Separate names with a comma.
Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by leslie naylor, Jan 18, 2004.
Can any one give me an indication of case life with new Lapau brass.
Using 190smk 2950fps
Hello from just up north there Aficionado,
Case life on the Lapua? Hard brass that is, but what have you found to be the case? I could get around 6 decent reloads from W-W brass, and have been eyeing the Lapua....
Aficionado & JR,I use the lapua 300winmag brass in my modified 300 win,it holds 2 grains of water less than std.It's good in the pressure area aswell as being quite useable for a fussy L/R benchrester like myself ..My speeds are 3230fps with a 187 gn projectile and is diffently high pressure,i have up to 10 reloads on some and are still good,but not without some work to refire..HHope this helps..JR..Jeff Rogers
I have had 8 or 9 "safe" reloads on the Lap brass. I have a rail gun I use to test my brass life, and I pushed a Norma Lap case with this bullet in my big 300 to 19 loadings before case / head sep, so about half that would be "safe". Web starts to thin around this area by about .005 - .007, so I would be careful. These were all loads within spec of the manual so that's no too bad. As stated above, the Norma brass is pretty hard, so anneal, anneal, anneal and you'll get better life. As for Win - Western brass, i've been getting about 7 or 8 loadings. Have pushed to 15 with the rail gun before rupture in the past, so I would consider about half that safe. Good luck bro.
[ 01-18-2004: Message edited by: Austin ]
Im just starting out with the 300wm going to try R19 for powder, 190smk, at 2950fps,hoping to get good velocities with not to much pressure.
Had very good case life with Lapau in 308 and thought it was a good place to start .
J.R..... Minsterley has 300 Lapau brass
One more thing you may try: I have noticed that this case seems to LOVE a near full capacity and I switched to H1000 and 872 with excellent results in 4 out of 5 300WM rifles. Also, I have been only neck-sizing this brass and that seems to give me 2 or 3 more safe loadings before I start to see problems with cross-sectioned cases.
Probably preaching to the choir to most of you, but with 300 WM, there are a couple of things you need to know before reloading it.
1. The 300WM is probably the only caliber out there where SAAMI standards are not held to by different manufacturers in the U.S.
2. A study of all belted magnums held the shoulder/datum line length to a minimum from the belt with the exception of the 300WM in both chambers, in brass, and reloading dies.
3. Chamber reamers from different sources can differ on the shoulder/datum line lengths and factory rifles can vary up to .035" to the datum line which makes reloading the 300WM a different story.
4. Brass is different as well, with .015" between different manufacturers. This has been offered as the reason 300WM chambers are so sloppy.
5. Reloading dies from different sources can be as varied as the brass on lengths.
6. Shooting rifles built in this manner often produces inconsistent case stretch, (datum line headspace length) shooting the same lot of ammunition in the same shooting session.
7. This produces inconsistent reloads, extreme deviations, and poor accuracy when not returning the datum lines to the same length when reloading by neck sizing only.
8. Full length resizing to return all the brass to the same datum line length overworks the brass and speeds up case head separations.
One US Customs' gunsmith spent a large number of dollars on reamer designs and came up with the 300WM reamer dimension the US Army AMU still uses today. I have his original reamer in my possession.
Several years ago, a guy approached Dave Brennan, Precision Shooting about the problems with 300WM's and the above issues. Brennan had several LR gunsmiths respond in a letter type forum. Many were unaware of the problem.
Before the 300WM, the US Military shot the 30-338 Winchester Magnum cartridge wildcat, headspacing the cartridge both on the belt and datum line. Excellent accuracy was obtained with this method.
The Accuracy gunsmiths who responded to Brennan's query determined several things based on the information provided.
1. The shooter picks a lot of brass. The gunsmith averages 10 pieces of the brass for datum line length. The smith lathes off the belt on a couple of pieces of the brass that are the absolute longest in the lot. Uses them for headspace gages.
2. The gunsmith will cut the chamber in to headspace on the now beltless brass. Generally the reamer will not go in far enough to start the belt cut.
3. The belt cut is then done on a lathe to a chosen headspace based on the lot of brass' general average headspace on that lot of brass.
4. Given this method, using new factory loads, the pressure could be expected to be slightly higher but not to a dangerous level.
5. Using this method, reduced the stretch of the 300WM brass, increasing reload numbers, and consistency in accuracy.
6. Using the shorter once fired brass, reduced the maximum load usable in the 300WM but maintained the velocities with load developement. The number of loadings in this type set-up can run from 15-20 reloads.
The downside is generally having to have a reloading die made for the rifle that meets the dimensions of the shorter fired cartridge.
Starting with a factory rifle, obtaining a chamber casting, and using a case gage to determine the maximum chamber dimensions, will give you an idea about the approximate number of reloads you may expect from your rifle with your brass.
With a case gage, the casting, and your chosen lot of brass, you can determine the stretch of a fired case and also decide if your reloading dies will over work the case when resizing.
Lots of trouble, but worth the effort for max accuracy with a 300WM.
Has anyone tried the innovative technologies die for accuracy loading?
What's your impression?
I have one and I can say that it definitely extends brass life, BUT, I cannot quantify exactly how much yet. My average brass life in the .300 Win. is about three or four loadings. The load is up there but it is very accurate. Am on loading number six and no sweat with that bunch of Fed. brass - no cracks and the primer pockets are tight. Hoped to have a lot more experience with the die than I do but my pans went to hell and I did not shoot the magnum stuff I hoped to. Will get loading with it again this spring, just have to get away from the .308 Win.
Only negative is that it adds another step to the reloading process. You can even use the die on loaded ammo but I use it after sizing. This is not a big deal, the benefit of the process is worth it to me. I have thrown away so much magnum brass in the past. I wish I had one when I shot the Weatherbys so much a few years ago.
Would I suggest buying one - yes.
looking forward to seeing just how far the brass can be kept with this type of sizing.
Jhuskey makes some good points above. It IS incosistent to an extent and I have noticed large ES's. Even with culled brass and bullets. Especially number 7. That one hits home all too hard. I learned this lesson the hard way. It took me three months to figger this one out and now I neck size in batches and the loads have been VERY consistent. I also began sizing the neck to where I leave approx. .010 of the base unsized. This has helped in aligned the pill a little more evenly with the bore. It's a tough load to develop, but Howa (Weatherby) seems to have the most consistently accurate 300WM I have yet to own. The only problem has been free-bore, which we all know is excessive in Weatherby/Howa's. It is a VERY picky cal. It will shoot sub MOA groups with Win West. brass, a 200gr. Sierra MatchKing, 82grs. 872, a Fed. 215 primer, with the bullet seated .002" off the lands. and groups open WAY up if any one of these elements is deviated from. I have to start all over when I get a new batch of any of these elements as well. All in all, if you have the patience, time, and money, it's an AWESOME long range round. Thus far, I have had the absolute best luck with WW brass (Ni plate to be exact). My first task would be to find the optimal seating depth for each bullet you plan to shoot and work from there. VERY picky caliber. Best of luck to you. If you run into problems, let us know, that's what we are all here for. To help each other and spread the knowledge in the world of the shooting sports. Good luck bro.
On another note: I have pushed the WW Ni plate brass to 15 loadings before seeing signs of impending case/head seps. This was using a rail gun with a remote trigger. Neck sizing only was used. The Lapua brass, I pushed in the same way and got about 11 loadings. The loads were ALL average and moderate using 82grs. 872, Fed 215 primer,a nd a 200gr SMK bullet seated to .002" off the lands. The one case that I DID use and abuse saw about 11 reloadings before impending signs of separation with the WW brass. 9 loads using the Lapua brass.
[ 01-20-2004: Message edited by: Austin ]
[ 01-20-2004: Message edited by: Austin ]
[ 01-20-2004: Message edited by: Austin ]
Austin,I am sorry for confusing the issue on Pressure with my previous post as we are talking of 2 different things..The case separation issue has to do with the strength of the action /barrel not the amount pressure the case can actually withstand.i have taken the Lapua cases you talk of to way higher pressures than your useing,getting 10 loads(so far) with zero thinning/separation in the web.I even took 6 cases to destruction with up to 82gns of H4831sc with a 190 gn bullet with no change in the area you speak of(my losses were to massive case head expansion..The reason that the Lapua would fail earlier is because the bottom part of the case is a lot harder than the Win.I would look to the mechanical side of things for these failures including barrel treads ,barrel tension, and the method of head spacing..JR..Jeff Rogers
Jeff: I have been spacing off the shoulder and not the belt and i've been pretty careful in my measurements, so I have (for the most part) ruled out headspace. But, as you say, I have seen excessive expansion around the area of the head, but the web seems to be OK. You could be right about the mech. issue since I have now started considering the fact that I might have a sloppy chamber. I scoped it the other day and it looks like someone took sandpaper and a screwdriver to it. There are quite a few tooling marks in the head-end of the chamber. Hmmm.... Doncha just LOVE factory bbls! Thanks for the tips bro!
Austin,The reason i say it's probably a mech/flex problem is because my action is so much overdesigned in strength i can make these assumptions.The action is home made of 709m moly steel ,it's 2.00 ins in dia ,12 ins long ,barrel tenion dia of 1.250x16tpi that is 1.125 long,weighs just under 7 lbs...It has 2 openings as it has a drop port for case ejection in the bottom of the action,even with this it is a way over design factor on a factory mauser style action...Even still to get a piece of brass the way i like it to shoot again ,i have to reswag the primer pocket and bump the shoulder every shot..I run the pressures well up there because i have found a better level of performance above 65000 psi but it's not for everyone..JR..Jeff Rogers