power55316
Gold $$ Contributor
thanks for the help guys I just ordered some Peterson brass
This is an old thread...but here is what I found with Lake City brass. I separated hundreds 18 LC brass into two weight classes only. Shot the same exact load in my long range rifle with both Lapua and Lake City brass.I have a five gallon pail of once fired lake city match brass and was wondering if its worth prossesing to shoot in f class
Out of my AR10 they are square after the 1st firing as I just measured them, no difference from Lapua..I have dual ejectors but I doubt that makes a difference. I'm a retired machinist, and have a surface inspection plate, with a drop indicator. The case is put into a holder machined on a Hardinge lathe to the same case taper at the 308 case.The taper locks the case into the machined holder parallel and perpendicular to the case head. Put on the Micro flat with the drop indicator, with a V Block to hold the case holder in place as you turn in place on the cartridge case head. No indicator movement means the case head is perpendicular to the body ...or square. Option 2 is put case and holder in a milled horizontal V groove in the Bridgeport mill the install the inspection indicator in the spindle collet ...zero the indicator and run it across the case head, no movement, means it's square to the case body. Use what ya want but LC cases have a place, I've tested them, they are not the best, but their pretty good, and capable, for a cheap price, so ya won't cry when ya lose em in the field.Even if it's fired with an out of square bolt face behind it?
AR10 bolt faces may well have the most square bolt faces from their maker. What percent of its barrels 3000 round best accuracy life will you sacrifice to get 300 square head cases?
How do you measure case heads for being square with their body and neck axis? Or bolt faces to chamber axis, for that matter?
I just tested some LC brass in bolt and ar 10.For fun, yes.
To win, no.
Military teams' 7.62 semiautomatic service rifles never had their bolt faces squared up. They shot very accurate with new cases.
Some teams tried reloading them without good results. Fired cases from them had heads out of square enough to shoot near 1 MOA bigger groups. They strung out mostly between 1 and 7 o'clock.
Most members let the civilians pick up those cases. I gave away thousands. Lots of commercial match cases were given away, too. Civvies paid for them with their income taxes.
Yep, perfect example, Lake City brass can get the job done, especially with a talented, dedicated, and confident shooter...I earned a Master card and a Distinguished badge shooting once fired Lake City 308 match brass in the service rifle and never knew that it was not suitable for my application. Just think what I could have done with the proper brass.
Was the load you shot for comparison developed on the lapua brass or the LC?This is an old thread...but here is what I found with Lake City brass. I separated hundreds 18 LC brass into two weight classes only. Shot the same exact load in my long range rifle with both Lapua and Lake City brass.
100 yd 5 shot group:
Lapua brass = .314" 2564 fps ave 2.4 S/D
Lake City Brass = .479" 2572 fos ave 4.8 S/D
Also Ar 10 130 Speer 47.7 gr 748 with this Lake City brass 5 shots into .377" very good for an AR 10.
Checked the fired AR 10 for squareness to the case body...they are nice and true zero indicator movement around or across the case head.
I have dual ejectors in the AR 10 so that may help with equal pressure on two sides when chambered, but probably has little influence.
Nothing drastically wrong with Lake City brass, but the edge goes to Lapua as you can see in the accuracy and velocity test, but unless you're group shooting Lake City is very usable...but confidence is the mental winner.
As a retired machinist I have the tools to check,.. there is alot of misinformation about out of square case heads. I didn't check any machinegun brass fresh out of the military guns, but after fired in my rifles and AR 10 they were square...plus these so called not square cases have shot 10 shot groups inside an inch at 100 yds...and 3 shots into .088" 4 into .222" and 5 into .377" with cheap Speer bullets and cheap LC brass and a mag feed AR 10 at 100 yds. So I use them, but not in all applications, as confidence in competition is half the battle.
The load was developed for Lapua brass, then the exact powder charge and bullet loaded in Lake City brass as an experiment to see the difference between the 2 cases Lake City and Lapua. As you can see LC is pretty good, especially for the price.Was the load you shot for comparison developed on the lapua brass or the LC?
What negative effect does an out of square case head have?
You can absolutely use it for F Class.I have a five gallon pail of once fired lake city match brass and was wondering if its worth prossesing to shoot in f class
Riflewoman, do you subscribe to the practice of using brass only 4 firings in a M1A? I know you competed with this rifle in the past, and I was wondering if you worried about the case head squareness when firing the last three loadings on the brass. Or did you only compete using virgin brass?How square is needed? The cartridge sits in a chamber larger than the cartridge so the axis of the cartridge isn’t necessarily coaxial with the barrel. When it is fired does it expand from where it sat or does it find the center? In reality it’s a mix of both. And if the chamber is tight and coaxial within a thousandth ( about the best you can get consistently) the cases will square within two firings.
As for measuring square? Optical comparator and you need to rotate the case 120 degrees to get three readings per case. Measure at .200 above the face and .200 below the datum diameter.
You can go up to 6 from new. In my era, we shot LC M118 match ammo then loaded the brass 5 times. Each time through I trimmed, and that made brass prep VERY tedious. That was as fired in M1A match rifles with good chambers. If you bought “surplus once fired” it was generally assumed it was fired in machine guns and you got one less reload. When I went to Perry I always volunteered to pick up any Marine shooters brass (OF Federal Match). I also cultivated friendships with USAR and NG shooters to trade off old brass. They had to turn in their brass in those days, but they didn’t care of it was many times fired. One of my best strings was fired from brass with three reloads.Riflewoman, do you subscribe to the practice of using brass only 4 firings in a M1A? I know you competed with this rifle in the past, and I was wondering if you worried about the case head squareness when firing the last three loadings on the brass. Or did you only compete using virgin brass?
LC Match and LC LR are very close. I can’t say that any LC match brass would be as good as (?) because some of the lots made in the late 1970s were pretty poor. The cases were decent but not great. The bullets were something else. The”better lots only had an eight or two in a string of 20. That’s why they developed the M852 with the 168 Sierra. Even the Army wouldn’t shoot 118 anymore. When they changed to the M118LR with the 175 Sierra things got way better.What's the difference between LC-match and LC-LR brass ? I was under the impression the LC-LR brass was there match brass , didn't realize they had both . I have a bunch of LC-LR brass that is very good stuff . Just as consistent as Lapua and was not crimped either at the mouth or the primer pocket .
I earned a Master card and a Distinguished badge shooting once fired Lake City 308 match brass in the service rifle and never knew that it was not suitable for my application. Just think what I could have done with the proper brass.
I agree with you completely. Now we have the AR and that makes the target even bigger. I tell new shooters to focus on standing and stick with basics on reloading.Congratulations on the badge.
Here is a counterpoint. Our across the course targets are very generous in precision perspective. 2 minute 10 ring through 600 does not require 1/4 minute precision rifle, not even a 1/2 minute to do well. A minute capable M1A is more than sufficient.