn't cause any case-heads marks to show when the brass has been properly sized and the shoulder 'bumped' back by one to two thou'.

I am neck sizing only, and thus far it is all 'once fired' brass.

 

Interestingly scuff marks are pretty common on the brass (from memory, not got fired cases here to look at), but I was getting a hard bolt lift on my higher weight charges, with bright brass where it had been scraped.

[dRb]

Swamp Donkey very kindly gave me 20x lap brass yesterday, so I'll full length size them, load them up, and see where I get to...

 

3moa up at 900 is a decent improvement to be chasing!

[Swamp Donkey]

Ross, might need your welder. Broke the 'hostage' target today :/

[Swamp Donkey]

That's my brass at 46.6gr

[dRb]

Ross, might need your welder. Broke the 'hostage' target today :/

It's like gremlins innit...only water = less than 150 ftlb!

 

You should be worried. Unclem Benjemin Sr. Is known to see off cats...

[dRb]

That's my brass at 46.6gr

T'is but a scratch!

 

[onehole]

Hi ,,,I have a stonking accurate load with 155,s A,max and Scenar at 44/140 in a 24" HV tube.This gives around 2750 .Not sure that thats enough for 1000 yards . Interestingly I am now in search of the next accurate node and went to the range yesterday and shot two tiny test groups with 44 but with 45 and 45.5 preloaded rounds theydidn,t perform as good as the 44g load.Primers still looking good so will retry with 45.8,,46 and 46.3 on next calm day,,,,hope its in there somwhere.

Lots of testing and hey ho found it ,,,,,46 is as tight as my 44,,,,kicks a fair bit more but no matter,,,,,,will check velocity and long range test ,,,,,bound to be an advantage so will move on up,,,,,,O

[Chris-NZ]

You should be more on the money velocity-wise for 1000 as 2950 is the ballpark for that distance. 2750 isn't up to it.

 

Interesting how the same load can vary in pressure in two different barrels. We recently rebarreled my son's F-TR rifle with a 32" Bartlein. I sent him some interim loads with 45.5 of AR2208 (Varget) and he reports they're very warm. A pic he sent of the brass def looks that way- very flat primers and slight scraping. He's bringing it back up this weekend so we'll do some systematic testing and chrono'ing

[Nicky]

Hi, using rem 308 with 24" barrel 1-12 twist, new lapua cases, Cci primers , and wanting to find ideal load !

Now for load data I think this is the term What is my start load and finally is there a finish load? Sorry it's seems a daft question.

In the past I was using N 140 and N 540. But powder is getting expensive . Was loading 46.4 grains but primers were showing signs of pressure.

I have purchased TR 140 loading 46.0 grains, but bullets are all over the place, have checked the lands of barrel again I think this is the term,and have moved O.A.L? but still cannot get consistent groups.

We're am I going wrong ?