OLD dogs ,New Tricks!
OLD dogs ,New Tricks!
Hi All, I pass something i learned but in no way do i recomemd that anyone else do it ,please do not follow these details as gospel as i will not be responseable for your actions .. I have just fireformed 50 cases ,they came up to my best standards straight away because of doing it in a way that i have not tried before ..1st i always set the new case up to have a crush fit to the chamber length at the shoulder or the shoulder/ neck junction (i have to be able to feel the case being griped as the bolt cams over).. I add to this the projectile jammed into the lands... When the case is held tight lengthways it has a better chance to expand into the chamber equally,thus staying more concentric.. Now what i did this time was to lube the case walls and run a low pressure fireform load at about 50000 psi( I used 68 gns of H4831 with a 175Smk)..This worked a treat the cases came out with next to no shortening and the case head squareness was corrected from up to .003 to less than .001..Neck concentricity was at less than .001 which is a first for me ..Problem with this is that because the case can't grip the chamber wall there is a big increase on bolt thrust ,hence the low pressure fireform load .. I gave 15 of those fireformed cases their 1st serious wack yesterday (propably above 70000 psi) and they came up smilein ,all were within .0005 in every area i check..Kiddies don't try this at home now..JR..Jeff Rogers
Pressure!
Malcolm, To start off with anything less than the best cases u can buy is a recipe for failure ..I started another post on here about the start prepartion i use on the Lapua 300 WM cases,go read that to ..The bloke i shoot with a lot has used the RWS cases, they are excelent just hard to get and way more expensive..I quite often find preformance in ultra high pressure , i once told the R&D person from Lapua the component details from my 6mm light gun ,she emailed back the next day to say that when she recorded the infomation into the Lapua Computer it came up with a dangerous warning of pressures in the 74000 to 78000 psi area.. Even though it was my own cartridge(i gave the h20 cap) i was using Lapua cases,Lapua Bullets and VihtaVuori powder so she had all the details right in front of her..I told here i was well aware of the pressure because of the amount of work i had to do on the case so i could fire it again.. Now i'm not sayin to go here but the lubed cases worked a treat for me ,just make sure the pressures are right 1st..JR..Jeff Rogers
malcolm wrote:aJR, what brand of cases are you fiddlin' with?
I must learn more about these intricate little tricks with cases.
Malcolm
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Ned Kelly
- .270 Winchester
- Posts: 1277
- Joined: Tue Oct 31, 2006 6:39 am
- Favourite Cartridge: 6PPC
- Location: Macedon Ranges Vic
G'Day aJR,
I've used a similar method for the 6ppc years ago with lapua 220 russian cases, a wipe with WD-40 on the from half of the case so the neck turned part would slide around the shoulder corner to avoid the "dreaded donut", bullet jammed into the lands and a soft fireform load, worked very well. At least, two more higher pressure loads and it's competition ready.
Mind you, it was in my Hall and I feel confident that this is a stonger action than you regular factory action...............as with anything caution must be taken
Cheerio Ned
I've used a similar method for the 6ppc years ago with lapua 220 russian cases, a wipe with WD-40 on the from half of the case so the neck turned part would slide around the shoulder corner to avoid the "dreaded donut", bullet jammed into the lands and a soft fireform load, worked very well. At least, two more higher pressure loads and it's competition ready.
Mind you, it was in my Hall and I feel confident that this is a stonger action than you regular factory action...............as with anything caution must be taken
Cheerio Ned
Details!
Ned ,I think the most important detail of this is the case head squareness .. To set up to machine the case head back to square is very time consumeing ,Most don't check their case in this area so in reality will never know .. Still if you can straighten them in the fireform ,it's money for jam..JR..Jeff Rogers
Ned Kelly wrote:G'Day aJR,
I've used a similar method for the 6ppc years ago with lapua 220 russian cases, a wipe with WD-40 on the from half of the case so the neck turned part would slide around the shoulder corner to avoid the "dreaded donut", bullet jammed into the lands and a soft fireform load, worked very well. At least, two more higher pressure loads and it's competition ready.
Mind you, it was in my Hall and I feel confident that this is a stonger action than you regular factory action...............as with anything caution must be taken
Cheerio Ned
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Ned Kelly
- .270 Winchester
- Posts: 1277
- Joined: Tue Oct 31, 2006 6:39 am
- Favourite Cartridge: 6PPC
- Location: Macedon Ranges Vic
G'Day aJR,
yeah I agree, however, I'm basically lazy, but I do like getting as much bang for my buck, if my rifle is set up right (and I have no reason to think otherwise) when fireformed, the case heads come out square and the case bodies are straight and true. Testimony to the gunsmith I figure. More to the point the rifle is competitve. The main question is whether I'm competitve on the day!
Cheerio Ned
yeah I agree, however, I'm basically lazy, but I do like getting as much bang for my buck, if my rifle is set up right (and I have no reason to think otherwise) when fireformed, the case heads come out square and the case bodies are straight and true. Testimony to the gunsmith I figure. More to the point the rifle is competitve. The main question is whether I'm competitve on the day!
Cheerio Ned
I just recently made up a tool for boring out and chamfering the primer pockets of 6 BR Lapua cases from small to large rifle primers. I was quite amazed at how much these little cases were out of square in the head area. Needless to say they are square now.
Incidently the large rifle primer (210M) and 80 thou flashhole conversion is worth 80 fps with the 33.5 grains of H4350 and 107 SMK, and i would expect another 50 fps when i go to the 215 M. Cases are not stressed in any way and SD is no different to the small primers. I would expect a 6 BR capable of 3100 fps with a 105/107 pill with an extended case life as opposed to a high charge of 2208 with the small primer to get to 2950 fps.
Later on today i shoot the 6 BR at the 600 yd IBS practice match and i will let you know how it went. Weather is real crap at the moment with 20-25 knots and the sun out boiling up a mirage that has to be seen to be believed from all the moisture and rain we have had lately. I imagine many will abandon any testing today and just try to get an elevation for our first match on the 11 th of March.
Tony Z.
Incidently the large rifle primer (210M) and 80 thou flashhole conversion is worth 80 fps with the 33.5 grains of H4350 and 107 SMK, and i would expect another 50 fps when i go to the 215 M. Cases are not stressed in any way and SD is no different to the small primers. I would expect a 6 BR capable of 3100 fps with a 105/107 pill with an extended case life as opposed to a high charge of 2208 with the small primer to get to 2950 fps.
Later on today i shoot the 6 BR at the 600 yd IBS practice match and i will let you know how it went. Weather is real crap at the moment with 20-25 knots and the sun out boiling up a mirage that has to be seen to be believed from all the moisture and rain we have had lately. I imagine many will abandon any testing today and just try to get an elevation for our first match on the 11 th of March.
Tony Z.
Grinners at 600!
Hi All , although there was never going to be any great things done today with our monsoon season in full swing, i had a great deal of fun shooting the new 600yd Benchrest target .. The little 6BRs were not disgraced ..Alpal nearly showed us all up with his 223 Varmint gun,, He's hooked!!, Bob N got a nice one in a just over 2 inchs,eric was lookin for the matchs at one period,TZ tried some different stuff ,very interesting ..I fired 3 different loads ,not unhappy at all ..This is really goin to go places this shoot,i reckon..JR..Jeff Rogers..ps ..Pic of the 3 loads at 600 yds
Well I went out today to give my 223 varmint rifle a run in preparation for the fly postal and to see how it would go, I went along to the 600yd practice here in Townsville.
I was actually quite surprised with how it went given and the number of groups I have shot at this range can be counted on one hand leaving much to be learnt.
The piccy shows a couple of the groups that I shot and as JR said.... hook, line and sinker
I was actually quite surprised with how it went given and the number of groups I have shot at this range can be counted on one hand leaving much to be learnt.
The piccy shows a couple of the groups that I shot and as JR said.... hook, line and sinker